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Post by tornado on May 20, 2015 21:51:43 GMT -5
29. Hawkins Field, Jackson, Mississippi, 20 (21) May 2015:For most of the past hour, Jackson-Hawkins Field (KHKS) had a thunderstorm: METAR KHKS 210153Z 06012G20KT 3/4SM +RA BR FEW007 BKN035 OVC060 22/21 A2999 RMK AO2 LTG DSNT E RAB36 TSB09E36 SLP147 P0051 T02220206 Apparently, ATC went home at 9 p.m. Central time, and put ASOS into AUTO mode. ASOS responded by continuing the "lightning distant east" remark at 0159Z: SPECI KHKS 210159Z AUTO 10003G19KT 2SM RA SCT013 BKN035 OVC085 23/20 A3000 RMK AO2 LTG DSNT E P0001 T02330200 However, this map shows otherwise; it has a valid time of 0200Z (1 minute after the SPECI above), and shows lightning, not just in the vicinity, but within 5 miles. Also, ALDARS had the direction as east, when the closer lightning had just struck to the southwest:  A lightning bolt hit Yarborough Park. The distance from that strike, to Hawkins Field, measured at 4.5 miles:  That strike alone, should have prompted ASOS to take a SPECI for a TS. However, there was an even closer lightning strike, just east of Interstate 220, on South Drive near Jayne Avenue:  That particular lightning strike measured 1.4 miles from Hawkins Field. At 0207Z, Hawkins Field took a SPECI for improving visibility, as the rain had let up: SPECI KHKS 210207Z AUTO 06004KT 10SM -RA FEW013 SCT035 BKN055 22/21 A2999 RMK AO2 LTG DSNT E P0001 T02220206 Yet, at 0206Z, a cluster of 3 lightning bolts hit to the southwest of the airfield:  The closest of those 3 bolts, struck right on McRaven Road, just on the south side of Interstate 20:  Measuring the distance from that bolt, to the airport, yielded a distance of 5.47 miles. At that point, the closest lightning would have supported reporting a VCTS; but the TS that should have been generated at 0200Z could not have ended before 0215Z. But what KHKS reported, was simply LTG DSNT E. That was an ALDARS error
in timing; and also in placement, as the closest and most recent lightning was SW.30. Laredo, Texas, 21 May 2015:Folks, this is the worst case yet! Upon checking the lightning data first thing, I noticed the Laredo, Texas (KLRD) area covered in lightning strikes:  That is the free lightning map from Vaisala, with a timestamp of 1240Z. Though it shows the big picture, one can plainly see that the Laredo area had plenty of lightning. The next map, from Weathertap.com, shows the same thing:  The lightning data from Weathertap shows the cluster of thunderstorms moving southeast, clearly having crossed over Laredo. Now to lightningmaps.org, which showed the past hour of lightning strikes, valid 1300Z:  The above chart showed dozens of lightning strikes near Laredo! There were some strikes that were current, and some up to an hour old. The way lightningmaps.org works, is that the colored circles representing the strikes, begin yellow and then grow darker as the hour progresses. Dark brown strikes are the oldest, and drop off the map after 1 hour. However, KLRD did not even report any thunder that past hour! METAR KLRD 211156Z 06012KT 10SM -RA BKN015 OVC023 24/23 A2999 RMK AO2 50015 60000 T02440227 10261 20244 BKN V OVC RAB51 P0000 SLP144= SPECI KLRD 211222Z 02019KT 3SM +RA BR FEW001 BKN012 OVC024 24/23 A3001 RMK AO2 P0000 SPECI KLRD 211226Z 02026G30KT 1 3/4SM +RA BR FEW001 BKN012 OVC024 23/22 A3002 RMK AO2 P0000 PK WND 02030/1223 SPECI KLRD 211236Z 01024G34KT 1 1/4SM +RA BR SCT001 OVC012 22/21 A3004 RMK AO2 P0000 PK WND 01034/1228 SPECI KLRD 211248Z 04025G30KT 1 1/2SM +RA BR SCT001 BKN010 OVC015 21/21 A3006 RMK AO2 P0000 PK WND 01034/1228 METAR KLRD 211256Z 07016KT 2SM +RA BR SCT001 BKN010 OVC015 22/20 A3005 RMK AO2 T02160200 VIS 1V5 P0000 PK WND 01034/1228 SLP164 SPECI KLRD 211303Z 10016KT 4SM +RA BR FEW001 SCT010 BKN016 22/21 A3003 RMK AO2 P0000 The heavy rain, and wind gust to 34 knots, was obviously the result of thunderstorms moving through Laredo. 3 different lightning websites showed that. But neither
ALDARS nor ATC reported any lightning, not even in remarks!As of 1307Z, the lightning was still striking nearby:  Here's a closer view, valid at 1309Z:  Imagine that much lightning being unreported at Houston or Dallas! It's not like the live lightning data is being picked up by just a few lightning detection sites. This bolt SE of Laredo was picked up by 21 lightning detection stations at 1402Z:  Here is the archived view, for a 90-minute period, centered on 1200Z-1300Z:  That's a lot of lightning that was missed! How is it that audible thunder was not heard and reported? Late edit: METAR KLRD 211356Z 07017G23KT 10SM CLR 22/20 A2998 RMK AO2 T02160200 RAE50 P0000 PK WND 10029/1321 SLP139 Clear skies? Then how did lightning strike so close at 1402Z? Check out the lightning-radar map valid at 1410Z. Does this look like Laredo should have reported clear skies? 
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Post by tornado on May 21, 2015 12:12:55 GMT -5
31. David Wayne Hooks Airport, Houston, Texas, 21 May 2015:
David Wayne Hooks Airport (KDWH) reported thunderstorm in the vicinity this past hour:
METAR KDWH 211553Z 33021G29KT 10SM VCTS -RA BKN014 BKN046
OVC070 24/21 A3007 RMK AO2 PK WND 33029/1551 LTG
DSNT ALQDS RAB53 SLP179 P0000 T02440211
SPECI KDWH 211605Z 01009KT 7SM VCTS -RA BKN014 BKN021 OVC070
23/21 A3008 RMK AO2 WSHFT 1545 LTG DSNT ALQDS
P0001 T02280206
SPECI KDWH 211640Z 36010KT 10SM VCTS BKN008 BKN019 OVC060
23/21 A3007 RMK AO2 WSHFT 1545 LTG DSNT NE-S RAE37
P0001 T02280211
METAR KDWH 211653Z 03006KT 10SM VCTS BKN008 BKN019 OVC060
23/21 A3008 RMK AO2 WSHFT 1545 LTG DSNT NE-S RAE37
SLP182 P0001 T02280211
However, at and shortly before 1611Z, there were lightning stirkes to the northeast of KDWH:
The lightning strike near the intersection of Spring Steubner Road and Northcrest Drive,
was measured to be 3 miles from the airport:
Of course, there were also 2 closer lightning strikes west of Gosling Road. That made 3 lightning
strikes of 3 miles or less, from the airport, that were not detected by ALDARS. A thunderstorm
should have been reported, beginning at or shortly after 1611Z, but VCTS remained the present
weather code that entire hour. There were other nearby lightning strikes at 1632Z:
At 1642Z, another bolt struck closer than the one that had been measured at 3 miles:
The above chart shows 10 lightning strikes within 5 miles. ALDARS missed them all!
Considering what happened at Laredo a few hours ago, it can be determined that ALDARS
misses a lot of lightning within 5 miles!
32. Baton Rouge, Louisiana, 21 May 2015:
Here is the weather from this past hour from Baton Rouge (KBTR):
METAR KBTR 211753Z 30009G17KT 9SM SCT035 BKN110 28/22 A3003
RMK AO2 SLP167 T02780222 10306 20233 58006
METAR KBTR 211853Z 31006KT 10SM SCT033 27/19 A3001 RMK AO2
SLP162 T02720194
So, there was no lightning reported, not even in remarks. Lightning data showed otherwise:
Lightning animation showed lightning strikes to the north side of Baton Rouge. That is where the airport is
located. At 1816Z, 2 lightning strikes registered to the west of KBTR:
The closest strike was just on the west side of the Mississippi River, at a distance of 6.98 miles:
That should have initiated a SPECI for a VCTS soon after 1816Z. But somehow, that bolt
escaped detection by ALDARS. At 1847Z, another bolt struck even closer:
That bolt measured at 6.22 miles away. Again, a VCTS (thunderstorm 5-10 miles away/"in the vicinity")
should have been reported. It wasn't. Not even LTG DSNT was reported.
