Hail and Damaging Winds in Minnesota, July 18, 2012

Name: Hail and Damaging Winds in Minnesota, July 18, 2012
Start: 2012-07-18T11:58
End: 2012-07-18T13:47
Location: Minnesota

July 18, 2012 · NWS ARX · 6 events in 3 counties and zones

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $70,000
Crop damage: None recorded
Events: 6

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.

What happened

The episode as NWS ARX wrote it up.

Severe thunderstorms developed rapidly during the late morning and afternoon along and behind a slow moving cold front. These thunderstorms produced large hail and some wind damage across portions of southeast Minnesota before the storms moved into northeast Iowa. The largest hail reported was 1.5 inches in Hayfield (Dodge County). Wind damage occurred in Lyle (Mower County) where a roof was blown off a business and in Spring Valley (Fillmore County) where trees that were blown down damaged a park pavilion, an apartment building and a house.

What forecasters said that day

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 La Crosse, WI wrote its last area forecast discussion before the first event at Jul 18, 11:40 AM CST, 18 minutes earlier.

Area forecast discussion, Jul 18, 11:40 AM CST, 18 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1240 PM CDT WED JUL 18 2012

.SHORT TERM...
1117 AM CDT WED JUL 18 2012

HAVE BEEN ASSESSING INFORMATION THIS MORNING AND HAVE BEEN WORKING
ON INCREASING THE RAIN AND STORM CHANCES. CONFIDENCE IS INCREASING...
BUT STILL MODERATE ON THE OUTCOMES OF THIS AFTERNOON AND EVENING.

WATCHING SOME KEY FEATURES INCLUDING THE SHORTWAVE TROUGH OVER THE
DAKOTAS WITH A LOCAL TIGHT CIRCULATION OVER KFSD RIGHT NOW PER
GOES WATER VAPOR AND SOME RADAR ECHO...HEADING TOWARD THE AREA. THE
MINNEAPOLIS CONVECTION AND NW-SE ARM OF THUNDER IS ALONG A
FRONTOGENETIC AREA IN THE 925-800MB LAYER AND THIS FORCING
CONTINUES...PER LATEST RAP/NAM TO REMAIN STATIONARY INTO THE
EVENING. WITH MU CAPE BUILDING AHEAD OF THE SYSTEM...THINK THE
RISK OF SEVERE WIND ACROSS CLARK-TAYLOR HAS INCREASED. IN ANY
CASE...RAIN SHOULD CONTINUE FOR MOST OF THE AFTERNOON UP THERE
TOO.

SPC HAS UPGRADED THE AREA TO A SLIGHT RISK OF STORMS AND WITH
SHORTWAVE ENERGY AND DYNAMICS COMING IN...MAIN CONCERN FOR SEVERE
WEATHER WOULD BE WIND. BY AFTERNOON AS THE KFSD MID-LEVEL WAVE
APPROACHES AND CONVERGENCE INCREASES WITH INSTABILITY BUILDING ACROSS
THE SOUTH IN VICINITY OF THE WARM/STATIONARY SURFACE FRONT AND
COLD FRONTAL INVERTED TROUGH IN THE WESTERN FORECAST
AREA...SUSTAINED UPDRAFTS ARE LIKELY. THIS WOULD CONGEAL INTO A
COLD POOL AND WITH STEEP LOW-LEVEL LAPSE RATES...WIND GUSTS IN THE
40-60 MPH RANGE ARE POSSIBLE. SO THE THOUGHT IS STRONG-SEVERE
STORMS SOUTH OF CURRENT ACTIVITY IN WI...IN THE 3-9PM TIME FRAME.

THE MINNEAPOLIS SYSTEM SEEMS POISED TO MOVE DOWN THE FRONTOGENETIC
AXIS AND CAUSE SOME WARNINGS THIS AFTERNOON IN WI. THIS WOULD
MAINLY AFFECT CLARK AND TAYLOR COUNTIES. WITH MU CAPE INCREASING
THERE /ABOUT 2K J/KG AT 11AM/...AND A BIT BETTER SHEAR...WE MAY
SEE A LINE WITH DAMAGING WIND BY EARLY-MID AFTERNOON. COULD SEE
2-3 INCHES OF RAIN TOO.

