As a carry over from July drought conditions reached the severe level in parts of north central and northwest Wisconsin during the first week of August before rainfall impacted the area around August 7th.
Every event with a place to put it; 2 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 ARX wrote it up.
As a carry over from July drought conditions reached the severe level in parts of north central and northwest Wisconsin during the first week of August before rainfall impacted the area around August 7th.
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 31, 2:04 PM CST, 9 hours 56 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 304 PM CDT FRI JUL 31 2009 .SHORT TERM...TONIGHT THROUGH MONDAY NIGHT MAIN FORECAST CONCERNS THIS PACKAGE...SHRA/TSRA CHANCES TONIGHT INTO SAT AND AGAIN SUN NIGHT/MON. DATA ANALYSIS AT 18Z HAD LOW PRESSURED CENTERED NEAR THE SOUTH END OF LK WINNIPEG WITH A TROUGH/FRONT SOUTHWEST INTO NORTHEAST CO. WV IMAGERY DEPICTED A RATHER VIGOROUS SHORTWAVE DROPPING INTO NORTHWEST ND...WITH A BAND OF GENERALLY POST FRONTAL -RA/-SHRA ACROSS NORTHEAST ND TO NORTHWEST SD IN THE BETTER LOWER LEVEL THERMO-DYNAMIC AND PV ADVECTION AHEAD OF IT. AIRMASS AHEAD OF THE FRONT ONLY MODERATELY UNSTABLE...WITH SFC DEW POINTS IN THE 50S ACROSS MUCH OF THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST. ACROSS MN/IA/WI...850-700MB COLD POOL STILL EVIDENT WITH SCT DIURNAL CUMULUS ACROSS MUCH OF THE REGION. EARLY AFTERNOON TEMPS REMAINS SEASONABLY COOL AS WELL...MOSTLY IN THE LOW-MID 70S ACROSS MN/IA/WI. 31.12Z NAM/GFS LOOK TO HAVE INITIALIZED WITHOUT MAJOR ERRORS. PER WV IMAGERY...GFS LOOKED BETTER WITH THE SHORTWAVE DETAILS IN THE TROUGH OVER SASKAT/NORTHERN MT WHILE NAM LOOKED BETTER WITH THE UPPER LOW OFF THE BC COAST. SOLUTIONS QUITE SIMILAR AND WELL SUPPORTED BY LOCAL/REGIONAL WRF AND NON-NCEP GUIDANCE THRU 48HRS. NAM/GFS THEN DIVERGE FOR SUN INTO MON NIGHT...GFS ONE OF THE FASTER WITH THE NEXT TROUGH ACROSS THE REGION...NAM ONE OF THE STRONGER/ SLOWER...ECMWF/GFS ENSEMBLE MEAN SPLIT THE DIFFERENCE AND LOOKS LIKE A GOOD COMPROMISE. DPROG/DT OF 500MB HGTS AT 31.12Z SHOWED NAM/GFS/ ECMWF RUNS OF 29.12Z AND 30.12Z VERIFIED QUITE WELL ACROSS NOAM/ EASTERN PAC. TREND DOES FAVOR STRONGER/FASTER SOLUTIONS WITH THE TROUGH IN SOUTHERN SASKAT/NORTHERN MT WITH ECMWF OFFERING THE BETTER RUN-TO-RUN CONSISTENCY. THRU 36HRS MODELS CONVERGING ON A COMMON SOLUTION FAVORING FASTER OF THE EARLIER RUNS ON THE TROUGH PASSAGE TONIGHT/SAT. THRU 60HRS TREND FAVORS A STRONGER SHORTWAVE DROPPING INTO ND. FOR 60-84HRS MODEL CONSENSUS IS CONVERGING ON A COMMON SOLUTION FOR A STRONGER TROUGH TO REMAIN OVER THE UPPER MIDWEST ON MON. RUN-TO-RUN CONSISTENCY ON THE DETAILS AGAIN DECREASES BY 84HRS. