An upper level disturbance moved over Lake Superior during the afternoon. A weak surface trough combined with daytime heating and the upper level system to produce isolated severe thunderstorms over east-central Wisconsin.
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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 GRB wrote it up.
An upper level disturbance moved over Lake Superior during the afternoon. A weak surface trough combined with daytime heating and the upper level system to produce isolated severe thunderstorms over east-central 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 Green Bay, WI wrote its last area forecast discussion before the first event at Aug 1, 2:19 AM CST, 10 hours 41 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 319 AM CDT FRI AUG 1 2008 .SHORT TERM...TODAY THROUGH SATURDAY... FORECAST CONCERNS FOCUSED ON TODAY WITH PRECIPITATION CHANCES AS SHORT WAVE PASSES TO THE NORTH OF STATE. WATER VAPOR IMAGERY SHOWING SHORT WAVE JUST NORTH OF MN ARROWHEAD. WEAK LOW PRESSURE EXTENDS FROM EAST CENTRAL WI...INTO NE IA. HI PRESSURE OVER WESTERN MN/DAKOTAS SHIFTING EAST. ISOLD SHOWER/TSTM ACTIVITY FORMED NE MN THIS EVENING ON OUTFLOW BOUNDARY...CONTINUES TO PUSH EAST INTO WI...SUPPORTED BY LFQ OF JET. EARLIER SHIFT BROUGHT POPS INTO NORTHERN WI FOR OVERNIGHT AND MORNING HOURS...WILL SHIFT THOSE POPS FURTHER SOUTH FOR THIS AM AND ADD THUNDER BASED ON CURRENT TRENDS. UPPER SHORT WAVE TO DROP SOUTHEAST INTO EASTERN TROF AMPLIFYING FLOW OVER AREA BY TONIGHT. BEST DYNAMICS TO BE OVER NORTHEAST WI MID DAY/AFTN. MODELS ALSO SHOWING MARGINAL INSTABILITY WITH 850 LIS AROUND -2 AND SFC CAPES BETWEEN .5 AND 1K DEPENDING ON WHAT MODELS. LOW LEVEL LAPSE RATES CONTINUE TO BE QUITE UNSTABLE. WILL GO WITH ISOLD TO SCT WORDING IN GRIDS. NW FLOW ALOFT WITH SFC HIGH PRESSURE BUILDING IN TONIGHT AND SAT. TRENDED TEMPS NEAR MAV FOR HIGHS...THOUGH NOT AS COLD ON MINS. .LONG TERM...SATURDAY NIGHT THROUGH NEXT THURSDAY HIGH PRESSURE SLIDE EAST OF THE AREA WITH RETURN FLOW SETTING UP AFTER MIDNIGHT. MODELS CONTINUE TO DIVERGE ON WHERE THE WARM ADVECTION PRECIPITATION WILL BREAK OUT. GFS WOULD SUGGEST WEST AND POSSIBLY NORTHWEST OF OUR AREA AND WHILE THE WRF MODEL FOCUS PRECIPITATION SOUTHWEST OF THE AREA. BASED ON STEEP MID LEVEL LAPSE RATES AND WEAK 850MB WARM ADVECTION FROM NORTHERN MINNESOTA TO SOUTHWEST WISCONSIN LATE SATURDAY NIGHT...WILL CONTINUE A SMALL CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE WEST. DEPENDING WHERE CONVECTION SETS UP...PRECIPITATION WILL SLIDE EAST/SOUTHEAST INTO SUNDAY. THEREFORE CONTINUED THE SMALL CHANCE FOR SHOWERS AND THUNDERSTORMS EXPECTING OVERNIGHT CONVECTION TO WORK ACROSS THE AREA. FORECAST BECOMES COMPLICATED SUNDAY NIGHT INTO MONDAY DEPENDING ON YOUR MODEL CHOICE. GFS DEPICTED ELEVATED CONVECTION SUNDAY NIGHT WHICH SHIFTS EAST OF THE AREA BY MONDAY AFTERNOON. GFS DEPICTING STRONG CAPPING OVER THE SOUTH MONDAY AFTERNOON. WEAKER CAP AND FRONTAL BOUNDARY OVER THE NORTH WOULD SUGGEST STRONG TO SEVERE THUNDERSTORMS WOULD BREAK OUT MONDAY AFTERNOON AND EVENING. THE GFS ALSO WOULD SUGGEST A DECENT TEMPERATURE GRADIENT ACROSS THE AREA AS 850MB TEMPERATURES WARM TO NEAR 24 C OVER THE SOUTH. AGAIN BOUNDARY AND LINGERING MORNING CONVECTION COULD HOLD TEMPERATURES DOWN A FEW DEGREES. THE WRF ON THE OTHER HAND KEEPS THE FRONT WELL SOUTH OF THE AREA AS OF MONDAY MORNING. THINKING OF A COMPROMISE IN THE FRONTAL POSITION. NOT CONFIDENT ENOUGH TO MENTION SEVERE WORDING IN THE HAZARDOUS WEATHER OUTLOOK DUE TO THE MUCH FURTHER SOUTH BOUNDARY ON THE WRF. WILL NEED TO SEE HOW CONVECTION SUNDAY IMPACTS THE LOCATION OF THE FRONTAL BOUNDARY. IF CONVECTION MORE VIGOROUS SUNDAY...A FURTHER SOUTH SOLUTION LIKE THE WRF WOULD BE PLAUSIBLE. LITTLE CHANGES MADE TO THE REST OF THE FORECAST. && .AVIATION...PATCHY FOG EARLY THIS AM WITH LCL LIFR VSBY/CIGS POSSIBLE THROUGH 11Z CENTRAL AND NORTH CENTRAL. MAINLY VFR CONDITIONS EXPECTED TODAY INTO TONIGHT...WITH ISOLD TO SCT MVFR VSBYS/CIGS IN SHOWER/TSTM ACTIVITY DURING DAYTIME PERIOD AS SHORT WAVES DROPS SOUTHEAST THROUGH LAKE SUPERIOR REGION. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && TE/ECKBERG
