A very unusual snow event unfolded across portions of south central Minnesota, as well as west central Wisconsin on the evening of Wednesday, May 1st. Snowfall amounts topped over a foot of snow, with locally higher amounts in a small band near Ellendale, Blooming Prairie, Owatonna, and Goodhue, Minnesota.
Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MPX wrote it up.
A very unusual snow event unfolded across portions of south central Minnesota, as well as west central Wisconsin on the evening of Wednesday, May 1st. Snowfall amounts topped over a foot of snow, with locally higher amounts in a small band near Ellendale, Blooming Prairie, Owatonna, and Goodhue, Minnesota.
This system was highly unusual due to the fact that May snowfall amounts average less than an inch. A strong Canadian air mass for early May allowed for critical temperatures to lower enough to produce snow across south central and east central Minnesota during the late afternoon and early evening of Wednesday May 1st.
A strong surge of moisture from the gulf interacted with the cold air mass to produce very heavy snowfall from Wednesday evening, through Thursday morning, before tapering off after 6 am. Snowfall rates were as high as 1-2 inches per hour during the height of the storm. A local CoCoRaHS observer southwest of Ellendale in Steele County, Minnesota, had a record 3 day snowfall report of 17.3 inches between May 1st, to May 3rd. This is a state record for May for a three day total. Ellendale's May monthly total also was 17.3 inches and this falls just short of Minnesota's all-time monthly May snowfall record of 17.8 inches set in Virginia (St. Louis County) in 1954.
Due to the heavy snowfall and high liquid water content, large tree branches broke off and caused damage to power lines, along with numerous power outages.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Twin Cities, MN wrote its last area forecast discussion before the first event at May 1, 2:58 PM CST, 1 hour 2 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
358 PM CDT WED MAY 1 2013
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 357 PM CDT WED MAY 1 2013
THIS IS A VERY COMPLEX AND UNCERTAIN FORECAST...CERTAINLY ONE OF A
KIND IN A FORECASTER/S CAREER. THE GRIDS REMAIN IN UNCHARTED WATERS
WITH RECORD MAY SNOWFALL AMOUNTS FORECAST FOR MANY AREAS ACROSS
SRN/ERN MN AND WRN WI. HAVING TO FORECAST RECORD SNOW AMOUNTS AND
DOUBLING THEM MAKES THIS DIFFICULT ENOUGH...LET ALONE THE SUBTLE
MODEL DIFFERENCES WHICH COULD PROVE SIGNIFICANT TO SENSIBLE WEATHER.
AN INCREDIBLY TIGHT SNOW GRADIENT IS LIKELY TONIGHT SOMEWHERE FROM
NEAR NEW ULM TO THE WESTERN TWIN CITIES METRO AND ALONG I-35 TO THE
NORTH. THIS GRADIENT WILL LIKELY BE TIGHTER THAN THE MODEL GRID
SPACING...THUS THE BAND MAY SHIFT WEST OR EAST A ROW OF COUNTIES FROM
WHAT IS CURRENTLY PREDICTED. HOWEVER...THE UNCERTAINTY HAS BEEN
ALLEVIATED EVER SO SLIGHTLY CONSIDERING THE 15Z HOPWRF HAS COME IN
VERY CLOSE TO THE OFFICIAL FORECAST IN TERMS OF PLACEMENT OF SNOW
AND TIMING. SO FAR SO GOOD.
A SMALL FINGER OF PRECIP EXTENDS NORTHEAST FROM NEAR FAIRMONT TO THE
TWIN CITIES AND BALSAM LAKE THIS AFTERNOON. IT HAS BEEN QUITE
STUBBORN AND HAS NOT DISSIPATED LIKE SOME MODELS HAD ANTICIPATED.
