Thunderstorms developed in a moist and unstable air mass ahead of a cold front. The storms expanded in coverage as they interacted with the outflow from morning thunderstorms.
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 developed in a moist and unstable air mass ahead of a cold front. The storms expanded in coverage as they interacted with the outflow from morning thunderstorms.
The storms produced heavy rain, large hail and damaging winds. A wind gust, estimated at 75 mph, downed trees and destroyed a camper trailer near Angelica (Shawano Co.). Most of the large hail ranged from quarter to golf ball size, but 2.25 inch diameter hail fell in the Town of Clayton (Winnebago Co.). Heavy rainfall caused some street flooding in Neenah (Winnebago Co.).
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 Jun 18, 12:05 PM CST, 1 hour 15 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 105 PM CDT MON JUN 18 2012 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .PREV DISCUSSION...ISSUED AT 404 AM CDT MON JUN 18 2012... SHORT TERM...TODAY/TONIGHT/TUESDAY. WITH ONGOING CONVECTION THIS MORNING...WILL KEEP THIS DISCUSSION SHORT. MCS COMPLEX WITH PLENTY OF RAINFALL CONTINUES TO SPREAD OVER THE FORECAST AREA EARLY THIS MORNING. AS HAS BEEN THE FORECAST ISSUE THE LAST FEW DAYS...THE AMOUNT OF CLOUDS IN THE WAKE OF THIS COMPLEX WITH AFFECTS ON TEMPERATURES AND AFTERNOON INSTABILITY. WILL NOT STRAY TOO FAR FROM ONGOING TEMPERATURES AS H8 TEMPS REMAIN WARM AND ANY BREAKS IN THE CLOUD COVER COMBINED WITH THE WARM MORNING START WILL PRODUCE ABOVE NORMAL TEMPS. OFF COURSE ANY SIG CLEARING TODAY WILL GREATLY AID WITH SEVERE POTENTIAL AS THE AIR MASS BECOMES MORE UNSTABLE AS DEEPER MOISTURE WORKS INTO THE AREA. EXPECT DIMINISHING PCPN FROM NORTH TO SOUTH TONIGHT AS THE COLD FRONT BEGINS TO SAG SOUTHWARD. THE CHALLENGE WITH THIS FRONT IS HOW FAR SOUTH THE FRONT GETS AS THE UPPER LOW REMAINS WESTERLY AND THEN EVENTUALLY UPPER HEIGHTS BUILD INTO TUESDAY TO LIFT THE FRONT NORTH AGAIN AS A WARM FRONT. POTENTIAL FOR HEAVY RAIN ALONG THE FRONTAL BOUNDARIES THROUGH TUESDAY AS WELL AS ANY OUTFLOW BOUNDARIES WHICH DEVELOP THIS MORNING. PWATS INCREASE TO NEAR 1.75 TODAY AND THEN FOCUS ON THE MAIN BOUNDARY TONIGHT BEFORE LIFTING NORTH TUESDAY AFTERNOON. RIBBON OF INSTABILITY WITH THESE HIGH PWATS FOR POTENTIAL OF HEAVY RAINFALL WITH THE STORMS. MUCH OF THE AREA CAN USE THE RAIN...AND WITH RATHER DRY INITIAL CONDITIONS...WILL OPT TO ISSUE AN ESF FOR NOW AND BRIEF THE DAY CREW OF A POSSIBLE NEED FOR A WATCH. LONG TERM...TUESDAY NIGHT THROUGH SUNDAY. MAIN CONCERN WILL BE CHANCES FOR THUNDERSTORMS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. WARM FRONT IS EXPECTED TO SHIFT NORTH INTO NORTHERN WISCONSIN TUESDAY NIGHT. WILL CONTINUE CHANCES FOR THUNDERSTORMS ACROSS THE NORTH AND KEEP IT DRY ACROSS THE SOUTH. SEVERE WEATHER PARAMETERS WOULD SUGGEST THERE IS STILL POTENTIAL FOR STRONG OR SEVERE STORMS ACROSS THE NORTH AS 0-6 KM SHEAR BETWEEN 35 AND 50 KNOTS...LIFTED INDICES WELL BELOW ZERO AND CAPES OF 1500 TO 2500 J/KG. YESTERDAY...IT APPEARED WEDNESDAY WOULD BE A VERY HOT DAY ACROSS EASTERN WISCONSIN. TONIGHT...THE 00Z WRF AND GFS BRING BOUNDARY AND CLOUDS ACROSS THE AREA THAT COULD HAMPER THE SEVERE POTENTIAL WEDNESDAY AFTERNOON. ON THE OTHER