The lightning project

163. Cahokia-St. Louis Downtown Airport, Illinois, 20 Jul 2015:
Scanning the period from 1400Z on July 20th, to 1400Z on July 21st, the observational data (METARs & SPECIs) showed

no thunderstorm activity. There were some  AUTO/TSNO observations in the overnight hours. However, lightning data

clearly showed nearby strikes:


Looking at the color scale, the blue lightning strikes are the oldest. That would place all the lightning strikes on the map,

at about 1400Z-1500Z on the 20th. But here were the observations coming out of Cahokia (KCPS) during that time:

METAR KCPS 201353Z 00000KT 2SM BR OVC003 24/23 A2990 RMK
AO2 SLP122 T02390228
SPECI KCPS 201447Z 00000KT 2SM BR SCT005 BKN047 BKN060 25/23
A2989 RMK AO2 RAB29E39 P0000
METAR KCPS 201453Z 25008KT 2SM -RA BR OVC004 25/23 A2991
RMK AO2 RAB29E39B48 SLP124 P0000 60000 T02500228
53008
METAR KCPS 201553Z 31009KT 2SM -RA BR OVC004 24/22 A2991
RMK AO2 SLP124 P0024 T02440222

The lightning map shows more lightning to the northwest. Spirit Of St. Louis Airport reported a thunderstorm:

SPECI KSUS 201435Z 28012KT 5SM -TSRA BR BKN004 OVC039 24/23
A2992 RMK AO2 TSB23RAB04 P0008

Also, the contract weather site at Lambert Field, had a near-severe thunderstorm that hour:

SPECI KSTL 201454Z 24040G48KT 1/4SM R30R/2200VP6000FT +TSRA
FG SCT014 BKN044CB OVC100 24/22 A2994 RMK AO2
FRQ LTGICCG ALQDS TS ALQDS MOV E PNO $

Yet, Cahokia did not report thunder that hour. This was despite 4 lightning bolts striking just off airport property:

The blue circles around each lightning strike plot, are known as “deviation circles”. The strikes are not plotted until 8 stations

have detected the strike. The smaller circles are where the stations best agree on the location of the lightning strike; the larger

circles have greater margins of error. In this case, 2 lightning strikes to the east, were resolved to within half a mile. There was

even a bolt in the grid at the farthest southeast corner of the map, where the resolution was less than 2000 feet. There was a

lot of lightning in the area at 1300Z:

There was still lightning in the area up to 2 hours later. A thunderstorm certainly should have been reported at KCPS during that time- but was not.

164. Ft. Pierce, Florida, 20 Jul 2015:
Ft. Pierce (KFPR) had several lightning strikes nearby on the 20th:

7 lightning bolts struck within the green 10-mile range ring. Determining the time of the strikes can be estimated from the color scale.

Since the strikes are blue to purple, they appear to have struck around 2000Z-2300Z. Was there anything going on at KFPR during

that time? Here are the reports:

METAR KFPR 202053Z 11016KT 10SM BKN065 33/24 A2995 RMK AO2
SLP141 T03280239 56017
METAR KFPR 202153Z 13013KT 10SM BKN060 31/24 A2995 RMK AO2
SLP141 T03110244
SPECI KFPR 202221Z 11009KT 1 1/2SM +RA FEW023 BKN045 OVC060
29/25 A2995 RMK AO2 RAB18 P0018 T02890250
SPECI KFPR 202231Z VRB03KT 3SM -RA SCT027 SCT032 OVC045 28/24
A2996 RMK AO2 RAB18 P0021 T02780244
SPECI KFPR 202240Z 06006KT 10SM BKN028 BKN035 OVC045 28/24
A2997 RMK AO2 RAB18E36 P0021 T02830244
METAR KFPR 202253Z 10009KT 10SM BKN028 BKN033 OVC048 26/24
A2997 RMK AO2 RAB18E36 SLP148 P0021 T02610239

There was no other rain or bad weather during the valid time of the lightning map. But there was definitely lightning close enough to

the airport, that a VCTS should have been generated. That was most likely during the time when the heavy rain was falling, or around

2221Z. But there weren’t even any DSNT LTG remarks during that period. KFPR missed a VCTS that day, according to the data.

165. Stillwater, Oklahoma, 21 Jul 2015:
During the period from 1300Z on 20 Jul, to 1330Z on 21 Jul, this was the lightning display around Stillwater (KSWO):

4 lightning bolts struck within the red 5-mile range ring; 1 bolt was right on the red range ring; while 5 more bolts struck within

the green 10-mile range ring. There should have been a VCTS and TS reported at KSWO during that time, but there wasn’t.

KSWO was put into AUTO/TSNO mode for the overnight hours. Since the strike plots are colored red, it does appear that the bolts

struck during the pre-dawn hours. There’s no doubt that this area sees a lot of lightning, as it did that night:

Tallying up the number of lightning strikes in the 4 grids closest to KSWO, produces a figure of 9,741 lightning strikes! Those all

struck near the same hour, as the lightning bolts are all about the same color. The peak activity seemed to be around 0400Z:

Now, as to whether or not ALDARS missed all that lightning. According to the NWS AMSS website, ALDARS had been installed:

www3.amss.nws.noaa.gov/amsstt.nsf/wSite%20Profiles/KSWO

(6) The sites ALDARS interface was activated on this date. MPM-04/25/00

(7) The AOMC monitoring for the availability of ALDARS was disabled on this date
as directed by FAA headquarters (email dated 07/29/02 -SI/RB). SLP-08/06/02

That message (7) seems to appear on many site profiles. AOMC apparently doesn’t monitor ALDARS at some sites anymore. Why is that?

A site with nearly 10,000 lightning strikes nearby in a 1-2 hour period, doesn’t warrant monitoring?

166. Northwest Arkansas Regional Airport, Fayetteville-Springdale, Arkansas, 20-21 Jul 2015:

This airport in NW Arkansas (KXNA) had ALDARS installed on 29 Mar 2001, according to its site profile:

www3.amss.nws.noaa.gov/amsstt.nsf/wFramesetTickets?OpenFrameSet&Frame=Main&Src=%2Famsstt.nsf%2FwSingleCatStatusSite%3FOpenForm%26AutoFramed

During the period 1300Z on the 20th of July, to 1300Z on the 21st; ALDARS at this site detected DSNT LTG (10-30 miles away)

during 2 time periods:

METAR KXNA 202353Z 26006KT 10SM -RA SCT095 BKN120 28/26 A2987
RMK AO2 LTG DSNT N-E RAB00 SLP100 P0000 60000
T02780256 10350 20278 56001
METAR KXNA 211053Z 22009KT 10SM -RA SCT029 BKN038 OVC110
23/22 A2996 RMK AO2 LTG DSNT SE-SW RAB32 SLP130
P0002 T02280222

So while lightning beyond 10 miles from the airport was detected, lightning within 10 miles was not. We know this as there were no

SPECIs nor METARs containing VCTS nor TS in present weather, during that time frame.

Lightning data showed otherwise:

If there were 2 separate thunderstorms near KXNA, 10 hours apart, one would expect to see lightning strikes plotted with 2 different colors.

That is what the above lightning map showed. Red lightning plots were E-SW; while purple lightning plots were NW-NNE. The purple plots are

older than the red lightning plots. This roughly matches the directions of the ALDARS-generated DSNT LTG remarks. The trouble was, ALDARS

ranged the lightning bolts as too far away. So the D (Detection) in ALDARS worked in this case, but the R (Ranging) did not.

167. Smyrna, Tennessee, 21 Jul 2015:
According to the NWS AMSS web page, this site does not have ALDARS enabled. Regardless, there was no indication of any lightning or

thunderstorm activity, on any of the weather reports coming out of KMQY on 20-21 Jul. However, lightning strike data showed otherwise:

Although there was much more lightning to the SE near Murfreesboro; there were still 7 lightning bolts that struck within the green 10-mile

range ring around Smyrna. That should have triggered ATC to start a thunderstorm, as it met VCTS criteria. Also, there were 2 lightning

bolts that struck within the red 5-mile range ring around KMQY, That met TS criteria. Again, there were no TS, VCTS, nor even LTG DSNT

data reported at Smyrna those 2 days. There was clearly a missed thunderstorm, probably around 1800Z on 20 Jul.

168. Huntington, West Virginia, 20-21 Jul 2015:
From 1400Z on the 20th, to 1400Z on 21 Jul, this was the lightning display around Huntington (KHTS):

There were 2 rounds of heavy rain in the pre-dawn hours on the 21st:

SPECI KHTS 210508Z 22005KT 2 1/2SM +RA BR BKN010 BKN110 24/23
A2979 RMK AO2 CIG 006V015 P0002 T02390233
SPECI KHTS 210822Z AUTO 19009KT 3/4SM +RA BR BKN028 OVC090
22/22 A2975 RMK AO2 P0037 T02220222 TSNO

The NWS AMSS web page does not mention that ALDARS is installed at this site. Looking at the color scale of the lightning strikes,

either of those rounds of rain showers could have produced the lightning. Possibly, both of them did. Looking at the big scale across

the United States, we can then zoom in timewise, to 15-minute blocks of data:

That map was valid at 0400Z on the 21st. It shows lightning located in the corner of West Virginia, where it meets Ohio and Kentucky;

that’s where Huntington is located. The heaviest rain was after 0400Z though, which often happens with decaying thunderstorms. The

0500Z map showed this:

Most of the lightning had moved east of KHTS. There had been 6 lightning strikes within 5 miles of the airfield, according to the first

map in this series. The first storm could have produced that lightning; but there were no reports of TS, VCTS, nor even LTG DSNT

around that time. The map also showed more lightning activity to the west. That reached the Huntington area by 0715Z:

Huntington had moderate rain just after that time:

SPECI KHTS 210732Z 21004KT 1 3/4SM RA BR OVC020 23/23 A2976
RMK AO2 VIS 3/4V5 RAB0654 P0001 T02280228

Still, there was no mention of lightning. By 0822Z, when heavy rain had caused the worst visibility (3/4SM); KHTS had put ASOS into

AUTO and TSNO modes, so no thunderstorm information was possible at that point. The second storm seemed to have passed mostly

south of KHTS with regards to its lightning activity; the first storm passed overhead. It appears to be the first thunderstorm that was missed.

