Very dry conditions during the first half of April 2009, combined with low relative humidities and strong winds, led to favored days of above normal and dangerous fire weather behavior. This led to several wild fires across western Wisconsin.
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.
Very dry conditions during the first half of April 2009, combined with low relative humidities and strong winds, led to favored days of above normal and dangerous fire weather behavior. This led to several wild fires across western Wisconsin.
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 Apr 10, 1:18 PM CST, 12 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 218 PM CDT FRI APR 10 2009 .SHORT TERM...TONIGHT THROUGH MONDAY MAIN FOCUS REVOLVES AROUND DRY AIRMASS INTO THE WEEKEND AND HEIGHTENED FIRE WEATHER CONCERNS. SEE SPECIAL FIRE WEATHER DISCUSSION BELOW. THERE MAY BE SOME RELIEF WITH RAIN CHANCES MONDAY. LATEST WATER VAPOR IMAGERY SHOWING INTENSE MID LEVEL LOW CHURNING EAST ACROSS SOUTHERN IL AT THIS TIME WITH STRONG CONVECTION TAKING PLACE EAST AHEAD OF IT. ANOTHER MUCH WEAKER CIRCULATION WAS LOCATED OVER THE NEBRASKA PANHANDLE. THESE TWO SYSTEMS JUST PRODUCING SOME SCATTERED-BROKEN CIRRUS MAINLY ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA. MEANWHILE...AT THE SURFACE...PRESSURE GRADIENT ACROSS THE AREA BETWEEN THE LOW OVER SOUTHERN IL AND STRONG HIGH PRESSURE MOVING INTO WESTERN ONTARIO WAS PRODUCING A NORTH/NORTHEAST FLOW ACROSS THE AREA. GOOD MIXING THROUGH 5-6KFT/SUBSIDENCE WAS AGAIN PRODUCING A MODERATE DOWNWARD TREND IN DEW POINTS AND RELATIVE HUMIDITIES. TEMPERATURES ACROSS THE AREA AT 2 PM WERE IN THE MID 40S TO LOWER 50S. THE 10.12Z NAM AND GFS ARE IN REASONABLE AGREEMENT THROUGH THE SHORT TERM. THERE IS A SMALL DIFFERENCE WITH THE TRACK OF A CLOSED LOW AFFECTING THE AREA BY MONDAY. LOOKING AT THE ECMWF/NAM/SREF...THE GFS SEEMS TO BE A BIT OF AN OUTLIER AS FAR AS THE NORTHWARD EXTENT OF RAIN. MORE ON THIS LATER. FOR TONIGHT...AS THE CLOSED LOW TO THE SOUTH MOVES FURTHER EAST INTO THE OHIO RIVER VALLEY...HIGH PRESSURE BECOMES CENTERED OVER HUDSON/S BAY WITH SOUTHERN PORTIONS OF THE RIDGE BUILDING INTO THE AREA. SO...EXPECT SKIES TO BECOME CLEAR EARLY ON WITH TEMPERATURES COLLAPSING RATHER QUICKLY. OVERNIGHT LOWS WILL BOTTOM OUT IN THE 20S ACROSS THE AREA WITH CLEAR SKIES/LIGHT WINDS AND DRY AIRMASS. THE HUDSON/S BAY HIGH WILL BE THE DOMINANT WEATHER FEATURE OF INFLUENCE THROUGH SUNDAY ACROSS THE AREA...PRODUCING DRY AND MOSTLY SUNNY/CLEAR CONDITIONS. HIGHS ON SATURDAY/SUNDAY WILL TOP OFF WELL INTO THE 50S. AS THE HIGH MOVES FROM HUDSON/S BAY INTO THE GREAT LAKES REGION ON SUNDAY...A FEW MORE HIGH CLOUDS WILL BEGIN FILTERING INTO THE AREA AHEAD OF LOW PRESSURE MOVING THROUGH THE ROCKIES. SPLIT FLOW REGIME BRINGS A CLOSED LOW FROM THE SOUTHERN PLAINS INTO SOUTHERN MO BY LATE MONDAY AFTERNOON. AS ALLUDED TO IN THE MODEL DISCUSSION ABOVE...THE NAM/WRF AS WELL AS THE ECMWF KEEP PRECIPITATION BAND ASSOCIATED WITH THIS WRAPPED-UP/CLOSED LOW CONFINED ACROSS THE EXTREME SOUTHERN PORTION OF THE FORECAST AREA WHILE THE GFS BROAD BRUSHES QPF UP TO THE I-90 CORRIDOR. WITH THE AMOUNT OF DRY AIR IN PLACE...WILL TAKE A LOT TO SATURATE THE COLUMN THAT FAR NORTH. WILL COMPROMISE AND CARRY CHANCY POPS ALONG I-90 WITH A GRADIENT TOWARD LIKELY POPS ACROSS THE FAR SOUTH. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY LATEST GFS/ECMWF CONTINUE TO SHOW AN ACTIVE FLOW PATTERN ACROSS THE CONUS THROUGH THE PERIOD. QUESTION IS WHERE EXACTLY CLOSED LOWS WILL TRACK WITHIN THIS FLOW. AS FAR AS MODEL TRENDS GO...HAVE TO GIVE THE NOD TO THE ECMWF AS IT SEEMS TO BE REFLECTING WHAT HAS BEEN THE TREND OVER THE LAST. BACK EDGE OF CLOSED LOW AND ASSOCIATED DEFORMATION RAIN APPEARS TO SCRAPE MAINLY ACROSS SOUTHERN/EASTERN PORTIONS OF THE AREA MONDAY NIGHT THROUGH TUESDAY. THE PERIOD WEDNESDAY THROUGH FRIDAY APPEARS LIKE IT WILL BE MAINLY DRY ACROSS THE AREA AS WE BECOME SANDWICHED BETWEEN HUDSON/S BAY HIGH AND ANOTHER CLOSED LOW MOVING FROM THE CENTRAL/SOUTHERN PLAINS INTO THE OHIO RIVER VALLEY REGION. DID INCLUDE A SMALL POP MAINLY SOUTH OF I-90 AS THIS AREA WILL BE ON VERY NORTHERN FRINGES OF THE PRECIPITATION BAND ASSOCIATED WITH THE LOW. WOULD NOT DOUBT WE TREND TOWARD DRIER FORECAST EVENTUALLY GIVEN THE RECENT TRENDS WITH DRY FLOW FROM HUDSON/S BAY. TIME WILL TELL. OTHERWISE...TEMPERATURES ARE EXPECTED HOVER RIGHT AROUND NORMAL SEASONAL VALUES THROUGH THE PERIOD. && .AVIATION...TONIGHT THROUGH SUNDAY HIGH PRESSURE...JUST SOUTH OF HUDSON BAY...WILL CONTINUE TO PROVIDE VFR CONDITIONS THROUGH SUNDAY. THE GUSTY NORTHEAST WINDS THIS AFTERNOON WILL QUICKLY SUBSIDE TONIGHT..AND REMAIN LIGHT NORTHEAST AND EAST WINDS ON SATURDAY AND SATURDAY NIGHT. AS THE SURFACE PRESSURE GRADIENT TIGHTENS ON SUNDAY...THE SOUTHEAST WINDS WILL GRADUALLY CLIMB INTO THE 10 TO 15 KNOT RANGE. && .FIRE WEATHER...TODAY THRU SUNDAY FIRE WEATHER WILL REMAIN CRITICAL THROUGH THE WEEKEND AS HUDSON/S BAY HIGH DOMINATES THE UPPER MISSISSIPPI RIVER VALLEY/GREAT LAKES REGION. DAYTIME MIXING IN THE LOWEST 5000-7000FT OF THE ATMOSPHERE WILL ALLOW EXTREMELY DRY AIR ALOFT TO FILTER TO THE SURFACE. THIS WILL PRODUCE DANGEROUSLY LOW MINIMUM RELATIVE HUMIDITY LEVELS IN THE 15 TO 25 PERCENT RANGE...ESPECIALLY IN ACROSS CENTRAL AND WESTERN WISCONSIN. THIS WILL ALSO CONTINUE TO DRY ALREADY CRITICALLY DRY FINE FUELS. SEE THE LATEST FIRE WEATHER PLANNING FORECAST FOR MORE DETAILS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && SHORT/LONG TERM...DAS AVIATION..........BOYNE FIRE WEATHER......DAS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LA CROSSE WI 430 AM CDT FRI APR 10 2009 IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034- 041>044-053>055-061-111100- 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- 430 AM CDT FRI APR 10 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF NORTHEAST IOWA... SOUTHEAST MINNESOTA AND SOUTHWEST INTO CENTRAL WISCONSIN. .DAY ONE...TODAY AND TONIGHT HIGH PRESSURE TO THE NORTH OF THE AREA WILL RESULT IN A DRY NORTHEASTERLY FLOW TODAY. MINIMUM HUMIDITIES OF 15 TO 25 PERCENT THIS AFTERNOON WILL LEAD TO INCREASED FIRE DANGER. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY HIGH PRESSURE SITUATED NEAR HUDSON BAY DURING THE WEEKEND SHOULD CONTINUE A DRY EASTERLY FLOW. MINIMUM HUMIDITIES OF 15 TO 25 PERCENT SATURDAY AND SUNDAY AFTERNOON WILL CONTINUE AN INCREASED FIRE DANGER. .SPOTTER INFORMATION STATEMENT... DUE TO INCREASED FIRE DANGER THROUGH THE WEEKEND...AWARENESS SHOULD BE HEIGHTENED FOR ANY UNUSUAL FIRE ACTIVITY. .EMERGENCY MANAGEMENT COORDINATION... NO CALL IS SCHEDULED. THOMPSON
The national radar mosaic for the moment the first event began.
2 wildfire. Local standard time, as filed.
A grass fire quickly became out of control in the Town of Shelby destroying several vehicles and burning 10 acres of farm fields, grass and woodlands.
A grass fire burned nearly 250 acres near County Road BC northwest of Sparta, WI in rural Monroe County. More than 50 fire fighters from seven different departments battled the blaze that began as a controlled burn but quickly got out of control.
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, April 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: 158737, 160182.