THE CURRENT RADAR IMAGE COULD BE AN INDICATION OF WHERE SOME OF THE
HEAVIER SNOW FALLS LATER THIS EVENING. THIS IS THE LOCATION WHERE
MID LEVEL FGEN INTERSECTS THE NORTHERN EXTENT OF DEEPER BOUNDARY
LAYER MOISTURE AND LIKELY WHERE THE DEFORMATION WILL BE MOST
EFFICIENT. THE UNSEASONABLY STRONG HIGH PRESSURE CENTERED OVER THE
DAKOTAS WILL CONTINUE TO ADVECT DRY AIR SOUTH...ALLOWING FOR A
GRADUAL LOWERING OF WETBULB TEMPS...AND RESULTING IN A VERY COLD
THERMAL PROFILE TONIGHT. IN FACT...850 MB TEMPS COULD FALL TO -5 TO
-7C OVERNIGHT. THE KEY IS HAVING ENOUGH DRY AIR TO LOWER WETBULB
TEMPS...BUT NOT TOO MUCH THAT CAUSES PRECIP TO EVAPORATE COMPLETELY.
SNOW WILL BE HEAVY FOR A TIME TONIGHT...PERHAPS AT A RATE OF AN INCH
OR TWO PER HOUR AS THE BETTER MOISTURE ARRIVES AND STRONG ISENTROPIC
LIFT TAKES HOLD /COINCIDENT WITH THE INTENSE OMEGA/FGEN IN THE DGZ/.
AFTER SEEING WHAT FELL ACROSS SWRN MN THIS MORNING /3 TO 5 INCHES
WITH I-90 COMPLETELY SNOW COVERED FOR A TIME/...THE LACK OF
INSOLATION TONIGHT WILL FURTHER THE POTENTIAL FOR ACCUMULATING
SNOWFALL. COBB TECHNIQUE HAS SOME SCARY SNOW RATIO VALUES OF 15 TO
17:1 OFF THE NAM...WITH AROUND AN INCH OF QPF. LOOKING AT JUST THE
THERMAL PROFILE...THIS WOULD SEEM REASONABLE. HOWEVER...THE GROUND
IS WARM ENOUGH TO CAUSE A LOT OF COMPACTION AND MELTING AT LEAST
UNTIL THE HEAVIER SNOW RATES ARRIVE LATE THIS EVENING.
THE BAND OF SNOW WILL PIVOT EAST SLOWLY LATE TONIGHT AND INTO
THURSDAY. MDT-OCCASIONALLY HVY SNOW WILL BE ONGOING THURSDAY MORNING
ACROSS WRN WI. IT DOES LOSE SOME OF ITS INTENSITY BY AFTERNOON...
UNFORTUNATELY IT DOES NOT DISSIPATE COMPLETELY.
STILL ANTICIPATING A BAND OF 6 TO 9 INCHES FROM SCTRL MN TO THE SERN
TC METRO AND INTO NWRN WI BY MIDDAY THURSDAY. DESPITE SOME TRIMMING
OF HEADLINES ON THE WESTERN EDGE DUE TO THE TIGHT GRADIENT
ASSOCIATED WITH DRY AIR...PREVIOUS FORECAST LOOKS PRETTY GOOD.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 357 PM CDT WED MAY 1 2013
A DEEP TROUGH ALOFT IN THE CENTER OF THE COUNTRY WILL BEGIN THE
LONGER TERM PORTION OF THE FORECAST. THE BASE OF THE TROUGH WILL
BECOME A CUTOFF LOW AS AN OMEGA BLOCK DEVELOPS FROM THE EASTERN
GREAT LAKES INTO QUEBEC.
THERE REMAIN QUITE A BIT OF SPREAD IN THE DETERMINISTIC SOLUTIONS
ON WHERE THE UPPER LOW WILL GO DURING THE UPCOMING WEEKEND. THE
GFS AND EC ARE IN SOME AGREEMENT ON DRIFTING THE UPPER LOW INTO
THE TENNESSEE VALLEY BY MONDAY WHILE THE GEM WOULD BE JUST SOUTH
OF THE BORDER. ON GOING WINTRY PRECIPITATION IS EXPECTED THURSDAY
NIGHT FROM SOUTH CENTRAL MN INTO WEST CENTRAL WI WITH ONLY LIGHT
SNOW ACCUMULATIONS. LOW LEVEL WAA FROM THE SOUTHEAST WILL CAUSE
THE SNOW TO MIX WITH OR CHANGE TO ALL RAIN EARLY FRIDAY ALONG WITH
A SLOW WESTWARD DRIFT TO THE RAIN.
