Credit: College of DuPage
It had been some time since a blizzard prompted mass rescues in Minnesota, but one on February 22-24, 2019 did just that, plastering southern Minnesota with blinding snowfall and enormous drifts.
During an already historically-snowy month, a winter storm began on February 22nd, 2019, and turned into a massive and crippling blizzard in southern Minnesota by February 23rd and 24th. The storm produced 10-14 inches of snow and 50 mph wind gusts, shutting down multiple hundreds of miles of Interstate, US, and state highways, stranding hundreds of motorists, and whipping up snow drifts the size of houses.
A low pressure system tracked out the southwestern US, where it had set snowfall records in Arizona, and then cut a familiar path from the Texas and Oklahoma panhandles February 22nd, through Kansas, northern Missouri, southeastern Iowa, and Wisconsin on the 23rd, and through Lake Michigan and into Ontario on the 24th. This particular system was of only moderate intensity when it entered the Great Plains, but by Sunday afternoon had intensified into one of the strongest Great Lakes area cyclones of the past year. Showcasing a pressure drop of approximately 24 millibars in 24 hours between Kansas and northern Lake Michigan, the rapid intensification qualified this storm as a rare "bomb cyclone." Such storms produce a wide array of hazards over a large area, and this one was no exception.
The storm had multiple phases, which is common with large and complex weather systems.
Snow first spread across northwestern and northern Minnesota on Friday February 22nd, lasting well into the night and producing several inches of accumulation. Separately, spoke-like bands of moderate snow worked south-to-north across the southern half of the state later in the night, ending Saturday morning, with 1-3 inches common. After a lull of approximately 12 hours, heavy snow with lightning, sleet, and even rain entered south-central Minnesota from Iowa, lasting through the evening and into early Sunday morning in some areas. An axis of very heavy snow set up from near Albert Lea, through Rochester and Wabasha, with snowfall rates of 1-2 inches per hour over a period of several hours. The snow was slightly lighter or shorter-lived elsewhere. After 8 PM on Saturday, the winds began increasing within the band of the heaviest snow, and by early Sunday morning, as the low pressure system underwent rapid intensification, the entire state began experiencing very strong winds, with gusts of 40-55 mph common. This led to instant blizzard conditions in open areas across southern and southeastern Minnesota, where the new snow and the abundant existing snow were easily lofted by the intense winds.
Image credit: NWS Chanhassen
The snow and wind led to extraordinary drifting in open areas, with many open-country roads covered with 5 to 8 feet of drifted snow. Images of isolated 15 and 20-drifts flooded social media. The harsh conditions ended up closing virtually all roads in the southern 1/5 of the state. Spun out cars became stranded for over 12 hours across southern and southeastern areas, and Governor Tim Walz declared a State of Emergency in Freeborn and Steele Counties of south-central Minnesota, where National Guard troops and equipment had to be activated to rescue many of the motorists. The St. Cloud State men's hockey team had to be rescued, and ended up sheltering in the Watonwan County Jail, in St. James, MN. On Sunday, even as the snow subsided, the winds continued gusting up to 50 mph, producing whiteout conditions. Some people who had ventured onto area lakes to go ice fishing became surrounded by snow drifts and were stranded.
This extraordinary storm perhaps was fitting, given the extraordinary February in which it occurred. The storm-total snowfall of 12.1 inches at Rochester boosted its monthly total to 39.7 inches, which is nearly twice as much as any other February on record.
Additional summaries of this event were provided by the National Weather Service offices in La Crosse, Wisconsin and the Twin Cities/Chanhassen. Those offices also provided the following snowfall totals and peak wind gust summaries. Please note that some of the values may change.
PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1052 AM CST SUN FEB 24 2019 ..SNOWFALL REPORTS LOCATION AMOUNT TIME/DATE PROVIDER ..MINNESOTA ..ANOKA COUNTY 2 NNE RAMSEY 1.8 IN 0800 AM 02/24 COCORAHS OAK GROVE 1.6 IN 0915 AM 02/24 PUBLIC BLAINE 2NNW 1.5 IN 0600 AM 02/24 COCORAHS EAST BETHEL 4ENE 1.0 IN 0315 AM 02/24 COCORAHS ..BLUE EARTH COUNTY MANKATO 3.0 IN 0515 AM 02/24 BROADCAST MEDIA ..BROWN COUNTY SVEADAHL 5NNW 2.0 IN 0725 AM 02/24 COCORAHS SPRINGFIELD 1NW 1.1 IN 0700 AM 02/24 COCORAHS ..CARVER COUNTY CHANHASSEN NWS 2.9 IN 0600 AM 02/24 OFFICIAL NWS OBS VICTORIA 1WSW 2.6 IN 0700 AM 02/24 COCORAHS WATERTOWN 2.0 IN 0445 AM 02/24 COCORAHS WACONIA 1.6 IN 0600 AM 02/24 UCOOP ..CHISAGO COUNTY STACY 1W 3.4 IN 0700 AM 02/24 COCORAHS NORTH BRANCH 1NNW 3.3 IN 0600 AM 02/24 COCORAHS RUSH CITY 3NE 2.2 IN 0700 AM 02/24 COCORAHS ..DAKOTA COUNTY MIESVILLE 4NNE 5.2 IN 0800 AM 02/24 COCORAHS APPLE VALLEY 3ESE 4.0 IN 0700 AM 02/24 COCORAHS LAKEVILLE 2NNE 3.0 IN 0700 AM 02/24 COCORAHS 1 NNW ROSEMOUNT 3.0 IN 0916 AM 02/24 TRAINED SPOTTER 1 W HASTINGS 2.9 IN 0700 AM 02/24 COCORAHS ..FARIBAULT COUNTY BRICELYN 7.2 IN 0700 AM 02/24 COOP BLUE EARTH 6.0 IN 0700 AM 02/24 COCORAHS WINNEBAGO 3.0 IN 0800 AM 02/24 COOP ..FREEBORN COUNTY ALBERT LEA 1WSW 11.5 IN 0700 AM 02/24 COCORAHS ..GOODHUE COUNTY ZUMBROTA 11.2 IN 0700 AM 02/24 COOP RED WING 8.0 IN 0801 AM 02/24 PUBLIC VASA 5NNE 7.6 IN 0700 AM 02/24 COCORAHS VASA 3ENE 7.2 IN 0700 AM 02/24 COCORAHS NERSTRAND 4E 7.0 IN 0700 AM 02/24 COCORAHS CANNON FALLS 6.0 IN 0800 AM 02/24 COCORAHS RED WING 6.0 IN 0815 AM 02/24 COOP ..HENNEPIN COUNTY MINNEAPOLIS ST. PAUL AIRPORT 3.5 IN 0600 AM 02/24 OFFICIAL NWS OBS EDINA 1SE 3.1 IN 0725 AM 02/24 COCORAHS RICHFIELD 1WNW 3.1 IN 0400 AM 02/24 COCORAHS EDINA 1SW 3.0 IN 0700 AM 02/24 COCORAHS RICHFIELD 2NNW 3.0 IN 0700 AM 02/24 COCORAHS LONG LAKE 4SW 2.5 IN 0731 AM 02/24 COCORAHS ROBBINSDALE 2.4 IN 0700 AM 02/24 COCORAHS EDEN PRAIRIE 3SE 2.3 IN 0913 AM 02/24 COCORAHS GOLDEN VALLEY 2.0 IN 0700 AM 02/24 COCORAHS MINNEAPOLIS DWTN 2.0 IN 0600 AM 02/24 COOP CHAMPLIN 1SW 1.5 IN 0700 AM 02/24 COCORAHS LONG LAKE 1.5 IN 0600 AM 02/24 COCORAHS ST. BONIFACIUS 2ENE 1.5 IN 0700 AM 02/24 COCORAHS MINNEAPOLIS 1.1 IN 0700 AM 02/24 COCORAHS ..LE SUEUR COUNTY LE CENTER 5NNW 2.5 IN 0800 AM 02/24 COCORAHS NEW PRAGUE 2.2 IN 