Thunderstorms that developed ahead of an approaching surface boundary moved south across Wisconsin. Some of the storms produced heavy rainfall that caused minor urban flooding, damaging winds that downed trees and power lines, and hail up to golf ball size across eastern Wisconsin.
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 GRB wrote it up.
Thunderstorms that developed ahead of an approaching surface boundary moved south across Wisconsin. Some of the storms produced heavy rainfall that caused minor urban flooding, damaging winds that downed trees and power lines, and hail up to golf ball size across eastern Wisconsin. As the storms moved across southern Lake Winnebago they produced gusts to around 40 mph that caused large waves to quickly develop, capsizing a boat with four people on board. Three of the boat's passengers reached shore while the fourth had to be rescued by the Winnebago County Sheriff's Department.
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 14, 10:45 AM CST, 2 hours 45 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 1145 AM CDT FRI AUG 14 2015 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND SATURDAY ISSUED AT 300 AM CDT FRI AUG 14 2015 AREA RADARS THIS MORNING SHOW A BAND OF LIGHT SHOWERS OR SPRINKLES DROPPING OVER CENTRAL WISCONSIN. THIS ELEVATED CONVECTION WAS WORKING WITH SOME PLENTY OF MID LEVEL INSTABILITY AND MAY PERSIST THROUGH DAY BREAK BEFORE LIKELY DISSIPATING. A SIMILAR CLUSTER OF LIGHT SHOWERS WERE SLIDING OVER SOUTHERN WISCONSIN. FURTHER NORTH ISOLATED SHOWERS AND STORMS WERE NOTED OVER LAKE SUPERIOR AND SLOWLY DROPPING SOUTHWARD. CONVECTION MAINLY DRIVEN BY WARM AIR ADVECTION INTO THIS MID LEVEL INSTABILITY AHEAD OF A VORT JUST NORTH OF INL EARLY THIS MORNING...PROGGED TO DROP INTO THE EASTERN HALF OF THE STATE TODAY. AT 08Z DID NOTICE A LONE STORM POPS OVER NORTHERN MINNESOTA AS THIS VORT APPROACHES THE ARROWHEAD OF MINNESOTA. PLENTY OF LOW LEVEL CIN TO OVERCOME EARLY THIS MORNING SO CONVECTION SHOULD BE MINIMAL. CHALLENGE WITH THE FORECAST TODAY WILL BE PCPN TRENDS AS THE CIN ERODES...ALONG WITH THE ARRIVAL OF THE VORT. WILL CONTINUE TO CONFINE BEST POPS OVER EASTERN WISCONSIN THIS AFTERNOON WITH DAY TIME HEATING. SOME MODELS HAVE TRENDED WITH A SLOWER DEPARTURE OF THE PCPN THIS EVENING DUE TO A LINGERING H850 BOUNDARY. WILL COMPROMISE WITH KEEPING LOWER END POPS GOING OVER CENTRAL AND EAST CENTRAL WISCONSIN THIS EVENING. POTENTIAL FOR SEVERE REMAINS ISOLATED. DEEPER LAYER SHEAR WILL LIKELY INCREASE TODAY AS THE UPPER FLOW BECOMES MORE NORTH. STORMS MAY ALSO TEND TO FOCUS ON MESOSCALE LAKE BOUNDARIES THIS AFTERNOON. UPPER RIDGE BUILDS BACK INTO THE STATE FROM THE WEST TONIGHT AND INTO SATURDAY FOR A CONTINUED DRY FORECAST...BUT WITH A CONTINUED WARM HUMID AIR MASS. MUGGY AIR MASS EARLY THIS MORNING ALSO AIDING WITH FOG DEVELOPMENT OVER THE FAR NORTH. WILL CONTINUE THE FOG MENTION TONIGHT AS DEWPOINTS DO NOT FALL OFF MUCH AND WINDS DIMINISH WITH THE APPROACH OF THE HIGH PRESSURE REGION. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY ISSUED AT 300 AM CDT FRI AUG 14 2015 TIMING OF CHANCES FOR SHOWERS AND STORMS IS THE MAIN CONCERN DURING THIS PART OF THE FORECAST. UPPER LEVEL FLOW IS FORECAST TO BECOME MORE ZONAL ACROSS THE REGION EARLY IN THE PERIOD. AN UPPER RIDGE AND SURFACE HIGH PRESSURE SHOULD KEEP THE AREA DRY FOR MOST OF THE WEEKEND AND TEMPERATURES WILL WARM ABOUT 10F TO 15F ABOVE NORMAL DURING THE DAY ON SUNDAY. THERE IS A CHANCE FOR SHOWERS AND STORMS STARTING SUNDAY NIGHT AND MONDAY...AND CONTINUING INTO MONDAY NIGHT ACROSS EAST CENTRAL WISCONSIN. MOST OF THE SHORT WAVE ENERGY IS EXPECTED TO PASS NORTH OF THE STATE BUT RAINFALL COULD STILL BE SIGNIFICANT WITH A SHOT OF GULF MOISTURE AHEAD OF THE FRONT. MOSTLY DRY AND MUCH COOLER WEATHER SHOULD RETURN TO THE AREA BY TUESDAY. RAIN CHANCES RETURN BY TUESDAY NIGHT AND CONTINUE THROUGH THURSDAY AS TEMPERATURES WARM A BIT ABOVE NORMAL BY THURSDAY. A LOW PRESSURE SYSTEM WILL PASS TO THE NORTHWEST AND DRAG A WARM FRONT NORTHEAST ACROSS THE FORECAST AREA AS AN UPPER TROUGH FROM THE PACIFIC NORTHWEST MAKES ITS WAY TOWARD THE PLAINS...RESULTING IN A MORE SOUTHWEST UPPER FLOW ACROSS THE REGION. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1139 AM CDT FRI AUG 14 2015 VFR CONDITIONS EARLY THIS AFTERNOON WILL GIVE WAY TO SCATTERED THUNDERSTORMS ACROSS THE REGION. THE GREATEST CONCENTRATION OF STORMS SHOULD BE ACROSS NORTHEAST AND EAST-CENTRAL WISCONSIN. SOME OF THE STRONGER STORMS COULD PRODUCE WIND GUSTS TO 40 KNOTS AND DROPPING VISIBILITIES INTO THE MVFR/IFR CATEGORY FOR A BRIEF PERIOD OF TIME. THE STORMS SHOULD DIMINISH OR END BY MID TO LATE EVENING. AREAS OF MVFR CONDITIONS ARE EXPECTED LATE TONIGHT DUE TO FOG WITH POCKETS OF IFR OR LOWER CONDITIONS ACROSS PORTIONS OF NORTH-CENTRAL WISCONSIN. ANY FOG SHOULD BURN OFF BY MID-MORNING ON SATURDAY WITH VFR CONDITIONS EXPECTED SATURDAY AFTERNOON AND EVENING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM.....TDH LONG TERM......MG AVIATION.......ECKBERG
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREEN BAY WI 1101 AM CDT FRI AUG 14 2015 WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-151615- VILAS-ONEIDA-FOREST-FLORENCE-NORTHERN MARINETTE COUNTY-LINCOLN- LANGLADE-MENOMINEE-NORTHERN OCONTO COUNTY-DOOR-MARATHON-SHAWANO- WOOD-PORTAGE-WAUPACA-OUTAGAMIE-BROWN-KEWAUNEE-WAUSHARA-WINNEBAGO- CALUMET-MANITOWOC-SOUTHERN MARINETTE COUNTY- SOUTHERN OCONTO COUNTY- 1101 AM CDT FRI AUG 14 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND NORTHEAST WISCONSIN. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A CHANCE FOR THUNDERSTORMS THIS AFTERNOON AND THIS EVENING. A FEW STORMS OVER NORTHEAST WISCONSIN MAY BE CAPABLE OF PRODUCING STRONG GUSTY WINDS TO 50 MPH...SMALL HAIL AND LOCALLY HEAVY RAINFALL. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY CHANCES FOR THUNDERSTORMS RETURN FOR SUNDAY NIGHT INTO MONDAY NIGHT AND AGAIN TUESDAY NIGHT THROUGH THURSDAY. IT IS TOO EARLY TO DETERMINE IF ANY OF THESE STORMS WILL BECOME SEVERE. .SPOTTER INFORMATION STATEMENT... FORMAL SPOTTER ACTIVATION IS NOT EXPECTED THIS AFTERNOON OR TONIGHT. HOWEVER...SPOTTER ARE REQUESTED TO REPORT WIND GUSTS OVER 40 MPH... HAIL OVER PEA SIZE AND HEAVY RAINFALL WITH AMOUNTS OVER AN INCH. LMZ521-522-541>543-151615- THE BAY OF GREEN BAY SOUTH OF A LINE FROM CEDAR RIVER MI TO ROCK ISLAND PASSAGE-LAKE MICHIGAN FROM WASHINGTON ISLAND TO SHEBOYGAN- 1101 AM CDT FRI AUG 14 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST LAKE MICHIGAN AND THE WATERS OF GREEN BAY. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A CHANCE OF THUNDERSTORMS THIS AFTERNOON AND THIS EVENING THAT COULD POSE A SIGNIFICANT HAZARD TO BOATERS. STRONG GUSTY WINDS AND FREQUENT CLOUD TO WATER LIGHTNING STRIKES ARE THE MAIN HAZARDS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THERE IS A CHANCE FOR THUNDERSTORMS SUNDAY NIGHT THROUGH MONDAY NIGHT AND AGAIN TUESDAY NIGHT THROUGH THURSDAY. ECKBERG
The Green Bay radar (KGRB), 118 km away, was scanning. The volume nearest the first event began at 19:29 UTC.
14 thunderstorm wind, 9 hail, 1 heavy rain. Local standard time, as filed.
Thunderstorm winds downed a few trees and power lines near Ellison Bay.
Nickel size hail fell northwest of Elton.
A thunderstorm dropped quarter size hail in Marinette.
Nickel size hail fell west of Peshtigo.
Quarter size hail fell just to the west of Oconto.
A thunderstorm dropped golf ball size hail as it passed through Sobieski.
A thunderstorm dropped golf ball size hail as it passed through Pulaski.
Thunderstorm winds downed power lines and a few large trees at the corner of West Point Road and Packerland Drive.
Thunderstorm winds downed power lines and a few large trees in Green Bay.
Thunderstorms produced a wind gust of 62 mph that was measured at Austin Straubel International Airport.
Thunderstorm winds downed trees in De Pere.
Thunderstorm winds downed trees and power lines on the west side of Green Bay.
Thunderstorm winds downed trees in Black Creek.
Thunderstorm winds tore shingles from a roof in Suamico.
Thunderstorm winds downed trees in Freedom.
Heavy rainfall caused street flooding on Highway 47 in Black Creek. Water was about six inches deep.
Thunderstorm winds downed trees in Kimberly, blocking a road.
Thunderstorms produced a wind gust of 59 mph that was measured at Little Chute High School.
Thunderstorm winds snapped large trees about five feet above the ground in Kaukauna.
Thunderstorm winds downed trees in Kaukauna.
Thunderstorm winds downed trees in Chilton.
Quarter size hail fell at the intersection of Highway 76 and Highway 96 in Greenville.
Nickel to quarter size hail fell in Clayton Township.
Quarter size hail fell near the intersection of Highway 76 AND Country Highway II.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2015Every state in 2015This day in weather historyWarnings in Wisconsin, August 2015
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: 599373, 599363, 599364, 599365, 599370, 599368, 599369, 599366, 599385, 599388, 599380, 599374, 599381, 599382, 599379, 599390, 599377, 599375, 599383, 599384, 599376, 599367, 599372, 599371.