A low pressure system moving in from Minnesota dropped moderate snow over portions of western Upper Michigan from the 22nd into the 23rd.
Every event with a place to put it; 5 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 low pressure system moving in from Minnesota dropped moderate snow over portions of western Upper Michigan from the 22nd into the 23rd.
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 Apr 22, 5:18 PM EST, 42 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 618 PM EDT FRI APR 22 2011 .SHORT TERM /THROUGH SATURDAY AFTERNOON/... FAIRLY COMPLEX FORECAST FOR THE NEXT 18 HOURS WITH CONCERNS CENTERED AROUND STRENGTH OF LOW PRESSURE MOVING THROUGH THE UPPER GREAT LAKES AND THE POTENTIAL FOR SOME SLUSHY SNOW ACROSS THE WEST OVERNIGHT. HIGH PRESSURE CONTINUES TO MOVE EAST TO THE EASTERN SEABOARD. A MUCH MORE COMPLEX PRESSURE PATTERN EXISTS OVER THE MIDSECTION OF THE COUNTRY WITH ONE AREA OF LOW PRESSURE OVER SD ASSOCIATED WITH A WELL DEFINED SHORTWAVE/UPPER LOW DEPICTED ON WV IMAGERY. ANOTHER SFC LOW IS LOCATED OVER NORTHERN MO. THE INTERACTION OF THESE 2 LOWS AS THEY MOVE TOWARDS THE UPPER GREAT LAKES WILL RESULT IN A PERIOD OF INCLEMENT WEATHER OVERNIGHT TONIGHT ACROSS UPPER MICHIGAN. MODELS ARE TRYING TO COME INTO BETTER AGREEMENT WITH THE OVERALL EVOLUTION OF THE LOWS TONIGHT BUT SOME DIFFERENCES STILL REMAIN EVEN AT THIS LATE IN THE GAME. SD LOW WILL MOVE EAST AND SHOULD SLOWLY WEAKEN AS NORTHERN MO LIFTS INTO THE WESTERN GREAT LAKES AND ESSENTIALLY BECOMES THE DOMINANT LOW. THE NAM THE LAST SEVERAL DAYS WAS THE MOST WOUND UP WITH THIS LOW OVER THE UPPER GREAT LAKES BUT ITS LATEST RUN HAS CHANGED COURSE A LITTLE TOWARDS A WEAKER LOW SIMILAR TO THE ECMWF. THE GFS NOW APPEARS TO BE THE STRONGEST OF THE MODELS WITH THE LOW OVER EXTREME EASTERN UPPER MI BY SATURDAY MORNING. AM A LITTLE CONCERNED ABOUT HOW IMPRESSIVE THE CURRENT UPPER AND SFC LOW LOOK LIKE OVER SD ON WV IMAGERY AND WHETHER OR NOT THIS WESTERN LOW WILL WEAKEN AS QUICKLY AS FORECAST AS IT MOVES EAST TOWARDS THE GREAT LAKES. MODELS ARE ALL HINTING AT .50-.75 INCHES OF QPF DESPITE THEIR DIFFERENCES. IF THE SD LOW REMAINS A LITTLE STRONGER AND TRACKS CLOSER AMOUNTS COULD BE A LITTLE HIGHER. WITH FAIRLY IMPRESSIVE DYNAMICS MOVING ACROSS THE REGION IN A RELATIVELY SHORT TIME WINDOW...MOST OF THE PRECIPITATION WILL FALL IN A 6 HOUR PERIOD OVERNIGHT. THERMAL PROFILES INITIALLY WILL SUPPORT ALL RAIN AT THE ONSET OF PRECIPITATION. HOWEVER...WITH DYNAMIC COOLING PRECIPITATION ACROSS THE WEST AND HIGHER TERRAIN SHOULD TRANSITION TO SNOW FOR A FEW HOURS. ALL MODEL SOUNDING SHOWING COOLING RESULTING IN A FAIRLY DEEP ISOTHERMAL LAYER JUST BELOW 0 C. THE CHALLENGE IS HOW MUCH PRECIPITATION WILL FALL AS LIQUID BEFORE SUCH A CHANGEOVER. WILL GO WITH THE IDEA OF AT LEAST HALF OF THE PRECIPITATION FALLING AS LIQUID ACROSS THE WEST...AND THEN WITH SNOW RATIOS IN THE 5-8:1 RANGE...AND