A cold front moved slowly eastward over southeast Minnesota during the late evening hours of September 30th. Thunderstorms developed along and ahead of the front, producing rainfall amounts of 3 to 5 inches in about two hours.
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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 ARX wrote it up.
A cold front moved slowly eastward over southeast Minnesota during the late evening hours of September 30th. Thunderstorms developed along and ahead of the front, producing rainfall amounts of 3 to 5 inches in about two hours. Law enforcement officials reported localized flash flooding across the northern part of Dodge County.
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 Sep 30, 2:11 PM CST, 7 hours 29 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 311 PM CDT SUN SEP 30 2007 .SHORT TERM...THROUGH TUESDAY NIGHT MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD. SURFACE ANALYSIS THIS AFTERNOON SHOWS AN AREA OF LOW PRESSURE OVER EASTERN NEBRASKA NEAR KOLU. LOCAL AND REGIONAL RADARS SHOWING SOME ACTIVITY OVER THE NORTHERN PART OF THE FORECAST AREA WITH OTHER ACTIVITY CLOSER TO THE LOW AND COLD FRONT. STILL LOOKING AT A POTENT STORM SYSTEM JUST WEST OF THE AREA TO IMPACT THE REGION TONIGHT. THE TRACK OF THE WHOLE SYSTEM IS NOW A LITTLE FARTHER SOUTH THAN PREVIOUS MODEL RUNS. HOWEVER...WILL STILL SEE SIGNIFICANT FORCING TO GENERATE WIDESPREAD RAIN TONIGHT...BUT SEVERE THREAT MAY BE PUSHED SOUTH AND LIMITED TO A VERY NARROW TIME WINDOW BEFORE THE INSTABILITY WANES. AS FOR THE FORCING...BETWEEN 24 AND 30 PVU/S OF VORTICITY ADVECTION IS EXPECTED THIS EVENING FROM THE SHORT WAVE TROUGH IN THE 500 TO 300 MB LAYER. GOOD DIVERGENCE ALOFT EXPECTED ON THE NORTH SIDE OF THE UPPER LEVEL LOW AND IN THE LEFT EXIT REGION OF THE 300 MB JET. ALSO...STILL EXPECT MODERATE TO STRONG LOW LEVEL FRONTOGENESIS AND FN VECTOR CONVERGENCE ALONG THE FRONT AS IT COME THROUGH. THE GFS STILL SHOWS UP TO 500 J/KG OF ML CAPE AVAILABLE THIS EVENING FROM ABOUT INTERSTATE 90 AND SOUTH. WITH THE FARTHER SOUTH TRACK OF THE SYSTEM...TORNADO THREAT LOOKS TO BE PRETTY MINIMAL BUT STILL SUFFICIENT SHEAR TO SUPPORT DAMAGING WINDS. WITH THE SOMEWHAT SLOWER ARRIVAL OF THE SYSTEM AND THE MORE SOUTHWARD TRACK...EXPECT TO SEE MORE RAIN OVER THE AREA AFTER MIDNIGHT IN THE DEFORMATION ZONE AND GENERALLY RAISED POPS FOR MUCH OF THE AREA. THIS ALSO CARRIES OVER INTO MONDAY MORNING AND BROUGHT SOME LOW END POPS BACK AS FAR WEST AS THE MISSISSIPPI RIVER. AFTER MONDAY MORNING...A SHORT PERIOD OF SHORT WAVE RIDGING WILL BE OVER THE AREA BEFORE THE NEXT FAST MOVING SYSTEM STARTS TO APPROACH LATE MONDAY NIGHT. MODELS HAVE TRENDED LESS AMPLIFIED WITH THIS SYSTEM WHICH LEADS TO A QUICKER ARRIVAL. A NARROW BAND OF 20 TO 25 PVU/S OF VORTICITY ADVECTION EXPECTED TO COME ACROSS DURING THE DAY TUESDAY. SINCE THE SYSTEM IS LESS AMPLIFIED...DIVERGENCE ALOFT IS NOT NEARLY AS IMPRESSIVE AS WITH THE SYSTEM FOR TONIGHT BUT SHOULD STILL SEE SOME FROM THE RIGHT ENTRANCE REGION OF THE 300 MB