33. Boise, Idaho, 21 May 2015:
Boise (KBOI) reported a VCTS this past hour:
METAR KBOI 211853Z 05003KT 10SM BKN100 21/08 A2988 RMK AO2
LTG DSNT E SLP098 T02110083
SPECI KBOI 211903Z 03006KT 10SM VCTS BKN100 21/09 A2988 RMK
AO2 LTG DSNT E TSB1857
METAR KBOI 211953Z 07009KT 10SM FEW060 SCT085 BKN100 19/09
A2987 RMK AO2 LTG DSNT NE AND E TSB1857E48 SLP099
T01890094
The lightning animation showed storms approaching both Boise; and Walla Walla, Washington.
Walla Walla properly began a TS 4 minutes after a lightning strike. However, the ALDARS at Boise
never reported lightning within 5 miles. Zooming in to the Boise area showed this at 1931Z:
One of those lightning bolts was just west of U.S. Highway 20/26, also west of Ivywild Park;
near the railway next to the Post Office:
That bolt measured 1.58 miles away; keep in mind there was an even closer lightning strike just
south of that one. Another bolt to the east, was also within 5 miles:
That lightning strike measured 4.53 miles from Boise Airport. That makes 3 lightning strikes within
5 miles, that ALDARS should have registered as a TS; but only VCTS was reported. Is this what
taxpayers deserve?
Ogden, Utah:
METAR KOGD 211853Z AUTO 32008KT 10SM FEW110 20/08 A2993 RMK
AO2 SLP097 T02000083 TSNO
METAR KOGD 211953Z AUTO 33008KT 10SM CLR 21/07 A2990 RMK
AO2 SLP087 T02060067 TSNO
Why this site is in AUTO mode, with no thunderstorm information, at this time of day is beyond me.
Especially with lightning nearby at 2030Z:
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Post by tornado on May 21, 2015 18:56:32 GMT -5
34. Mobile-Downtown Airport, Alabama, 21 (22) May 2015:
After reporting a thunderstorm from 2107Z-2122Z, this site (KBFM) began another
thunderstorm at 2310Z. In the meantime, they had reported VCTS:
METAR KBFM 212153Z 17004KT 10SM FEW040 BKN049 OVC090 28/21
A2998 RMK AO2 LTG DSNT SW AND W TSB07E22 SLP151
T02780211
SPECI KBFM 212251Z 28004KT 10SM VCTS OVC038 27/22 A3000 RMK
AO2 LTG DSNT SE-W
METAR KBFM 212253Z 27004KT 10SM VCTS OVC038 27/21 A3000 RMK
AO2 LTG DSNT SE-W SLP157 T02670211
SPECI KBFM 212316Z 35006KT 10SM TS OVC038 28/21 A3000 RMK
AO2 LTG DSNT ALQDS TSB10 T02830206
However, lightning data valid at 2247Z, showed a strike about a mile south of
the airport:
Somehow, ALDARS missed that bolt. Remember, the 2nd thunderstorm began
at 2310Z; that means VCTS was reported for 23 minutes, when TS should have
been reported for the first 15 of those minutes, based on that bolt alone. But
there were more:
By 2304Z, the map above showed a bolt striking in the northwest part of the
suburb of Tilman's Corner. But another recent strike was even closer:
That strike to the WSW measured at 4.77 miles away. There was another bolt
that hit over Mobile Bay:
That bolt measured at 3.78 miles away. At 2314Z, a bolt showed up as being several
minutes old, as its color was dark yellow. I refer to the one that hit near the Dog River.
That bolt appears to be the one that triggered ALDARS to take a SPECI for the
TS beginning at 2310Z:
The trouble with this, is that the bolt that finally triggered the TS, was right next to
the older, closer lightning bolt that didn't trigger a TS! ALDARS is not reliable if it can catch one bolt at one time, and not detect another bolt within a mile at a time when TS should have been reported! The first 3 bolts that were within 5 miles were not detected by ALDARS; it took a 4th bolt striking within 5 miles, to start a thunderstorm (TS).
Perhaps ALDARS misses so many lightning bolts, because it uses a process known as triangulation. Lightning detection stations listen for
the radio waves known as sferics (short for atmospherics). 3 lighting detection stations that catch the sferics of the same bolt, can then
pinpoint that bolt's location.
Lightningmaps.org uses many more stations than that. On the below map, there were 4 lightining bolts in a cluster that struck near
Flagstaff, Arizona, a short while ago. The westernmost bolt was detected by 31 stations:
I turned the stations setting to "on", to see how many stations would catch a bolt in the western United States. The west has good
coverage as well. The blue and green lines are drawn from the detection stations, to the lightning locations. Below is a map, zoomed
out to show 2 other strikes that were detected:
The strike in northern Nevada was detected by stations in Portland OR, Bismarck ND, San Antonio TX; and many others, including one
in Mexico. The bolt that struck in east-Central Utah was detected by stations in South Dakota, Wisconsin, and many others; including
southern Canada, and one site so far east it was off the map. ALDARS uses the NLDN, but we don't know how many sensors nationwide
feed NLDN data into ADAS, from which local ASOS units get their information This is apparently why lightningmaps.org is picking up
lightning bolts that ALDARS isn't: it has more detection sites.
35. Grand Junction, Colorado, vs. McCarran Intl Airport, Las Vegas, Nevada; 22 May 2015:
Which site was more accurate this past hour in their lightning reporting? First, the METAR from Grand Junction, Colorado (KGJT):
METAR KGJT 221853Z 06008KT 10SM TS CLR 14/09 A2992 RMK AO2
LTG DSNT NE AND SW RAB13E36 TSB18E33B35 SLP091
TS N MOV NE OCNL LTGCG P0009 T01390089
Was there a thunderstorm to the north? Yes. Were skies clear? No. But somehow, ALDARS missed even closer lightning, than
that which struck to the north:
Why the 1853Z METAR concentrated on the storm to the north, when there were 2 bolts that struck within 5 miles to the south;
and 2 bolts that struck within 5 miles to the east, is unknown. Also, the lightning that struck to the east and south, was more
recent than the almost hour-old bolts that hit further to the north.
The situation at McCarran Intl Airport in Las Vegas, was this:
METAR KLAS 221856Z 14007G15KT 10SM RA SCT070 BKN120 BKN160
18/12 A2981 RMK AO2 LTG DSNT W RAB42 SLP081 P0010
T01830117
At 1857Z, this was the lightning display:
The closest lightning bolt was indeed to the west; in the mountains just west of Blue Diamond:
That strike measured 17.26 miles away. Since the definition of "distant" regarding ALDARS is lightning 10-30
miles away, the CWO office at KLAS was more accurate in its assessment of lightning location and distance,
than was the LAWRS office at KGJT. Why trade accuracy for inaccuracy?
36. St. Lucie County Intl Airport, Ft. Pierce, Florida, 22 May 2015:
2 consecutive METARs at KFPR showed clear skies, with no remarks:
METAR KFPR 221853Z 05012G16KT 10SM CLR 30/24 A3007 RMK AO2
SLP183 T03000239
METAR KFPR 221953Z 07009KT 10SM CLR 29/23 A3009 RMK AO2 SLP188
T02940233
However, at 1947Z, the lightning display with radar overlaid, showed this:
The closest lightning bolt, was to the north of state highway 70:
That bolt measured at 11.72 miles from the airport. Given that data, it should not have been reported as "clear"
in sky condition. Remarks probably ought to have read, "LTG DSNT SW CB DSNT S-W". ALDARS failed
to detect lightning strikes 10-30 miles away from the site. ASOS didn't do much better, by reporting CLR; and
ATC allowed the METAR to transmit, with no mention of the hazards to the south and west of the airport.
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Post by tornado on May 22, 2015 15:42:54 GMT -5
37. Grand Canyon Airport, Arizona, 22 May 2015:
By 1926Z, there had been 5 lightning strikes that were clearly within 5 miles of the airport (KGCN):  The scale on the above map is 2000 feet. Although KGCN took a SPECI at 1921Z, no mention was made of any lightning:
METAR KGCN 221854Z 33005KT 10SM BKN055 OVC095 09/01 A2998
RMK AO2 RAE03 SLP122 P0000 T00890011
SPECI KGCN 221921Z 24012KT 4SM RA BR BKN029 BKN034 OVC055
03/02 A3001 RMK AO2 PK WND 23031/1909 WSHFT 1903
RAB1856 P0011 T00330022
METAR KGCN 221954Z 00000KT 10SM -RA SCT010 BKN037 OVC075
06/05 A3001
By 1943Z, lightning within 10 miles was still in progress:
That bolt to the northeast measured at 8.2 miles:
So 5 lightning bolts that should have generated a TS were missed; plus the bolt to the NE that should have
generated a VCTS was missed. There wasn't even a mention of LTG DSNT that hour! Thunderstorms
were in the TAF:
KGCN 221740Z 2218/2318 21012G20KT P6SM SCT035 BKN050
TEMPO 2218/2222 VRB20G30KT 5SM TSRA OVC035CB
FM222200 22010KT P6SM VCSH BKN035 OVC060
Plus, animated lightning data showed strikes near Grand Canyon in the hour before 2010Z:
Late edit:
METAR KGCN 221954Z 00000KT 10SM -RA SCT010 BKN037 OVC075
06/05 A3001
METAR KGCN 222054Z NIL
METAR KGCN 222154Z NIL
I wonder why the last 2 METARs have been missing from KGCN. Lightning?