0700 AM 02/24 COCORAHS ..MCLEOD COUNTY GLENCOE 1.5 IN 0800 AM 02/24 COCORAHS SILVER LAKE 1NNW 1.1 IN 0700 AM 02/24 COCORAHS HUTCHINSON 5N 0.8 IN 0700 AM 02/24 COCORAHS ..NICOLLET COUNTY NEW ULM 3SE 1.7 IN 0531 AM 02/24 COOP ..RAMSEY COUNTY MENDOTA HGTS 2WNW 2.9 IN 0700 AM 02/24 COCORAHS NORTH ST. PAUL 1WNW 2.5 IN 0700 AM 02/24 COCORAHS ROSEVILLE 2WNW 2.0 IN 0600 AM 02/24 COCORAHS ..REDWOOD COUNTY REDWOOD FALLS 1.0 IN 0700 AM 02/24 COOP ..RENVILLE COUNTY BIRD ISLAND 7SSE 2.1 IN 0700 AM 02/24 COOP ..RICE COUNTY VESELI 1W 6.5 IN 0500 AM 02/24 COCORAHS FARIBAULT 6.2 IN 0700 AM 02/24 COOP MONTGOMERY 3ENE 5.0 IN 0600 AM 02/24 COCORAHS ..SCOTT COUNTY JORDAN 1SW 2.6 IN 0530 AM 02/24 COOP 2 W NEW PRAGUE 2.6 IN 0333 AM 02/24 TRAINED SPOTTER SHAKOPEE 2.5 IN 0700 AM 02/24 COCORAHS ..SHERBURNE COUNTY ORROCK 2SE 1.5 IN 0700 AM 02/24 COCORAHS ..STEARNS COUNTY ST. JOSEPH 0.5 IN 0700 AM 02/24 COCORAHS ..STEELE COUNTY ELLENDALE 11.0 IN 0700 AM 02/24 COCORAHS OWATONNA 8.0 IN 0715 AM 02/24 PUBLIC ..WASECA COUNTY WASECA 4.0 IN 1100 PM 02/23 TRAINED SPOTTER ..WASHINGTON COUNTY WOODBURY 3.0 IN 0700 AM 02/24 COCORAHS STILLWATER 1NE 2.0 IN 0753 AM 02/24 COCORAHS ..WRIGHT COUNTY ST. MICHAEL 1E 2.5 IN 0800 AM 02/24 COCORAHS HANOVER 1WNW 1.8 IN 0800 AM 02/24 COCORAHS OBSERVATIONS ARE COLLECTED FROM A VARIETY OF SOURCES WITH VARYING EQUIPMENT AND EXPOSURES. WE THANK ALL VOLUNTEER WEATHER OBSERVERS FOR THEIR DEDICATION. NOT ALL DATA LISTED ARE CONSIDERED OFFICIAL. ---- PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 406 PM CST SUN FEB 24 2019 ..FEBRUARY 23-24 SNOWFALL REPORTS LOCATION AMOUNT TIME/DATE LAT/LON ..MINNESOTA ..DODGE COUNTY 2 NE KASSON 13.0 IN 0700 AM 02/24 44.05N/92.72W HAYFIELD 11.5 IN 0830 AM 02/24 43.89N/92.85W ..FILLMORE COUNTY CHATFIELD 12.0 IN 0750 AM 02/24 43.85N/92.18W RUSHFORD 10.5 IN 0704 AM 02/24 43.81N/91.75W 1 S PETERSON 9.8 IN 0942 AM 02/24 43.77N/91.83W 2 NW WYKOFF 9.7 IN 0240 AM 02/24 43.73N/92.30W 1 SSE PILOT MOUND 9.1 IN 0700 AM 02/24 43.79N/92.03W FOUNTAIN 9.0 IN 0756 AM 02/24 43.74N/92.13W MABEL 5.0 IN 0700 AM 02/24 43.52N/91.76W ..HOUSTON COUNTY CALEDONIA 5.5 IN 0734 AM 02/24 43.64N/91.50W HOKAH 4NW 4.4 IN 0608 AM 02/24 43.80N/91.43W SPRING GROVE 4.0 IN 1126 AM 02/24 43.56N/91.64W 4 NNE HOUSTON 4.0 IN 0545 AM 02/24 43.80N/91.53W 4 NW EITZEN 3.5 IN 0800 AM 02/24 