HAND...12Z ECMWF AND 00Z CANADIAN ARE SOMEWHAT SLOWER WHICH WOULD ALLOW FOR A HOT DAY AND STRONG TO SEVERE STORMS DURING THE AFTERNOON. THE SCENARIO WILL END UP SOMEWHERE IN THE MIDDLE WHERE CLOUDS AND BOUNDARY WILL DIMINISH THE POTENTIAL FOR STRONG OR SEVERE STORMS ACROSS NORTH CENTRAL AND PORTIONS OF CENTRAL WISCONSIN...WHILE NORTHEAST AND EAST CENTRAL WISCONSIN ROAST WITH HIGHS IN THE LOWER TO MIDDLE 90S ASSUMING A DECENT AMOUNT OF SUNSHINE BEFORE THE STORMS ARRIVE. FOR NOW...THINK BEST CHANCE FOR SEVERE STORMS WILL BE ACROSS NORTHEAST AND EAST CENTRAL WISCONSIN BASED ON THE 00Z CANADIAN AND 12Z ECMWF. THE STORMS SHOULD END WEDNESDAY NIGHT WITH HIGH PRESSURE BUILDING INTO THE REGION THURSDAY AND THURSDAY NIGHT. UPPER AIR PATTERN WILL BE NOTED BY NORTHWEST FLOW ALOFT. FIRST DISTURBANCE WILL BRING A CHANCE OF SHOWERS AND STORMS TO THE FAR NORTH FRIDAY. ANOTHER DISTURBANCE WILL BRING A CHANCE OF SHOWERS AND STORMS ON FRIDAY NIGHT AND SATURDAY. TEMPERATURES WILL RETURN CLOSER TO NORMAL BY THE END OF THE WEEK. && .AVIATION...A COOL FRONT WILL DROP ACROSS NORTHERN WISCONSIN TODAY BEFORE STALLING ACROSS CENTRAL WISCONSIN TONIGHT...THEN LIFTING BACK NORTH ON TUESDAY. SHOWERS AND STORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON ALONG THIS BOUNDARY. SOME STORMS MAY TURN SEVERE WITH STRONG GUSTY WINDS AND LARGE HAIL AS THE MAIN THREATS. MVFR STRATO-CU CIGS WILL LIKELY REMAIN IN PLACE ACROSS MOST OF THE TAF SITES THIS AFTERNOON AND THEN SINK SOUTH WITH THE FRONT. STORMS WILL LIKELY DISSIPATE WITH LOSS OF HEATING BY MID-EVENING AND THEN RE-FIRE OVER MINNESOTA TONIGHT. SOME STORMS FROM MINNESOTA MAY TRY TO MOVE INTO CENTRAL AND NORTH-CENTRAL WISCONSIN LATE TONIGHT INTO TUESDAY MORNING. MPC && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREEN BAY WI 1030 AM CDT MON JUN 18 2012 WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-191530- 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- 1030 AM CDT MON JUN 18 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND NORTHEAST WISCONSIN. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A SLIGHT RISK OF SEVERE STORMS THIS AFTERNOON INTO THIS EVENING. THUNDERSTORMS WILL BE ON THE INCREASE AGAIN THIS AFTERNOON AND EVENING. AT THIS TIME...THE BEST CHANCE OF STRONG TO SEVERE THUNDERSTORMS WILL OCCUR FROM CENTRAL TO FAR NORTHEAST WISCONSIN. IN ADDITION TO HEAVY RAINFALL...STORMS WILL BE CAPABLE OF PRODUCING LARGE HAIL ...DAMAGING WINDS...AND ISOLATED TORNADOES. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THUNDERSTORMS ARE POSSIBLE AT TIMES TUESDAY THROUGH WEDNESDAY NIGHT. SEVERE STORMS WITH DAMAGING WINDS AND LARGE HAIL ARE POSSIBLE WEDNESDAY AFTERNOON AND WEDNESDAY EVENING. HEAVY RAINFALL IS ALSO POSSIBLE. THUNDERSTORMS ARE POSSIBLE ACROSS THE NORTH FRIDAY AND ACROSS THE ENTIRE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT. IT IS STILL TOO EARLY TO MAKE A MEANINGFUL ASSESSMENT OF THE POTENTIAL FOR SEVERE WEATHER WITH THESE STORMS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING. IN ADDITION...ANY OBSERVATIONS OF GUSTY WINDS OR HEAVY RAINFALL SHOULD BE FORWARDED TO THE NATIONAL WEATHER SERVICE IN GREEN BAY. LMZ521-522-541>543-191530- THE BAY OF GREEN BAY SOUTH OF A LINE FROM CEDAR RIVER MI TO ROCK ISLAND PASSAGE-LAKE MICHIGAN FROM WASHINGTON ISLAND TO