WILL ALSO BE INCREASING THE RAIN CHANCES TONIGHT TO ACCOUNT FOR
LATE AFTERNOON WEATHER TO SHIFT ACROSS THE FORECAST AREA. MAIN
ACTIVE PERIOD APPEARS TO BE 00-03Z. MORE TO COME IN LATER
DISCUSSION.

.LONG TERM...SATURDAY THROUGH TUESDAY
334 AM CDT WED JUL 18 2012

18.00Z MEDIUM RANGE MODELS IN REASONABLY GOOD AGREEMENT FOR THE SAT
THRU TUE PERIOD. SHORTWAVES MOVING ACROSS CENTRAL/SOUTHERN CAN
FLATTEN THE MID NOAM RIDGING SAT. BY SUN/MON THE MID LEVEL RIDGE
AXIS REBUILDS FURTHER WEST OVER MT/WY/DAKOTAS INTO ALB/SASKAT...
LEAVING THE UPPER MIDWEST UNDER BROAD NORTHWEST FLOW ALOFT. THE
NORTHWEST FLOW BY SUN/MON ALLOWS THE PASSING SHORTWAVES TO PUSH TO A
COLD FRONT/SFC TROUGH SOUTHEAST INTO/ACROSS THE AREA LATER IN THE
WEEKEND AND FOR EARLY NEXT WEEK. PLENTY OF DETAIL DIFFERENCES WITH
LOWER LEVEL MOISTURE...CAPE AND THERMO-DYNAMIC FORCING MECHANISMS IN
THE SUN-TUE TIME-FRAME...BUT IMPROVED MODEL CONSISTENCY AND LARGER
SCALE SIGNAL SUPPORTS 20-35 PERCENT SHRA/TSRA CHANCES IN THESE TIME
PERIODS. WITH GENERAL SOUTHWEST/WEST LOW/MID LEVEL FLOW...MODEL
CONSENSUS OF TEMPS REMAINING ABOVE NORMAL IN THE DAY 4-7 PERIOD
LOOKS GOOD AS WELL.

&&

.AVIATION...THROUGH 18Z THURSDAY
1240 PM CDT WED JUL 18 2012

WATER VAPOR IMAGERY SHOWING A TROUGH OF LOW PRESSURE OVER THE
DAKOTAS/NEBRASKA...MOVING EAST TOWARD THE AREA. LIFT AHEAD OF THIS
WAVE EXPECTED TO KICK OFF/INCREASE CONVECTION ACROSS THE AREA
THROUGH THIS AFTERNOON AND INTO THIS EVENING. SOME OF THIS
CONVECTION COULD BECOME STRONG TO SEVERE BETWEEN 3 PM AND 8 PM
GENERALLY ALONG AND SOUTH OF I-90 ACROSS MINNESOTA INTO WISCONSIN.
DAMAGING WIND WOULD BE THE MAIN THREAT. LOOKING FOR A GENERAL
DECREASE IN SHRA/TS COVERAGE AFTER MIDNIGHT AS THE TROUGH AXIS
SHIFTS EAST OF THE AREA. HOWEVER...SOME LINGERING SHRA/TS EXPECTED
TO CONTINUE AFTER MIDNIGHT WITH FAIRLY STEEP LAPSE RATES STILL
OVERHEAD. MODELS THEN INDICATE BROKEN DECK OF MVFR CLOUD AFTER 09Z
AS THE BOUNDARY LAYER COOLS BEHIND THE DEPARTING WAVE. EXPECTING THIS
MVFR CLOUD COVER TO LINGER THROUGH THURSDAY MORNING..THEN SCOURING
OUT BY AFTERNOON AS HIGH PRESSURE BUILDS IN.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
334 AM CDT WED JUL 18 2012

WI...NONE.
MN...NONE.
IA...NONE.