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED NAM/GFS REASONABLE WITH THE SFC MASS FIELDS AND 12Z-18Z PRECIP ACROSS THE NORTH-CENTRAL CONUS. PER WV IMAGERY...NAM APPEARED A BIT BETTER WITH THE SHORTWAVE DETAILS IN THE UPSTREAM TROUGH OVER THE NORTHERN PLAINS. NO MODEL FAVORITE AGAIN THIS CYCLE...AND TRENDED TOWARD THE MODEL/ENSEMBLE COMPROMISE. FEW DIFFERENCES EARLY ON...BUT THIS LEADS TO FAVORING ECMWF/ENSEMBLE MEAN WITH THE NEXT SYSTEM FOR SUN NIGHT/MON. FORECAST CONFIDENCE GOOD EARLY ON...THEN BELOW AVERAGE BY MON WITH THE DIFFERENCES AMONG GFS/ECMWF/NAM SOLUTIONS. IN THE SHORT TERM...TIGHT MODEL CONSENSUS FOR SHORTWAVE TROUGH AND STRONGEST PV ADVECTION/DIVERGENCE ALOFT PUSH ACROSS THE FORECAST AREA IN THE 09Z-12Z TIME FRAME SAT MORNING. SFC TROUGH/FRONT IS NEAR A KMDZ-EAST OF KLSE-KOLZ LINE AT 12Z SAT...WITH A RATHER NARROW BAND OF PW VALUES OF 1 TO 1.25 INCHES WITH/AHEAD OF IT. STRONGER DYNAMICS WITH THE SHORTWAVE PASS NORTH OF THE FORECAST AREA...WHILE STRONGEST LOWER LEVEL MOISTURE TRANSPORT/THETA-E CONVERGENCE/INSTABILITY REMAIN SOUTH OF THE FORECAST AREA...LEAVING THE AREA WITH A WEAKENING TROUGH/FRONT AS IT PASSES AND MOST UNSTABLE CAPE VALUES OF AROUND 250 J/KG TONIGHT/SAT MORNING. MODEST 850-700MB AND 700-500MB FN CONVERGENCE PUSH ACROSS WITH THE TROUGH...AGAIN STRONGEST OVER THE WEST END THE FORECAST AREA AROUND 06Z...WEAKENING AS IT REACHES THE EAST SIDE OF THE FORECAST AREA AROUND 12Z. INCREASING INSTABILITY AHEAD OF THE FRONT TO HELP GENERATE BKN LINE OF SHRA/TSRA ALONG THE FRONT THIS AFTERNOON...AND THIS OCCURRING ACROSS ND/SD. THIS TO PUSH EAST TONIGHT...MAINTAINING SOME STRENGTH THRU ABOUT 06Z AS BETTER FN CONVERGENCE REMAINS WITH THE TROUGH...THEN GRADUALLY WEAKENS/DIMINISHES AS IT MOVES ACROSS THE FORECAST AREA OVERNIGHT/SAT MORNING. WITH VERY LIMITING INSTABILITY AND WANING FORCING...LOWERED TSRA MENTION TO ISOLATED. 60-70 PERCENT LIKELY RANGE RAIN CHANCES REASONABLY LATE TONIGHT INTO SAT MORNING. WITH THE CONTINUED FASTER PUSH OF THE FRONT/TROUGH THRU THE AREA AND STRONGER DRYING/SUBSIDENCE BEHIND IT...REMOVED RAIN CHANCES FROM MOST OF THE AREA FOR SAT AFTERNOON. COOL/DRIER AIRMASS AND WEAK RIDGE OF HIGH PRESSURE SETTLE ACROSS THE AREA FOR SAT NIGHT INTO SUN MORNING. MODELS HINTING AT SOME INCREASE OF 850-700MB MOISTURE IN THE NORTHWEST FLOW ALOFT FOR SUN AFTERNOON...MAINLY OVER THE NORTH END OF THE FORECAST AREA. THIS ALONG WITH SOME WEAK INSTABILITY AND 850-700MB