43.56N/91.51W CALEDONIA 3.3 IN 0247 AM 02/24 43.63N/91.50W 3 W STODDARD 2.6 IN 0700 AM 02/24 43.65N/91.28W ..MOWER COUNTY 1 SW AUSTIN 11.3 IN 0100 PM 02/24 43.66N/92.98W AUSTIN 10.5 IN 0831 AM 02/24 43.67N/92.97W 2 SW AUSTIN 10.5 IN 0810 AM 02/24 43.65N/92.99W 4 WSW AUSTIN 9.0 IN 0755 AM 02/24 43.64N/93.05W ..OLMSTED COUNTY 2 NNW ROCHESTER 13.5 IN 0700 AM 02/24 44.05N/92.49W 4 W POTSDAM 12.5 IN 0937 AM 02/24 44.16N/92.43W 1 SSW ORONOCO 12.3 IN 0908 AM 02/24 44.15N/92.54W 6 E DOUGLAS 11.0 IN 0715 AM 02/24 44.10N/92.46W 2 NE ROCHESTER 11.0 IN 0600 AM 02/24 44.04N/92.44W 4 ESE DOUGLAS 10.9 IN 0745 AM 02/24 44.08N/92.51W ROCHESTER INTERNATIONAL AIRP 10.5 IN 0554 AM 02/24 43.91N/92.50W 2 W CHESTER 10.3 IN 1130 PM 02/23 44.01N/92.38W 1 NNW ROCHESTER 10.2 IN 1002 AM 02/24 44.02N/92.48W ELGIN 2SSW 10.1 IN 0700 AM 02/24 44.10N/92.27W 2 SW PREDMORE 10.0 IN 0925 AM 02/24 43.92N/92.35W 3 ESE DOUGLAS 10.0 IN 0757 AM 02/24 44.09N/92.51W 2 S PREDMORE 10.0 IN 0727 AM 02/24 43.90N/92.34W ..WABASHA COUNTY THEILMAN 1SSW 12.2 IN 0730 AM 02/24 44.28N/92.19W 2 N KELLOGG 12.0 IN 0730 AM 02/24 44.34N/92.01W WABASHA 11.0 IN 0448 AM 02/24 44.37N/92.04W 3 SW ZUMBRO FALLS 9.3 IN 0745 AM 02/24 44.24N/92.46W ..WINONA COUNTY 1 NW GOODVIEW 12.5 IN 1004 AM 02/24 44.07N/91.72W 4 S WINONA 12.0 IN 1106 AM 02/24 43.99N/91.60W MINNESOTA CITY 12.0 IN 0944 AM 02/24 44.09N/91.76W LEWISTON 12.0 IN 0721 AM 02/24 43.99N/91.86W WINONA 10.0 IN 0542 AM 02/24 44.05N/91.66W WINONA 4SW 8.0 IN 1035 AM 02/24 43.98N/91.71W LA CRESCENT DAM 7 2.5 IN 0800 AM 02/24 43.87N/91.31W ---- PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 723 PM CST SUN FEB 24 2019 ..PEAK WIND GUSTS TODAY LOCATION SPEED TIME/DATE LAT/LON ROCHESTER INTERNATIONAL AIRP 58 MPH 1226 PM 02/24 43.91N/92.50W 2 W OELWEIN 55 MPH 0155 PM 02/24 42.68N/91.97W OELWEIN MUNICIPAL AIRPORT 55 MPH 0155 PM 02/24 42.68N/91.97W PLATTEVILLE MUNICIPAL AIRPOR 55 MPH 1155 AM 02/24 42.69N/90.44W MAYO HELIPAD 54 MPH 1255 PM 02/24 44.02N/92.48W 1 ENE DEXTER 54 MPH 0135 PM 02/24 43.73N/92.68W BYRON 52 MPH 0115 PM 02/24 44.04N/92.64W 3 N STEWARTVILLE 52 MPH 0205 PM 02/24 43.90N/92.48W 2 NNW ZUMBRO FALLS 51 MPH 0203 PM 02/24 44.32N/92.44W CHARLES CITY AIRPORT 51 MPH 0155 PM 02/24 43.07N/92.61W DECORAH MUNICIPAL AIRPORT 51 MPH 1255 PM 02/24 43.28N/91.74W 2 E KASSON 51 MPH 