Archived data showed lightning striking much closer than 8.2 miles:
The closest bolt was more like 1/2 a mile from the Airport Reference Point.
38. Boise, Idaho, 23 May 2015:
The weather sequence from Boise, Idaho (KBOI) this past hour, showed thunderstorms in the
vicinity:
METAR KBOI 232153Z 29013G25KT 10SM -RA SCT065 BKN080 24/09
A2982 RMK AO2 LTG DSNT NE AND E RAB52 SLP077 P0000
T02440089
SPECI KBOI 232225Z 33012G26KT 10SM VCTS BKN070 BKN120 24/08
A2982 RMK AO2 PK WND 31026/2218 LTG DSNT NW-E
TSB19RAE10 P0000
METAR KBOI 232253Z 31015G20KT 10SM VCTS FEW065 SCT090 25/08
A2983 RMK AO2 PK WND 31026/2218 LTG DSNT NE AND
SE TSB19RAE10 SLP079 P0000 T02500083
Now, here is a map with range rings around the Boise airport, at 5 and 10 miles:
A lightning map at 2253Z- the exact minute of the METAR- showed this:
By comparing the 2 maps above, one can clearly see a lightning strike within the
red range ring, which represents 5 miles. 2 other strikes are right about on the red
ring. Boise should have reported TS instead of VCTS, for at least 15 minutes
during the past hour. 39. Grand Junction, Colorado, 23 May 2015:The weather sequence from Grand Junction. Colorado (KGJT) this past hour, showed lightning to the DSNT SE-SW (10-30 miles from the site): METAR KGJT 232153Z 33014KT 10SM FEW038 SCT100 13/04 A2996 RMK AO2 RAE2056B12E40 SLP113 P0000 T01330044 METAR KGJT 232253Z 35008KT 5SM -RA BKN044 BKN060 OVC090 10/06 A2995 RMK AO2 LTG DSNT SE-SW RAB33 SLP120 P0001 T01000056 Now, here is a map with range rings around the Grand Junction airport, at 5 and 10 miles:  Remembering that the lightning strikes don't drop off the map for one hour, here were the lightning strikes near KGJT valid at 2259Z:  By comparing the 2 maps, it can be discerned that there were 3 lightning bolts between the 2 METARs, that struck within 10 miles of KGJT airport. That should have generated a
SPECI for VCTS, but did not. |
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Post by kukblue1 on May 23, 2015 13:58:28 GMT -5
Can you check why at 1:30pm central time Wiley Post was reporting LTG DSNT SW-NW and Norman was reporting DSNT N and SE. No storms I saw on radar SW of Wiley Post and No Storms SE of Norman? Ok storms forming but not sure if there was LTG in them yet.
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Post by tornado on May 23, 2015 18:40:05 GMT -5
Can you check why at 1:30pm central time Wiley Post was reporting LTG DSNT SW-NW and Norman was reporting DSNT N and SE. No storms I saw on radar SW of Wiley Post and No Storms SE of Norman? Ok storms forming but not sure if there was LTG in them yet.
Ok. First thing to do, is see where is 30 miles away from Wiley Post:
Then the lightning display at 1830Z:
Archived lightning data:
That yellow strike to the SW of Wiley Post, near Pocasset on U.S. Highway 81, was right on the blue 30-mile range ring. But you're right; it doesn't appear there were any active storms with lightning, SE of Norman.
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Post by tornado on May 23, 2015 22:34:15 GMT -5
40. Waco, Texas, 23 (24) May 2015:
Waco Regional Airport (KACT) reported thunderstorm in the vicinity this past hour. That meant
the lightning strikes could be no closer than 5 miles from the site.
METAR KACT 240151Z 16003KT 8SM -RA FEW050 SCT070 BKN110 22/21
A2996 RMK AO2 SLP141 P0000 T02220211
SPECI KACT 240238Z 25004KT 4SM VCTS -RA BR SCT080 BKN100
22/21 A2994 RMK AO2 LTG DSNT NE AND S AND W RAE0155B13
PRESFR P0002 T02220211
METAR KACT 240251Z 00000KT 4SM VCTS -RA BR FEW080 OVC100
22/22 A2995 RMK AO2 LTG DSNT ALQDS RAE0155B13
SLP136 P0003 60005 T02220217 58003
However, lightning data revealed that there had been strikes within 5 miles. At 0240Z, a bolt
struck to the SE, just on the other side of Lake Waco:
Measuring the distance from that strike, to the airport, yields a distance of 3.78 miles:
At 0245Z, 5 bolts struck the ground to the NE-E or KACT:
Another bolt had struck just before that. Measuring its distance yielded a figure of 3.97 miles:
But there were 2 bolts that struck closer than that one. The closest was just on the west side
of the Brazos River, just north of Highway 3051, at 0245Z:
That bolt struck 2.26 miles away. Yet, the ALDARS at KACT reported VCTS from 0238Z-
0251Z.
41. Laredo, Texas, 23 (24) May 2015:
Laredo (KLRD) took a SPECI for VCTS becoming TS, at 0239Z.
METAR KLRD 240156Z AUTO 09007KT 10SM -VCTSRA SCT039 BKN050
27/23 A2988 RMK AO2 T02720233 LTG DSNT ALQDS TSB40RAB23
P0000 SLP105
SPECI KLRD 240239Z AUTO 26015G23KT 4SM +TSRA BR FEW001 SCT011
BKN036 26/24 A2991 RMK AO2 BKN V OVC LTG DSNT
ALQDS P0000 PRESRR
However, by 0225Z, there had already been 4 lightning strikes within 5 miles of the site:
Here is the 5-mile range ring for Laredo (KLRD):
By comparing those 2 maps, one can see each of those 4 lightning strikes was within
the red circle that is 5 miles from the airport. That included the strike near Shiloh Drive
and Highway 83; the strike to the east of state Highway 20 and Del Mar Blvd.; the
strike near Clark Blvd. and Springfield Ave.; and the closest strike between Springfield
Ave. and McPherson Road. Any or all of those strikes should have generated a TS at
KLRD; the northernmost of those 2 bolts were several minutes old, as the circles that
represented them were turning orange. ALDARS at KLRD was at least 14 minutes
late in getting a TS reported. At least this time it did eventually detect the lightning!