169. Norfolk International Airport, Virginia, 21 Jul 2015:

Norfolk Intl (KORF) was in AUTO/TSNO mode for the period 21/1300Z-22/1300Z. That is the time range of the lightning plot map below:

KORF shouldn’t have been in TSNO mode, as there was lightning to detect. Certainly, there was enough lightning for VCTS criteria;

as well as one lightning bolt that met TS within 5 miles criteria. How close was that bolt?

The above map measured it at 2.76 miles away. It had a fairly small deviation circle, so the strike plot accuracy was good; even the

outer edge of the "deviation circle" was well within 5 miles. Can we narrow down the time of the missed thunderstorm at KORF?

Nearby Norfolk Naval Air Station, 3 miles to the northwest of KORF, produced these reports:
SPECI KNGU 212055Z 24011G21KT 8SM TS SCT040CB BKN160 BKN260
32/23 A2965 RMK AO2 TSB49B51B52 FRQ LTGICCG N
TS N MOV SE T1 SET
METAR KNGU 212059Z 24015G21KT 8SM TS SCT040CB BKN160 BKN260
32/23 A2964 RMK AO2 TSB49B51B52 SLP038 FRQ LTGICCG
N TS N MOV SE T1 SET T03220228 56002
METAR KNGU 212159Z 27014G21KT 10SM SCT040CB BKN160 BKN260
32/23 A2965 RMK AO2 PK WND 24026/2102 TSE59 SLP041
FRQ LTGICCG OHD TS OHD MOV SE T1 SET T03170228

Since the thunderstorm (with frequent lightning) over KNGU was moving southeast; and KORF lies to the SE of KNGU; we can ascertain

that KORF likely had the close lightning strike sometime during the same period. According to the color scale on the first strike map in

this series, we’d expect the closest lightning strikes to be purple; and that is what was plotted. At 1930Z, the USA lightning map did show

strikes near KORF:

There was more lightning as late as 2130Z:

So the 2 maps above, plus the KNGU data, place the time of the missed thunderstorm at KORF; between 1900Z-2200Z, when KORF

was in AUTO/TSNO mode. That is 3-6 p.m. EDT. Why would one of the busiest airports in Virginia, be in AUTO/TSNO mode during the

late afternoon, with thunderstorm activity nearby?

176. Great Falls, Montana, 27 Jul 2015:

The lightning display around Great Falls (KGTF) during the period 26/1400Z-27/1400Z is shown below:

There were 3 lightning strikes within the green 10-mile range ring, that met VCTS criteria. However, the METAR data within

that 24-hour period, mentioned no lightning at all. About 50 lightning strikes were within the blue 30-mile range ring, but no

LTG DSNT remarks were recorded. There was only 1 AUTO/TSNO report in that time frame, coming at 27/0653Z.

The lightning plots are reddish in color, making the likely time of the strikes to be late in the 24-hour period. This matches with

the only time heavy rain was recorded during the 24-hour period:

METAR KGTF 270953Z 30008KT 6SM +RA BR BKN060 BKN085 OVC120
13/12 A2993 RMK AO2 RAE15B51 SLP107 P0002 T01330117

The most likely time for the 3 strikes that should have triggered the VCTS, would have been around the time of the heavy rain.

177. Hector Intl Airport, Fargo, North Dakota, 28 Jul 2015:

This airport has had lightning issues before (see cases 64, 70, 122 and 175).
Here is the lightning display for the period 27/1300Z-28/1343Z around Hector Intl (KFAR):

There were 6 lightning bolts that struck within the red 5-mile range ring; an additional 2 bolts struck right on the range ring.

10 more bolts struck within the green 10-mile range ring. Some of the lightning struck just SW of the airport, on the other

side of Interstate 29:

Yet, scanning the METARs and SPECIs from that same time period, shows NO mention of any lightning, not even in remarks!

That was despite .52” of rain falling in hour before 0953Z:

METAR KFAR 280853Z 14011G20KT 10SM BKN100 24/21 A2962 RMK
AO2 SLP024 T02440211 58031
SPECI KFAR 280919Z 16023G30KT 2SM +RA BR BKN021 BKN049 OVC060
23/22 A2968 RMK AO2 PK WND 16030/0919 VIS 3/4V5
RAB0858 PRESRR P0004 T02330217
SPECI KFAR 280926Z 16019G33KT 1SM +RA BR BKN021 OVC050 23/22
A2967 RMK AO2 PK WND 17033/0922 RAB0858 P0022
T02280217
SPECI KFAR 280939Z 16007KT 2SM +RA BR FEW009 OVC019 23/22
A2965 RMK AO2 PK WND 17033/0922 RAB0858 P0046
T02280217
SPECI KFAR 280948Z 15013G18KT 4SM RA BR FEW009 BKN017 OVC090
23/21 A2965 RMK AO2 PK WND 17033/0922 RAB0858
P0050
METAR KFAR 280953Z 14013G18KT 5SM RA BR BKN017 BKN095 OVC110
23/21 A2965 RMK AO2 PK WND 17033/0922 RAB0858
SLP035 P0052 T02280211

Notice that the winds had gusted to 33 knots. That, plus the heavy rain, is enough to make a seasoned meteorologist question whether

or not this site had thunder. Upon further investigation, it certainly had lightning close enough, to trigger both VCTS and TS. This was

another missed thunderstorm!

178. Rochester, Minnesota, 28 Jul 2015:

This LAWRS site reported VCTS on the morning of Tue 28 Jul 2015. It should have reported TS. 1.63” of rain fell in the 24 hours preceding

1154Z on the 29th; yet TS was not reported, only VCTS. However, the below lightning plot map, shows that TS criteria was indeed met:

There were 2 lightning bolts that struck within the red 5-mile range ring. OCNL LTGCG N AND W could have been reported, but wasn’t.

Most of the other lightning within 10 miles, was to the west. Yet, lightning closer than what was recorded, did strike near KRST:

The following lightning animation from Weather Tap, shows lines of thunderstorms passing through Minnesota and Iowa that morning:


179. Minneapolis-Crystal Airport, Minnesota, 28 Jul 2015:

According to the NWS AMSS site profile, this site has had ALDARS enabled for 15+ years:
(5) The sites ALDARS interface was activated on this date. KMC-06/14/00

So why was ALDARS turned off in the overnight hours? ATC put ASOS into AUTO/TSNO mode at 0353Z. Prior to the ATCT reopening,

conditions had worsened to low IFR due to heavy rain, on more than one report:

SPECI KMIC 281124Z AUTO 17016G22KT 3/4SM +RA BR BKN013 BKN075
OVC100 23/22 A2978 RMK AO2 PK WND 15026/1056 P0028
T02330217 TSNO
SPECI KMIC 281139Z AUTO 25014G21KT 1/2SM +RA FG FEW005 OVC013
23/22 A2986 RMK AO2 PK WND 15026/1056 WSHFT 1123
PRESRR P0087 T02330217 TSNO

When ATC signed back on to ASOS, more low IFR condition were reported:

METAR KMIC 281153Z 16023G29KT 1/2SM +RA FG FEW005 OVC011
23/22 A2986 RMK AO2 PK WND 17029/1152 WSHFT 1123
SLP104 P0144 60144 70144 T02280217 10256 20228
53019

Yet no LTG, TS, VCTS, nor LTG DSNT remarks were recorded.

But looking at the lightning display above, there were 13 bolts that struck within the red 5-mile range ring around KMIC.

Many more strikes were within the green 10-mile range ring. But ALDARS was disabled at the time; and ATC did not report

lightning either. The climatology for this site should have counted a thunderstorm day for 28 Jul; but unless they report another

one later today, that will be missed.

If there’s any doubt that lightning struck near the airport, here is a zoomed in view:

Also, here is a lightning animation from Weather Tap. The last panel is valid at 1410Z, and it shows a line of thunderstorms passing

through the Twin Cities:


180. Clarksburg, West Virginia, 27-28 Jul 2015:

Clarksburg (KCKB) reported distant lightning (LTG DSNT) on 2 reports during the sampling period:

METAR KCKB 271853Z 32005KT 10SM BKN038 OVC055 29/21 A3000
RMK AO2 LTG DSNT E AND W AND NW SLP140 T02890211
METAR KCKB 271953Z 28010KT 10SM FEW039 SCT070 28/22 A3000
RMK AO2 LTG DSNT W-NE RAB1859E14 SLP143 P0000
T02830217

Distant is defined by ALDARS as between 10-30 miles from the site. That certainly verified, as in the grid to the west of KCKB,

there were 141 lightning strikes that met that criteria:

There was also a lot of lightning 10-15 miles to the NE, and some about 10-12 miles to the east. The problem is, there was lightning

within 10 miles, which met VCTS criteria. No VCTS was recorded during the sampling period. Arguably, 2 of the lightning bolts struck

within the red 5-mile range ring; which would have met TS criteria. In any event, this site missed a thunderstorm.