JET. HOWEVER...LOW LEVEL FRONTOGENESIS AND FN VECTOR CONVERGENCE IS ONLY WEAK WITH SOME STRENGTHENING EXPECTED DURING THE AFTERNOON OVER THE FAR EAST. MAIN ADJUSTMENTS TO THE PREVIOUS FORECAST WAS SPEED UP THE TIMING OF THE SYSTEM FOR TUESDAY AFTERNOON AND EVENING. THIS LEADS TO HAVING LIKELY POPS FOR THE ENTIRE AREA DURING THE AFTERNOON AND THEN GOING DOWN TO CHANCE FOR THE EVENING WITH ONLY SOME LOW END CHANCE POPS AFTER MIDNIGHT TUESDAY ACROSS THE FAR EAST. SEVERE THREAT WITH THIS SYSTEM LOOKS PRETTY MINIMAL AS THE GFS SHOWS NO SURFACE BASED CAPE BUT THERE MAY BE AROUND 250 J/KG OF ELEVATED CAPE ABOVE 1 KM. .LONG TERM...WEDNESDAY THROUGH SUNDAY MEDIUM RANGE MODELS IN VERY GOOD AGREEMENT TODAY. UPPER AIR PATTERN EXPECTED TO START OUT ZONAL BUT GRADUALLY TRANSITION TO A SOUTHWEST FLOW AHEAD OF A LONG WAVE TROUGH. THIS SYSTEM IS THEN EXPECTED TO CROSS THE CENTRAL PART OF THE COUNTRY NEXT WEEKEND DRIVING A COLD FRONT ACROSS THE AREA. AS THE FLOW TRANSITIONS...BOTH THE ECMWF AND GFS SHOW A GOOD LOW LEVEL WARM AIR ADVECTION REGIME SETTING UP OVER THE AREA THURSDAY NIGHT. THE BEST MOISTURE TRANSPORT LOOKS TO BE INTO MINNESOTA CATCHING THE WESTERN PARTS OF THE FORECAST AREA. BASED ON THIS...WILL ADD SOME POPS IN FOR THURSDAY NIGHT AND CARRY THESE INTO FRIDAY TO CATCH THE LINGERING ACTIVITY AS IT TRANSITIONS OUT OF THE REGION. THE BEST CHANCE FOR RAIN CURRENTLY LOOKS TO BE SATURDAY AND SATURDAY NIGHT AS THE LONG WAVE TROUGH AND COLD FRONT WORK ACROSS THE AREA. ONLY REAL TEMPERATURE ADJUSTMENTS WERE TO START RAISING VALUES AHEAD OF THE COLD FRONT FROM THURSDAY INTO SATURDAY. && .AVIATION... THUNDERSTORMS AND ASSOCIATED THREATS /CONVECTIVE WINDS AND POTENTIAL HAIL AS WELL AS IFR VSBYS IN +RA/ WILL AFFECT THE KRST/KLSE TAF SITES THROUGH THE EARLY EVENING HOURS BEFORE LOSS OF INSTABILITY TRANSITIONS THREATS OVER TO MVFR VISIBILITIES IN MODERATE RAIN AS LOW PRESSURE CROSSES NORTHERN IOWA INTO WISCONSIN TONIGHT. EXPECT A HIGH COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS THE SITES FROM MID AFTERNOON THROUGH EARLY EVENING...BEFORE ACTIVITY BECOMES MORE SCATTERED AFTER 03Z OR SO. AS COLD FRONT SHIFTS THROUGH THE SITES FROM 04Z-06Z...EXPECT SFC WINDS TO TURN NWLY WITH POTENTIAL FOR MVFR OR EVEN IFR CEILINGS IN STRATOCUMULUS FIELD WITH THE ARRIVAL OF THE COOLER AIR. THIS WOULD BE EXPECTED TO IMPACT SITES IN THE 06Z-14Z TIMEFRAME BEFORE DRIER AIR AND INCREASED MIXING BEGINS TO BREAK THE LOW CEILINGS ON MONDAY MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && SHORT/LONG TERM...04 AVIATION...BINAU
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LA CROSSE WI 153 PM CDT SUN SEP 30 2007 IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034- 041>044-053>055-061-011000- ADAMS-ALLAMAKEE-BUFFALO-CHICKASAW-CLARK-CLAYTON-CRAWFORD-DODGE- FAYETTE-FILLMORE-FLOYD-GRANT-HOUSTON-HOWARD-JACKSON-JUNEAU-LA CROSSE- MITCHELL-MONROE-MOWER-OLMSTED-RICHLAND-TAYLOR-TREMPEALEAU-VERNON- WABASHA-WINNESHIEK-WINONA- 153 PM CDT SUN SEP 30 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST IOWA... SOUTHEAST