(see case 30)
Pilot and resources on the ground need as much lead-time for lightning and thunderstorm
activity; one reason, is that this can happen:
A CWO would report that as OCNL LTGCG AT AP
42. Mobile-Downtown Airport, Alabama, 24 May 2015:
Here was the situation recently at Mobile-Downtown (KBFM):
SPECI KBFM 241545Z 15015G22KT 10SM VCTS CLR 29/24 A3018 RMK
AO2 T02890239
METAR KBFM 241553Z 15015G22KT 10SM VCTS SCT028 28/24 A3017
RMK AO2 SLP217 TCU DSNT NE T02830239
Here was the lightning data:
I found a program that will allow me to overlay layers on top of a base map. Anyway,
one lightning bolt, which occurred to the SE before 1555Z, was clearly within the 5 mile range ring. ALDARS should have begun a TS, but the next report out of KBFM was this:
SPECI KBFM 241608Z 15014G20KT 10SM SCT028 29/24 A3017 RMK
AO2 LTG DSNT NE-SE RAB1554E04 TCU DSNT NE P0000
T02890239
Note that none of the 3 reports posted, were correct. 1545Z had a thunderstorm
vicinity with clear skies; 1553Z and 1608Z implied lightning was being produced
by TCU. |
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Post by tornado on May 24, 2015 17:34:08 GMT -5
43. North Las Vegas, Nevada, 24 May 2015:At 1937Z today, this was the lightning display around North Las Vegas Airport (KVGT) in Nevada:  The closest bolt had struck to the north, measuring a distance of 8.4 miles away from the airport:  Yet, these were the METARs that hour (there were no SPECIs): METAR KVGT 241853Z 00000KT 10SM CLR 24/08 A2988 RMK AO2 SLP118 T02440078 METAR KVGT 241953Z VRB06KT 10SM CLR 26/07 A2987 RMK AO2 SLP111 T02560072 This was the radar at 1952Z:  That was the same time the METAR was processing. Although KGVT reported clear skies, the radar showed otherwise. Also there was no mention of lightning at all in either METAR; even though with lightning at 8.4 miles away, a SPECI for VCTS should have been generated. 44. Monroe, Louisiana, 24 May 2015:Just before 2019Z, a lightning bolt struck near the Monroe Regional Airport:  That bolt measured at 1.92 miles away from the airport:  While KMLU had been reporting a VCTS, that lightning bolt 1.92 miles away, should have resulted in a SPECI for VCTS becoming a TS. Yet, while TS was eventually recorded, it wasn't reported until 2047Z: METAR KMLU 241953Z 19009G22KT 6SM VCTS -RA BKN041 BKN050 28/22 A2996 RMK AO2 LTG DSNT SW-NW RAB36 SLP145 P0000 T02780222 METAR KMLU 242053Z 17007G16KT 10SM -TSRA FEW037 SCT070 BKN100 25/20 A2996 RMK AO2 LTG DSNT NE-S TSB47 SLP144 P0000 60000 T02500200 56013 That was 28-minute delay in getting the VCTS promoted to a TS. The lightning bolt that triggered the TSB47, can be seen on this map:  That map was valid at 2047Z. So we see that 2 lightning bolts, about the same distance from the airport; had different results. The older bolt was not detected by ALDARS, while the younger bolt was. They were separated in time by 28 minutes. Is this what we really want- a lightning detection system that doesn't detect strikes within 2 miles, with LAWRS observers also too busy to record all of them? Or perhaps LAWRS observers were trusting ALDARS to record all the strikes? Here is the audio feed from LiveATC.net, from 2000Z-2030Z at KMLU on May 24th: KMLU-May-24-2015-2000Z.mp3 (3.6 MB) 45. Tupelo, Mississippi, 24 May 2015:Here are Tupelo's weather reports for the past hour: METAR KTUP 242053Z 18011G16KT 10SM FEW041 SCT050 BKN095 29/20 A3003 RMK AO2 RAB29E40 SLP164 P0001 60001 T02940200 56029 SPECI KTUP 242121Z 19006G27KT 2SM +RA FEW026 SCT041 SCT065 26/21 A3002 RMK AO2 PK WND 20027/2114 LTG DSNT SE AND SW RAB15 P0007 T02560206 SPECI KTUP 242130Z 20006KT 10SM FEW026 FEW041 FEW055 26/22 A3003 RMK AO2 PK WND 20027/2114 LTG DSNT SE-W RAB15E27 P0007 T02560217 SPECI KTUP 242140Z 18007KT 10SM VCTS FEW026 FEW042 SCT060 26/22 A3004 RMK AO2 PK WND 20027/2114 LTG DSNT SE-W RAB15E27 P0007 T02560217 METAR KTUP 242153Z 24011G20KT 1 1/4SM +TSRA FEW021 SCT037 BKN060 24/21 A3004 RMK AO2 PK WND 20027/2114 VIS 1/2V5 LTG DSNT ALQDS RAB15E27B43 TSB41 SLP169 P0024 T02390206 At 2139Z, a lightning bolt struck just within 5 miles south of the airport:  Somehow, ASOS transmitted a SPECI at 2140Z for VCTS, even though the bolt measured as being 4.96 miles away:  Granted, that is so close to the 5 mile range ring, and we don't know exactly from what point ALDARS/ASOS was measuring. But that does appear to be the bolt that began the thunderstorm within 5 miles, as the remark was TSB41. Yet, TS was not reported to the users until the 2153Z METAR. There was no SPECI for VCTS becoming a TS, as ALDARS is supposed to generate. This means for 12-14 minutes, there was lightning within 5 miles of the airfield, that was being reported as 5-10 miles away from the airfield.
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Post by tornado on May 24, 2015 21:43:53 GMT -5
46. Hawkins Field, Jackson, Mississippi, 24 (25) May 2015:
Firstly, here is the 5-mile range ring for Hawkins Field (KHKS):
By 25/0104Z (the evening of the 24th), the lightning display looked like this:
The next graphic is the archived lightning display, from 0000Z-0105Z. The chart overlays the 5 mile range ring
upon the 0105Z lightning strike chart (in other words, it combines the 2 charts above in a different format). How
many lightning strikes within 5 miles can you count?
The green range ring represents 10 miles. Many more lightning strikes can be counted inside that range ring.
So strikes within the red ring should have triggered a TS; while strikes within the green ring should have
triggered a VCTS. Yet, here were the weather reports from KHKS, surrounding that time:
METAR KHKS 250053Z 16009KT 10SM SCT060 SCT080 BKN120 26/22
A3002 RMK AO2 LTG DSNT S SLP158 T02560217
SPECI KHKS 250109Z 20017G30KT 2 1/2SM -RA SCT020 BKN028 BKN110
23/20 A3006 RMK AO2 PK WND 21030/0107 LTG DSNT
S RAB04 PRESRR P0012 T02330200
I monitored that site, and kept waiting for KHKS to report a TS within 5 miles.
By 0117Z, they had reported heavy rain, but no lightning within 10 miles:
SPECI KHKS 250117Z 19009G24KT 1SM +RA BR BKN023 BKN032 OVC120
21/20 A3005 RMK AO2 PK WND 21030/0107 LTG DSNT
S RAB04 P0031 T02110200
Yet, at 0112Z, a lightning bolt struck on the west side of the airport:
I zoomed in at 0113Z, so that the position of the lightning strike could be seen better:
That bolt hit airport property, between the tarmac and Shop St. That was certainly
LTGCG AT AP... but what was the frequency?
I counted 6 lightning bolts hitting around the airport at 0114Z alone. CONS LTGCG
AT AP could have been reported; although the frequency wouldn't mean that all 6
bolts hit at the airport. 18 lightning detections sites picked up one of the bolts at 0114Z:
Yet, the next SPECI to come out of KHKS was this:
SPECI KHKS 250121Z 19007G18KT 1 1/2SM VCTS +RA BR FEW023
OVC031 21/20 A3005 RMK AO2 PK WND 21030/0107 LTG
DSNT SE AND S RAB04 P0034 T02110200
A bolt hit the airport, and 6 more nearby within 2 minutes; and ALDARS reported
VCTS? ALDARS did eventually catch up, and report TS:
SPECI KHKS 250128Z 15011KT 2SM +TSRA BR FEW023 OVC037 21/19
A3005 RMK AO2 PK WND 21030/0107 LTG DSNT SE AND
S RAB04 TSB28 P0044 T02110194
Did this bolt at 0122Z, that hit to the east of the airport, finally trigger ALDARS
to report a TS?
Or was it this closer pair of bolts that struck at 0125Z?
It's unknown which bolt triggered ALDARS to send a signal to ASOS to take a
SPECI for VCTS becoming TS; Since the time of the SPECI to begin the TS was
the same as the TSB28 remark, perhaps the LAWRS observer finally intervened.
But the LAWRS observers should have known storms were coming:
That was the lightning animation, with the last panel valid at 0120Z. Surely there
was a convective SIGMET out for those storms. Why then was there at least a
24-minute delay in reporting TS? Remember, there were 41 lightning bolts that
struck within 5 miles, earlier than 0104Z!
Late edit:
SPECI KHKS 242115Z 13022G36KT 2 1/2SM VCTS RA FEW021 BKN038 BKN048 26/20 A3000 RMK AO2 PK WND 14036/2113 LTG DSNT ALQDS RAB14 TSE14 P0006 T02610200
SPECI KHKS 242122Z 12014G36KT 1SM VCTS RA FEW021 BKN035 BKN048 24/21 A3000 RMK AO2 PK WND 14036/2113 LTG DSNT ALQDS RAB14 TSE14 P0015 T02390211
SPECI KHKS 242223Z 16009KT 10SM VCTS CLR 26/21 A2999 RMK AO2 LTG DSNT SW AND W T02610211
METAR KHKS 242253Z 16015G19KT 10SM VCTS CLR 27/22 A3000 RMK AO2 LTG DSNT N AND NW SLP149 T02670217
SPECI KHKS 250121Z 19007G18KT 1 1/2SM VCTS +RA BR FEW023 OVC031 21/20 A3005 RMK AO2 PK WND 21030/0107 LTG DSNT SE AND S RAB04 P0034 T02110200
SPECI KHKS 250128Z 15011KT 2SM +TSRA BR FEW023 OVC037 21/19 A3005 RMK AO2 PK WND 21030/0107 LTG DSNT SE AND S RAB04 TSB28 P0044 T02110194
Between 2114Z-0128Z, VCTS was reported, but no TS. Setting a lightning display map, to run from 2115Z-0120Z, should therefore show no lightning within 5 miles. That was not the case:
Lightning struck just off the western edge of the airport at 2353Z:
That was in the midst of these reports:
SPECI KHKS 242322Z 15011KT 10SM FEW024 26/22 A3000 RMK AO2 LTG DSNT N AND S T02610217
METAR KHKS 242353Z 21007KT 180V260 10SM FEW029 SCT041 BKN055 26/22 A3001 RMK AO2 SLP154 60015 T02610217 10306 20239 53004
METAR KHKS 250053Z 16009KT 10SM SCT060 SCT080 BKN120 26/22 A3002 RMK AO2 LTG DSNT S SLP158 T02560217
Of course, the issue at 0114Z was even worse.