181. Bloomington-Normal Airport, Illinois, 28 Jul 2015:

This LAWRS site did report thunderstorms overnight while ASOS was in AUTO mode. But before that, there was an hour with a

suspicious rain shower:

METAR KBMI 281856Z VRB04KT 10SM VCSH BKN030 32/24 A3000 RMK
AO2 RVRNO T03160244 P0000 SLP144
SPECI KBMI 281912Z 35030G43KT 1SM RA BR OVC010 25/23 A3001
RMK AO2 RVRNO RAB10 P0010 PK WND 32043/1904
SPECI KBMI 281948Z 04009KT 1 1/2SM +RA BR BKN010 OVC044 22/22
A3001 RMK AO2 RAB10 P0043 PK WND 32043/1904
METAR KBMI 281956Z 02003KT 7SM -RA BKN010 BKN044 23/22 A3001
RMK AO2 T02270222 RAB10 P0043 PK WND 32043/1904
SLP150

Are we to believe that was a "near-severe rain shower"? Or was there more than 1 thunderstorm at KBMI on the 28th?

The plot of lightning strikes around KBMI, clearly shows there were 2 thunderstorms, separated by several hours:

Note the difference in the colors of the lightning plots.

Bloomington-Normal is located in east-central Illinois. Here is a lightning strike animation of the hour from 1900Z-2000Z on the

evening of July 28th:

Note that a thunderstorm passed right through east-central Illinois during that hour. That would have affected KBMI, and explained

why there was .43” of rain that hour, plus a wind gust to 43 knots. KBMI missed a thunderstorm that hour!

182. Dannelly Field, Montgomery, Alabama, 28 Jul 2015:

This LAWRS site recorded a VCTS at 2053Z on the 28th:

METAR KMGM 282053Z 01021G26KT 10SM VCTS CLR 33/23 A2998 RMK AO2 PK WND
02026/2052 LTG DSNT ALQDS PRESRR SLP146 T03330228 55003

Other than that, the site recorded LTG DSNT NW-NE in remarks the previous hour. However,
Lightning strike data shows that a TS should have been recorded:

Within the red 5-mile range ring around KMGM, there were 2 lightning strikes. That met criteria for a TS; yet only VCTS was reported.

190. Northeast Philadelphia Airport, Pennsylvania, 30 Jul 2015:

Simply put, this LAWRS site missed a lot of lightning on this date, because it put ASOS into AUTO/TSNO mode all day. It’s not

a site that is listed as having ALDARS installed on the NWS AMSS master site profile; so why did ATC not report all the lightning

shown below?

21 lightning bolts struck within the red 5-mile range ring around KPNE Airport; arguably, there were more, as 5 or 6 bolts struck

right on the ring. One would never know that by looking at the reports coming out of KPNE; the report having the worst weather,

only showed moderate rain in IFR visibility:

SPECI KPNE 302003Z AUTO 21008KT 2SM RA BKN037 BKN060 OVC080
26/21 A2985 RMK AO2 P0003 T02560211 TSNO $

Putting ASOS into AUTO/TSNO mode, in the middle of the day, is no excuse for not reporting a thunderstorm.

191. Hawkins Field, Jackson, Mississippi, 30 Jul 2015:

This LAWRS site had 1 report on the 30th that contained a thunderstorm:

METAR KHKS 301853Z 36010KT 10SM VCTS SCT055 36/22 A3000 RMK
AO2 LTG DSNT ALQDS SLP149 T03610222

However, note how close to the airport there were lightning bolts striking:

There were 6 bolts that struck inside the red 5-mile range ring, which would be TS criteria. Other bolts struck within the 10-mile

range ring and met VCTS criteria. Somehow, the VCTS was reported- but the TS was not.


192. St. Lucie County Intl Arpt, Fort Pierce, Florida, 29 Jul 2015:

This site just had a case the previous day. On Thursday, KFPR had a couple of reports of heavy rain:

SPECI KFPR 302032Z 31010G26KT 2SM +RA BR BKN035 BKN060 OVC080
24/22 A2998 RMK AO2 PK WND 27030/2021 WSHFT 2012
RAB21 PRESRR P0026 T02390222
SPECI KFPR 302202Z 26008KT 3/4SM +RA BR SCT045 SCT080 BKN110
24/23 A2999 RMK AO2 P0011 T02440228

But there was no mention of lightning on the 30th. There should have been:

That map clearly shows a lightning strike within 10,000 feet (about 2 miles) to the NE of the runway. There were 16 bolts that met

VCTS criteria, and 2 that met TS criteria:

Yet, KFPR did not even mention lightning in its weather reports on the 30th.

193. Lawton, Oklahoma, 31 Jul 2015:

This LAWRS site had its ALDARS activated on 9 Mar 2000, according to the NWS AMSS website. While ASOS was in AUTO/TSNO mode

overnight, it appears an earlier thunderstorm passed nearby around 2100Z:

Looking at the 2-hour block of lightning data from 2100Z-2300Z, a thunderstorm was confirmed:

Note the lack of any mention of LTG, on either of the METARs that were superimposed on the map above. That means none of that

lightning was reported! Here is a zoomed in lightning plot map of the same 2-hour time span::

The closest lightning bolt, just west of the airport, struck around 2232Z.

The above map is valid for the 5-minute period of 2230Z-2235Z.

Here’s how much lightning struck nearby:

The “VCTS zone” would be between the red and green range rings; that is, between 5 and 10 miles from the airport. VCTS criteria was

obviously met. But within the red 5-mile range ring, there were 8 lightning strikes; so TS criteria was also met. While there was a wind

gust to 31 knots recorded at 2239Z, KLAW did not record any lightning data. Thus, this was a missed thunderstorm.

194. Mobile Downtown Airport, Alabama, 31 Jul 2015:

The “R” in ALDARS stands for “ranging”. ALDARS ranged lightning at this LAWRS site on the 31st, to be 5-10 miles away from the airfield.

Does this look like 5-10 miles away from the airport?

ALDARS was installed at this site on 15 May 2001, according to the NWS AMSS master site profile. So ALDARS successfully detected the

lightning between 5 and 10 miles from the airport, because ASOS recorded SPECIs for VCTS.

However, ASOS did not record a TS, despite the closest lightning bolt measuring at 1.32 miles away:

So ALDARS either ranged that bolt incorrectly; or did not detect it. Lightningmaps.org does not plot a lightning strike position, unless it is

detected by a minimum of 8 stations. ALDARS simply failed to detect the closest lightning in this case.

195. North Perry Airport, Hollywood, Florida, 31 Jul 2015:

Observations coming out of North Perry Airport (KHWO) showed heavy rain from 1853Z-1901Z:

METAR KHWO 311753Z 16008KT 10SM SCT043 BKN055 33/23 A3001
RMK AO2 SLP162 T03280233 10344 20278 58013
METAR KHWO 311853Z AUTO 33010G16KT 3/4SM +RA 26/21 A3004
RMK AO2 RAB11B45 SLP173 P0010 T02560206 TSNO $
SPECI KHWO 311855Z AUTO 33009G16KT 1 1/4SM +RA 25/20 A3004
RMK AO2 P0002 T02500200 TSNO $
SPECI KHWO 311901Z AUTO 35007G16KT 3SM +RA 24/21 A3003 RMK
AO2 P0005 T02440206 TSNO $
METAR KHWO 311953Z 28008KT 10SM -RA FEW046 FEW075 BKN110
26/21 A3003 RMK AO2 RAE22B51 SLP167 P0021 T02560211

That is early afternoon in south Florida. Why ASOS was put into AUTO mode at that time, is unknown. This LAWRS site has had ALDARS

activated since 23 Mar 2001, so it is also unknown why ATC would put ASOS into TSNO mode. Because ASOS was inexplicably placed in

AUTO/TSNO mode, it missed this:

That was a lot of nearby lightning in less than 2 hours, none of which was recorded at KHWO! Here is the summary of how much

lightning was nearby:

There were 23 lightning strikes plotted within the red 5-mile range ring around North Perry Airport. That easily met TS criteria.

VCTS criteria was also easily met. In short, ASOS wasn’t given the opportunity to have ALDARS detect this thunderstorm, because

ATC put ASOS into AUTO/TSNO mode. The question is, why?

I decided that this would be a good time to go back to the week I was on vacation, since there was a lot of adverse weather

in the areas to where I traveled. I’m glad I looked at the data.

202. Burke-Lakefront Airport, Cleveland, Ohio, 30 May 2015

Some of these sites are “repeat offenders”. So when I went to go back chronologically beginning on 30 May, KBKL was the first

site with a lightning issue. It had also been listed in case 201.

This site began a thunderstorm at 2310Z on 30 May, which was 7:10 p.m. local time:

SPECI KBKL 302310Z 24008KT 7SM TSRA BKN025 BKN039 OVC070 20/18 A2999 RMK AO2 PK WND 23033/2256 TSB10 OCNL LTGICC TS NW MOVE E P0050 T02000183

However before that, between 2200Z and 2300Z, there was plenty of lightning that was missed:

Now, since ALDARS was enabled at this site on 30 May 2000, this was the 15-year anniversary of ALDARS at KBKL.

One wonders just how much lightning has been missed in the past 15 years!

Between 2100Z and 2200Z, there was also more lightning missed:

So, somehow, ALDARS verified the lightning one hour, but missed it the previous 2 hours:

Let’s zoom in on those 2 hours’ worth of missed lightning strikes:

The purplish strikes are from the first (unreported) thunderstorm that struck before 2200Z; while the yellow strikes

are from the second (unreported) thunderstorm that struck after 2200Z. Zooming in on the time of the closest bolts

from the first storm, we can determine that there were 3 bolts that struck around 2112-2113Z:

The closest bolt from the second storm, hit right along the shoreline at 2259Z:

So instead of ALDARS providing lead time by recording a VCTS first; the first lightning it reported was almost 2 hours after

2 bolts struck just SE of Progressive Field. Lead time provided to pilots and other users would have been no better than -1:58

in this case.

