Strong thunderstorms formed along the lake breeze and affected the coastal and near shore areas of Lake Michigan, producing gusty winds and large hail.
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 MKX wrote it up.
Strong thunderstorms formed along the lake breeze and affected the coastal and near shore areas of Lake Michigan, producing gusty winds and large hail.
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 Milwaukee, WI wrote its last area forecast discussion before the first event at Aug 19, 3:03 PM CST, 29 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 403 PM CDT SUN AUG 19 2012 .SHORT TERM... .TONIGHT AND MONDAY...FORECAST CONFIDENCE MEDIUM. PASSING SHORTWAVE TROUGH WITH WEAK SURFACE BOUNDARY IN THE AREA HELPING DRIVE SCATTERED SHOWERS AND THUNDERSTORMS. STEEP LOW LEVEL LAPSE RATES AND LOW LEVEL MEAN LAYER CAPES AIDING THIS AS WELL. THESE SHOULD LINGER THROUGH THE AFTERNOON INTO THE EARLY EVENING BEFORE DIMINISHING. SOME CLOUDS AND SHOWERS MAY LINGER IN THE FAR SOUTHEAST COUNTIES LATER TONIGHT INTO MONDAY MORNING...CLOSEST TO SOUTHERN LAKE MICHIGAN CONVERGENCE ZONE. SHOULD SEE VALLEY FOG DEVELOP LATER TONIGHT WITH LIGHT WINDS AND CLEARING SKIES. ISOLATED SHOWERS ARE EXPECTED MONDAY AFTERNOON IN THE EASTERN COUNTIES. ONSHORE WINDS WITH HIGHER DEWPOINTS BRING WEAK INSTABILITY HERE...AND COMBINE WITH APPROACHING SHORTWAVE TROUGH TO BRING LOW END POPS. COOL TEMPERATURES EXPECTED AGAIN TONIGHT AND MONDAY. MONDAY NIGHT THROUGH TUESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. MODELS DON/T HAVE ANY STRONG SHORT-WAVE TROUGHS DURING THIS TIME PERIOD WITH ASSOCIATED FRONTO-FORCING OR ISENTROPIC LIFT. ON TUESDAY SLIGHT RIDGING TAKES PLACE ALOFT. AT THE SURFACE HIGH PRESSURE HIGH PRESSURE DROPS SOUTHEAST ACROSS WESTERN GREAT LAKES REGION. THEREFORE WILL KEEP DRY FORECAST GOING. LIGHT WINDS AND LONGER NIGHTS SPELL RIVER VALLEY FOG MONDAY NIGHT AND TUESDAY NIGHT...BUT MORE LIKELY MONDAY NIGHT. SLOW WARM-UP DURING THIS TIME WITH DAYTIME TEMPS GETTING BACK TO UPPER 70S TO 80 ON TUESDAY. WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE IS MEDIUM. MODELS DIFFER ON WEAK SHORT-WAVE TROUGH POSITIONS AS WARM AIR ADVECTION AND SOUTHWEST FLOW SET UP IN LOWER LEVELS. 925 TEMPS WARM TO +24 TO +26 BY THURSDAY WHICH SUPPORTS MID TO UPPER 80S...BUT WILL KEEP THE MID 80S GOING FROM PREVIOUS FORECAST IN ORDER TO BLEND IN WITH THE NEIGHBORS. AT THE SURFACE...HIGH PRESSURE SETS UP OVER THE OHIO RIVER VALLEY...WITH DRY MID-LEVEL RETURN FLOW DUE TO SUBSIDENCE. THURSDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE IS LOW. A 500MB TROUGH CONSISTING OF TWO SHORT-WAVES...IS FORECAST MOVE THROUGH WISCONSIN LATE THIS WEEK INTO THE WEEKEND. THERE ARE DIFFERENCES BETWEEN THE ECMWF AND GFS WITH THE STRENGTH AND TIMING OF THIS FEATURES. GFS LOOKS LIKE IT HAS CONVECTIVE FEEDBACK ISSUES WITH THE FIRST ONE...AND BRINGS A BULLSEYE OF RAIN ACROSS SOUTHERN WISCONSIN ON FRIDAY. ECMWF IS A BIT SLOWER IN GENERATING RAIN...AND HAS LESS RAIN PERIOD. HAVE TRENDED TOWARD ECMWF. LONG TERM... && .AVIATION/00Z TAFS/... SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL AFFECT TAF SITES FROM TIME TO TIME INTO EARLY THIS EVENING BEFORE DISSIPATING. VFR CONDITIONS MAINLY EXPECTED...WITH MVFR VISIBILITIES POSSIBLE WITH ANY THUNDERSTORMS. SOME MID LEVEL CLOUDS SHOWERS MAY CONTINUE TO AFFECT THE EASTERN SITES UNTIL AROUND 05Z MONDAY...AND AGAIN MONDAY AFTERNOON. OTHERWISE...SKIES SHOULD GRADUALLY CLEAR OUT TONIGHT. LIGHT WINDS AND CLEARING SKIES SHOULD ALLOW FOR VFR/MVFR FOG AT TAF SITES FROM 08Z TO 14Z MONDAY. MORE SCATTERED TO BROKEN DIURNAL CUMULUS CLOUDS ARE EXPECTED TO DEVELOP MONDAY AFTERNOON. && ,MARINE... ISOLATED WATERSPOUTS REMAIN POSSIBLE LATE THIS AFTERNOON AND EVENING ACROSS THE NEARSHORE WATERS. SEE SHORT TERM MARINE PRODUCTS FOR MORE DETAILED INFORMATION ON CURRENT TRENDS. COMBINATION OF DELTA T