WARM ADVECTION. SMALL -SHRA/TSRA CHANCE NORTH OF I-94 SUN AFTERNOON REASONABLE FOR NOW. STRONGER MOISTURE/INSTABILITY INCREASE INDICATED AHEAD OF THE NEXT SHORTWAVE TROUGH FOR SUN NIGHT/MON... ALONG WITH DECENT SHOT OF CONVERGENCE/LIFT. IF TREND OF MODEL CONSENSUS IN LATER CYCLES IS TOWARD SLOWER/STRONGER ECMWF/NAM... SHRA/TSRA CHANCES WILL HAVE TO BE INCREASED FOR SUN NIGHT/MON. GIVEN MODEL DIFFERENCES/LOWER CONFIDENCE...20-25 PERCENT RAIN CHANCE SUN NIGHT AND 30-ISH PERCENT CHANCE MON GOOD FOR NOW AND BLENDS WELL WITH NEIGHBORING GRIDS. BETTER CONSENSUS FOR DRIER HIGH PRESSURE TO BUILD IN MON NIGHT AND LEFT THIS PERIOD DRY. NUMERICAL TEMP GUIDANCE QUITE SIMILAR FOR TONIGHT THRU SUN NIGHT AND LOOK TO BE IN THE BALLPARK. USED A BLEND OF GFS MEX/ENSEMBLE MOS AND HPC GUIDANCE FOR HIGHS/LOWS MON/MON NIGHT. .LONG TERM...TUESDAY THROUGH FRIDAY 30.00Z GFS/ECMWF/CAN-GEM/UKMET IN REASONABLE AGREEMENT WITH EACH OTHER AND THEIR PREVIOUS RUNS ON THE LONG-WAVE FEATURES ACROSS NOAM/ EASTERN PAC ON TUE. THIS DOES NOT LAST AS BOTH BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY ALREADY STARTS TO DEGRADE BY WED...WITH SIGNIFICANT DIFFERENCES BETWEEN GFS/ECMWF AND THEIR PREVIOUS RUNS BY FRI...ECMWF MUCH LESS PROGRESSIVE THAN GFS WITH THE EASTERN NOAM LONG-WAVE REMAINING OVER OR WEST OF THE AREA. GFS/ECMWF ENSEMBLE MEANS SIDE WITH THE MORE PROGRESSIVE GFS BY LATE NEXT WEEK. OVERALL TREND IS LESS PROGRESSIVE WITH THE ENTIRE PATTERN AND WESTERN NOAM UPPER RIDGE BREAKDOWN THAN RUNS OF A DAY OR 2 AGO. GIVEN THIS... LONG-TERM FORECAST CONFIDENCE AVERAGE ON TUE...TAILING OFF TO LOW BY THU/FRI. WITH ECMWF APPEARING AS THE OUTLIER THIS CYCLE...FAVORED THE MORE TIGHTLY CLUSTERED GFS AND GFS/ECMWF ENSEMBLE GROUP OF MODELS. FRONT/TROUGH FROM MON SHOULD BE WELL SOUTH OF THE AREA BY TUE WITH CANADIAN HIGH PRESSURE BUILDING INTO THE REGION. WITH THE OVERALL SLOWER EVOLUTION/PROGRESSION OF THE PATTERN...NEXT STRONGER PIECE OF ENERGY DROPPING INTO THE EASTERN NOAM TROUGH MORE CENTERED ON WED NIGHT/THU. TRENDED SHRA/TSRA CHANCE DOWN ON WED AND ADDED A CHANCE TO THU. PRESENT TIMING WOULD BUILD ANOTHER CANADIAN HIGH SOUTH INTO THE REGION FOR FRI AND LEFT THIS PERIOD DRY. AGAIN CONFIDENCE IN THE DETAILS BY THU/FRI QUITE LIMITED. GFS MEX/ENSEMBLE MOS AND HPC GUIDANCE ALL QUITE SIMILAR FOR TUE-FRI AND LOOK GOOD FOR NOW. && .AVIATION...TONIGHT AND SATURDAY FOCUS FOR AVIATION WITH COLD FRONTAL PASSAGE LATE TONIGHT/SATURDAY MORNING AT THE TAF SITES AND ASSOCIATED WEATHER IMPACTS. SHOULD SEE DIURNAL CUMULUS FIELD DISSIPATE THIS EVENING BUT THEN BE REPLACED BY THICKENING