47. Laredo, Texas, 25 May 2015:
At 1356Z, a lightning bolt struck north of the Laredo (KLRD) Airport:
The distance to that bolt was 7.46 miles:
Another bolt struck at 1420Z:
The distance to that bolt was 7.4 miles:
Yet, here were the METARs before and after those times (there were no SPECIs that hour):
METAR KLRD 251356Z 13008KT 10SM OVC018 25/23 A2986 RMK AO2
T02500227 SLP098
METAR KLRD 251456Z 15009KT 10SM FEW017 BKN022 OVC036 26/23
A2987 RMK AO2 53018 60000 T02610233 SLP104
So, there was lightning within 10 miles, which should have generated a SPECI for a VCTS.
Yet, not even DSNT LTG was reported that hour!
48. Gulfport, Mississippi, 25 May 2015:
Gulfport-Biloxi Regional Airport (KGPT) had just ended a thunderstorm in the hour previous
to 1453Z:
METAR KGPT 251453Z 18004KT 9SM FEW014 BKN018 BKN032 24/21
A3009 RMK AO2 LTG DSNT ALQDS RAB03E27 TSE27 SLP188
P0004 60004 T02390211 50010 $
No SPECIs were taken the next hour, and the METAR at 1553Z was as follows:
METAR KGPT 251553Z 19008G18KT 6SM -RA FEW014 BKN018 BKN032
23/19 A3010 RMK AO2 PK WND 17029/1521 LTG DSNT
W-NE RAB17 SLP193 P0004 T02280194 $
Yet at 1513Z, lightning struck just to the east of the airport!
There was more lightning within 5 miles of KGPT at 1515Z:
And also at 1518Z:
How much lightning struck within 5 miles? The following map is valid for the period 1500Z-1550Z; and has
5 and 10-mile range rings overlaid. It also contains map grids, with a lightning stroke counter in the upper left
hand corner of each grid:
20 lightning bolts struck within the red 5-mile range ring. For any or all of those lightning bolts, ALDARS should have generated a SPECI for TS. But all that was reported that hour, was LTG DSNT. That was a missed thunderstorm!
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Post by tornado on May 25, 2015 15:06:00 GMT -5
49. Abilene, Texas, 25 May 2015:At 1452Z, the METAR from Abilene Airport did not mention any lightning or thunder: METAR KABI 251452Z 14024G29KT 10SM FEW120 22/18 A2977 RMK AO2 PK WND 15029/1452 PRESFR SLP057 T02170183 58023 $ Abilene did eventually report a thunderstorm on the next METAR (there were no intervening SPECIs), beginning at 1547Z: METAR KABI 251552Z 25019G32KT 10SM TS FEW017 BKN028 BKN110 18/13 A2992 RMK AO2 PK WND 28032/1543 TSB47 PRESRR SLP110 T01780128 $ However, at 1535Z, a lightning bolt struck to the west of the airport:  That bolt measured at 4.54 miles from the airport.  By 1546Z, much more lightning was striking nearby, especially to the west:  But the closest lightning strike was to the south, measuring at 3.68 miles away:  So there was a 12-minute delay in getting TS reported. If the TS had been reported right after the 1535Z lightning strike, perhaps pilots would have been more prepared for the wind gust to 32 knots that came at 1543Z, before the thunderstorm was actually detected by ALDARS. 50. Waco, Texas, 25 May 2015:During the time period 1651Z-1748Z, Waco reported DSNT LTG, eventually beginning a thunderstorm within 5 miles at 1748Z: METAR KACT 251651Z 17016KT 10SM -RA BKN021 BKN029 OVC044 25/21 A2991 RMK AO2 LTG DSNT SW SLP123 P0000 T02500211 METAR KACT 251751Z 19012KT 10SM -TSRA FEW040 BKN085 OVC110 23/22 A2993 RMK AO2 LTG DSNT SW-NW TSB48 SLP128 P0001 60001 T02330217 10256 20222 53006 However, as early as 1717Z, lightning struck within 10 miles of Waco (KACT):  That lightning bolt measured at 7.31 miles away.  That should have triggered ALDARS to take a SPECI for VCTS, but it didn't. By 1738Z, there was more lightning within 10 miles:  That bolt measured at 5.8 miles away:  At 1741Z, there was a cluster of strikes nearby:  And by 1746Z, a bolt struck just off airport property:  Likely, that triggered ALDARS to begin a thunderstorm at 1748Z. But there should have already been at least a VCTS in progress. Pilots were unaware of the lightning hazards in the weather reports, until a bolt had already struck very close to the runway. Also, resources on the ground did not have notification of the thunderstorm in the vicinity; and the notification for thunderstorm within 5 miles, did not come until after that bolt hit very close to the airport. 51. Lawton, Oklahoma, 25 May 2015:The weather reports out of Lawton (KLAW) between 1753Z-1853Z, made no mention of lightning or thunderstorm activity: METAR KLAW 251753Z 17007KT 10SM BKN021 BKN032 23/20 A2989 RMK AO2 SLP113 T02330200 10244 20206 53008 SPECI KLAW 251805Z 18006KT 10SM SCT023 BKN033 23/19 A2990 RMK AO2 T02330194 METAR KLAW 251853Z 30014G25KT 7SM -RA FEW018 SCT037 OVC085 18/14 A2992 RMK AO2 PK WND 30029/1839 RAB35 SLP126 P0002 T01780144 Yet, there were lightning bolts within 10 miles, one of which struck just before 1820Z:  Another struck at 1845Z:  The 1853Z METAR recorded a wind gust to 25 knots. Perhaps there was still a thunderstorm nearby? Yes, because a lightning bolt hit at 1900Z:  That bolt struck 4.28 miles from Lawton airport:  Since it was within 5 miles that bolt should have triggered ALDARS to take a SPECI for TS. But not only was there no mention of lightning in the previous observations, nor was there in the next observation: METAR KLAW 251953Z 10SM -RA FEW030 BKN075 BKN095 17/14 A2974 RMK AO2 PK WND 25032/1904 SLP063 P0013 T01670144 The ALDARS at KLAW missed a VCTS, then a TS.
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Post by tornado on May 25, 2015 18:07:17 GMT -5
52. Macon Regional Airport, Georgia, 25 May 2015:
Sometime before 2149Z, there had been several lightning strikes within 10 miles of
Macon (KMCN) Regional Airport:
One of those lightning bolts was just to the east of U.S. Highway 129, which forms
the eastern boundary of the airport. That bolt struck within a mile of where the
runways cross. So while the further lightning strikes should have generated a VCTS,
the bolt a mile away should have prompted ALDARS to begin a TS. However, this
was the following METAR:
METAR KMCN 252153Z 09010KT 10SM FEW034 24/19 A3019 RMK AO2
PK WND 14027/2128 RAE2059 SLP217 P0000 T02390194
There was no mention of a TS, VCTS, or even DSNT LTG! That gust to 27 knots was
probably due to the nearby thunderstorms as well. ALDARS, if installed at that site,
failed to detect any of that lightning.
Late edit: it is now possible to go back to see how much lightning there was within 5 and 10 miles of KMCN
on that date:
The above chart is valid from 2100Z-2150Z on 25 May 2015. 3-5 lightning bolts (2 of them are right upon the 5-mile
range ring) struck within 5 miles of the airport during that 50 minute period. We can also now ascertain when the closest
bolt struck:
By setting the valid time of the map to 2135Z-2140Z, the lightning strike appears. By its purple color, which is about 2
minutes into the 5 minute period on the color scale; we can even deduce that the bolt struck at 2137Z.
53. Stillwater, Oklahoma, 25 May 2015:
As with Macon, Stillwater (KSWO) had no mention of lightning or thunder:
METAR KSWO 252053Z 15010KT 10SM SCT033 24/18 A2981 RMK AO2
SLP084 T02390183 58018
METAR KSWO 252153Z 17010KT 10SM -RA BKN037 BKN049 BKN060
23/18 A2985 RMK AO2 RAB19 SLP097 P0001 T02280183
Yet, lightning struck within 10 miles several times that hour:
That was at 2145Z. The lightning bolt that hit to the south-southwest, was about the same
distance away from KSWO as the older bolt that had struck almost due west of the airport.
