A warm frontal boundary was the catalyst for isolated severe weather over Central Minnesota.
Every event with a place to put it. 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 warm frontal boundary was the catalyst for isolated severe weather over Central Minnesota.
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 Sep 17, 6:11 PM CST, 2 hours 19 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 711 PM CDT MON SEP 17 2007 .UPDATE...ADDED AVIATION DISCUSSION FOR 00Z TAFS && .AVIATION.../FOR 00Z TAFS/ WEATHER TO BECOME MORE ACTIVE OVER THE NEXT SEVERAL HOURS. FOCUS WARM FRONT EXTENDS FROM APPROX KAXN-KFCM-KRGK. ITS PROGRESS HAS SLOWED IN THE PAST HOUR OR SO AND IT APPEARS TO HAVE SLIPPED SLIGHTLY SOUTHWESTWARD. THIS HAS ALLOWED WINDS IN THE KMSP AREA TO RETURN TO A 130-150 DIRECTION. THIS WILL PROBABLY CONTINUE TO BE THE CASE FOR A FEW HOURS BEFORE WINDS BECOME MORE SOUTHERLY. MAIN CONCERN WITH THIS ISSUANCE IS THUNDERSTORM TIMING AND COVERAGE. STARTING TO SEE SOME ISOLATED ACTIVITY ACROSS WEST CENTRAL MN AND INTO SOUTHEAST SODAK WHICH IS RAPIDLY MOVING NORTHEAST. SATELLITE SHOWS CU FIELD HAS INCREASED LAST HOUR OR 2. KRWF AND KAXN AT RISK FROM THE START WITH KSTC ON THE EASTERN FRINGE BUT ACTIVITY WILL LIKELY REMAIN SCATTERED FOR THE NEXT HOUR OR 2...BEFORE CHANCES OF MORE WIDESPREAD DEVELOPMENT INCREASE /APPROX BETWEEN 01-03Z/. ONCE STORMS BECOME BETTER ORGANIZED STRONG WIND GUSTS AND HAIL WILL BE A POSSIBILITY AND HEAVY DOWNPOURS WILL CUT VISIBILITY SIGNIFICANTLY. EXPECT A LINE OF STORMS TO BE GOING BY LATE EVENING ACROSS WEST CENTRAL MINNESOTA. EASTWARD PROGRESS OF THE LINE LOOKS TO BE SOMEWHAT SLOW. TIMING THE ACTIVITY INTO KMSP AND KRNH TROUBLESOME BUT EXPECT IT WILL BE TOWARDS MIDNIGHT. THE HAIL AND WIND THREAT WILL CONTINUE AND MAY HAVE INCREASED BY THIS TIME. OTHER CONCERN IS LOW LEVEL WIND SHEAR OUTSIDE OF STORMS. LOW LEVEL JET INCREASES TO NEAR 50 KTS AT 2 KFT...ESPECIALLY OVER KRWF/KMSP/KRNH AND THEN KEAU LATER ON. COLD FRONT TAKES IT/S TIME MOVING ACROSS THE AREA TUESDAY. WITH VERY MOIST AIR CONTINUING TO MOVE INTO THE AREA PERIODS OF RAIN ARE EXPECTED FROM EARLY MORNING THROUGH . LOW CIGS AND REDUCED VIS ALSO LIKELY. ..MDB.. && .PREV DISCUSSION... /ISSUED 342 PM CDT MON SEP 17 2007/ DISCUSSION... WARM FRONT HAS SURGED TO NEAR A KAQP-KSYN LINE AS OF 20Z...WITH MOST OF ELEVATED CONVECTION CONTINUING TO PUSH NORTH. STILL LOTS OF SBCIN IN PLACE OVER SOUTH CENTRAL MN BUT WEAKENING...THOUGH THE WEAKENING IS WELL SOUTH OF THE WARM FRONT. RUC TRENDS SUGGEST THAT THE STRONG THETA E ADVECTION WILL CONTINUE TO PUSH NORTH THIS EVENING...AND THE TREND OF LESS STEEP MID LEVEL LAPSE RATES THAT HAS BEEN IN THE MODELS SINCE YESTERDAY..WILL BE SPREADING OVER THE CWA AT LEAST FOR THIS EVENING. CHANCE OF SVR THIS EVENING STILL POSSIBLE NORTH OF KNCB TO KSTC BUT CAP IS STILL STRONG IN THAT AREA. LOW LEVEL JET STILL CRANKS UP LATER TONIGHT AND CHANCE OF SEVERE WILL PROBABLY INCREASE FROM SW INTO CENTRAL MN ALONG THE MID LEVEL INSTABILITY AXIS AND IN AREA OF THICKNESS DIFLUENCE IN SAME AREA. WIDESPREAD SHOWERS AND THUNDERSTORMS STILL LIKELY ON TUESDAY AS SHORT WAVE APPROACHES ALONG WITH STRONG 850 MB MOISTURE TRANSPORT...ESPECIALLY OVER EASTERN CWA IN THE AFTERNOON. NEXT CHANCE OF STORMS WITH RETURNING WARM FRONT LATER THURSDAY INTO FRIDAY BUT BEST SURGE OF INSTABILITY AIMED AT NORTHERN MN. BASED ON TODAYS HOT PROD...HAVE RAISED TEMPS IN SOUTHERN MN FOR FRIDAY AHEAD OF SLOWING COLD FRONT. WILL GO WITH MID 80S FOR NOW BUT THAT MAY NOT BE WARM ENOUGH. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && MDB/JPR