By the way, if ALDARS had detected that lightning and started a thunderstorm, it would have shown up in the 2 previous METARs:

METAR KBKL 302153Z 25007KT 1SM +RA SCT018 SCT042 OVC055 21/17 A2997 RMK AO2 PK WND 14039/2131 WSHFT 2126 RAB10 SLP146 P0062 T02060172
METAR KBKL 302153Z 25007KT 1SM +RA SCT018 SCT042 OVC055 21/17 A2997 RMK AO2 PK WND 14039/2131 WSHFT 2126 RAB10 SLP146 P0062 T02060172

By the lack of TS data in remarks (remember, the SPECI to begin the thunderstorm had TSB10 in remarks), we can determine that

no thunderstorm was recorded either of those 2 hours.

203. Hawkins Field, Jackson, Mississippi, 30 May 2015:

This is another “repeat offender” site. ALDARS was enabled here on 10 Mar 2000. After 15 years in service, how much of this lightning

do you think ALDARS detected in the below 2-hour period?

The answer: NONE of it! The observations coming out of KHKS keyed me in to looking more closely at this situation:

METAR KHKS 302053Z 26007KT 10SM -RA FEW043 BKN090 OVC110 28/22 A3001 RMK AO2 LTG DSNT E-S RAB23 SLP153 P0000 60000 T02830222 56018
SPECI KHKS 302156Z 28012KT 1 3/4SM +RA BR FEW034 BKN047 OVC075 21/19 A3006 RMK AO2 LTG DSNT SE AND S P0005 T02110194
METAR KHKS 302205Z 30008KT 1/2SM +RA FG SCT034 BKN045 OVC070 21/19 A3004 RMK AO2 LTG DSNT SE PRESFR P0029 T02060194
SPECI KHKS 302212Z 23004KT 2 1/2SM -RA BR SCT032 BKN050 OVC110 21/20 A3004 RMK AO2 P0029 T02060200
METAR KHKS 302253Z 06003KT 7SM -RA OVC110 21/19 A3004 RMK AO2 SLP164 P0032 T02110194

Notice that heavy rain reduced the visibility to 1/2SM on the 2205Z SPECI. That should have been a clue for ATC to watch out for lightning.

As it was, this was how much lightning was striking near the airport:

Notice that there was one lightning bolt that struck the airport! The best position returned by the detection stations, placed the bolt as

having struck the runway. This would have been between 2155Z-2200Z:

Also notice that during the 5-minute valid time of the above chart, that there were 10 other strikes nearby (2 of them are hard to see,

because their plots and deviation circles are in yellow, but they are to the SW). According to the 7900.5C, Table 10-8, about 1-6 flashes

per minute would be defined as “frequent” (FRQ). Since there were 11 bolts that struck within 5 minutes, ALDARS missed FRQ LTGCG

not only around the airport; it also missed at least OCNL LTGCG AT AP in this case. Perhaps when ALDARS failed to detect that lightning

activity, the heavy rain was causing the LAWRS observer and other ATC specialists, to be busy with other duties. This is why nearby

KJAN ought to retain its CWO office- so that dozens of lightning strikes don’t go unreported!

As a late edit, time stamps are now available with the lightning strikes. The time stamp on the strike that hit the runway, was 2156Z:

The distance from the control tower (notice the shadow to the north), to the position of that lightning strike, was 987 feet!

204. Bowman Field, Louisville, Kentucky, 30 May 2015:

In this case, there were only a few lightning bolts in question:

Yet, there were 6 lightning strikes that met VCTS criteria, as they fell within the green 10-mile range ring. There were also 2 bolts that

struck within the red 5-mile range ring between 2000Z-2100Z.

2 of those lightning strikes were just W-NW of the airport:

Lightning that close to the airport, ought to be reported. But there was no report of any thunderstorm activity that day at Bowman Field.

During the hour in question, heavy rain fell; but no lightning was reported:

METAR KLOU 301953Z 20013G19KT 10SM FEW060 FEW110 29/19 A2998 RMK AO2 SLP148 T02890194
SPECI KLOU 302034Z 18012G32KT 1 3/4SM +RA FEW036 BKN060 BKN075 23/19 A3000 RMK AO2 PK WND 20032/2031 RAB26 P0009 T02280189
METAR KLOU 302053Z 15004KT 3SM HZ FEW035 SCT065 BKN090 23/21 A2998 RMK AO2 PK WND 20032/2031 RAB26E51 SLP148 P0017 60019 T02330206 56011
METAR KLOU 302153Z 17011G16KT 10SM FEW110 27/19 A2997 RMK AO2 SLP142 T02720194

The time of the closest lightning bolts can be resolved to have been between 2020Z-2030Z- which is close to the time heavy rain was

recorded, plus the peak wind of 32 knots at 2031Z:

If the pilots had been aware that there was actually a thunderstorm in progress at the airfield, they could have anticipated heavy

rain and gusty winds.

205. Lakefront Airport, New Orleans, Louisiana, 30 May 2015:

Here is another site that has had problems before. Between 1700-1800Z, the chart below shows that KNEW should have recorded

a thunderstorm:

There were 4 bolts that struck within the green 10-mile range ring, that met VCTS criteria; there were an additional 3 lightning strikes

within the red 5-mile range ring that met TS criteria. As you can see by the METAR superimposed near the bottom of the graphic, there

was no LTG/TS activity reported that hour. That was despite 3 bolts striking fairly close to the airport:

That was another missed thunderstorm.

206. Toledo Express Airport, Ohio 30 May 2015:

This date was hard on “repeat offenders”; one of which has been KTOL. While the case above at KNEW had no weather clues that

would have indicated to look for LTG/TS activity, this one did:

As can be seen by the SPECI superimposed near the bottom of the graphic, there was heavy rain reducing the visibility to 3/4SM.

There was also a wind gust to 35 knots. That should have clued in ATC to look for lightning (ALDARS isn’t installed at KTOL, accor-

ding to the NWS AMSS web site). But notice how many lightning bolts were missed. All the bolts clustered NW-NE went unreported;

the closer bolts within the red 5-mile range ring also went unreported. Things improved by the next METAR:

METAR KTOL 301952Z 28007KT 10SM CLR 26/19 A2994 RMK AO2 PK WND 25035/1904 RAB06E32 SLP135 P0023 T02560194

Yet, there were no lightning remarks. None appeared the hour prior, either:

METAR KTOL 301852Z 20009KT 10SM BKN044 BKN055 BKN110 28/18 A2995 RMK AO2 SLP136 T02780178

That was despite a bolt striking, probably at 1908Z, just north of airport property on the other side of state Highway 2:

Airport workers were not warned of the lightning-within-5 mile hazard.

207. Cecil Field, Jacksonville, Florida, 30 May 2015:

KVQQ had issues for awhile on this date. Around 1602Z, there was a lightning strike on or near the south end of airport property:

Although a SPECI was recorded at 1610Z, it did not mention that lightning strike. Nor did the subsequent METAR. Around 1718Z,

another bolt struck in almost the same spot:

Again, there was no mention of even a bare-minimum 15-minute thunderstorm from that lightning bolt. Here is a chart comparing

the 2 strikes:

LTGCG AT AP, or very close to that, was ignored twice at KVQQ on that date.

208. Willow Run Airport, Ypsilanti, Michigan, 30 May 2015:

At this airport SW of Detroit, there was no thunderstorm recorded on 30 May. There should have been 2. The first missed

thunderstorm came around 1838Z, when lightning struck just off the end of runway 05/23:

That bolt was either on the SW side of the airport; or next to it, as the bolt could have struck anywhere inside the red deviation circle.

The best position is plotted. However, the weather reported around that time, mentioned no LTG/TS activity:

SPECI KYIP 301818Z 28006KT 1 3/4SM R05R/4000VP6000FT +RA BKN042 BKN050 BKN070 24/20 A2999 RMK AO2 VIS 3/4V5 P0006 T02390200
SPECI KYIP 301828Z 00000KT 3SM R05R/4500VP6000FT -RA SCT042 BKN050 OVC085 24/21 A2998 RMK AO2 P0008 T02440206
METAR KYIP 301853Z 00000KT 10SM -RA FEW030 SCT044 BKN050 25/21 A2997 RMK AO2 SLP141 P0011 T02500211

So a thunderstorm went unreported between 1800Z-1900Z. In the minutes before 2115Z, 2 more nearby lightning bolts struck:

The weather reports around the time of those bolts, ignored them:

SPECI KYIP 302109Z 1 3/4SM R05R/2800VP6000FT -RA FEW010 BKN027 OVC040 23/20 A2998 RMK AO2 VIS 1/2V5 RAB2055 CIG 018V032 P0008 T02330200
SPECI KYIP 302117Z 29006KT 3/4SM R05R/2800VP6000FT +RA FEW011 BKN027 OVC050 23/19 A2998 RMK AO2 RAB2055 P0019 T02280194
METAR KYIP 302153Z 08005KT 10SM BKN110 23/19 A2997 RMK AO2 RAB2055E34 SLP142 P0034 T02280194

That was the 2nd missed thunderstorm at Willow Run on May 30th. To summarize, these nearby lightning strikes went unreported:

The blue bolts were from the first storm, while the red bolts were from the second storm. How much lightning was missed?

The above chart shows that the older storm, with its lightning strikes depicted in blue, produced most of its lightning to the south

of the airport, but was closer than the second storm. That second storm had most of its lightning strikes to the north of the airport.

However, since KYIP did not report a thunderstorm at all that day; there were 2 missed thunderstorms at Willow Run on May 30th.

209. Sikorsky Memorial Airport, Bridgeport, Connecticut, 31 May 2015:

New England got into the missed thunderstorm act on 31 May, when Sikorsky memorial (KBDR) had an issue. First, lightning struck

on or very near airport property, around 2217Z:

The SPECIs around that time (which this site sent out as METARs) showed heavy rain, even restricting visibility to 1/2SM at 2215Z;

but there was no mention of lightning in the SPECI before the strikes on the map, nor after the time of the strikes on the map.