The bolt that struck at 2145Z measured as being 4.78 miles from the airport. Yet, there was
no TS, VCTS or even DSNT LTG in the METAR 8 minutes later. Other lightning within
10 miles was still hitting at 2201Z:
Not only did ALDARS ignore the bolts to the west, those occurred about the same time as
the peak wind of 28 knots in the next report:
METAR KSWO 252253Z 12010G15KT 10SM -RA CLR 20/17 A2978 RMK
AO2 PK WND 20028/2200 SLP073 P0001 T02000172
Of course, rain with clear skies was not what was actually happening. A TS and
VCTS is what actually occurred during the time period discussed above, even though one
wouldn't know it to look at the METARS!
54. NW Florida Beaches Regional Airport, Panama City, Florida, 26 May 2015:
During the past 2 hours, NW Florida Beaches Regional Airport (KECP) reported lightning 10-30 miles away:
METAR KECP 261553Z 15016G22KT 10SM SCT028 31/23 A3017 RMK
AO2 LTG DSNT N SLP225 T03060228
METAR KECP 261653Z COR 17015G22KT 10SM SCT030 31/22 A3015
RMK AO2 LTG DSNT N-E SLP221 T03110222
METAR KECP 261753Z 17018G24KT 10SM BKN020 31/23 A3014 RMK
AO2 LTG DSNT NE AND E SLP217 60000 T03110233 10311
20244 58001
Well, that was true! Look at how much lightning there was to the N-E at 1701Z:
What wasn't reported, was the lightning within 10 miles:
That map was valid at 1700Z. Measuring the lightning bolts, we find one struck to the SE at a distance of 5.44 miles:
Another bolt struck to the SSE at a distance of 7.68 miles:
KECP should have reported VCTS due to those 2 bolts, but did not. Somehow, ALDARS
missed them.
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Post by tornado on May 26, 2015 14:04:14 GMT -5
55. Montgomery, Alabama, 26 May 2015:
Montgomery (KMGM) reported VCTS for an entire hour this morning:
METAR KMGM 261653Z 24008KT 6SM VCTS -RA FEW037 BKN055 OVC075
26/22 A3018 RMK AO2 LTG DSNT ALQDS TSB02RAB23
PRESRR SLP218 P0001 T02560222
SPECI KMGM 261700Z 29017G28KT 2SM VCTS +RA SCT018 BKN048
OVC075 22/19 A3020 RMK AO2 PK WND 27028/1656 LTG
DSNT ALQDS P0012
SPECI KMGM 261724Z 22008KT 2SM VCTS +RA SCT018 BKN048 OVC075
22/19 A3019 RMK AO2 PK WND 27028/1656 LTG DSNT
ALQDS TSE22B24 P0036
METAR KMGM 261753Z 18005KT 10SM VCTS -RA SCT050 BKN075 22/19
A3020 RMK AO2 PK WND 27028/1656 LTG DSNT ALQDS
TSE22B24 SLP224 P0040 60041 T02170194 10272 20206
53008
However, there was lightning within 5 miles at 1719Z:
That lightning bolt struck to the east, between state highway 8 and U.S Highway 331.
It measured at a distance of 4.67 miles:
Since that is so close to 5 miles, and we don't know from exactly where ALDARS was
taking the reading; wasn't until 1726Z that a bolt definitively struck within 5 miles:
That lightning bolt, on the west side of Interstate 65 near Hope Hull, measured at 3.38 miles away:
A bit later, there were other lightning bolts nearby. One struck at 1732Z to the SW:
Another bolt struck just before 1739Z, just to the east of I-65:
Despite all this, KMGM reported VCTS, but no TS that hour.
56. Fulton County Airport, Atlanta, Georgia, 26 May 2015:
Here's a case where something was definitely wrong. This past hour, this site reported as such:
METAR KFTY 261853Z 14007KT 10SM SCT031 28/21 A3015 RMK AO2
LTG DSNT SW-N SLP201 T02780206
SPECI KFTY 261950Z 25018G27KT 1 3/4SM RA FEW012 SCT020 OVC032
21/18 A3020 RMK AO2 PK WND 24027/1948 LTG DSNT
ALQDS RAB46 TSE48 P0022
METAR KFTY 261953Z 26015G27KT 3/4SM RA BR SCT010 BKN026 OVC035
21/19 A3021 RMK AO2 PK WND 24027/1948 LTG DSNT
ALQDS RAB46 TSE48 SLP222 P0047 T02060189
SPECI KFTY 261956Z 24007G27KT 1/2SM RA FG SCT010 BKN020 OVC035
20/19 A3021 RMK AO2 WSHFT 1940 LTG DSNT ALQDS
P0014 T02000189=
Those were consecutive observations. Thunder was not reported in the body of any report. Yet, TSE48 was
recorded in remarks at 1950Z. But what was the beginning time? Where was the SPECI to start a thunderstorm?
There's no doubt there was a thunderstorm there this past hour; at 1939Z, lightning was striking to the west:
At 1947Z, lightning struck the airport:
ALDARS (if it is installed at that site) should have generated a SPECI for a TS at that time, if a TS was not
already in progress. That would have been in force until 2002Z. but none of the 3 reports between 1950Z and
1956Z even mentioned lightning within 10 miles, let alone 5 miles. I checked 3 different websites to try to
find the "missing SPECI" that would have started the thunderstorm; but I couldn't find such a SPECI.
I had been monitoring a nearby level D in Marietta, Georgia (KRYY), and they reported a thunderstorm within 5 miles:
SPECI KRYY 261907Z 34008KT 7SM TS SCT007 BKN030 24/19 A3019=
METAR KRYY 261955Z 34008KT 7SM TSRA BKN023 OVC095 19/18 A3019
RMK OCNL LTG CG TSB1907 TS E MOV E
The above map was valid at 1912Z. Somehow, a level D site near Atlanta, reported a thunderstorm with lightning several miles
away; while a level C site near Atlanta, reported no lightning within 10 miles after having a lightning bolt strike at the airport!
Late edit: archived data also shows lightning struck the airport that day:
Archived data shows how bad this case was:
Since TS was not included in the body of the reports,
The time of the lightning strike to the airport, was 1947Z:
Archived data supports this being a level 7 case on the FLAWD scale.
57. Peachtree-DeKalb Airport, Atlanta, Georgia, 26 May 2015:
There was a lot of lightning to the west of this site (KPDK) in the past hour:
However, an older lightning bolt, struck outside the main line of thunderstorms at 1936Z:
That lightning bolt struck 1.79 miles SW of the airport:
Yet, ALDARS somehow ranged that strike as being outside of 5 miles, because KPDK reported
VCTS, not TS:
METAR KPDK 261853Z 15007KT 6SM HZ BKN024 BKN032 27/21 A3015
RMK AO2 LTG DSNT SW-NW SLP196 T02720211
SPECI KPDK 261951Z 16006KT 6SM VCTS HZ BKN024 BKN032 26/22
A3016 RMK AO2 LTG DSNT SW-N RAB29E46 P0001
Here's an audio archive from LiveATC.net, for the time period in question:
KPDK-Twr-May-26-2015-1930Z.mp3 (3.6 MB)
The audio begins at 1930Z. The Peachtree controller states rain shower overhead, diameter about 4 miles;
states cell dissipating… all within 5 minutes of begin of feed. That would be up to 1935Z.
As shown above, a lightning bolt struck 1.79SM SW of KPDK at 1936Z.
At about 7 minutes into the audio feed (about 1937Z), a controller mentions heavy-extreme precipitation at least 20 miles in diameter, over McCollum (Cobb Cty Arpt). At 7:41 into the feed, (1937Z) she read their weather, “wind 340 at 8, visibility 7, thunderstorm, 7 hundred scattered, 3000 broken." This was the weather report she referred to:
SPECI KRYY 261907Z 34008KT 7SM TS SCT007 BKN030 24/19 A3019
At 12:00 into the feed (1942Z), she mentions that the "heavy precipitation appears to be just north of the field now, some is dissipating." At 16:00 into the feed, she tells a pilot to taxi down to next intersection; change gate, due to weather. At 23:00 into the audio file, another controller reads hazardous weather information for the Georgia area.
There were no mentions of thunderstorm activity at or near KPDK during that half hour. The only mention was reading the KRYY
weather to a pilot, which did include a thunderstorm. There was no mention of the lightning that struck at 1936Z. By 1951Z, KPDK reported VCTS, but there was no mention of that in the last minutes of the feed.