&&

SHORT TERM...BAUMGARDT/SCHMIDT
LONG TERM....RRS
AVIATION...DAS

Hazardous weather outlook, Jul 18, 11:44 AM CST, 14 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
1244 PM CDT WED JUL 18 2012

WIZ017-029-191100-
CLARK-TAYLOR-
1244 PM CDT WED JUL 18 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF NORTH CENTRAL
WISCONSIN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS WILL CONTINUE INTO THIS EVENING. BESIDES
PERIODIC HEAVY RAIN...A FEW STRONGER STORMS COULD PRODUCE GUSTY WIND
AS THEY MOVE THROUGH. LOCALIZED RAINFALL COULD ALSO REACH 1 TO 1.5
INCHES DEPENDING ON HOW THE STORMS TRACK.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

ADDITIONAL THUNDERSTORMS COULD BE IN THE AREA EARLY ON THURSDAY
BUT THE SEVERE WEATHER RISK DOES NOT LOOK FAVORABLE.

THERE ARE ALSO SMALL THUNDERSTORM CHANCES FROM THE WEEKEND INTO
EARLY NEXT WEEK BUT THE RISK OF ANY WIDESPREAD SEVERE WEATHER LOOKS
LOW.

.SPOTTER INFORMATION STATEMENT...

WIDESPREAD SPOTTER ACTIVATION IS NOT LOOKING FAVORABLE BUT ANY
REPORTS OF HAIL OR GUSTY WINDS...IN ADDITION TO RAINFALL TOTALS...
WOULD BE APPRECIATED.

.EMERGENCY MANAGEMENT COORDINATION...

NO WEBINAR IS SCHEDULED.

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ032>034-041>044-
053>055-061-191100-
ADAMS-ALLAMAKEE-BUFFALO-CHICKASAW-CLAYTON-CRAWFORD-DODGE-FAYETTE-
FILLMORE-FLOYD-GRANT-HOUSTON-HOWARD-JACKSON-JUNEAU-LA CROSSE-
MITCHELL-MONROE-MOWER-OLMSTED-RICHLAND-TREMPEALEAU-VERNON-WABASHA-
WINNESHIEK-WINONA-
1244 PM CDT WED JUL 18 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF SOUTHEAST
MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST INTO CENTRAL
WISCONSIN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

HOT TEMPERATURES WILL IMPACT MAINLY NORTHEAST IOWA AND NEIGHBORING
AREAS WITH HEAT INDEX READINGS IN THE 95 TO 105 RANGE INTO THE
EVENING. PRECAUTIONS FOR HEAT SHOULD BE USED.

THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER PARTS OF SOUTHEAST
MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON...AND COULD SPREAD MORE
INTO WESTERN WISCONSIN BY EVENING. STORMS HAVE A THREAT FOR LOCALLY
HEAVY RAIN...HAIL AND DAMAGING WINDS INTO TONIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE COULD BE LINGERING THUNDERSTORMS EARLY THURSDAY BUT
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME.

THERE ARE ALSO SMALL STORM CHANCES THIS WEEKEND INTO EARLY NEXT
WEEK BUT THE OVERALL RISK OF WIDESPREAD SEVERE WEATHER APPEARS
LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED AT TIMES THIS AFTERNOON AND INTO
THE EVENING. PEAK WIND GUSTS OR ANY OBSERVED DAMAGE REPORTS WOULD BE
USEFUL...IN ADDITION TO HAIL OR RAINFALL TOTALS.

.EMERGENCY MANAGEMENT COORDINATION...

NO WEBINAR IS SCHEDULED.

SHEA

In the hours before

Special weather statement, Jul 18, 7:35 AM CST, 4 hours 23 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
835 AM CDT WED JUL 18 2012

WIZ029-034-181430-
CLARK-JACKSON-
835 AM CDT WED JUL 18 2012

...STRONG THUNDERSTORMS MOVING ACROSS CLARK COUNTY WISCONSIN...

AT 830 AM...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS OVER HOG
CORNERS...NORTHWEST OF NEILLSVILLE WISCONSIN. THE STORMS WERE MOVING
SOUTHEAST AT 20 MPH.