SHEBOYGAN- 1030 AM CDT MON JUN 18 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST LAKE MICHIGAN AND THE WATERS OF GREEN BAY. .DAY ONE...THIS AFTERNOON AND TONIGHT INCREASING SOUTH WINDS WILL PRODUCE WAVES WHICH MAY BE HAZARDOUS TO SMALL CRAFT TODAY AND TONIGHT. THERE IS A SLIGHT RISK OF SEVERE STORMS THROUGH THIS EVENING. LARGE HAIL...DAMAGING WINDS AND FREQUENT LIGHTNING WILL BE POSSIBLE WITH THE STRONGEST STORMS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY GUSTY SOUTH WINDS ON TUESDAY INTO TUESDAY NIGHT MAY PRODUCE WAVES HAZARDOUS TO SMALL CRAFT. IN ADDITION...THUNDERSTORMS COULD POSE A HAZARD TO BOATERS AT TIMES TUESDAY THROUGH WEDNESDAY NIGHT AND AGAIN FRIDAY NIGHT THROUGH SATURDAY NIGHT. SOME SEVERE STORMS ARE POSSIBLE WEDNESDAY AFTERNOON AND EVENING...WITH LARGE HAIL AND DAMAGING WINDS AS THE MAIN THREATS. MPC
The Green Bay radar (KGRB), 151 km away, was scanning. The volume nearest the first event began at 19:17 UTC.
16 hail, 4 thunderstorm wind, 2 heavy rain, 2 funnel cloud. Local standard time, as filed.
Thunderstorms produced quarter size hail near Irma. Time of report was estimated based on radar data.
Thunderstorms produced quarter size hail near Colby.
Thunderstorms produced quarter size hail and a wind gust to 42 mph east of Abbotsford.
Thunderstorms produced golf ball size hail at Summit Lake.
Thunderstorms produced 1.25 inches of rain in about 30 minutes at Caldron Falls Reservoir.
Thunderstorms produced half dollar size hail at Brokaw.
Thunderstorms produced penny size hail at Plover.
Thunderstorm winds downed several trees in the town of Sharon blocking traffic east of Country Highway J.
A funnel cloud was spotted at Eland.
Thunderstorms produced quarter size hail at King.
Thunderstorms produced quarter to half dollar size hail at Clintonville.
Thunderstorms produced penny size hail at Waupaca.
Thunderstorms produced walnut size hail at Peshtigo.
A funnel cloud was spotted over Oconto.
Thunderstorm winds destroyed a camper trailer and downed numerous trees in the Angelica area.
Golf ball size hail fell near the intersection of U.S. Highways 10 and 45, northwest of Winchester.
Thunderstorms produced half dollar size hail for about 6 minutes in Neenah.
Quarter size hail fell in Menasha.
Quarter size hail fell near Darboy in extreme northwest Calumet County.
Quarter size hail fell about 2 miles southwest of Darboy in extreme northwest Calumet County.
Heavy rainfall produced some street flooding in Neenah. Water was as high as the bottom of an SUV at the intersection of Maple Street and Haylett Street.
Thunderstorm winds knocked a tree onto a home on Fire Lane 8, on the shore of Lake Winnebago. The tree caused damage to the roof of the house and broke a window.
Thunderstorms produced hail slightly smaller than tennis ball size in the Town of Clayton.
Thunderstorm winds downed several trees on the north side of the city of Manitowoc.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2012Every state in 2012This day in weather historyWarnings in Wisconsin, June 2012
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: 387796, 387797, 387798, 387799, 392227, 387800, 387801, 392230, 392204, 387802, 387803, 387804, 387805, 392205, 392231, 392207, 392208, 392209, 392211, 392214, 392229, 392232, 392220, 392233.