SPECI KPDK 261951Z 16006KT 6SM VCTS HZ BKN024 BKN032 26/22
A3016 RMK AO2 LTG DSNT SW-N RAB29E46 P0001
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Post by tornado on May 26, 2015 18:37:59 GMT -5
58. Athens, Georgia, 26 May 2015:
There were heavy rain showers that moved across the Athens Airport (KAHN) this past hour:
METAR KAHN 262151Z VRB05KT 10SM FEW050 27/21 A3019 RMK AO2
SLP217 T02720206
SPECI KAHN 262208Z 25017G33KT 1 1/2SM -RA FEW020 SCT040 BKN050
24/20 A3025 RMK AO2 PK WND 26033/2205 RAB07 PRESRR
P0000 T02390200
SPECI KAHN 262210Z 26014G33KT 3/4SM +RA BR FEW017 BKN040
BKN050 22/19 A3025 RMK AO2 PK WND 26033/2205 RAB07
PRESRR P0001 T02170194
SPECI KAHN 262217Z 26009G23KT 1/4SM +RA FG FEW009 BKN020
OVC050 20/19 A3023 RMK AO2 PK WND 26033/2205 RAB07
P0029 T02000189
SPECI KAHN 262222Z 26009G17KT 3/4SM +RA BR FEW009 BKN033
OVC040 19/19 A3023 RMK AO2 PK WND 26033/2205 RAB07
P0034 T01940189
SPECI KAHN 262231Z 27009G17KT 1 1/4SM RA BR BKN036 BKN085
OVC110 19/18 A3022 RMK AO2 PK WND 26033/2205 RAB07
P0043 T01940183
SPECI KAHN 262234Z 25007G16KT 2 1/2SM RA BR FEW009 BKN034
OVC110 19/18 A3023 RMK AO2 PK WND 26033/2205 RAB07
P0044 T01940183
SPECI KAHN 262241Z 24006G14KT 3SM RA BR FEW009 BKN041 OVC100
19/18 A3025 RMK AO2 PK WND 26033/2205 RAB07 P0045
T01940183
SPECI KAHN 262248Z VRB03KT 2 1/2SM RA BR SCT009 BKN048 OVC110
19/18 A3025 RMK AO2 PK WND 26033/2205 RAB07 P0047
METAR KAHN 262251Z VRB04KT 3SM RA BR BKN009 BKN050 OVC110
19/18 A3025 RMK AO2 PK WND 26033/2205 RAB07 SLP238
P0048 T01940183
8 SPECIs were recorded, and a wind gust to 33 knots occurred at 2205Z. The
rain total that hour was .48" of an inch.
And now for the rest of the story.
There was no lightning nor thunder mentioned on any of those 9 weather reports.
Surely, however, there was a convective SIGMET out for a line of thunderstorms:
The lightning animation above, runs from 2130Z-2300Z on the 25th of May.
The TAF mentioned thunderstorms:
TAF AMD KAHN 262118Z 2621/2718 15008KT P6SM VCTS SCT035CB
TEMPO 2622/2702 25020G35KT 2SM +TSRA BKN025CB FM270400
13003KT P6SM BKN025 FM270800 14003KT P6SM VCSH BKN008
FM271500 15006KT P6SM -SHRA BKN015
At 2200Z, there was lightning around 10 miles away; to the ENE; to the SE
(south of Arnoldsville); and to the SW.
Somehow, that lightning was ignored. It shouldn't have been. At 2209Z, a bolt
struck at the end of the runway:
As of 2300Z, here is an overlay of lightning strikes within 5 miles of KAHN, with a 5-mile range ring in red; also drawn is a 10-mile range ring, in green. How many lightning strikes can you spot within 5 miles?
That was a lot of lightning activity within 5 and 10 miles; yet, KAHN recorded no lightning activity at all that hour! There should have been a TS/VCTS for most of that hour, but somehow, ALDARS and LAWRS missed reporting it.
59. Shreveport-Downtown Airport, Louisiana, 26 (27) May 2015:
The Shreveport-Downtown Airport (KDTN) reported a thunderstorm, beginning at
0027Z:
METAR KDTN 262353Z 16008KT 10SM FEW040 BKN048 BKN060 28/21
A2997 RMK AO2 LTG DSNT SE-SW SLP147 T02830206
10300 20267 56014
SPECI KDTN 270021Z 16009KT 10SM VCTS FEW050 BKN080 BKN100
28/21 A3000 RMK AO2 LTG DSNT SE-SW T02780211
SPECI KDTN 270033Z 17008KT 10SM TS FEW070 SCT080 28/21 A3000
RMK AO2 LTG DSNT E-SW TSB27 T02780206
However, just before 0011Z, a lightning bolt struck on Highway 3094, near the
park north of Milam Street:
That lightning bolt measured at 3.07 miles SW of the airport:
That was a delay of 16 minutes for ALDARS to generate a SPECI, and a total of
22 minutes for ASOS to transmit the information. There was certainly more lightning:
The above map was valid at 0038Z. That's 22 minutes of lead time, that ALDARS
and ASOS did not provide.
60. Stillwater, Oklahoma, 26 (27) May 2015:
As with Athens, heavy rain showers moved across Stillwater (KSWO) this past hour:
METAR KSWO 270153Z 04008KT 10SM FEW034 OVC048 22/19 A2995
RMK AO2 RAB0057E03 SLP133 P0000 T02220194
SPECI KSWO 270229Z 07003KT 1 3/4SM +RA BR SCT024 SCT060 BKN075
21/19 A2995 RMK AO2 RAB20 P0024 T02060194
SPECI KSWO 270240Z 05005KT 3SM RA BR SCT042 BKN070 OVC090
20/18 A2995 RMK AO2 RAB20 P0033 T02000178
METAR KSWO 270253Z 04005KT 7SM -RA SCT041 BKN070 OVC100 20/18
A2995 RMK AO2 RAB20 SLP132 P0037 60037 T02000183
50014
However, this one chart, valid at 0302Z, shows just how many nearby lightning strikes
there were in the past hour; that is, since 0202Z:
The furthest lightning strike on that map, north of Highway 51 and west of Cottonwood
Road, measured at 5.31 miles from the airport:
What that means, then, is that all the other lightning strikes on the first chart, were
within 5 miles. There were 7 strikes to the west of the runways; and 7 strikes to the east.
Somehow, ALDARS missed all 14 of those lightning bolts, and never recorded any
lightning or thunder activity from 0153Z right past 0302Z!
From the archives: here is a lightning map, valid 0200-0300Z on the 27th:
18 lightning strikes were actually recorded within 5 miles, during that hour. From 0100-0500Z, this was the lightning display:
The total number of lightning strikes within 5 miles, was 35. Within 10 miles, the approximate number of lightning strikes during the period 0100-0500Z, was 105. Zooming in on the archived data showed this:
Upon further review, this case rates a level 6 on the FLAWD scale. Attachments:
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Post by tornado on May 27, 2015 9:38:25 GMT -5
61. Lafayette, Louisiana, 27 May 2015:
The Lafayette Regional Airport (KLFT) had an interesting case this morning. It's harder to see lightning,
when the ceiling is 200 feet:
METAR KLFT 271253Z 00000KT 5SM BR OVC003 24/23 A3013 RMK
AO2 PRESRR SLP203 T02390233
METAR KLFT 271353Z 36013KT 5SM VCTS BR OVC002 24/23 A3018
RMK AO2 LTG DSNT ALQDS SLP220 T02390233
So ALDARS must have picked up lightning 5-10 miles away, just before the 1353Z METAR. But notice what
happened at 1356Z:
A lightning bolt struck about 2 miles to the SSE of the airport at that time. However, there had already been an
even closer bolt of lightning to the west, a few minutes earlier:
That bolt struck 1.78 miles to the WSW. Judging from its color, it was a few minutes old, which would make it around
1353Z- the same time the VCTS began at KLCH. So, how long did it take ALDARS to catch up, by taking a SPECI
for a TS? Not by 1408Z, when KLFT was still reporting a VCTS:
SPECI KLFT 271408Z 35017G34KT 2SM VCTS -RA BR SCT002 BKN019
OVC040 20/18 A3018 RMK AO2 PK WND 34034/1402 LTG
DSNT ALQDS RAB03 P0004 T02000183
A wind gust to 34 knots had occurred at 1402Z. That was during the time when TS should have been reported,
but wasn't. Pilots and other users had to wait until 1412Z for ALDARS/ASOS/LAWRS to catch up:
SPECI KLFT 271412Z 35018G33KT 1 1/4SM +TSRA BR SCT002 BKN026
OVC039 19/18 A3022 RMK AO2 PK WND 34034/1402 LTG
DSNT ALQDS RAB03 TSB12 PRESRR P0012 T01940183
In the meantime, other lightning had been striking nearby:
That map was valid at 1359Z. The bolt that apparently triggered the TS SPECI, occurred at 1409Z:
In any event, there was a delay of about 19 minutes, in getting the TS reported. The weather reports
from KLCH would have us believe that the peak gust to 34 knots occurred during a VCTS; when in fact it happened during a TS.