SMALL HAIL AND TORRENTIAL DOWNPOURS MAY ACCOMPANY THIS STRONG
THUNDERSTORM. MOVE INDOORS AS THESE STORMS CROSS THE AREA.

LOCATIONS THAT MAY BE AFFECTED INCLUDE...SNYDER LAKE...THE
HIGHGROUND...CHRISTIE...SIDNEY AND NEILLSVILLE.

SHEA

Special weather statement, Jul 18, 11:27 AM CST, 31 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1227 PM CDT WED JUL 18 2012

MNZ086-087-181830-
DODGE-OLMSTED-
1227 PM CDT WED JUL 18 2012

...STRONG THUNDERSTORM WEST OF ROCHESTER...

AT 1220 PM...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER
COUNTY ROADS 3 AND 6...IN CENTRAL DODGE COUNTY MINNESOTA. THIS STORM
WAS SLOWLY MOVING SOUTHEAST AT 10 MPH.

OCCASIONAL HAIL AND TORRENTIAL DOWNPOURS ARE EXPECTED WITH THIS
STORM IN ADDITION TO LIGHTNING. THERE COULD EVEN BE BRIEF FUNNEL
CLOUD REPORTS WITH THIS STORM...ALTHOUGH NO TOUCHDOWNS ARE EXPECTED.

LOCATIONS THAT MAY BE AFFECTED INCLUDE INCLUDE HAYFIELD AND RURAL
SECTIONS OF SOUTHERN DODGE COUNTY. THE STORM MAY ALSO TRACK TOWARDS
THE ROCHESTER AIRPORT AND STEWARTVILLE.

SHEA

The radar

The Minneapolis radar (KMPX), 121 km away, was scanning. The volume nearest the first event began at 17:57 UTC.

Open the radar archive at this moment

Event by event

3 hail, 3 thunderstorm wind. Local standard time, as filed.

Hail, Dodge

When: July 18, 11:58 AM CST
Where: Dodge County, 1.21 mi NE of Hayfield
Measured: 3 in hail
Reported by: Broadcast Media
Coordinates: 43.890, -92.850

Hail ranging in size from golf ball to baseball fell in Hayfield.

Thunderstorm Wind, Mower

When: July 18, 12:15 PM CST
Where: Mower County, 1.83 mi S of Sargeant
Measured: 50 kt (58 mph) estimated gust
Property damage: $2,000
Reported by: Newspaper
Coordinates: 43.774, -92.814

Several trees were blown down south of Sargeant.

Hail, Mower

When: July 18, 12:47 PM CST
Where: Mower County, 2.85 mi ENE of Dexter
Measured: 0.88 in hail
Reported by: Trained Spotter
Coordinates: 43.740, -92.670

Hail, Mower

When: July 18, 1:27 PM CST
Where: Mower County, 1.7 mi SE of Racine
Measured: 0.75 in hail
Reported by: Trained Spotter
Coordinates: 43.760, -92.480

Thunderstorm Wind, Fillmore

When: July 18, 1:32 PM CST
Where: Fillmore County, 0.85 mi NE of Spring Vly
Measured: 50 kt (58 mph) estimated gust
Property damage: $13,000
Reported by: Emergency Manager
Coordinates: 43.690, -92.390

At least six trees were blown down in Spring Valley damaging a park pavilion, an apartment building and a home when a 100 year old tree landed on the roof. Some localized street flooding also occurred.

Thunderstorm Wind, Mower

When: July 18, 1:47 PM CST
Where: Mower County, 1.46 mi ENE of Lyle
Measured: 52 kt (60 mph) estimated gust
Property damage: $55,000
Reported by: Newspaper
Coordinates: 43.505, -92.942

The roof was blown off an auto repair shop in Lyle destroying a car that was parked in front of the business. Trees were blown across town with at least one of them landing on top of a house.

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Minnesota in 2012 Every state in 2012 This day in weather history Warnings in Minnesota, July 2012

Sources

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: 394261, 400416, 394262, 394263, 394264, 400172.