A warm front over Wisconsin generated severe thunderstorms with large hail over portions of western Upper Michigan on the 11th.
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 MQT wrote it up.
A warm front over Wisconsin generated severe thunderstorms with large hail over portions of western Upper Michigan on the 11th.
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 Marquette, MI wrote its last area forecast discussion before the first event at May 9, 4:03 PM EST, 10 hours 21 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 503 PM EDT MON MAY 9 2011 .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS INDICATED AN AMPLIFIED PATTERN WITH A MID/UPPER LEVEL TROUGH OVER THE WRN CONUS AND A RIDGE FROM THE LOWER MS VALLY TO THE WRN GREAT LAKES. AT THE SFC...LOW PRES WAS LOCATED OVER NEBRASKA WITH A WARM FRONT TO THE SE INTO SRN IL. A TIGHT GRADIENT BTWN THE LOW AND A RDG FROM QUEBEC INTO THE CNTRL LAKES WAS BRINGING GUSTY SE WINDS TO THE REGION. THE PERIOD OF STRONG/DAMAGING WINDS INTO FAR WEST UPPER MI NEAR LITTLE GIRLS POINT RESULTED FROM A WAKE LOW GENERATED BY THE MCS OVER WI THIS MORNING. AN AREA OF SHOWERS FROM NE MN INTO WRN LAKE SUPERIOR WAS SUPPORTED BY THE MCV/VORT OVER NE MN. THE TSRA HAD SLID WELL TO THE SOUTH...OVER SRN WI...IN CLOSER PROXIMITY TO THE 850 MB FRONT. && .SHORT TERM...TONIGHT AND TUESDAY MODELS INDICATE THAT THE SHORTWAVE/VORT AND ASSOCIATED QVECTOR CONV AND ISENTROPIC LIFT WILL SLIDE TO THE EAST THROUGH UPPER MI TONIGHT. HOWEVER...RADAR/SATELLITE TRENDS SUGGEST THAT THE AREA OF SHOWERS MAY SLIDE MORE QUICKLY THROUGH THE WRN CWA THIS EVENING. IN ADDITION...EXPECT THAT TSRA DEVELOPMENT CLOSER TO THE STRONGER INSTABILITY OVER SRN WI WILL LIMIT MOISTURE INFLOW TO THE NORTH AND PRECIP DEVELOPMENT OVER THE CWA WITH ANY PRECIP AMOUNTS GENERALLY OF ONLY AROUND A TENTH OF AN INCH. SO...ONLY INCLUDED CHANCE/SCT POPS ACROSS THE CWA AND DID NOT MENTION TSRA. THE WRN CONUS TROUGH WILL CONTINUE TO DIG INTO THE ROCKIES AND NRN PLAINS ON TUES AND AMPLIFY THE RIDGE BEHIND THE EXITING SHORTWAVE. THIS SHOULD BRING AN END TO ANY LINGERING PCPN OVER THE ERN CWA DURING THE MORNING. PROMINENT CAPPING...PER NAM/GFS SOUNDINGS SHOULD LIMIT PCPN CHANCES BY TUE AFTERNOON EVEN WITH THE PRESENCE OF GREATER LOW LEVEL MOISTURE. .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... THE 500MB RIDGE STRETCHING FROM THE GULF OF MEXICO THROUGH ONTARIO WILL REMAIN STRONG TO BEGIN THIS PERIOD...AS THE FIRST LOW OVER THE WESTERN DAKOTAS RIDES UP THE RIDGE AND EXITS INTO CENTRAL CANADA WEDNESDAY. LOOK FOR THE BREAKDOWN OF THE 500MB RIDGE TO BEGIN WEDNESDAY NIGHT...WITH A WEST TO EAST ORIENTED RIDGE ATTEMPTING TO BUILD BACK IN THURSDAY...IN BETWEEN THE NORTHERN LOW AND THE SECONDARY LOW SET UP OVER THE CENTRAL PLAINS. MODEL DISCREPANCIES BEGIN TO SHOW THEMSELVES WEDNESDAY NIGHT WITH THE EVOLUTION OF THE 2 LOW 500MB LOWS. THE ECMWF WOULD PREFER TO KEEP THEM SEPARATE...WHILE THE