From the 7900.5C:
Illinois:
Moline:
SPECI KMLI 111334Z 30021G29KT 6SM -SN BR BKN009 OVC065 00/M02
A2980 RMK AO2 PK WND 31029/1329 RAE14
UPB14E24SNB24
P0001 T00001017 $
Was there some freezing rain from 1314-1324Z? We don’t know, as UP was reported. The onset of freezing rain would have been SPECI criteria.
Minnesota:
Minneapolis-Crystal:
SPECI KMIC 101500Z 03012G19KT 7SM
UP SCT009 BKN016 OVC026
M02/M04 A2967 RMK AO2 UPB00SNE00 P0001 T10171044
SPECI KMIC 101508Z 03011G19KT 10SM
UP BKN013 OVC026 M02/M04
A2967 RMK AO2 UPB00SNE00 P0001 T10171044
METAR KMIC 101653Z 03009G16KT 1 1/4SM
UP BR OVC010 M02/M04
A2964 RMK AO2 UPB32SNE32 SLP046 P0009 T10171039
Several reports contained UP. UP (Unknown Precipitation) is only used by automated weather observing systems (Table 10-1, pg. 68)
Rochester:
SPECI KRST 102229Z 02016KT 2 1/2SM
UP BR OVC004 00/M01 A2958
RMK AO2 SFC VIS 3 RAB16E24UPB24 P0000 T00001006
METAR KRST 110154Z 01018G23KT 6SM
UP BR OVC006 M02/M03 A2968
RMK AO2 PK WND 01027/0106 UPB06E23B41FZRAB23E32SNE06B32E41
SLP066 P0000 I1001 T10171028
METAR KRST 110254Z 01015G27KT 10SM
UP OVC006 M02/M03 A2971
RMK AO2 PK WND 01027/0250 SLP077 P0000 60001 I3001
T10171028 53022
SPECI KRST 110327Z 36019G26KT 7SM -FZRA OVC006 M02/M03 A2974
RMK AO2 PK WND 36026/0324 UPE21FZRAB21 P0000 I1000
T10171028
SPECI KRST 110511Z 35015KT 1/2SM R31/4000V5500FT FZFG OVC006
M02/M03 A2976 RMK AO2 SNEMM P0002 T10171028 $
METAR KRST 110554Z 36015G22KT 1SM R31/5000VP6000FT BR OVC006
M02/M03 A2976 RMK AO2
SNEMMB17SNEMM SLP089 P0007
60008 I6003 T10171028 11006 21017 400281017 50002 $
SPECI KRST 110621Z 35020G26KT 2SM -SN BR BKN007 OVC012 M03/M04
A2976 RMK AO2 PK WND 35028/0601 SNB04 P0001 T10281039 $
Several reports contained UP. There had been freezing rain at times; you’d think pilots and airlines would want to know if the UP was really FZRA. At 0511Z, it appears the precipitation sensor went out, so it could have been snowing at 0554Z.
St. Cloud:
METAR KSTC 101553Z 02014G21KT 1/4SM +SN VV004 M03/M06 A2972
RMK AO2 SLP084 P0017 T10331061
METAR KSTC 101653Z 02013G18KT M1/4SM +SN FZFG VV003 M03/M06
A2972 RMK AO2 SLP085 P0017 T10331056
METAR KSTC 101753Z 03009G17KT 1/4SM FZFG VV004 M03/M06 A2972
RMK AO2
SNEMM SLP086 P0019 60092 T10331056 11033
21039 55010
$
SPECI KSTC 101818Z
02010G20KT 1/4SM HZ VV005 M03/M06 A2972
RMK AO2 P0007 T10281056 $
METAR KSTC 101853Z 01014G20KT 1/4SM FZFG VV006 M03/M06 A2971
RMK AO2 SLP083 P0012 T10331056 $
SPECI KSTC 101922Z
01019G24KT 1/2SM HZ VV009 M03/M06 A2970
RMK AO2 T10281056 $
SPECI KSTC 101929Z
01018G26KT 1/2SM HZ VV011 M03/M06 A2971
RMK AO2 PK WND 01026/1926 T10281056 $
SPECI KSTC 101941Z
01016G25KT 1SM HZ VV016 M03/M06 A2972
RMK AO2 PK WND 01026/1926 T10281056 $
METAR KSTC 101953Z 36016G27KT 1 1/4SM HZ FEW014 OVC023 M03/M06
A2973 RMK AO2 PK WND 36027/1944 SLP090 T10281056 $
METAR KSTC 102053Z 36016G23KT 1 1/4SM HZ FEW009 FEW012 OVC021
M03/M06 A2977 RMK AO2 PK WND 36028/2003 SLP105
60012 T10331061 51020 $
METAR KSTC 102153Z
01014G25KT 3/4SM HZ OVC021 M03/M06 A2977
RMK AO2 SLP105 T10331061 $
This looks suspicious. Heavy snow was falling at 1553Z and 1653Z. From 1753Z to 2153Z, there was no more snow reported. Yet, haze was reported as restricting visibility so badly, that the visibility was 1/4SM with a total obscuration? With the vertical visibility into the haze 500 feet? And all that haze or freezing fog, with gusty winds? Since the dollar sign appeared at 1753Z, along with the remark of SNEMM, it was almost certainly continuing to snow during the period 1753Z-2153Z. This was late morning into early afternoon. A story from Weather Underground said, “Some of the highest totals from Winter Storm Astro came from Stearns County, Minnesota, which includes St. Cloud. The town of St. Augusta reported 16.5 inches of snow Monday afternoon. The official total in St. Cloud was 13.2 inches, breaking the all-time November calendar-day record of 12.0 inches set Nov. 21, 1898.” I wonder who measured that? Is this what we really want- an incomplete climatological record during a record-breaking snow event?
