Thunderstorms developed in a moist and unstable air mass ahead of an approaching cold front. Clusters of storms with torrential rain caused flooding and flash flooding.
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 an approaching cold front. Clusters of storms with torrential rain caused flooding and flash flooding. Rainfall totals were mainly in the 1 to 3 inch range, with locally higher amounts. The heaviest rainfall was across northern Door County where more than 6 inches of rain fell in the Baileys Harbor area, flooding basements and campgrounds and washing out the shoulders of roads. The flooding caused damage to some documents at the Ephraim Historical Society. Isolated storms produced large hail and wind damage.
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 Sep 4, 4:15 PM CST, 3 hours 45 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 515 PM CDT THU SEP 4 2014 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...UPDATED... ISSUED AT 442 PM CDT THU SEP 4 2014 LARGE BUT DISORGANIZED AREA OF THUNDERSTORMS CONTINUE TO TREK ACROSS MARATHON...SHAWANO...INTO SOUTHERN OCONTO COUNTIES. OVERALL...AREAL COVERAGE HAS INCREASED LAST HOUR OR SO BUT INTENSITY HAS NOT CHANGED MUCH. THIS ACTIVITY DEVELOPING ALONG AXIS OF ELEVATED INSTABILITY NORTH OF SURFACE WARM FRONT EXTENDING FROM NEAR FOND DU LAC TO NORTH OF LA CROSSE. COULD BE SOME LOCALIZED HEAVY RAINFALL AND PERHAPS SOME ISOLATED URBAN STREET FLOODING OR PONDING OF WATER WHERE STORMS HAVE BEEN AFFECTING THE SAME GENERAL AREA. RADAR ESTIMATES LAST THREE HOURS INDICATE 2 TO 2.5 INCHES OF RAINFALL ESPECIALLY ACROSS NORTHERN MARATHON COUNTY FROM ABBOSTFORD TO WAUSAU AREA. ADDITIONAL SCATTERED STORMS UPSTREAM OVER CLARK COUNTY WILL LIKELY AFFECT THIS SAME GENERAL WHICH MAY AGGRAVATE THE SITUATION SOMEWHAT NEXT COUPLE OF HOURS. SOUTHWESTERLY 850 MB FLOW JUST UPSTREAM OF THIS ACTIVITY CONTINUES TO FEED VERY UNSTABLE AIR INTO WEST CENTRAL WISCONSIN. THESE STORMS ARE SHOWING SOME SIGNS OF INCREASED ORGANIZATION LAST 30 MINUTES OR SO AND WILL CONTINUE TO MONITOR. SOME OF THESE STORMS ARE CAPABLE OF HAIL UP TO PENNY SIZE IN ADDITIONAL TO TORRENTIAL RAINFALL. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 246 PM CDT THU SEP 4 2014 NORTHWEST UPPER FLOW TO PROVIDE DRY AND PLEASANT WEATHER FRIDAY NIGHT THROUGH MONDAY. THEN SPLIT FLOW EXPECTED TO RESULT IN A TRICKY FORECAST FOR THE MIDDLE OF NEXT WEEK WITH JET ENERGY PASSING BY TO THE NORTH AND SOUTH OF THE AREA. THERE MAY BE SUFFICIENT SUPPORT FOR A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY NIGHT. THE APPROACH OF A SIGNIFICANT UPPER LOW SHOULD BRING A BETTER CHANCE OF PRECIPITATION WEDNESDAY NIGHT AND THURSDAY. THEN MUCH COOLER FOR THE END OF THE WEEK WITH LAKE EFFECT CLOUDS AND SHOWERS POSSIBLE IN NORTHERN WISCONSIN. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 514 PM CDT THU SEP 4 2014 SHOWERS AND THUNDERSTORMS WILL CONTINUE TO IMPACT CENTRAL TO NORTHEAST WISCONSIN THROUGH THE EVENING HOURS AHEAD OF A COLD FRONT...AND WILL GENERALLY PROVIDE POOR FLYING CONDITIONS. MVFR CIGS AND IFR VSBYS WILL BE COMMON NEAR THUNDERSTORM ACTIVITY. AS THE COLD FRONT MOVES THROUGH NORTH-CENTRAL WISCONSIN LATE THIS EVENING AND NORTHEAST WISCONSIN LATE TONIGHT...CIGS WILL IMPROVE AND THE THREAT OF THUNDERSTORMS WILL EXIT. VFR WEATHER WILL RETURN TOMORROW WITH ONLY HIGH CLOUDS OVERHEAD. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM.....ESB LONG TERM......RDM AVIATION.......MPC