There were 3 bolts nearby, not just the one that possibly hit at the airport. Zooming out, one can see those 3 bolts, as well as many

others in the 2100Z-2300Z time frame:

There were dozens of lightning strikes within the green 10-mile range ring around KBDR; and perhaps 2 dozen that also fell within

the red 5-mile range ring. Zooming back in for that entire 2-hour period, there was certainly enough nearby lightning that should

not have been missed:

But a thunderstorm was not recorded at all on that day at this site, making this a missed thunderstorm.

217. Lakefront Airport, New Orleans, Louisiana, 31 May 2015:

This airport recorded a moderate rainshower on the 1653Z METAR. That METAR is superimposed on the bottom of this lightning map:

What wasn’t recorded, was a TS. There were 2 lightning bolts which struck within the red 5-mile range ring, meeting TS criteria.

That occurred about 1630-1645Z, according to the color scale on the map. Those were both ignored or undetected.


218. Peachtree-De Kalb Airport, Atlanta, Georgia, 31 May 2015:

The last case for May 2015 was from the Atlanta metro area. There was a lot of lightning over downtown Atlanta between

1600Z-1800Z that day; also, there was a lot of lightning to the NE of KPDK:

But notice there was also lightning within the green 10-mile range ring around KPDK; and within the red 5-mile range ring.

While this site began a thunderstorm at 1924Z, it did not report thunder before then:

METAR KPDK 311653Z 18008KT 9SM SCT036 BKN048 BKN100 29/20 A3008 RMK AO2 SLP168 T02890200SPECI KPDK 311722Z 24011KT 1 3/4SM RA FEW032 SCT070 BKN090 24/19 A3009 RMK AO2 WSHFT 1708 RAB14 P0003 T02390194
SPECI KPDK 311736Z 21007KT 4SM -RA SCT046 BKN090 OVC110 23/19 A3008 RMK AO2 WSHFT 1708 RAB14 P0007 T02280194
METAR KPDK 311753Z 17006KT 7SM -RA FEW044 SCT090 OVC110 22/19 A3008 RMK AO2 WSHFT 1708 RAB14 SLP173 P0007 60007 T02170189 10289 20211 56011
METAR KPDK 311853Z 09003KT 9SM FEW070 FEW100 26/21 A3005 RMK AO2 RAE1758 SLP163 P0000 T02560211
METAR KPDK 311930Z 10010G16KT 070V140 9SM TS FEW018 SCT070 BKN120 24/20 A3006 RMK AO2 TSB24 T02390200

ALDARS was activated at KPDK on 6 Mar 2001. So while ALDARS was able to detect the later thunderstorm, it missed all the lightning

between 1600Z-1800Z. Some of that lightning was so close to the west of the airport, that it’s hard to see how it was missed:

ALDARS works properly sometimes; other times, it does not. We don’t know when those other times will be; but do we really want

this happening at nearby KATL?

219. Athens, Georgia, 1 Jun 2015:

On to June we go, just down the road to Athens, Georgia. Between 2100Z-2200Z on June 1st, here was the lightning display around

Athens (KAHN):

While there were several lightning bolts that met VCTS criteria by striking within the green 10-mile range ring around KAHN;

there were also 5 lightning bolts that met TS criteria, by striking within the red 5-mile range ring. That was not evident in the

weather reports from this site that day:

METAR KAHN 012051Z 24004KT 10SM FEW049 SCT075 BKN095 27/19 A3001 RMK AO2 RAB38E49 SLP154 P0000 60000 T02670189 56026
METAR KAHN 012151Z 31003KT 5SM -RA BR OVC100 21/19 A3004 RMK AO2 RAB02 SLP167 P0007 T02110189
SPECI KAHN 012228Z 25004KT 2SM RA BR FEW075 BKN095 OVC120 21/19 A3003 RMK AO2 P0006 T02060194

There was no thunderstorm recorded at Athens on June 1st. There should have been, according to the lightning data. Zooming in

to a 10-minute window, in order to isolate the time of the closest lightning bolt, shows that the strike to the south of the airport,

south of US Highway 78, was about 2124Z:

But there were 6 other lightning bolts to the NW-NE during that 10-minute period. None of those were reported either.

220. Panama City, Florida, 1 Jun 2015:

This site just had case #212. On June 1st, there was a lot of LTG DSNT W-N of KECP between 1830Z-1930Z:

The trouble was, there was some lightning within 10 miles, to the north. Plus, there were 2 lightning bolts very close to the airport:

Now, this site had ended a thunderstorm at 1723Z:

SPECI KECP 011714Z 13009KT 10SM TS FEW030 29/21 A3005 RMK AO2 LTG DSNT ALQDS TSB08 T02890211
SPECI KECP 011729Z 18009KT 10SM BKN030 28/21 A3005 RMK AO2 LTG DSNT N-E TSB08E23 T02830206

Plus, there was another thunderstorm in the vicinity that began at 2023Z:

METAR KECP 012023Z 33010KT 10SM VCTS FEW023 BKN030 OVC048 24/21 A3004 RMK AO2 WSHFT 1955 LTG DSNT N AND NE T02390206

But what about the 2 lightning bolts that struck on or near airport property around 1859Z? Here is a plot that shows those 2 bolts:

Yet, the reports around that time, did NOT mention thunderstorm activity:

METAR KECP 011853Z 19006KT 10SM FEW032 SCT075 BKN100 27/19 A3004 RMK AO2 LTG DSNT ALQDS SLP185 T02670194
METAR KECP 011953Z AUTO 25006KT 10SM SCT037 BKN047 BKN055 27/21 A3004 RMK AO2 LTG DSNT ALQDS SLP183 T02720211

So while this site did report 2 thunderstorms that day, it missed one in between those 2 storms. And that missed storm produced

lightning that struck at the edge of airport property. Could ATC putting ASOS into AUTO mode have had something to do with that?

221. Gulfport, Mississippi, 1 Jun 2015:

Gulfport-Biloxi International Airport (KGPT) had a thunderstorm in the vicinity that began at 0335Z on the 1st (2nd Jun UTC):

SPECI KGPT 020335Z 00000KT 10SM VCTS CLR 24/21 A2999 RMK AO2 T02440211

However, before that, there was lightning and thunder that went unreported:

The above chart is valid between 2200Z-2300Z on the 1st. There were 8 lightning bolts within the green 10-mile range ring that

met VCTS criteria; one of those bolts also fell within the red 5-mile range ring around KGPT, meeting TS criteria. Yet that earlier

thunderstorm was not reported:

METAR KGPT 012153Z 20006KT 10SM SCT035 29/20 A2996 RMK AO2 SLP146 T02890200
METAR KGPT 012253Z 00000KT 10SM CLR 29/20 A2996 RMK AO2 SLP144 T02890200
METAR KGPT 012353Z COR 18005KT 10SM FEW050 28/19 A2996 RMK AO2 SLP146 T02830194 10300 20283 55001

Although some of the lightning was over the Gulf Of Mexico, some was not:

A VCTS or TS was missed in this case.

222. Leesburg, Florida, 1 Jun 2015:

This site had heavy rain and thunderstorms, officially beginning at 1956Z:

SPECI KLEE 012002Z 01010KT 10SM TS CLR 33/19 A2999 RMK AO2 LTG DSNT ALQDS TSB1956 T03280189
SPECI KLEE 012046Z 13014G22KT 2 1/2SM -TSRA FEW024 BKN046 OVC055 27/22 A3001 RMK AO2 WSHFT 2031 LTG DSNT ALQDS RAB26 TSB1956E14B15 PRESRR P0009 T02720217

Yet, before that time, there had been a fairly close lightning strike that went unreported, around 1722Z:

So while ALDARS was activated at this site on 3 May 2000, it still managed to miss a nearby lightning strike. It did put LTG DSNT

in the METARs however:

METAR KLEE 011653Z 17005KT 10SM CLR 31/21 A3007 RMK AO2 LTG DSNT N AND NE SLP182 T03110206
METAR KLEE 011753Z 14005KT 10SM CLR 32/21 A3005 RMK AO2 LTG DSNT N-E SLP174 T03220206 10328 20250 58016

That was a failure of the R in ALDARS- the “ranging” aspect of the system; unless of course the D in ALDARS- the “detection”

aspect- failed.

223. Gulfport, Mississippi, 2 Jun 2015:

Gulfport-Biloxi International Airport (KGPT) just had a missed thunderstorm in case #221, from the previous day. On the map below,

the reports from that hour are shown near the bottom:

There was brief heavy rain; .17” had fallen by the time of the 2023Z SPECI; while .29” had fallen by the 2053Z METAR. LTG/TS was

not recorded. Of course, that ignored the 10 lightning bolts that struck within the green 10-mile range ring around KGPT- 5 of which

were also within 5 miles. This went down climatologically as a thunderstorm day, only because a nocturnal thunderstorm that ended

at 1:13 a.m. was recorded.

The trouble with that unrecorded thunderstorm, is that one of the lightning bolts struck on or very near the north end of runway 18/36:

Other nearby bolts were also missed/unreported:


224. Norfolk International Airport, Virginia, 2 Jun 2015:

Norfolk Intl (KORF) remains enigmatic with regards to when its ASOS is placed into AUTO mode- with most of that time also spent

in TSNO mode. On June 2nd, KORF did record a thunderstorm, beginning at 1714Z:

SPECI KORF 021714Z 09005KT 2 1/2SM TSRA BR FEW020CB BKN030 OVC041 23/21 A3000 RMK AO2 TSB14 CB SW W MOV E P0010 T02330211

So, the below chart, valid from 1705Z-1800Z, verifies the reported thunderstorm:

The trouble was, that there was also a lot of lightning in the area during the previous hour. Below is the lightning display from 1600Z-1705Z:

During the period that map is valid, the ASOS at KORF was in AUTO/TSNO mode! Why was that? June 2nd was a Tuesday. This site was in

AUTO/TSNO mode until they could ignore the lightning no longer, by the looks of it!