St. Paul:
METAR KSTP 101553Z 05011G19KT 10SM
UP OVC015 M02/M04 A2968
RMK AO2 UPB51 SLP056 P0000 T10171039
METAR KSTP 101653Z 05015KT 3SM
UP BR OVC018 M01/M03 A2965
RMK AO2 SLP047 P0001 I1000 T10111033
SPECI KSTP 101738Z 01009KT 2 1/2SM
UP BR OVC014 M01/M03 A2965
RMK AO2 P0005 T10111028
METAR KSTP 101753Z 36009KT 1 3/4SM
UP BR OVC014 M02/M03 A2966
RMK AO2 SLP051 P0007 60012 I6000 T10171028 11011
21028 55006
SPECI KSTP 101759Z 02011KT 1SM
UP BR FEW010 OVC014 M02/M03
A2965 RMK AO2 P0000 T10171028 RVRNO
SPECI KSTP 101807Z 02011KT 1/4SM -SN FZFG FEW010 OVC014 M02/M03
A2965 RMK AO2 UPE00SNB00 P0001 T10171028 RVRNO
Several reports contained UP. UP (Unknown Precipitation) is only used by automated weather observing systems (Table 10-1, pg. 68). The onset of precipitation was 1551Z; the type of precipitation was not determined until 1800Z. That’s 2:09 hours of unknown precip type reported to the airlines, during the late morning when there were flights scheduled to depart and land.
METAR KSTP 102053Z 02012KT 1 3/4SM UP BR OVC016 M01/M02 A2969
RMK AO2
UPB1957E06B51FZRAB06E09SNE1957B09E51 SLP060
P0001 60003 I1001 I3003 T10111022 53018
That remark is what happens when precip type is left solely to ASOS to determine.
SPECI KSTP 102055Z 02015G20KT 2SM
UP BR BKN013 OVC018 M01/M02
A2969 RMK AO2 P0000 T10111022
SPECI KSTP 102110Z 01015G24KT 2SM -SN BR BKN015 OVC020 M01/M02
A2970 RMK AO2 UPE01SNB01 P0000 T10111022
SPECI KSTP 102120Z 36015G24KT 2SM
UP BR BKN014 OVC020 M01/M02
A2970 RMK AO2 UPE01B19SNB01E19 P0000 T10111022
SPECI KSTP 102136Z 02011G23KT 2 1/2SM
-FZRA BR OVC014 M01/M02
A2971 RMK AO2
UPE01B19E30FZRAB30SNB01E19 P0000
I1001 T10111022
More UP, with snow and freezing rain also falling at times. We just don’t know exactly which times; it could have been 2055Z and/or 2120Z as well.
Wisconsin:
Eau Claire:
SPECI KEAU 111216Z 35011G20KT 1 1/2SM
-SN BR OVC016 M02/M04
A2987 RMK AO2 P0000 T10221044
METAR KEAU 111256Z 35010G21KT 1 3/4SM BR OVC014 M03/M04 A2989
RMK AO2
SNEMM SLP134 P0000 T10281044
$
SPECI KEAU 111307Z 35011G20KT 1 3/4SM BR OVC016 M03/M04 A2990
RMK AO2 T10281044 $
SPECI KEAU 111321Z 35012G19KT
1SM BR VV014 M03/M04 A2991
RMK AO2 T10281044 $
SPECI KEAU 111329Z 35013G18KT 3/4SM BR FEW010 OVC014 M03/M04
A2991 RMK AO2 T10281044 $
SPECI KEAU 111333Z 35012G18KT
1SM BR VV015 M03/M04 A2991
RMK AO2 T10281044 $
METAR KEAU 111356Z 35011G18KT
1SM BR VV017 M03/M05 A2993
RMK AO2 SLP145 T10281050 $
Here is another case, similar to St. Cloud, Minnesota. Snow had been falling, Then, sometime between 1217-1255Z, the precip indicator became inoperative. We know this because the maintenance indicator ($) first showed up on the same report on which SNEMM was reported. While fog could certainly produce VV014 or VV017, would mist do that? Or was it more likely that it was still snowing, and the present weather was not backed up?
Green Bay:
SPECI KGRB 101530Z 06012KT 4SM
UP BR OVC004 01/00 A2978 RMK
AO2 UPB28SNE28 P0001 T00060000
UP (Unknown Precipitation) is only used by automated weather observing systems (Table 10-1, pg. 68)
La Crosse:
METAR KLSE 110153Z 34013KT 10SM OVC012 02/00 A2968 RMK AO2
RAEMMB26RAEMMUPB18UPEMMB23E26 SLP059 P0000 T00220000 $
It appears ASOS struggles to identify wintry precipitation.
Oshkosh:
METAR KOSH 111353Z 34009KT 3SM
UP BR BKN009 OVC013 01/00
A2970 RMK AO2 UPB36 SLP065 P0000 T00110000
UP (Unknown Precipitation) is only used by automated weather observing systems (Table 10-1, pg. 68)