THAT MIGHT BE GENEROUS...THAT WOULD YIELD 1-3 INCHES WITH LOCALLY HIGHER AMOUNTS OF SLUSHY SNOW ACROSS THE WEST. GIVEN THE FACT IT IS IN THE 40S TO NEAR 50 TODAY...PRECIP WILL BE FALLING DURING THE OVERNIGHT HOURS...AND IT WILL QUICKLY WARM INTO THE 30S AND 40S ON SATURDAY DO NOT ANTICIPATE HUGE IMPACTS FROM THE SNOW. THE SNOW MAY COME DOWN HARD FOR AN HOUR OR 2 SO THERE COULD BE A BRIEF PERIOD OF SLUSHY CONDITIONS ON THE ROADWAYS. WILL REISSUE THE SPS HIGHLIGHTING THE POTENTIAL FOR A COUPLE INCHES OF SNOW OVERNIGHT. ACROSS THE EAST...MAINLY LIQUID RAIN IS EXPECTED. THE LOW WILL QUICKLY LIFT NORTHEASTWARD ON SATURDAY WITH IMPROVING CONDITIONS ACROSS THE AREA. WITH NO REALLY COLD AIR BEHIND THE LOW AND SOME GRADUAL CLEARING DURING THE DAY...TEMPERATURES SHOULD MAKE IT TO NEAR NORMAL INTO THE 40S TO NEAR 50 SOUTH. .LONG TERM DISUCCSION /SAT NGT THRU FRI/... SAT NGT...UNDER UPR CONFLUENCE ZN...SFC HI PRES IS PROGGED TO DRIFT INTO WI BY 12Z SUN. SO EXPECT A QUIET NGT OF WX OVER UPR MI. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCNTRL CLOSER TO THE HI PRES CENTER/WEAKER PRES GRADIENT. SHARPER PRES GRADIENT ON THE NRN FLANK OF HI CENTER/STRONGER H925 FLOW OVER THE NRN TIER WL RESTRICT DIURNAL FALL OF TEMP NEAR LK SUP. SUN...ALTHOUGH THERE MAY BE SOME MID/HI CLDS STREAMING THRU THE UPR GRT LKS ON SRN FLANK OF LO PRES MOVING W-E ACRS NRN ONTARIO UNDER ZONAL FLOW ALF...EASTER SHOULD BE A RELATIVELY PLEASANT DAY WITH H85 TEMPS FCST TO RISE TO ARND 2C AND SFC HI CENTER SHIFTING TO UNDER LK HURON BY 00Z MON. MIXING TO H75 ON NAM/GFS FCST SDNGS INDICATE THE HIER NAM MOS TEMPS WOULD BE MOST APPROPRIATE. TEMPS NEAR LK MI WL BE HELD DOWN A BIT BY THE SW FLOW OFF LK MI...BUT WLY H925 FLOW TO 18Z WL LIMIT THE MODERATION W OF ESC AND THE INLAND PUSH OF THE SGNFT MODERATION EVEN FARTHER E. THE GFS FCST SDNGS APPEAR TOO MOIST IN THE LLVLS. IN FACT...THE GFS GENERATES SOME LGT PCPN OVER THE INTERIOR W HALF. BUT PROXIMITY OF UPR CONFLUENCE ZN AND LINGERING HI PRES RDG SUG THE DRIER NAM PROFILE IS MORE RSNBL. SUN NGT...EXPECT ANOTHER QUIET NGT OF WX WITH SHARPENING SFC-H7 RDG AXIS UNDER AREA OF UPR CONFLUENCE. ALTHOUGH THERE MAY BE SOME HI CLDS DRIFTING IN AS THE UPR FLOW BEGINS TO BACK MORE SW AHEAD OF A DEEPENING TROF TO THE W...THE OVERNGT WL BE MOCLR. MON...HI CLDS WL BE ON THE INCRS AS UPR FLOW CONTINUES TO BACK SW WELL TO THE NE OF DVLPG LO PRES IN THE CNTRL PLAINS. H85 TEMPS ARE FCST TO REACH 4C IN THE AFTN...SO FCST SOME MAX TEMPS INTO THE 60S OVER THE INTERIOR W FAVORED BY DOWNSLOPE SSE FLOW ON WRN FLANK OF HI PRES DEPARTING TO THE E. ALTHOUGH THERE ARE QUESTIONS AS TO HOW FAR N ACCOMPANYING PCPN WL MOVE INTO THE ANTECEDENT DRY AIR IN THE UPR LKS...OPTED TO MAINTAIN GOING SCHC POPS FOR THE FAR SCNTRL IN THE AFTN AS THE FASTER 12Z GFS SHOWS INCRSG DEEPER MSTR IN THAT AREA BY 00Z TUE UNDER ENHANCED UPR DVGC IN RRQ OF UPR JET OVER SE CAN. OPS MODELS REMAIN IN GOOD