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREEN BAY WI 304 PM CDT THU SEP 4 2014 WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-052015- 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- 304 PM CDT THU SEP 4 2014 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND NORTHEAST WISCONSIN. .DAY ONE...THIS EVENING INTO THE OVERNIGHT SCATTERED THUNDERSTORMS ARE EXPECTED TO PERSIST ACROSS MUCH OF CENTRAL AND NORTHERN WISCONSIN THIS EVENING NORTH OF A WARM FRONTAL BOUNDARY. SOME OF THE STORMS MAY BE SEVERE...WITH LARGE HAIL...DAMAGING WINDS AND TORRENTIAL RAINFALL. AS A COLD FROM APPROACHES FROM MINNESOTA LATER THIS EVENING...STRONG TO SEVERE STORMS ARE ALSO POSSIBLE OVER THE SOUTHERN PORTION OF THE FORECAST AREA INCLUDING THE FOX VALLEY AND LAKE SHORE AREAS...BUT THE PROBABILITY OF SEVERE WEATHER IN THIS AREA IS LESS CERTAIN AT THIS TIME. BE SURE TO CLOSELY MONITOR THE LATEST FORECASTS AND STATEMENTS ON THIS ACTIVE WEATHER SITUATION...ESPECIALLY IF YOU HAVE OUTDOOR ACTIVITIES PLANNED FOR THIS EVENING. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH THURSDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TODAY AND TONIGHT. LMZ521-522-541>543-052015- THE BAY OF GREEN BAY SOUTH OF A LINE FROM CEDAR RIVER MI TO ROCK ISLAND PASSAGE-LAKE MICHIGAN FROM WASHINGTON ISLAND TO SHEBOYGAN- 304 PM CDT THU SEP 4 2014 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST LAKE MICHIGAN AND THE WATERS OF GREEN BAY. .DAY ONE...TONIGHT GUSTY SOUTH WINDS AND BUILDING WAVES WILL CREATE CONDITIONS HAZARDOUS FOR SMALL CRAFT. A SMALL CRAFT ADVISORY IS IN EFFECT. IN ADDITION...AREAS OF MARINE FOG MAY CAUSE NAVIGATION PROBLEMS. IN ADDITION...SCATTERED THUNDERSTORMS ARE ALSO POSSIBLE AGAIN THIS EVENING AND INTO THE OVERNIGHT OVER THE ENTIRE MARINE FORECAST AREA. SOME OF THE STORMS COULD BE SEVERE...WITH STRONG WINDS...LARGE HAIL AND TORRENTIAL RAINFALL. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH THURSDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREEN BAY WI
337 PM CDT THU SEP 04 2014
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0337 PM HEAVY RAIN LAC DU FLAMBEAU 45.96N 89.88W
09/04/2014 M3.42 INCH VILAS WI TRAINED SPOTTER
RAINFALL WITH THE MORNING STORMS.
&&
SCOTTCSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREEN BAY WI 357 PM CDT THU SEP 4 2014 WIZ020-021-074-042200- MENOMINEE-NORTHERN OCONTO COUNTY-SOUTHERN OCONTO COUNTY- 357 PM CDT THU SEP 4 2014 ...STRONG THUNDERSTORM OVER MENOMINEE COUNTY... AT 354 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER WEST CENTRAL MENOMINEE COUNTY...MOVING EAST AT 30 MPH. PENNY SIZE HAIL...WINDS 30 TO 40 MPH...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THIS STORM. * THE THUNDERSTORM WILL BE NEAR... INTERSECTION OF HWY 55 AND COUNTY M BY 415 PM CDT... HAYES AND BREED BY 435 PM CDT... SURING BY 440 PM CDT... HICKORY CORNERS BY 450 PM CDT... GUSTY WINDS MAY CAUSE LIGHT WEIGHT OBJECTS TO BE BLOWN OVER. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED. RDM
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREEN BAY WI 452 PM CDT THU SEP 4 2014 WIZ031-039-074-042245- BROWN-SHAWANO-SOUTHERN OCONTO COUNTY- 452 PM CDT THU SEP 4 2014 ...SPECIAL WEATHER STATEMENT... AT 448 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM STILES TO PULASKI TO NAVARINO...MOVING SOUTHEAST AT 35 MPH. PEA SIZE HAIL...WINDS 30 TO 40 MPH...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THESE STORMS. * THUNDERSTORMS WILL BE NEAR... SUAMICO BY 520 PM CDT... HOWARD BY 520 PM CDT... GREEN BAY BY 520 PM CDT... GUSTY WINDS MAY CAUSE LIGHT WEIGHT OBJECTS TO BE BLOWN OVER. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THESE STORMS HAVE PASSED. RDM