Zooming in on the airfield, shows that lightning was indeed striking close to the airport, before ASOS was taken out of AUTO mode:

The yellow and yellow-orange plots, would be lightning strikes not long before 1705Z. Remember that the thunderstorm officially

began at KORF at 1714Z. But the red and purple colored lightning position plots, would have been about half an hour older. That’s

30 minutes of lead time that was not provided to pilots in the air. Also, users on the ground could have used that 30 minutes of

lead time; while lightning did not strike the airport during that time, it was very close (lightning did appear to strike the airport

about 1738Z).

On the backside of the storm, KORF officially ended the thunderstorm at 1835Z:

METAR KORF 021851Z 05008KT 3SM -RA BKN065 BKN075 OVC100 21/18 A2999 RMK AO2 WSHFT 1743 TSE35 SLP154 CB NE MOV NE CB DSNT NW W AND SW P0147 T02060178

ASOS was not put into AUTO/TSNO mode until 0251Z; and there were no more reports of a thunderstorm on June 2nd. But there was

still lightning within 5 miles after 1845Z:

It appears that the thunderstorm activity at KORF on June 2nd, was officially begun too late, and officially ended too soon.

225. Cecil Field, Jacksonville, Florida, 2 Jun 2015:

This site also had case # 207 recently. Climatologically, June 2nd was not a thunderstorm day at Cecil Field (KVQQ), meaning

they did not record thunder during the calendar day. They should have.

During the half hour between 2030Z-2100Z, there was a lot of lightning striking near the airport:

If the airport property is the grey-shaded area south of Normandy Blvd., then up to 6 lightning bolts struck the airport! So what did

KVQQ report around that time?

METAR KVQQ 021950Z 00000KT 10SM BKN040 29/20 A2996
METAR KVQQ 022050Z 15010G20KT 10SM BKN040 25/19 A2996
METAR KVQQ 022150Z 18008KT 2SM RA BR OVC012 19/18 A2998

There wasn’t any adverse weather reported, until the 2150Z METAR contained IFR visibility of 2SM due to moderate rain. No SPECIs

were taken during the day on the 2nd of June at KVQQ. That means all the lightning in the above graphic went unreported! We can

take a 5-minute slice of time, from 2050Z-2055Z, to see when the peak lightning activity occurred:

There are 16 lightning bolts shown on that map, all striking within 5 minutes. That would constitute FRQ LTGCG. Also, 2 bolts struck

the airport during those 5 minutes. That should have been reported as LTGCG AT AP. But again, no lightning was reported at all!

The location of the control tower at Cecil Field, is circled in red:

The distance from the tower to the nearest lightning strike, as best as can be resolved, was 3,508 feet:

If thunder cannot be heard from that distance, inside the glass enclosure of a control tower; then there is a high risk of thunderstorms going

unreported. That means the hazards associated with thunderstorms, may not be noticed and passed on to pilots and users on the ground.

As of 14 Jan 2016, there are 46 cases of lightning striking airports which are LAWRS sites, when no thunder was reported!

226. Albany, Georgia, 3 Jun 2015:

Albany (KABY) did report a thunderstorm late in the day, beginning at 0012Z when ASOS was in AUTO mode:

SPECI KABY 040012Z AUTO 02010KT 10SM VCTS CLR 24/19 A2992 RMK AO2 LTG DSNT SE AND W T02390194

That indicates that ALDARS was enabled and working at that point. The trouble was right before that.

In a 3-hour period from 2000Z-2300Z, here was the lightning display around Albany GA:

One can see that the criteria for both TS and VCTS were met. However, before 0012Z, no thunderstorm was recorded at KABY:

METAR KABY 031953Z 20009KT 10SM FEW047 32/19 A2990 RMK AO2 SLP122 T03170189
METAR KABY 032053Z 24008KT 10SM CLR 30/18 A2989 RMK AO2 LTG DSNT NW SLP120 T03000183 56018
METAR KABY 032153Z VRB03KT 10SM CLR 31/19 A2988 RMK AO2 LTG DSNT N AND NE SLP116 T03060189
METAR KABY 032253Z 28004KT 10SM BKN120 32/18 A2989 RMK AO2 LTG DSNT N-E SLP118 T03170183
METAR KABY 032353Z AUTO 04011G17KT 10SM FEW060 26/20 A2992 RMK AO2 LTG DSNT SE AND S AND NW SLP128 T02560200 10322 20256 53008

ALDARS detected the lightning beyond 10 miles, as evidenced by the LTG DSNT remarks. But it failed to detect and report

the lightning within 10 miles during that period. The closest lightning bolt during that time, struck at about 2221Z:

That bolt struck just NE of the airport, on the other side of Georgia Highway 91. If something that close was not reported,

but lightning beyond 10 miles was reported, then there was a problem with ALDARS.

227. Athens, Georgia, 3 Jun 2015:

Moving upstate to Athens, Georgia (KAHN), there was another problem. In a 45-minute period from 2300Z-2345Z, here was

the lightning display around Athens:

At the bottom of the graphic, the METAR and a SPECI following the valid time of the chart are posted. That’s why I set the time of the

lightning plot display, to end at 2345Z. By 2351Z, heavy rain was falling, but no thunder was recorded. A SPECI was taken and sent at

2355Z to begin a thunderstorm (although no thunderstorm beginning time was recorded). So we can determine that the thunderstorm

began soon after the 2351Z METAR. So, what about all the lightning on the map? It all struck before the 2351Z METAR. The older bolts

were up to 50 minutes before the METAR, while the newest bolt was still 6 minutes prior to the METAR. In other words, none of the

lightning on the map was actually reported! If even a lightning strike during the last minute of the valid period- 2345Z- had been recor-

ded, it would have been reported on the 2351Z METAR. No reference to LTG/TS appeared in that METAR at all.

Going back to the 5-minute window of 2320Z-2325Z, we find that there was lightning that struck the airport:

The best-resolved position of the LTG, had it striking the south end of runway 02/20. There were 10 other lightning bolts that struck near

the airport during that 5-minute window. But, none of it was reported. Despite LTGCG AT AP as early as 2325Z, a thunderstorm was not

officially begun at KAHN for another half hour; lead time in this case was at least -30 minutes.

228. Craig Field, Jacksonville, Florida, 3 Jun 2015:

Craig Field (KCRG) recorded a thunderstorm in the vicinity (VCTS) on 3 Jun:

METAR KCRG 031953Z 10013KT 10SM CLR 30/17 A2992 RMK AO2 LTG DSNT N AND NW SLP130 T03000172
METAR KCRG 032053Z 11011G18KT 10SM VCTS BKN110 28/18 A2992 RMK AO2 LTG DSNT N AND NW SLP130 T02780183 55011
SPECI KCRG 032134Z 10009KT 10SM SCT055 BKN080 BKN100 27/20 A2991 RMK AO2 LTG DSNT SW AND W T02670200

Since only a few sites record thunderstorm beginning times with VCTS (why that isn’t standardized nationwide is a mystery), it can be

determined from the lack of any TSB time, that the VCTS began at the time of the observation in which it first appeared. In other words,

the VCTS began at 2053Z. The chart below shows the problem with this:

KCRG took a SPECI to end the VCTS at 2134Z. There wasn’t a TS recorded during the valid time of the map, which is 2000Z-2130Z.

That means that ALDARS, which is enabled at KCRG, did not detect the 3 lightning strikes within 5 miles, that should have triggered

a TS. The closest strike, shown below, occurred about 2107Z:


That bolt struck not far to the NE of Craig Field. VCTS was recorded, when TS should have been as well.

229. Hector International Airport, Fargo, North Dakota, 2 (3) Jun 2015:

Neither June 2nd nor 3rd were thunderstorm days, according to the observations coming out of Hector Intl (KFAR).

METAR KFAR 030153Z 14011KT 10SM FEW060 25/17 A2968 RMK AO2 RAE13 SLP048 P0000 T02500172
METAR KFAR 030253Z 15014KT 10SM SCT060 BKN080 OVC100 24/17 A2967
METAR KFAR 030353Z 16019G25KT 10SM FEW070 SCT090 24/17 A2965 RMK AO2 SLP038 T02440167 $
METAR KFAR 030453Z 17017G23KT 10SM CLR 23/17 A2964 RMK AO2 SLP035 T02280167 $
METAR KFAR 030553Z 17011G20KT 10SM CLR 22/17 A2967 RMK AO2 SLP042 60000 T02220167 10261 20222 402670161 55001 $

The 0553Z METAR was at 12:53 a.m. on June 3rd, local time; the other METARs were late on June 2nd. None of those reports showed

any adverse weather. Yet, this was the lightning display around Fargo for the period 0200Z-0500Z on the 3rd, UTC:

Notice the amount of lightning to the north. None of that triggered a LTG DSNT remark. But a VCTS and even a TS should have been

reported during that period, according to the lightning data. Zooming in, it’s hard to see how the closer lightning was missed:

The time of the nearest strikes were from 0205Z-0215Z:

But the sky condition went from FEW060 to SCT060 BKN080 OVC100 that hour, with no mention of thunder between or on the

METARs. Later, between 0345Z-0350Z, there was another nearby lightning strike:

Again, that should have triggered a SPECI for a TS. But while the winds were 16019G25KT in the 0353Z METAR right after that

lightning strike, there was no other hazardous weather mentioned. Since the NWS AMSS site does not mention ALDARS as being

installed at this site, the LAWRS observer did not include the lightning in the report. If there was no LAWRS observer present

because the tower had closed for the night, they should not be signed on to ASOS; that is, ASOS should be in AUTO mode in that

case. By not being in AUTO mode, it gives users the impression that someone is there monitoring the weather. We don’t know if

that was the case here, but we do know that nearby lightning was not reported.