VALUES OF 12 TO 13 DEGREES CELSIUS WITH DEEP CONVECTIVE CLOUD DEPTH AND LINGERING UPPER TROUGH FAVOR WATERSPOUT FORMATION. SWI INDEX ALSO IN THE FAVORABLE RANGE DURING THIS TIME. KEPT ISOLATED WATERSPOUT MENTION IN FORECAST THROUGH THIS EVENING...AND AGAIN MONDAY MORNING SOUTH OF WIND POINT...CLOSEST TO SOUTHERN LAKE MICHIGAN CONVERGENCE AREA. MAY HAVE TO EXTEND WATERSPOUT WORDING THROUGH THE DAY MONDAY IN LATER FORECASTS...WITH ISOLATED SHOWERS EXPECTED IN THE AFTERNOON. && .AVIATION/00Z TAFS/... && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && TONIGHT/MONDAY AND AVIATION/MARINE...WOOD MONDAY NIGHT THROUGH SUNDAY...KAPELA
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 341 PM CDT SUN AUG 19 2012 WIZ046-047-051-052-056>060-062>072-201000- MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE- WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE- LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA- 341 PM CDT SUN AUG 19 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL WISCONSIN...SOUTH CENTRAL WISCONSIN AND SOUTHEAST WISCONSIN. .DAY ONE...TONIGHT ISOLATED THUNDERSTORMS THIS EVENING. SMALL HAIL POSSIBLE. LOCALLY DENSE FOG POSSIBLE WISCONSIN RIVER VALLEY. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY LOCALLY DENSE FOG POSSIBLE WISCONSIN RIVER VALLEY MONDAY NIGHT AND AGAIN TUESDAY NIGHT. SLIGHT CHANCE OF THUNDERSTORMS THURSDAY NIGHT WEST OF A LINE FROM MONTELLO TO THE DELLS TO BARABOO TO DARLINGTON. CHANCE FOR THUNDERSTORMS FRIDAY INTO SATURDAY ACROSS THE ENTIRE AREA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. HOWEVER...SPOTTERS NEAR LAKE MICHIGAN SHOULD BE ON LOOKOUT FOR WATERSPOUTS. LMZ643>646-201000- SHEBOYGAN TO PORT WASHINGTON WI- PORT WASHINGTON TO NORTH POINT LIGHT WI- NORTH POINT LIGHT TO WIND POINT WI- WIND POINT WI TO WINTHROP HARBOR IL- 341 PM CDT SUN AUG 19 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN. .DAY ONE...TONIGHT ISOLATED THUNDERSTORMS. WATERSPOUTS POSSIBLE. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY ISOLATED THUNDERSTORMS WITH A POSSIBLE WATERSPOUT MONDAY MORNING. CHANCE FOR THUNDERSTORMS FRIDAY INTO SATURDAY. KAPELA/WOOD WWW.WEATHER.GOV/MKX
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 124 PM CDT SUN AUG 19 2012 WIZ066-071-191900- MILWAUKEE-RACINE- 124 PM CDT SUN AUG 19 2012 ...STRONG THUNDERSTORM MOVING THROUGH EAST CENTRAL MILWAUKEE COUNTY... AT 122 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM NEAR DOWNTOWN MILWAUKEE...MOVING EAST SOUTHEAST AT 15 MPH. PEA SIZE HAIL...WINDS GREATER THAN 40 MPH...CLOUD TO GROUND LIGHTNING AND BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THIS STORM. * THE THUNDERSTORM WILL BE NEAR... DOWNTOWN MILWAUKEE BY 130 PM CDT... MILWAUKEE HOAN BRIDGE AND UW-MILWAUKEE CAMPUS BY 135 PM CDT... ST. FRANCIS AND MILWAUKEE INTERNATIONAL AIRPORT BY 150 PM CDT... CUDAHY BY 155 PM CDT... GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS TO BLOW AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED. WOOD
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
247 PM CDT SUN AUG 19 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0238 PM HEAVY RAIN SHEBOYGAN 43.75N 87.72W
08/19/2012 M0.71 INCH SHEBOYGAN WI TRAINED SPOTTER
HEAVY RAIN, 0.71 INCHES IN 20 MINUTES. SMALL HAIL ABOUT
1/8INCH.
&&
ETThe Milwaukee radar (KMKX), 70 km away, was scanning. The volume nearest the first event began at 21:30 UTC.
1 marine hail, 1 marine thunderstorm wind. Local standard time, as filed.
Nickel size hail observed by trained spotter just southwest of downtown Port Washington.
Trained spotter observed estimated 39 knot winds and one half inch hail at the intersection of Mequon Road and Interstate 43.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Lake Michigan in 2012Every state in 2012This day in weather history
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: 395326, 395327.