WHAT IS APPARENT IN THE SOLUTIONS IS THAT A WAVE WILL DRIVE
WESTWARD AROUND THE UPPER LOW FROM FRIDAY THROUGH SATURDAY. THIS
WILL LIKELY DRIVE RAIN BACK WEST ACROSS ALL OF THE CWA BY FRIDAY
EVENING WITH RAIN LIKELY IN MOST AREAS FRIDAY NIGHT AND SATURDAY.
THE THREAT FOR RAIN IS FORECAST TO DIMINISH ON SUNDAY WITH PERHAPS
MONDAY BEING A DRY DAY IN MOST AREAS. AGAIN...THIS IS GOING TO
DEPEND ON THE TRACK OF THE UPPER LOW. RAIN CHANCES COME BACK
TUESDAY AND WEDNESDAY AS MORE UPPER ENERGY APPROACHES FROM THE
SOUTHWEST. HIGH/LOW TEMPERATURES WILL BE WELL BELOW NORMAL THROUGH
SUNDAY WITH NEAR NORMAL READINGS FROM MONDAY ONWARD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 119 PM CDT WED MAY 1 2013
PESKY BAND OF RAIN AND SNOW STILL EXTENDS FROM JUST WEST OF RNH TO
MSP AND SOUTHEAST OF RWF. THINK A DIMINISHING TREND WILL CONTINUE
DURING THE AFTERNOON BEFORE THE NEXT ROUND BEGINS TO PUSH IN FROM
THE SOUTHWEST. THE NEXT ROUND THIS EVENING WILL BE MAINLY
SNOW...EXCEPT TOWARD EAU WHERE IT WILL REMAIN A MIX INTO THE
OVERNIGHT. COULD SEE BANDS OF HEAVY SNOW FROM MKT TO MSP AND
NORTHEAST AROUND MIDNIGHT...BEFORE THE PRECIP BEGINS TO INCH
EASTWARD INTO THURSDAY MORNING. RWF/STC/AXN SHOULD MISS OUT ON
PRECIPITATION FOR THE REST OF THE PERIOD WITH VFR CONDITIONS
EXPECTED.
KMSP...MAIN FORECAST CONCERN IS HOW MUCH SNOW STICKS TO PAVEMENT
TONIGHT. LOOKING AT A PERIOD OF HEAVY SNOW POTENTIALLY LATE THIS
EVENING AND OVERNIGHT WHILE TEMPERATURES HOVER NEAR FREEZING. THIS
COULD BE SUFFICIENT TO GET ACCUMULATING SNOW.
/OUTLOOK FOR KMSP/
FRI...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA/-SN. NE WINDS 10-15
KT.
SAT...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA. ENE WINDS 5 KT.
SUN...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA. LGT/VRBL WINDS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 10 AM CDT THURSDAY FOR MNZ053-060>063-
068>070-075>077-082>085-091>093.
WINTER WEATHER ADVISORY UNTIL 7 AM CDT THURSDAY FOR MNZ052-067-
074.
WINTER STORM WARNING UNTIL 7 PM CDT THURSDAY FOR MNZ078.
WI...WINTER STORM WARNING UNTIL 7 PM CDT THURSDAY FOR WIZ014>016-
023>027.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT THURSDAY FOR WIZ028.