AGREEMENT AND CONSISTENT ON DEVELOPMENT OF TROFFING IN THE PLAINS FOR MUCH OF NEXT WEEK. HOWEVER...THERE ARE DIFFERENCES ON THE TIMING/TRACK/INTENSITY OF INDIVIDUAL LO PRES CENTERS RELATED TO PASSAGE OF SHRTWVS THRU THE MEAN TROF. PER NCEP GUIDANCE...TENDED TOWARD THE 00Z ECMWF FOR FCST DETAILS. THIS MODEL...AND THE MAJORITY OF THE OTHER OPS MODELS...SHOW AN OCCLUDING SFC LO TRACKING INTO THE UPR GRT LKS LATE TUE...SO HI LIKELY POPS SEEM APPROPRIATE FOR TUE. THE ECMWF THEN SHOWS THE OCCLUSION LIFTING TO THE N WITH SOME DRYING IMPACTING THE CWA. BUT MAINTAINED CHC POPS TO ACCOUNT FOR LINGERING CYC FLOW AND UNCERTAINTY ON TIMING AND TRACK OF SECOND LO FCST TO MOVE NE INTO THE GRT LKS ON THU. VARIOUS MODELS SHOW ENUF COLD AIR WRAPPING INTO THE UPR LKS ON WED/THU TO SUPPORT AT LEAST A MIX WITH SN...ESPECIALLY ON THU UNDER DEEPER CYC NLY FLOW ASSOCIATED WITH DEEPENING OF SECOND SFC LO TRACKING TO THE E OF UPR MI. THEN WENT DRY FOR FRI FCST WITH HUDSON BAY HI PRES FCST TO BUILD INTO THE UPR LKS. && .AVIATION /FOR THE 18Z TAF ISSUANCE/... VFR CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE AFTERNOON BEFORE CEILINGS AND VSBYS LOWER OVERNIGHT. AS SURFACE LOW DEVELOPS AND LIFTS NORTHEASTWARD INTO EASTERN PORTIONS OF THE UPPER GREAT LAKES A 6-8 HOUR PERIOD OF PRECIPITATIONS WILL ACCOMPANY THE LOW PASSAGE. PRECIPITATION WILL INITIALLY BEGIN AS RAIN DURING THE EVENING...BUT THEN ENOUGH DYNAMIC COOLING WILL OCCUR TO ALLOW THE RAIN TO MIX WITH OR CHANGE TO SNOW AT BOTH SITES OVERNIGHT. WITH THE MOISTENING LOW LEVELS AND PRECIPITATION...CEILINGS AND VSBYS WILL LOWER INTO THE MVFR RANGE OVERNIGHT WITH A PERIOD OF VFR CONDITIONS POSSIBLE. THE LOW WILL QUICKLY MOVE OFF TO THE EAST ON SATURDAY WITH IMPROVING CONDITIONS. && .MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/... QUICK MOVING LOW LIFTING THROUGH THE UPPER GREAT LAKES WILL RESULT IN SOME GUSTY WINDS OVERNIGHT AND EARLY SATURDAY...BUT WITH LACK OF COLD AIR ASSICATED WITH THE LOW WINDS SHOULD REMAIN BELOW 25 KNOTS. HIGH PRESSURE OVERHEAD ON SUNDAY AND MOST OF MONDAY WILL RESULT IN TRANQUIL CONDITIONS. ANOTHER POTENTIALLY STRONG LOW PRESSURE SYSTEM WILL LIFT INTO THE UPPER GREAT LAKES ON TUESDAY. MODELS STILL VARY QUITE A BIT WIT HTHE ACTUAL TRACK OF THE LOW...BUT CURRENT THINKING OF THE LOW TRACKING ACROSS THE U.P. SHOULD KEEP WINDS BELOW GALES BOTH AHEAD AND BEHIND THE LOW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && SHORT TERM...MZ LONG TERM...KC AVIATION...MZ MARINE...MZ