230. Macon, Georgia, 3 Jun 2015:

This site began a thunderstorm at 1852Z. The METAR containing the thunderstorm is shown near the bottom of the below chart:

TSB52 is shown in red. The reason being, is that the chart is valid from 1710Z-1840Z. Any lightning that occurred at 1840Z, would

have been processed by ALDARS/ASOS no later than 1846Z. So the thunderstorm that was reported, would have resulted from a

lightning strike no earlier than 1846Z- still after the valid time of the chart. That means that KMCN did not report any of the lightning

on the above chart! Here are the observations surrounding the period in question:

METAR KMCN 031653Z 14006KT 10SM CLR 29/19 A2997 RMK AO2 SLP142 T02890194
METAR KMCN 031753Z 17005KT 10SM BKN039 BKN050 BKN085 28/18 A2994 RMK AO2 SLP134 T02830178 10294 20194 58013
METAR KMCN 031853Z 05014G21KT 10SM TS FEW023CB SCT038 BKN075 27/17 A2993 RMK AO2 WSHFT 1827 TSB52 SLP130 OCNL LTGCG TS NE W MOV MOV E T02670167

Note the lack of any thunderstorm in present weather or remarks, until the 1853Z METAR. There was not even a LTG DSNT remark

on the 1653Z nor 1753Z METAR. Zooming in on KMCN Airport shows how much nearby lightning there was during the 90 minutes

prior to the reported thunderstorm:

None of the lightning on the map above, triggered the beginning of a thunderstorm.

231. Crystal Airport, Minneapolis, Minnesota, 3 Jun 2015:

Much further north, Minneapolis-Crystal Airport (KMIC) did not record a thunderstorm on June 3rd. Yet around 1800Z, there had

been lightning in the area:

The above map is valid for the 40 minute period of 1720Z-1800Z. The observations coming out of KMIC during that time,

were as such:

METAR KMIC 031653Z 20008KT 10SM OVC018 19/15 A2985 RMK AO2 SLP106 T01940150
SPECI KMIC 031728Z 21005KT 1 3/4SM +RA BKN019 OVC049 19/16 A2988 RMK AO2 RAB20 P0005 T01890156
SPECI KMIC 031743Z 18004KT 2SM RA BR FEW014 BKN050 OVC070 18/16 A2988 RMK AO2 RAB20 P0011 T01830161
SPECI KMIC 031750Z 21003KT 2 1/2SM -RA BR SCT014 BKN023 OVC070 18/16 A2988 RMK AO2 RAB20 P0012
METAR KMIC 031753Z 00000KT 2 1/2SM -RA BR SCT014 BKN055 OVC070 18/16 A2987 RMK AO2 RAB20 SLP113 P0013 60013 T01830161 10200 20183 50016

.81” of rainfall was recorded that day (as per the 04/1153Z 24-hour rainfall group); but no thunderstorm was recorded.

.13” of that fell in the hour before 1753Z. The map above shows that 7 lightning bolts struck the ground within the red

5-mile range ring around KMIC. That should have triggered a TS SPECI, but did not. That was despite the nearness of

some of the lightning:

A low overcast or heavy rain could have prevented a human from seeing lightning during daytime hours, as this period was between

noon and 1 p.m. But ALDARS was activated at this site on 14 Jun 2000, and ALDARS wouldn’t be affected by how bright the sky

could have been, or how dark the overcast or rain would have made it. ALDARS failed to detect any of those 7 lightning strikes within

5 miles of KMIC, and the LAWRS observer did not report them either. This issue continued into the next hour:

The above chart is for the hour between 1800Z-1900Z. More lightning within 5 miles, 7-9 bolts (2 were almost right on the red

5-mile range ring), struck during that hour. While the reports showed heavy rain reducing visibility to 1/2SM during that hour,

no lightning (LTG) nor thunder (TS) was mentioned::

SPECI KMIC 031812Z 14004KT 1 3/4SM RA BR SCT014 BKN048 OVC070 18/17 A2989 RMK AO2 PRESRR P0008 T01780167
SPECI KMIC 031823Z VRB04KT 1/2SM +RA FG FEW009 SCT017 OVC029 18/16 A2988 RMK AO2 P0030 T01780161
SPECI KMIC 031829Z 00000KT 1SM -RA BR FEW009 SCT017 OVC037 18/16 A2988 RMK AO2 P0031 T01780161
SPECI KMIC 031839Z 13004KT 2 1/2SM RA BR SCT009 BKN029 OVC070 18/17 A2988 RMK AO2 P0033 T01780167
SPECI KMIC 031850Z 06003KT 2SM -RA BR BKN007 BKN019 OVC050 18/17 A2986 RMK AO2 P0034
METAR KMIC 031853Z 00000KT 2SM -RA BR SCT007 BKN035 OVC075 18/17 A2987 RMK AO2 SLP112 P0034 T01830167

That was despite the nearness of LTG S-W-N to the airport:

Nearby KMSP should retain its CWO office, instead of relying on ALDARS and LAWRS to report all lightning and thunderstorms properly.

The FAA claims it wants to be proactive and not reactive; retaining CWOs would be a proactive move.

Aug 25, 2015 14:56:20 GMT -5 fu said:

You spent your vacation in Cleveland and Toledo???

No. I spent it in the Dakotas, Colorado, and Wyoming. See next case.

232. Cheyenne, Wyoming, 4 Jun 2015:

This site recently had case #211. On June 4th, this was the lightning display around Cheyenne (KCYS) for the 2-hour period from

2000Z-2200Z:

June 4th was not a thunderstorm day, according to the METARs and SPECIs coming out of KCYS that day. For the 2-hour period

in question, here are the relevant observations:

METAR KCYS 041953Z 14012G24KT 10SM FEW029 21/14 A3005 RMK AO2 SLP098 T02110139
METAR KCYS 042053Z 11011KT 10SM CLR 19/14 A3007 RMK AO2 SLP111 T01940139 53004
METAR KCYS 042153Z 11010KT 10SM BKN030 18/14 A3007 RMK AO2 SLP113 T01830139
METAR KCYS 042253Z 10010KT 10SM FEW021 SCT028 BKN110 19/14 A3007 RMK AO2 SLP110 T01890144

Notice the lack of any lightning (LTG) or thunderstorm (TS) entries in either present weather, or remarks. There were not even any

LTG DSNT remarks. Before you say, “Surely there couldn’t have been thunderstorms nearby, with the ceiling and visibility so good”,

this is a case I can personally attest to. I was on vacation, driving towards Cheyenne on Interstate 25 on this date, when I encountered

heavy rain and lightning. There were even electronic billboards over the freeway that informed motorists that a severe thunderstorm

warning was in effect. So while the worst of the weather may have passed just north or NW of the city and airport (which is where

most of the lightning was), there was certainly a thunderstorm close enough that should have been recorded by KCYS. VCTS criteria

(lightning detected between 5-10 miles from the airport) was easily met; there was also 1 lightning strike close to the airport:

The bolt on the map above, stuck between 2115Z-2120Z, probably at 2119Z. KCYS did not report that, nor any of the LTG that

met VCTS criteria.

241. Spirit Of St. Louis Airport, Missouri, 5 Jun 2015:

Spirit Of St. Louis Airport (KSUS) did record a thunderstorm on June 5th, beginning at 1046Z. The trouble was, that even though

ALDARS is enabled at this site, it was turned off prior to 1046Z! Below is the lightning display for the 1:45 minutes before the

officially reported beginning of the thunderstorm:

Of course, this was around dawn. But since ALDARS is installed at this site, why was it turned off overnight? The red lightning

plots on the map are well before the time that KSUS began reporting thunder. Some of that lightning was fairly close as well:


ALDARS won’t work if ATC doesn’t leave it turned on overnight. A CWO is under instructions only to turn ALDARS off, if it is

not representative. Of course, by virtue of this project, we now know that is more often than previously thought.

242. Willow Run Airport, Ypsilanti, Michigan, 5 Jun 2015:

Ypsilanti (KYIP) had case #208. On June 5th, here was the lightning display around KYIP for the period 1630Z-1730Z:

I didn’t bother putting range rings on the above map. Here’s why:

On the map above, I zoomed in to the airport; but also narrowed the time down to the period 1650Z-1705Z. One can see 5

lightning bolts that struck very close to the airport, plus 1 bolt that struck at the airport. We weather observers like to report

that as LTGCG AT AP. Given that, one would expect to see LTG/TS in reports coming out of KYIP around that time. But this is

what was reported:

METAR KYIP 051553Z 22006KT 10SM HZ FEW090 28/17 A3000 RMK AO2 SLP153 T02830172
METAR KYIP 051653Z 27023G49KT 160V300 1/2SM R05R/1000VP6000FT +RA HZ FEW012 SCT039 BKN070 24/17 A2999 RMK AO2 PK WND 26049/1652 RAB47 SLP151 P0010 T02390172
SPECI KYIP 051655Z 28029G49KT 1/4SM R05R/1000VP6000FT +RA HZ FEW009 BKN039 BKN085 22/17 A3000 RMK AO2 PK WND 28043/1654 P0006 T02220167
SPECI KYIP 051706Z 10006KT 1SM R05R/1200VP6000FT -RA HZ SCT020 BKN039 OVC090 24/15 A2998 RMK AO2 PK WND 28043/1654 P0039 T02390150
SPECI KYIP 051714Z 05004KT 10SM HZ SCT017 BKN065 OVC100 23/17 A2999 RMK AO2 PK WND 28043/1654 RAE13 P0055 T02330172

As one can see, NO lightning (LTG) nor thunder (TS) was recorded during that time- despite the previous chart with its LTGCG AT AP!