CIRRUS/MID CLOUD AS THE NIGHT WEARS ON. AS COLD FRONT APPROACHES...BOUNDARY LAYER MIXING SHOULD REMAIN DESPITE ONSET OF DARKNESS...SO KEPT WINDS UP OUT OF SLY/SWLY DIRECTION. STILL SOME CONCERN FOR LOW LEVEL WIND SHEAR MAINLY OVERNIGHT AS THE FRONT APPROACHES AND LOW LEVEL JET INCREASES. CONDITIONS KIND OF MARGINAL WITH RATHER UNIDIRECTIONAL FLOW FROM SFC-2KFT...THOUGH SPEED SHEAR DOES PUSH VALUES CLOSE TO LLWS CRITERIA. IF IT OCCURS...WILL BE FOCUSED AROUND 06Z-09Z RIGHT AHEAD OF THE COLD FRONT...AND WOULD ESPECIALLY AFFECT KLSE SINCE WINDS ON THE VALLEY FLOOR LIKELY TO BE LIGHTER AND MORE LOCALLY BACKED /TO THE SOUTH/ VERSUS KRST WHICH WILL BE STRONGER AT THE SFC AND MORE FROM THE SOUTHWEST. MAY WAIT FOR MORE RAPID UPDATE/SHORT TERM GUIDANCE /RUC/ FOR ITS HANDLING OF THIS TIMEFRAME BEFORE TAF INCLUSION. OTHERWISE...SHOULD SEE BAND OF VFR/OCCASIONALLY MVFR SHOWERS WORK FROM WEST TO EAST ACROSS THE TAF SITES OVERNIGHT...LOSING INTENSITY AS THEY WORK EAST OF THE MISSISSIPPI RIVER. HINTS IN LAMP DATASETS AND BUFR SOUNDINGS OF A PERIOD OF MVFR CIGS FOR A FEW HOURS AFTER RAIN ENDS...BUT SURGE OF VERY DRY AIR SATURDAY LATE MORNING/EARLY AFTERNOON SHOULD ERODE THIS QUICKLY. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && SHORT/LONG TERM...RRS AVIATION..........BINAU
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LA CROSSE WI 532 AM CDT FRI JUL 31 2009 IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034- 041>044-053>055-061-011100- 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- 532 AM CDT FRI JUL 31 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST INTO CENTRAL WISCONSIN. .DAY ONE...TODAY AND TONIGHT A CANADIAN COLD FRONT WILL PRODUCE THUNDERSTORMS AS IT MOVES SOUTHEAST THROUGH THE REGION LATE THIS EVENING AND OVERNIGHT. NONE OF THESE THUNDERSTORMS ARE EXPECTED TO BECOME SEVERE. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THUNDERSTORMS ARE POSSIBLE FROM SATURDAY THROUGH MONDAY...AND FROM WEDNESDAY INTO WEDNESDAY NIGHT. AT THIS TIME...NONE OF THESE THUNDERSTORMS ARE EXPECTED TO BECOME SEVERE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED. .EMERGENCY MANAGEMENT COORDINATION... NO CALL IS SCHEDULED. BOYNE
The national radar mosaic for the moment the first event began.
2 drought. Local standard time, as filed.
Dry summer weather continued into early August.
Dry summer weather continued into early August.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2009Every state in 2009This day in weather historyWarnings in Wisconsin, August 2009
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: 188795, 188796.