GFS LOOKS TO BE THE OUTLIER...COMBINING THEM OVER THE NORTHERN PLAINS STATES ON THURSDAY. HAVE HEDGED THE FORECAST AWAY FROM THE GFS AFTER WEDNESDAY NIGHT. AS FOR WEATHER SPECIFICS DURING THE PERIOD...FEW SIGNIFICANT CHANGES WERE MADE TO THE ONGOING FORECAST. BR/FG STILL LOOKS LIKE A GOOD BET OVER THE GREAT LAKES TUESDAY NIGHT THROUGH THURSDAY. ADDED THE WESTERN LAND AREAS LATE WEDNESDAY NIGHT INTO EARLY THURSDAY AS WELL...AS TEMPS AND DEW POINTS COLLIDE IN THE MID 50S...WITH THE TIGHTEST PRESSURE GRADIENT SLIDING INTO EASTERN UPPER MI. OTHERWISE...I WARMED UP AFTERNOON HIGH TEMPS FOR LATER THIS WEEK...PARTICULARLY NEAR LAKE SUPERIOR AS SOUTH TO SOUTHEASTERLY WINDS REMAIN IN CONTROL THROUGH THURSDAY NIGHT. HOWEVER...NORTHERLY LAKE BREEZES MAY BEGIN TO CREEP BACK IN THURSDAY. EITHER WAY...HAVE INCLUDED A MORE GRADUAL COOL DOWN THURSDAY THROUGH SATURDAY...AND KEPT TEMPERATURES INLAND NEAR THE WISCONSIN BORDER A BIT WARMER. ADDED AFTERNOON THUNDER AWAY FROM LAKE SUPERIOR FRIDAY...BUT ONLY SLIGHT CHANCE AT THIS POINT...WITH THE BEST CHANCE OF CONVECTION REMAINING OVER WI AND LOWER MI. && .AVIATION /FOR THE 18Z TAF ISSUANCE/... MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE FCST PERIOD. A BRIEF PERIOD OF LIGHT SHOWERS WILL BE POSSIBLE TONIGHT BUT SHOULD NOT HAVE A SIGNIFICANT IMPACT ON CIG/VSBY. LOW LEVEL WIND SHEAR IS ALSO EXPECTED AGAIN TONIGHT WITH STRONG SE WINDS ABOVE THE DECOUPLING SURFACE LAYER. && .MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/... SE WINDS OF 15 TO 25 KT WILL CONTINUE TONIGHT INTO WED DUE TO A TIGHT GRADIENT BTWN HUDSON BAY HIGH PRESSURE MOVING EAST INTO QUEBEC AND LOW PRES SLOWLY LIFTING NORTH THROUGH THE CENTRAL PLAINS. THE STRONGEST WINDS WILL BE OVER CENTRAL AND EASTERN LAKE SUPERIOR. WINDS WILL DECREASE BLO 20 KNOTS BY WED EVENING AS THE LOW PRESSURE TROUGH OVER THE NRN PLAINS MOVES INTO WESTERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && SYNOPSIS...JLB SHORT TERM...JLB LONG TERM...KF AVIATION...JLB MARINE...JLB
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MARQUETTE MI 421 PM EDT MON MAY 9 2011 MIZ001>007-009>014-084-085-101200- KEWEENAW-ONTONAGON-NORTHERN HOUGHTON-BARAGA-MARQUETTE-ALGER-LUCE- GOGEBIC-IRON-DICKINSON-MENOMINEE-DELTA-SOUTHERN SCHOOLCRAFT- SOUTHERN HOUGHTON-NORTHERN SCHOOLCRAFT- 421 PM EDT MON MAY 9 2011 /321 PM CDT MON MAY 9 2011/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WESTERN UPPER MICHIGAN AND CENTRAL UPPER MICHIGAN. .DAY ONE...TONIGHT ELEVATED FIRE DANGER WILL CONTINUE INTO EARLY EVENING ACROSS MUCH OF THE AREA...PARTICULARLY AWAY FROM THE LAKE MICHIGAN SHORELINE. THIS IS A RESULT OF RECENT DRY WEATHER...GUSTY SOUTHEASTERLY WINDS...AND ABOVE NORMAL TEMPERATURES. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THUNDERSTORMS WILL BE POSSIBLE TUESDAY NIGHT THROUGH THURSDAY. .SPOTTER INFORMATION STATEMENT... THE NEED FOR WEATHER SPOTTER REPORTS IS NOT ANTICIPATED AT THIS TIME. LSZ162-240>251-263>267-101200- LAKE SUPERIOR WEST OF A LINE FROM SAXON HARBOR WI TO GRAND PORTAGE MN BEYOND 5NM-SAXON HARBOR WI TO BLACK RIVER MI- BLACK RIVER TO ONTONAGON MI- ONTONAGON TO UPPER ENTRANCE OF PORTAGE CANAL MI- UPPER ENTRANCE OF PORTAGE CANAL TO EAGLE RIVER MI- EAGLE RIVER TO MANITOU ISLAND MI- MANITOU ISLAND TO POINT ISABELLE MI- POINT ISABELLE TO LOWER ENTRANCE OF PORTAGE CANAL MI- LOWER ENTRANCE OF PORTAGE CANAL TO HURON ISLANDS MI INCLUDING KEWEENAW AND HURON BAYS-HURON ISLANDS TO MARQUETTE MI- MARQUETTE TO MUNISING MI-MUNISING TO GRAND MARAIS MI- GRAND MARAIS TO WHITEFISH POINT MI- LAKE SUPERIOR FROM SAXON HARBOR WI TO UPPER ENTRANCE TO PORTAGE CANAL MI 5NM OFF SHORE TO THE US/CANADIAN BORDER INCLUDING ISLE ROYALE NATIONAL PARK- LAKE SUPERIOR FROM UPPER ENTRANCE TO PORTAGE CANAL TO MANITOU ISLAND MI 5NM OFF SHORE TO THE US/CANADIAN BORDER- LAKE SUPERIOR WEST OF LINE FROM MANITOU ISLAND TO MARQUETTE MI BEYOND 5NM FROM SHORE- LAKE SUPERIOR EAST OF A LINE FROM MANITOU ISLAND TO MARQUETTE MI AND WEST OF A LINE FROM GRAND MARAIS MI TO THE US/CANADIAN BORDER BEYOND 5NM FROM SHORE- LAKE SUPERIOR FROM GRAND MARAIS MI TO WHITEFISH POINT MI 5NM OFF SHORE TO THE US/CANADIAN BORDER- 421 PM EDT MON MAY 9 2011 /321 PM CDT MON MAY 9 2011/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN LAKE SUPERIOR...CENTRAL LAKE SUPERIOR AND WESTERN LAKE SUPERIOR. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THUNDERSTORMS WILL BE POSSIBLE TUESDAY NIGHT THROUGH THURSDAY. .SPOTTER INFORMATION STATEMENT... THE NEED FOR WEATHER SPOTTER REPORTS IS NOT ANTICIPATED AT THIS TIME. LMZ221-248-250-101200- GREEN BAY NORTH OF LINE FROM CEDAR RIVER MI TO ROCK ISLAND PASSAGE-SEUL CHOIX POINT TO POINT DETOUR MI- 5NM EAST OF A LINE FROM FAIRPORT MI TO ROCK ISLAND PASSAGE- 421 PM EDT MON MAY 9 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHERN LAKE LAKE MICHIGAN. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THUNDERSTORMS WILL BE POSSIBLE TUESDAY NIGHT THROUGH THURSDAY. .SPOTTER INFORMATION STATEMENT... THE NEED FOR WEATHER SPOTTER REPORTS IS NOT ANTICIPATED AT THIS TIME. KF
The Marquette radar (KMQT), 125 km away, was scanning. The volume nearest the first event began at 07:24 UTC.
4 hail, 1 lightning. Local standard time, as filed.
There were multiple reports of estimated quarter-sized hail between Bruce Crossing and Trout Creek. Time of the reports was estimated from radar imagery.
Lightning struck and damaged the steeple tower of the Keweenaw Heritage Center at St. Anne's located in Calumet Township on the early morning of the 11th.
Pea to penny-sized hail was reported. Time of the report was estimated from radar.
Hail tapered off to pea-sized by 237 am CST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Michigan in 2011Every state in 2011This day in weather historyWarnings in Michigan, May 2011
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: 302253, 302287, 302254, 302259, 302260.