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 135 PM CDT MON SEP 17 2007 MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028- 181200- DOUGLAS-TODD-MORRISON-MILLE LACS-KANABEC-STEVENS-POPE-STEARNS- BENTON-SHERBURNE-ISANTI-CHISAGO-LAC QUI PARLE-SWIFT-CHIPPEWA- KANDIYOHI-MEEKER-WRIGHT-HENNEPIN-ANOKA-RAMSEY-WASHINGTON- YELLOW MEDICINE-RENVILLE-MCLEOD-SIBLEY-CARVER-SCOTT-DAKOTA- REDWOOD-BROWN-NICOLLET-LE SUEUR-RICE-GOODHUE-WATONWAN-BLUE EARTH- WASECA-STEELE-MARTIN-FARIBAULT-FREEBORN-POLK-BARRON-RUSK- ST. CROIX-PIERCE-DUNN-PEPIN-EAU CLAIRE- 135 PM CDT MON SEP 17 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND SOUTH CENTRAL MINNESOTA...AND WEST CENTRAL WISCONSIN. .DAY ONE...THIS AFTERNOON AND TONIGHT A WARM FRONT WILL CONTINUE TO LIFT NORTH ACROSS CENTRAL MINNESOTA THIS EVENING. VERY MOIST AND UNSTABLE AIR WILL FLOW OVER THE REGION. AS A RESULT...THUNDERSTORMS WILL BE ON THE INCREASE OVER THE OUTLOOK AREA. A FEW STORMS COULD BECOME SEVERE OVER CENTRAL MINNESOTA INTO WEST CENTRAL WISCONSIN...THIS AFTERNOON AND OVERNIGHT ...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREAT. THERE STILL EXISTS A CHANCE FOR AN ISOLATED TORNADO NEAR THE WARM FRONT LATE THIS AFTERNOON AND THIS EVENING. AT THIS TIME...THE BEST LOCATION FOR A STORM THAT COULD PRODUCE A TORNADO WOULD BE OVER WEST CENTRAL MINNESOTA...NORTH OF A LINE FROM BENSON TO ST CLOUD. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THE THREAT FOR SEVERE THUNDERSTORMS...WITH LARGE HAIL AND DAMAGING WINDS...WILL CONTINUE OVER EAST CENTRAL AND SOUTH CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN ON TUESDAY AND TUESDAY NIGHT AS A COLD FRONT MOVES SLOWLY EASTWARD ACROSS THE AREA. IN ADDITION...PERIODS OF HEAVY RAIN WILL BE POSSIBLE ON TUESDAY OVER THIS SAME AREA...WHICH MAY LEAD TO FLOODING OF POOR DRAINAGE AREAS AS WELL AS LOWLAND AREAS. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION MAY BE NEEDED LATER THIS AFTERNOON AND TONIGHT AND AGAIN TUESDAY.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 824 PM CDT MON SEP 17 2007 MNZ043-180230- MORRISON- 824 PM CDT MON SEP 17 2007 ...SIGNIFICANT WEATHER ALERT FOR MORRISON COUNTIES UNTIL 930 PM CDT... AT 820 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 8 MILES SOUTHWEST OF LITTLE FALLS...OR 19 MILES NORTH OF ALBANY...AND MOVING NORTHEAST AT 40 MPH. ONE HALF INCH DIAMETER HAIL IS EXPECTED WITH THIS STORM. PEOPLE IN MORRISON COUNTY...SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 859 PM CDT MON SEP 17 2007 MNZ056-064-180300- CHIPPEWA-YELLOW MEDICINE- 859 PM CDT MON SEP 17 2007 ...SIGNIFICANT WEATHER ALERT FOR CHIPPEWA AND YELLOW MEDICINE COUNTIES UNTIL 1000 PM CDT... AT 858 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 8 MILES WEST OF GRANITE FALLS...OR 15 MILES NORTH OF COTTONWOOD...AND MOVING NORTHEAST AT 40 MPH. ONE HALF INCH DIAMETER HAIL...AND WINDS AROUND 50 MPH ARE EXPECTED WITH THIS STORM. CLARA CITY AND MONTEVIDEO ARE IN THE PATH OF THIS STORM. PEOPLE IN EASTERN CHIPPEWA AND NORTHERN YELLOW MEDICINE COUNTIES...SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN.
The Minneapolis radar (KMPX), 132 km away, was scanning. The volume nearest the first event began at 02:28 UTC.
1 thunderstorm wind. Local standard time, as filed.
Damage occurred near and at Upsala High School. Roof vent blown off, power outage, 12 by 4 foot plexiglass sheet ripped off greenhouse. Metal gate pulled loose. Multiple trees were downed across from Upsala High School, one of which had a diameter of 20-24 inches.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2007Every state in 2007This day in weather historyWarnings in Minnesota, September 2007
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: 59657.