0520 PM 02/24 44.02N/92.71W 1 SSE KELLOGG 49 MPH 0915 AM 02/24 44.28N/91.99W 5 NW FRANKVILLE 49 MPH 0132 PM 02/24 43.25N/91.70W DODGE CENTER AIRPORT 49 MPH 0115 PM 02/24 44.02N/92.83W AUSTIN MUNICIPAL AIRPORT 48 MPH 1256 PM 02/24 43.66N/92.93W PRAIRIE DU CHIEN AIRPORT 48 MPH 1115 AM 02/24 43.02N/91.12W 2 N IONIA 48 MPH 1040 AM 02/24 43.07N/92.46W 2 SE DOUGLAS 47 MPH 1145 AM 02/24 44.08N/92.55W LA CROSSE REGIONAL AIRPORT 47 MPH 1227 PM 02/24 43.88N/91.26W MEDFORD AIRPORT 47 MPH 1255 PM 02/24 45.10N/90.30W 2 SE EYOTA 47 MPH 0520 PM 02/24 43.96N/92.21W BOSCOBEL AIRPORT 47 MPH 0250 PM 02/24 43.16N/90.67W MAUSTON AIRPORT 45 MPH 1055 AM 02/24 43.84N/90.14W BLACK RIVER FALLS AREA AIRPO 44 MPH 0355 PM 02/24 44.25N/90.86W 1 E BLACK RIVER FALLS 40 MPH 0315 PM 02/24 44.30N/90.83W 3 NE LUBLIN 39 MPH 0514 PM 02/24 45.11N/90.69W PRESTON AIRPORT 39 MPH 0255 PM 02/24 43.68N/92.18W WINONA MUNICIPAL AIRPORT 39 MPH 0115 PM 02/24 44.08N/91.71W 1 ENE BOSCOBEL 38 MPH 1103 AM 02/24 43.15N/90.68W SPARTA/FORT MCCOY AIRPORT 37 MPH 0235 PM 02/24 43.96N/90.74W 2 NNE ROCHESTER 37 MPH 0210 PM 02/24 44.05N/92.45W 2 E CATARACT 36 MPH 0403 PM 02/24 44.09N/90.79W 3 SW HAMMOND 36 MPH 0246 PM 02/24 44.18N/92.41W 3 W SAINT JOSEPH 34 MPH 0654 PM 02/24 43.78N/91.10W LAKE CITY 32 MPH 1245 PM 02/24 44.45N/92.27W ---- PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 626 PM CST SUN FEB 24 2019 ...PEAK WIND REPORTS AS OF 6 PM.. LOCATION SPEED TIME/DATE PROVIDER ST. PAUL DWTN AP 62 MPH 1049 AM 02/24 ASOS CLARA CITY 2WSW 55 MPH 1005 AM 02/24 MNDOT NEW ULM AP 55 MPH 1055 AM 02/24 AWOS WASECA AP 54 MPH 0119 PM 02/24 AWOS REDWOOD FALLS AP 54 MPH 1132 AM 02/24 ASOS WILLMAR AP 52 MPH 1036 AM 02/24 AWOS FAIRMONT AP 52 MPH 1109 AM 02/24 AWOS ALEXANDRIA AP 51 MPH 1219 PM 02/24 ASOS ELLENDALE 5NNE 51 MPH 1141 AM 02/24 MNDOT WINTHROP 2W 50 MPH 1145 AM 02/24 MNDOT CANNON FALLS 7SSE 50 MPH 1215 PM 02/24 MNDOT BENSON AP 49 MPH 1236 PM 02/24 AWOS EAU CLAIRE AP 49 MPH 0340 PM 02/24 ASOS MANKATO AP 49 MPH 1025 AM 02/24 AWOS BLUE EARTH 2NW 49 MPH 1110 AM 02/24 MNDOT NEW GERMANY 1NW 49 MPH 0945 AM 02/24 MNDOT WASECA 1SSE 49 MPH 1120 AM 02/24 MNDOT ST. CLOUD AP 49 MPH 0211 PM 02/24 ASOS EDEN PRAIRIE AP 48 MPH 1237 PM 02/24 ASOS GLENWOOD AP 48 MPH 1116 AM 02/24 AWOS LITCHFIELD 3S 48 MPH 1211 PM 02/24 RAWS CRYSTAL AP 48 MPH 1246 