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREEN BAY WI 1207 PM CDT FRI AUG 1 2008 WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-021715- VILAS-ONEIDA-FOREST-FLORENCE-NORTHERN MARINETTE-LINCOLN-LANGLADE- MENOMINEE-NORTHERN OCONTO-DOOR-MARATHON-SHAWANO-WOOD-PORTAGE- WAUPACA-OUTAGAMIE-BROWN-KEWAUNEE-WAUSHARA-WINNEBAGO-CALUMET- MANITOWOC-SOUTHERN MARINETTE-SOUTHERN OCONTO- 1207 PM CDT FRI AUG 1 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND NORTHEAST WISCONSIN. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A SLIGHT RISK OF SEVERE STORMS THIS AFTERNOON AND EVENING EAST OF A LINE FROM WAUSAUKEE TO CLINTONVILLE TO RIPON. LARGE HAIL AND DAMAGING WINDS ARE THE PRIMARY THREATS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THUNDERSTORMS ARE POSSIBLE LATE SATURDAY INTO NEXT WEEK. AT THIS TIME...SEVERE STORMS ARE POSSIBLE SUNDAY NIGHT INTO MONDAY AS A WARM FRONT LIFTS NORTH INTO THE STATE. BE SURE TO MONITOR LATER FORECASTS WHICH WILL BE BETTER ABLE TO ESTIMATE THE SEVERE RISK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NECESSARY THIS AFTERNOON AND EVENING. LMZ521-522-541>543-021715- THE BAY OF GREEN BAY SOUTH OF A LINE FROM CEDAR RIVER MI TO ROCK ISLAND PASSAGE-LAKE MICHIGAN FROM WASHINGTON ISLAND TO SHEBOYGAN- 1207 PM CDT FRI AUG 1 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A SLIGHT RISK OF SEVERE STORMS THIS AFTERNOON AND EVENING OVER MOST OF LAKE MICHIGAN AND THE BAY OF GREEN BAY. LARGE HAIL AND DAMAGING WINDS ARE THE PRIMARY THREATS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THUNDERSTORMS ARE AGAIN POSSIBLE LATE SATURDAY THROUGH NEXT WEDNESDAY. BE SURE TO MONITOR LATER FORECASTS WHICH WILL BE BETTER ABLE TO ESTIMATE THE SEVERE RISK THAT MAY BE POSED BY THESE STORMS.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREEN BAY WI 117 PM CDT FRI AUG 1 2008 WIZ011>013-019>021-031-036>039-045-048-049-073-074-011915- BROWN-CALUMET-FLORENCE-FOREST-LANGLADE-MENOMINEE-NORTHERN MARINETTE COUNTY-NORTHERN OCONTO COUNTY-OUTAGAMIE-PORTAGE-SHAWANO-SOUTHERN MARINETTE COUNTY-SOUTHERN OCONTO COUNTY-WAUPACA-WAUSHARA-WINNEBAGO- 117 PM CDT FRI AUG 1 2008 ...STRONG THUNDERSTORMS OVER EASTERN WISCONSIN... AT 112 PM...DOPPLER RADAR INDICATED THAT THUNDERSTORMS WERE RAPIDLY DEVELOPING FROM NORTHERN MARINETTE COUNTY...SOUTHWEST TO EASTERN PORTAGE COUNTY. THESE STORMS WERE MOVING SOUTHEAST AT 25 MPH. HAIL UP TO ONE HALF INCH IN DIAMETER...OCCASIONAL CLOUD TO GROUND LIGHTNING...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THESE STORMS. LOCATIONS THAT MAY BE AFFECTED INCLUDE... CLINTONVILLE...FREMONT...NEW LONDON...LAKE POYGAN AND GILLETT. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THESE STORMS HAS PASSED. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 PM FRIDAY EVENING FOR NORTHEASTERN WISCONSIN. KALLAS
The Green Bay radar (KGRB), 98 km away, was scanning. The volume nearest the first event began at 18:59 UTC.
8 hail, 3 thunderstorm wind. Local standard time, as filed.
Penny size hail was reported at the intersection of State Highway 180 and County Road JJ.
An estimated 60 mph wind gust was reported in the town of Neenah.
Nickel size hail was reported in the town of Menasha.
Ten 12-inch diameter trees were blown down due to damaging wind gusts. Spotters estimated a wind gust of 70 mph.
Nickel size hail was reported at the Fox River Mall in Appleton.
Penny size hail was reported in the town of Menasha.
Penny size hail was reported in the city of Appleton.
Quarter size hail was reported in the town of Menasha.
Spotters reported half-dollar size hail on the east side of Menasha.
Damaging winds knocked down trees and power lines at the intersection of State Highway 55 and County Road EE.
Nickel size hail was reported on the east side of Menasha.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2008Every state in 2008This day in weather historyWarnings in Wisconsin, August 2008
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: 127858, 127871, 127860, 127868, 127861, 127863, 127864, 127866, 127873, 127870, 127867.