62. Baton Rouge, Louisiana, 27 May 2015:
This past hour, Ryan Field at Baton Rouge (KBTR) reported brief heavy rain showers:
METAR KBTR 271453Z 28020G31KT 210V330 7SM BKN009 OVC018 24/23
A3016 RMK AO2 PK WND 32031/1453 SLP212 T02440228
51024
SPECI KBTR 271459Z 30016G31KT 8SM -RA SCT009 BKN022 OVC038
21/17 A3018 RMK AO2 PK WND 31031/1454 RAB55 PRESRR
P0000 T02110172
SPECI KBTR 271507Z 30014G26KT 7SM -RA FEW009 BKN034 OVC042
20/17 A3018 RMK AO2 PK WND 31031/1454 WSHFT 1451
RAB1455 P0000 T02000172
SPECI KBTR 271514Z 30014G23KT 1 3/4SM +RA BR FEW009 BKN035
OVC042 19/18 A3018 RMK AO2 PK WND 31031/1454 WSHFT
1451 RAB1455 P0004 T01940178
SPECI KBTR 271524Z 29012G23KT 3SM -RA BR FEW016 BKN041 OVC080
19/18 A3018 RMK AO2 PK WND 31031/1454 WSHFT 1451
RAB1455 P0014 T01940178
METAR KBTR 271553Z 27006KT 9SM -RA BKN070 19/18 A3019 RMK
AO2 PK WND 31031/1454 WSHFT 1451 RAB1455 SLP224
P0015 T01940183
There was no mention of lightning or thunderstorms in any of those reports.
However, by 1512Z, there was at least a thunderstorm within 10 miles:
By 1526Z, a lightning bolt had struck on Highway 190 to the south of the airport:
The distance to that lightning bolt was 1.92 miles away.
There had also been another bolt that struck somewhere at the ExxonMobil refinery to the SW,
also within 5 miles. LAWRS and ALDARS both missed those bolts of lightning, and failed to generate a thunderstorm SPECI. Late edit: Archived data showed those strikes within 5 miles:  This case rated a level 4 on the FLAWD scale. New Orleans-Lakefront, Louisiana, 27 May 2015:As an aside, I'm wondering why this site is in AUTO/TSNO mode, when airnav.com lists the tower operating hours as "continuous"? METAR KNEW 271653Z AUTO 18007KT 10SM FEW029 FEW034 FEW075 29/22 A3016 RMK AO2 SLP205 T02940222 TSNO  Above map valid 1706Z. SPECI KNEW 271719Z AUTO 29026G34KT 2 1/2SM -RA BKN024 BKN032 25/20 A3017 RMK AO2 PK WND 30034/1719 VIS 3/4V5 RAB11 P0006 T02500200 TSNO SPECI KNEW 271723Z AUTO 30035G43KT 3/4SM +RA FEW022 BKN027 BKN032 24/19 A3016 RMK AO2 PK WND 29043/1722 RAB11 P0016 T02390194 TSNOObviously, that wind and poor visibility, was from a thunderstorm... which was still around as of 1731Z:  63. Coleman A. Young Intl Airport, Detroit, Michigan, 27 May 2015:This past hour, Coleman A. Young Airport (KDET) reported a VCTS beginning at 1700Z, then at TS beginning at 1748Z: METAR KDET 271653Z 21017G20KT 10SM SCT042 SCT055 BKN075 26/17 A2996 RMK AO2 SLP140 T02560167 SPECI KDET 271700Z 24014KT 10SM VCTS SCT042 SCT055 SCT070 26/17 A2996 RMK AO2 LTG DSNT W T02610172 METAR KDET 271753Z 20011KT 10SM -TSRA FEW030 SCT039 BKN080 23/19 A2996 RMK AO2 LTG DSNT ALQDS RAB04 TSB48 SLP139 P0002 60002 T02280189 10261 20206 58002 However, lightning struck within 5 miles of the airport, as early as 1707Z:  The distance to that lightning strike was 4.06 miles:  At 1718Z, a bolt struck even closer, to the east:  The strike to the east measured at 3.4 miles from the airport:  Yet, KDET did not report a TS until 1748Z. That was a delay of 41 minutes by ALDARS,
which reported VCTS while TS was in progress from 1707Z-1748Z. |
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Post by tornado on May 28, 2015 12:35:45 GMT -5
64. Hector Intl Airport, Fargo, North Dakota, 28 May 2015:
This morning at Hector Intl Airport (KFAR), there was no mention of thunder or lightning in the 2
hours from the 1153Z to the 1353Z METAR; and there were no SPECIs those housr:
METAR KFAR 281153Z 4SM RA BR SCT070 OVC090 16/14 A2996 RMK
AO2 SLP142 P0005 60007 70007 T01610144 10194 20161
55000
METAR KFAR 281253Z 10004KT 6SM -RA BR FEW055 BKN090 OVC110
16/14 A2992 RMK AO2 RAE21B38 SLP130 P0004 T01610144
METAR KFAR 281353Z 12008KT 5SM -RA BR SCT070 BKN090 OVC110
17/15 A2991 RMK AO2 RAE30B49 SLP126 P0002 T01720150
Yet by 1310Z, there had been 5 lightning bolts that had struck within 10 miles of the airport:
The furthest lightning bolt measured at a distance of 9.84 miles:
Which means that the other 4 lightning bolts were even closer. KFAR should have reported a VCTS
sometime during that time period, but did not. Somehow, ATC missed those 5 bolts, because not
even LTG DSNT was recorded. ALDARS is not listed as being installed at this site, according to the NWS AMSS "site profile" at: www3.amss.nws.noaa.gov/amsstt.nsf/wSite%20Profiles/KFAR
65. Pensacola Regional Airport, Florida, 28 May 2015:
This airport (KPNS) shows up as Pensacola International Airport on Google maps. They did report VCTS this morning:
METAR KPNS 281353Z 06006KT 10SM SCT012 SCT023 26/23 A3014
RMK AO2 SLP209 T02560228
METAR KPNS 281453Z 11008KT 10SM SCT012 26/23 A3014 RMK AO2
LTG DSNT SW AND W SLP206 T02560228 50003
SPECI KPNS 281509Z 13009KT 10SM VCTS FEW016 BKN025 BKN035
26/22 A3014 RMK AO2 LTG DSNT SW AND W T02610222
But the VCTS didn't begin until the 1509Z SPECI. 50 minutes earlier, at 1419Z, this was the lightning display
near KPNS:
The distance to that bolt to the west was 4.68 miles:
Now, we don't know from which exact point, ALDARS at KPNS would measure lightning. But the zero point on the
above map is exactly where the runways cross at the airport. A TS should have been reported due to that bolt. But even
if we allow that the bolt was 5+ miles away, that should have begun a VCTS 50 minutes earlier than was actually recorded.
ALDARS somehow failed to pick up that bolt.
Apparently, ALDARS took the SPECI for VCTS at 1509Z, for these lightning bolts (at 1507Z):
Is this what we want? A system that detects lightning 9-10 miles away, but ignores lightning 4-5 miles away? See the
next case.
66. Midland, Texas, 28 May 2015:
Midland (KMAF) also had a VCTS this morning:
METAR KMAF 281553Z 15017KT 6SM -RA FEW025 FEW080 SCT110 23/19
A3004 RMK AO2 RAB35 SLP128 P0000 T02280194
SPECI KMAF 281606Z 14016KT 7SM VCTS SCT120 24/19 A3004 RMK
AO2 RAE1554 P0000 T02440194
SPECI KMAF 281634Z 14021G27KT 7SM CLR 26/19 A3004 RMK AO2
PK WND 14027/1633 LTG DSNT E RAE1554 P0000 T02610189
Perhaps ALDARS picked up these lightning bolts at 1558Z:
Now, a SPECI for VCTS was transmitted at 1606Z, 8 minutes after those bolts struck.
But look what happened right at 1606Z:
That bolt struck within a mile of where the runways cross at the Midland airport! Yet, no TS
was ever reported at KMAF that hour. Like KPNS, ALDARS at KMAF detected the more
distant lightning bolts; yet did not detect a lightning strike at close range.
Philadelphia-Northeast Airport, Pennsylvania:
METAR KPNE 281754Z AUTO VRB05KT 9SM CLR 31/19 A3016 RMK AO2
SLP211 T03060189 10317 20228 58010 TSNO
How safe is having ASOS in AUTO/TSNO mode; and ASOS reporting clear skies, with lightning striking nearby?
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