That was a near-severe thunderstorm that was not reported as such. The wind gusted to 49 knots, and a 50-knot gust would have made

it a severe thunderstorm- if only thunder had been reported! Somehow, ATC thought it was important to lock in haze with 10 miles

visibility, and keep that locked in, even after the thunderstorm. This is why the weather observing community contends that making errors

in observations can be critical. By locking in haze (HZ), TS wasn’t able to be entered into present weather. ALDARS is not enabled at this

site, according to the NWS AMSS web site; so this falls on ATC.

Again, compare the 1653Z METAR shown on this map, to the lightning data:

That map is valid only for the 5 minutes from 1650Z-1655Z. That METAR was not only incomplete and incorrect, it was dangerous!

243. Cheyenne, Wyoming, 6 Jun 2015:

This site had its 3rd lightning issue of the week. Between 1900Z-2000Z, here was the lightning display around Cheyenne (KCYS):

Included on the map is the METAR from 1953Z, which showed heavy rain restricting the visibility to 3SM. A wind gust to 31 knots

had occurred at 1945Z. Those are clues to an observer to look for lightning and listen for thunder. Indeed, the map shows plenty

of thunder within 10 miles, but one bolt struck very close. This is shown below:

The best-resolved time of the lightning strike, would be 1949Z. That bolt hit on or near US Highway 85, just west of the airport.

It was not recorded in the 1953Z METAR. For fairness, here is the following report:

METAR KCYS 062053Z 30008KT 10SM SCT070 BKN090 17/11 A3006 RMK AO2 RAE53 SLP111 P0007 60007 T01720111 58004

So if there had been a thunderstorm triggered by the close 1949Z lightning strike, it could have been delayed by ASOS report

processing as late as 1955Z. But in that case, TSB1955 would have shown up on the 2053Z METAR, and 2 more SPECIs would

have been generated. That didn’t happen; so this was another missed thunderstorm at KCYS.

244. Wilmington, Delaware, 6 Jun 2015:

Wilmington (KILG) did not record a thunderstorm on June 6th. Yet, there was one nearby lightning strike:

That occurred around 1718Z. But the observations around that time, showed no indication of any thunderstorm or lightning activity:

METAR KILG 061651Z 35015KT 10SM BKN038 OVC048 24/17 A2995 RMK AO2 SLP140 T02390167
METAR KILG 061751Z 01012KT 10SM FEW039 BKN065 BKN080 25/16 A2993 RMK AO2 SLP136 T02500161 10267 20194 50001

So the one LAWRS site in Delaware had a missed thunderstorm that day.

245. Ithaca, New York, 5 (6) Jun 2015:

In upstate New York, Ithaca (KITH) had an issue late in the day on the 5th, which would have been the 6th UTC. Here was the

lightning display around KITH from 0230Z-0330Z on the 6th UTC (June 5th local time):

Included at the bottom of the map are 2 observations relevant to that time. It shows that ALDARS at KITH did report VCTS.

But while that verified, ALDARS somehow did not report any of the lightning that struck within the red 5-mile range ring

around Ithaca. That was at least 19 bolts! Several bolts struck just to the SW of the airport during that hour:

Since the maps are valid from 0230Z-0330Z, did KITH report TS after the 0253Z METAR? No.

SPECI KITH 060302Z AUTO 31016KT 8SM VCTSRA FEW008 BKN014 OVC036 17/16 A2997 RMK AO2 LTG DSNT ALQDS RAB0259 P0004
SPECI KITH 060314Z AUTO 33007KT 7SM RA FEW008 SCT014 BKN039 17/16 A2997 RMK AO2 LTG DSNT E-SW TSE08RAB0259 P0009
METAR KITH 060356Z AUTO 00000KT 8SM -RA SCT009 BKN055 OVC100 17/17 A2997 RMK AO2 T01720166 402720144 LTG DSNT E-S TSE08RAB0259 P0013 SLP143

So this is a site where ASOS is programmed to record TSB 9thunderstorm beginning) and TSE (thunderstorm ending) times for VCTS.

The VCTS ended at 0308Z, meaning that thunderstorm within 5 miles was not reported in this case.

246. Danbury, Connecticut, 6 Jun 2015:

In the pre-dawn hours, Danbury (KDXR) had some lightning around. The following map is valid from 0700Z-0800Z:

The 0753Z METAR is shown on the map. It shows that there had been .45" of rainfall during the past hour. That is one clue that

there could have been thunder. But despite the 5 lightning bolts that struck within the TS Zone, no TS was recorded that hour.

Not even a VCTS was recorded, nor was there any LTG DSNT remark. However, here were the observations prior to that METAR:

SPECI KDXR 060702Z AUTO 00000KT 1 3/4SM +RA BKN050 BKN075 OVC090 15/12 A2988 RMK AO2 P0004 T01500122
SPECI KDXR 060707Z AUTO VRB03KT 3/4SM +RA BR SCT037 BKN050 OVC085 14/12 A2988 RMK AO2 P0016 T01440122
SPECI KDXR 060727Z AUTO VRB03KT 1 1/4SM +RA BR BKN033 OVC045 14/13 A2987 RMK AO2 P0045 T01440128
SPECI KDXR 060733Z AUTO 00000KT 3SM -RA BR BKN033 OVC044 14/13 A2987 RMK AO2 P0045 T01440128

Despite heavy rain being detected, lightning was not detected. This was after the tower had closed for the night; so ALDARS,

which has been enabled at this site since 2001, failed to detect a thunderstorm.

247. Charlotte County Airport, Punta Gorda, Florida, 6 Jun 2015:

A case similar to the Ithaca case, occurred on the 6th in Punta Gorda (KPGD). From 1600Z-1800Z, here was the lightning activity

around Punta Gorda:

The 1753Z METAR is shown near the bottom of the map. It shows that a VCTS was recorded. Of course, that ignored the 4 lightning

bolts that struck within the red 5-mile range ring around KPGD. One of those bolts was just on the west side of Interstate 75, from

Charlotte County Airport:

Was there any TS reported, anytime close to 1753Z? No:

METAR KPGD 061653Z 31015G19KT 10SM FEW047 32/21 A2996 RMK AO2 SLP144 T03170206
SPECI KPGD 061737Z 32011KT 9SM VCTS -RA FEW047 SCT055 BKN070 25/22 A2995 RMK AO2 LTG DSNT SE AND S RAB20 P0000 T02500217
METAR KPGD 061753Z 30009KT 10SM VCTS -RA SCT032 SCT050 BKN070 28/23 A2994 RMK AO2 LTG DSNT SE AND S RAB20 SLP138 P0000 60000 T02780228 10322 20222 58007
SPECI KPGD 061801Z 31009KT 10SM FEW029 SCT060 SCT110 28/22 A2994 RMK AO2 LTG DSNT SE AND S RAE1757 P0000 T02780222
METAR KPGD 061853Z VRB04KT 10SM CLR 30/22 A2992 RMK AO2 RAE1757 SLP133 P0000 T03000222

So while the VCTS was detected properly, a closer TS was missed.

248. St. Petersburg-Clearwater International Airport, Florida, 6 Jun 2015:

Florida will also provide the next 4 cases. First is St. Petersburg-Clearwater International Airport (KPIE). This is a case of timing.

The below graphic shows why:

The valid time of the map is 1830Z-1900Z. According to the 1844Z SPECI that is superimposed on the chart, a thunderstorm ended at

1838Z; while a VCTS was still in progress. Because of the 15-minute rule, that means the lightning that triggered the thunderstorm

struck as early as 1818Z, but only as late as 1823Z. That is because a thunderstorm can’t end until at least 15 minutes after the last

observed lightning if detected by an automated system; or 15 minutes after the last audible thunder if detected by a human observer.

So, therein lies the problem. All of the lightning on the map, struck after 1830Z; the last observed lightning by ALDARS, within 5 miles,

would have been 1823Z or earlier. The 11 lightning bolts that struck within the red 5-mile range ring, mean that ALDARS ended the

thunderstorm too early! Zooming in, here is a map showing nearby lightning bolts, from 1840Z-1855Z:

If lightning was still striking that close to KPIE at 1840Z, a thunderstorm couldn’t have possibly ended before 1855Z. But it was-

at 1838Z. In this case, workers on the ground were given an “all clear- no more lightning within 5 miles”, when that was not

warranted at all! And that was the case for at least 17 more minutes.

249. Southwest Florida International Airport, Ft. Myers, Florida, 6 Jun 2015:

At SW FL Intl (KRSW), a nearby thunderstorm put out a lot of lightning beyond 10 miles, which was recorded:

The map above is valid from 2000Z-2100Z on June 6th. The 2053Z METAR is superimposed on the top half of the map. It shows LTG

DSNT NE-S in remarks. While that was true, none of the lightning within the green 10-mile range ring around KRSW was reported!

Those 5 lightning bolts are numbered on the map; 1 of those also met the criteria for TS. But, not even VCTS was reported around

that time. Bolt #1, which should have triggered a SPECI for a TS, struck just east of the airport:

It probably scared a lot of wild turkeys, as it hit on the edge of a wild turkey preserve! Anyway, the best guess for the time of that

strike would be 2033Z, as the red color means it struck about halfway through the valid time of 2030Z-2035Z.

So while LTG DSNT was recorded at KRSW that late afternoon, neither VCTS nor TS was recorded:

METAR KRSW 061953Z 33013G18KT 10SM CLR 30/20 A2990 RMK AO2 LTG DSNT E AND SE SLP122 T03000200
METAR KRSW 062053Z 34008KT 10SM CLR 31/19 A2988 RMK AO2 LTG DSNT NE-S SLP115 T03060194 58011
METAR KRSW 062153Z 11020G24KT 10SM FEW039 SCT060 OVC110 28/19 A2990 RMK AO2 LTG DSNT E AND SE SLP123 T02780194
SPECI KRSW 062208Z 12013KT 10SM FEW039 BKN060 BKN070 27/19 A2991 RMK AO2 WSHFT 2148 T02720194

That was another missed thunderstorm at a Florida LAWRS site.