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREEN BAY WI 515 PM CDT THU SEP 4 2014 WIZ019>021-030-031-035>037-074-042315- LANGLADE-MARATHON-MENOMINEE-NORTHERN OCONTO COUNTY-PORTAGE-SHAWANO-SOUTHERN OCONTO COUNTY-WAUPACA-WOOD- 515 PM CDT THU SEP 4 2014 ...STRONG THUNDERSTORMS MOVING ACROSS MARATHON COUNTY... AT 508 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS IN WESTERN MARATHON ALONG A LINE EXTENDING FROM 11 MILES WEST OF WAUSAU TO 33 MILES SOUTHWEST OF WAUSAU...MOVING EAST AT 40 MPH. ANOTHER AREA OF THUNDERSTORMS WERE LOCATED OVER EASTERN MARATHON COUNTY...JUST EAST OF MOSINEE TO WESTON ALSO MOVING EAST AT 40 MPH. PEA SIZE HAIL...WINDS 40 TO 45 MPH...FREQUENT CLOUD TO GROUND LIGHTNING...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THESE STORMS. BRIEF TORRENTIAL RAINFALL AND LOCALIZED URBAN FLOODING IS ALSO POSSIBLE AS THESE STORMS MOVE ACROSS THE COUNTY. ADDITIONAL STRONG STORMS EXTENDED FURTHER EAST INTO SHAWANO COUNTY. * THUNDERSTORMS WILL BE NEAR... WAUSAU AND RIB MOUNTAIN BY 530 PM CDT... WESTON AND MOSINEE BY 540 PM CDT... BEVENT BY 605 PM CDT... WITTENBERG BY 615 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 THESE STORMS HAVE PASSED. EB
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREEN BAY WI 619 PM CDT THU SEP 4 2014 WIZ031-036>039-045-048>050-074-050015- BROWN-CALUMET-MANITOWOC-OUTAGAMIE-PORTAGE-SHAWANO-SOUTHERN OCONTO COUNTY-WAUPACA-WAUSHARA-WINNEBAGO- 619 PM CDT THU SEP 4 2014 ...SPECIAL WEATHER STATEMENT... AT 616 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 5 MILES EAST OF SHAWANO TO 10 MILES NORTH OF WAUPACA TO 30 MILES NORTHWEST OF WAUTOMA...MOVING SOUTHEAST AT 40 MPH. WINDS 30 TO 40 MPH...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THESE STORMS. * THUNDERSTORMS WILL BE NEAR... NAVARINO WILDLIFE AREA BY 625 PM CDT... HARTMAN CREEK STATE PARK BY 630 PM CDT... WAUPACA AND PLAINFIELD BY 635 PM CDT... NEW LONDON BY 640 PM CDT... FREMONT AND BLACK CREEK BY 645 PM CDT... WAUTOMA BY 655 PM CDT... GUSTY WINDS MAY CAUSE LIGHT WEIGHT OBJECTS TO BE BLOWN OVER. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THESE STORMS HAVE PASSED. RDM
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREEN BAY WI
821 PM CDT THU SEP 04 2014
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0821 PM HEAVY RAIN ASHWAUBENON 44.46N 88.08W
09/04/2014 M2.39 INCH BROWN WI OFFICIAL NWS OBS
SO FAR TODAY.
&&
SACThe Green Bay radar (KGRB), 11 km away, was scanning. The volume nearest the first event began at 02:00 UTC.
2 hail, 1 lightning, 1 heavy rain, 1 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Lightning struck a building on the east side of Green Bay, damaging its roof and facade. The time of this event is estimated.
Heavy rainfall from thunderstorms caused street flooding in Marinette.
Thunderstorms produced a wet microburst that uprooted or snapped about a dozen trees near Little Sturgeon Bay. Winds were estimated at 60 to 70 mph.
Heavy rainfall flooded basements, resorts, and campgrounds, and damaged roads in the Sister Bay, Fish Creek, and Baileys Harbor areas. In excess of 6 inches of rain in Baileys Harbor caused nearly every home there to sustain a backup from the sewage disposal plant. Flood waters damaged documents at the Ephraim Historical Society. The flooding also washed out shoulders of several roads in the area.
Thunderstorms dropped quarter size hail near Amberg.
Quarter size fell from thunderstorms near Wausaukee.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2014Every state in 2014This day in weather historyWarnings in Wisconsin, September 2014
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: 542920, 542927, 542922, 542926, 542923, 542924.