MINNESOTA...AND SOUTHWEST INTO CENTRAL WISCONSIN. .DAY ONE...THIS AFTERNOON AND TONIGHT SEVERE THUNDERSTORMS WILL BE POSSIBLE BETWEEN 5 PM AND 9 PM OVER PORTIONS OF THE AREA AS A STRONG WEATHER SYSTEM ALOFT AND SURFACE LOW PRESSURE MOVE THROUGH IOWA. ONGOING THUNDERSTORMS IN SOUTHEAST MINNESOTA ARE NOT EXPECTED TO BE SEVERE THROUGH THE MIDDLE AFTERNOON HOURS. THE GREATEST POTENTIAL FOR SEVERE WEATHER WILL REMAIN WEST OF THE MISSISSIPPI RIVER...IN THE LATE AFTERNOON AND EARLY EVENING HOURS. WHILE A SEVERE STORM OR TWO MAY CROSS OVER THE MISSISSIPPI RIVER THIS EVENING...STORMS WILL GRADUALLY WEAKEN AFTER SUNSET AND THE STORMS PRESS FURTHER INTO WISCONSIN. THE MAIN THREATS FROM THESE STORMS...SHOULD THEY BECOME SEVERE...WILL BE HAIL TO THE SIZE OF NICKELS AND WIND GUSTS TO 65 MPH. HOWEVER...CONDITIONS MAY COME TOGETHER OVER PORTIONS OF NORTHEAST IOWA AND EXTREME SOUTHEAST MINNESOTA TO SUPPORT THE DEVELOPMENT OF A FEW TORNADOES. THE TORNADO THREAT IS OF A MUCH LOWER PROBABILITY THAN LARGE HAIL OR DAMAGING WINDS...BUT REMAINS POSSIBLE NONETHELESS. IN ADDITION...SOME LOCATIONS MAY PICK UP A QUICK 1 TO 2 INCHES OF RAINFALL THROUGH THE AFTERNOON AND EVENING. THIS MAY LEAD TO PONDING IN LOW LYING AREAS...AND ALSO IN URBANIZED AND POOR DRAINAGE AREAS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY ANOTHER STRONG LOW PRESSURE SYSTEM WILL PROVIDE A CHANCE OF THUNDERSTORMS ON TUESDAY AND TUESDAY NIGHT. A FEW OF THESE THUNDERSTORMS MAY BECOME SEVERE ON TUESDAY AFTERNOON AND EVENING. AT THIS TIME...DAMAGING WINDS AND LARGE HAIL LOOK TO BE THE MAIN SEVERE WEATHER THREATS. ADDITIONAL THUNDERSTORM CHANCES WILL BE FOUND FROM FRIDAY THROUGH SATURDAY AS YET ANOTHER LOW PRESSURE SYSTEM MOVES THROUGH THE REGION. IT IS STILL TOO EARLY TO DISCERN THE SEVERE THUNDERSTORM POTENTIAL FOR THIS TIME PERIOD. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BECOME NECESSARY...ESPECIALLY ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA...BETWEEN 5 AND 9 PM. GROUPS IN WISCONSIN WILL WANT TO MONITOR UPSTREAM THUNDERSTORM ACTIVITY AND BE PREPARED TO DEPLOY IF STORMS REMAIN SEVERE INTO THE EVENING HOURS. IN ADDITION...THERE MAY BE ANOTHER NEED FOR SPOTTER ACTIVATION ACROSS THE ENTIRE AREA ON TUESDAY AFTERNOON AND EVENING. .EMERGENCY MANAGEMENT COORDINATION... NO CALL IS SCHEDULED. BOYNE/BINAU
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
702 PM CDT SUN SEP 30 2007
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0650 PM TSTM WND DMG MONONA 43.05N 91.39W
09/30/2007 CLAYTON IA LAW ENFORCEMENT
LARGE TREES AND SOME POWERLINES DOWN. POWER OUT.
&&
BINAUThe Minneapolis radar (KMPX), 91 km away, was scanning. The volume nearest the first event began at 03:40 UTC.
1 flash flood. Local standard time, as filed.
Heavy rainfall caused flooding over County Roads 24, 5, and 1. Cars stalled in flood waters and local fire department personnel had to evacuate people from nearby homes and farm, in addition to the rescue of stranded motorists.
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: 56129.