&&
SHORT TERM...BORGHOFF
LONG TERM...RAH
AVIATION...BORGHOFFHAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 359 PM CDT WED MAY 1 2013 MNZ052-053-060>063-067>070-074>078-082>085-091>093-WIZ014>016- 023>028-022100- ISANTI-CHISAGO-HENNEPIN-ANOKA-RAMSEY-WASHINGTON-SIBLEY-CARVER- SCOTT-DAKOTA-BROWN-NICOLLET-LE SUEUR-RICE-GOODHUE-WATONWAN- BLUE EARTH-WASECA-STEELE-MARTIN-FARIBAULT-FREEBORN-POLK-BARRON- RUSK-ST. CROIX-PIERCE-DUNN-PEPIN-CHIPPEWA-EAU CLAIRE- 359 PM CDT WED MAY 1 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MINNESOTA...EAST CENTRAL MINNESOTA...SOUTH CENTRAL MINNESOTA... SOUTHEAST MINNESOTA...NORTHWEST WISCONSIN AND WEST CENTRAL WISCONSIN. .DAY ONE...TONIGHT SNOW WILL REDEVELOP AND BECOME HEAVY AT TIMES WITH RATES OF 1 AND 2 INCHES PER HOUR POSSIBLE...ALLOWING FOR THE POTENTIAL FOR SEVERAL INCHES OF ACCUMULATION. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY HEAVY SNOW FROM TONIGHT IS EXPECTED TO CONTINUE INTO THURSDAY AFTERNOON ACROSS WESTERN WISCONSIN. THIS EVENT WILL FEATURE A PROLONGED PERIOD OF PRECIPITATION THAT WILL CONTINUE THROUGH AT LEAST THURSDAY NIGHT ACROSS FAR EASTERN MINNESOTA AND WESTERN WISCONSIN. TOTAL MELTED PRECIPITATION AMOUNTS THROUGH FRIDAY COULD EXCEED 1 TO 2 INCHES ACROSS SOUTHERN AND EASTERN MINNESOTA AND WEST CENTRAL WISCONSIN. LOCALLY HIGHER AMOUNTS OF 2 TO 4 INCHES ARE POSSIBLE IN PORTIONS OF WEST CENTRAL WISCONSIN. IF THESE AMOUNTS OCCUR...AREAL FLOODING...ESPECIALLY NEAR STREAMS AND RIVERS IS POSSIBLE. .SPOTTER INFORMATION STATEMENT... SPOTTERS AND SNOWFALL OBSERVERS ARE URGED TO REPORT SNOWFALL AMOUNTS TO THE NATIONAL WEATHER SERVICE. MNZ041>045-047>051-054>059-064>066-073-022100- DOUGLAS-TODD-MORRISON-MILLE LACS-KANABEC-STEVENS-POPE-STEARNS- BENTON-SHERBURNE-LAC QUI PARLE-SWIFT-CHIPPEWA-KANDIYOHI-MEEKER- WRIGHT-YELLOW MEDICINE-RENVILLE-MCLEOD-REDWOOD- 359 PM CDT WED MAY 1 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MINNESOTA...EAST CENTRAL MINNESOTA...SOUTHWEST MINNESOTA AND WEST CENTRAL MINNESOTA. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED. BORGHOFF
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
115 PM CDT WED MAY 01 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0100 PM SNOW NEW ULM 44.31N 94.46W
05/01/2013 E2.0 INCH BROWN MN DEPT OF HIGHWAYS
MAINLY ON GRASSY SURFACES. ROADS SLUSHY IN SPOTS.
0100 PM SNOW ST JAMES 43.98N 94.63W
05/01/2013 E1.5 INCH WATONWAN MN DEPT OF HIGHWAYS
MAINLY ON GRASSY SURFACES. ROADS SLUSHY IN SPOTS.
&&
JRBThe national radar mosaic for the moment the first event began.
8 winter storm. Local standard time, as filed.
Snowfall amounts ranged from 6 to 10 inches across far northeast Faribault County where Wells measured 10 inches by early Thursday morning, May 2nd.
Snowfall amounts ranged from 6 to 14 inches across southeast Waseca County, with the heaviest near New Richland.
Snowfall amounts ranged from 8 to 15 inches across the county, with the heaviest in the far northeast near Maple Island.
Snowfall amounts ranged from 10 to 17.3 inches across the county, with the heaviest in the southwest corner near Ellendale which measured a three day total of 17.3 inches.
Snowfall amounts ranged from 6 to 12 inches across the southeast part of Rice County, with the highest near Moland.
Snowfall amounts ranged from 6 to 8 inches in the far southeast part of the county with locally 8 inches near Hastings.
Snowfall amounts ranged from 6 to 17 inches across the county with the heaviest near Goodhue.
Snowfall amounts ranged from 6 to 8 inches in the far southeastern part of the county where locally 8 inches fell near Cottage Grove, and Afton.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2013Every state in 2013This day in weather historyWarnings in Minnesota, May 2013
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 441148, 441149, 441150, 441152, 441153, 441155, 441156, 441157.