PM 02/24 ASOS STARBUCK 8SSW 48 MPH 1100 AM 02/24 MNDOT MORRIS AP 48 MPH 1136 AM 02/24 AWOS MINNEAPOLIS-ST. PAUL AP 48 MPH 1224 PM 02/24 ASOS ALEXANDRIA 2SSE 47 MPH 1130 AM 02/24 MNDOT SAUK CENTRE 2SE 47 MPH 1110 AM 02/24 MNDOT LITCHFIELD AP 46 MPH 1115 AM 02/24 AWOS LAKEVILLE AP 46 MPH 1216 PM 02/24 AWOS HANLEY FALLS 46 MPH 1040 AM 02/24 MNDOT MADELIA 3ENE 46 MPH 1045 AM 02/24 MNDOT OLIVIA AP 46 MPH 0259 PM 02/24 AWOS OWATONNA AP 46 MPH 1052 AM 02/24 AWOS CUMBERLAND AP 46 MPH 0435 PM 02/24 AWOS LONG PRAIRIE AP 45 MPH 1016 AM 02/24 AWOS GRANITE FALLS AP 45 MPH 1036 AM 02/24 AWOS RICE 1NNW 45 MPH 0320 PM 02/24 MNDOT STANLEY 1SSE 45 MPH 1056 AM 02/24 WIDOT ALBERT LEA AP 44 MPH 0456 PM 02/24 AWOS BLAINE AP 44 MPH 0145 PM 02/24 AWOS MENOMONIE AP 44 MPH 0155 PM 02/24 AWOS NEW RICHMOND AP 44 MPH 0235 PM 02/24 AWOS STANTON AP 44 MPH 0115 PM 02/24 AWOS SAUK CENTRE AP 43 MPH 1155 AM 02/24 AWOS MADISON AP 43 MPH 1055 AM 02/24 AWOS GLENCOE AP 43 MPH 1115 AM 02/24 AWOS HUTCHINSON AP 43 MPH 1035 AM 02/24 AWOS 1 NW CAMP RIPLEY 43 MPH 0356 PM 02/24 NONFEDAWOS CLEARWATER 1SE 43 MPH 1015 AM 02/24 MNDOT BELGRADE 3ESE 43 MPH 1045 AM 02/24 MNDOT RED WING 4W 43 MPH 0900 AM 02/24 MNDOT MARIETTA 5SSW 43 MPH 0820 AM 02/24 MNDOT MONTEVIDEO AP 43 MPH 0135 PM 02/24 AWOS OSCEOLA AP 43 MPH 0235 PM 02/24 AWOS PRINCETON AP 43 MPH 1256 PM 02/24 AWOS CARVER 3S 43 MPH 1049 AM 02/24 RAWS RIVER FALLS 4NW 43 MPH 0256 PM 02/24 WIDOT HARDING 3WNW 42 MPH 1220 PM 02/24 MNDOT CAMBRIDGE AP 41 MPH 0356 PM 02/24 AWOS LADYSMITH 2SW 41 MPH 0505 PM 02/24 RAWS TONY AP 41 MPH 0335 PM 02/24 AWOS RICE LAKE AP 41 MPH 0155 PM 02/24 AWOS SOUTH ST. PAUL AP 41 MPH 0215 PM 02/24 AWOS LAKE ELMO AP 40 MPH 0136 PM 02/24 AWOS MAYER 1NE 40 MPH 0400 PM 02/24 MNDOT CHETEK AP 40 MPH 0135 PM 02/24 AWOS APPLETON AP 39 MPH 0104 PM 02/24 AWOS CANBY AP 39 MPH 0959 AM 02/24 AWOS SKYLINE 39 MPH 1130 AM 02/24 MNDOT NEW PRAGUE 2W 39 MPH 1045 AM 02/24 MNDOT SOUTH ST. PAUL 1WSW 39 MPH 1246 PM 02/24 MNDOT RED WING AP 39 MPH 0215 PM 02/24 AWOS SANTIAGO 3E 38 MPH 0120 PM 02/24 RAWS GORDONSVILLE 38 MPH 0300 PM 02/24 GOES MORA AP 38 MPH 0556 AM 02/24 AWOS OBSERVATIONS ARE COLLECTED FROM A VARIETY OF SOURCES WITH VARYING EQUIPMENT AND EXPOSURES. WE THANK ALL VOLUNTEER WEATHER OBSERVERS FOR THEIR DEDICATION. NOT ALL DATA LISTED ARE CONSIDERED OFFICIAL.