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MARQUETTE MI 408 PM EDT FRI APR 22 2011 MIZ001>007-009>014-084-085-231200- KEWEENAW-ONTONAGON-NORTHERN HOUGHTON-BARAGA-MARQUETTE-ALGER-LUCE- GOGEBIC-IRON-DICKINSON-MENOMINEE-DELTA-SOUTHERN SCHOOLCRAFT- SOUTHERN HOUGHTON-NORTHERN SCHOOLCRAFT- 408 PM EDT FRI APR 22 2011 /308 PM CDT FRI APR 22 2011/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WESTERN UPPER MICHIGAN AND CENTRAL UPPER MICHIGAN. .DAY ONE...TONIGHT A LOW PRESSURE SYSTEM MOVING THROUGH THE CENTRAL GREAT LAKES WILL DROP AS MUCH AS 2 TO 4 INCHES OF WET SNOW TONIGHT OVER THE HIGHER TERRAIN NORTHWEST OF A LINE FROM IRON MOUNTAIN TO MARQUETTE. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... THE NEED FOR WEATHER SPOTTER REPORTS IS NOT ANTICIPATED AT THIS TIME. LSZ162-240>251-263>267-231200- 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- 408 PM EDT FRI APR 22 2011 /308 PM CDT FRI APR 22 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...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... THE NEED FOR WEATHER SPOTTER REPORTS IS NOT ANTICIPATED AT THIS TIME. LMZ221-248-250-231200- 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- 408 PM EDT FRI APR 22 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...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... THE NEED FOR WEATHER SPOTTER REPORTS IS NOT ANTICIPATED AT THIS TIME. KC
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MARQUETTE MI 349 PM EDT FRI APR 22 2011 MIZ001>005-009>011-084-230400- KEWEENAW-ONTONAGON-NORTHERN HOUGHTON-BARAGA-MARQUETTE-GOGEBIC- IRON-DICKINSON-SOUTHERN HOUGHTON- INCLUDING THE CITIES OF...COPPER HARBOR...ONTONAGON...HOUGHTON... HANCOCK...L'ANSE...GWINN...MARQUETTE...IRONWOOD...IRON RIVER... IRON MOUNTAIN...KENTON...SIDNAW 349 PM EDT FRI APR 22 2011 /249 PM CDT FRI APR 22 2011/ ...LIGHT SLUSHY SNOW ACCUMULATIONS TONIGHT... A STORM SYSTEM MOVING INTO THE UPPER GREAT LAKES TONIGHT WILL BRING RAIN INTO WESTERN UPPER MICHIGAN LATER THIS EVENING. AS THE RAIN COOLS THE AIRMASS...THE RAIN WILL TRANSITION TO SNOW WEST OF A MARQUETTE TO IRON MOUNTAIN LINE. THE SNOW MAY FALL MODERATE TO HEAVY FOR A BRIEF TIME RESULTING IN WET...SLUSHY SNOW ACCUMULATIONS OF 1 TO 3 INCHES. LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE ACROSS THE HIGHER TERRAIN OF THE HURON MOUNTAINS. WHILE THE RECENT MILD CONDITIONS SHOULD ACT TO LIMIT THE OVERALL IMPACTS ON AREA ROADWAYS...ROADS MAY BRIEFLY BECOME SLUSH COVERED AS THE HEAVIER SNOW MOVES ACROSS THE AREA LATER TONIGHT.
The national radar mosaic for the moment the first event began.
5 winter weather. Local standard time, as filed.
Nearly four inches of snow fell in a 12-hour period at the National Weather Service in Negaunee Township.
A widespread four to five inches of snow fell across the county in just over a 12-hour period. Some greater than one-inch per hour snowfall rates were reported on the evening of the 22nd.
The observer near Alberta measured nearly four inches of wet snow in ten hours.
Storm total snowfall amounts included 5.5 inches of snow near Alston and five inches near Redridge.
The spotter near Rockland measured three inches of wet snow in eight hours.
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, April 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: 297653, 297652, 297654, 297657, 297655.