A low pressure system advancing from the Northern Plains brought periods of wet heavy snow to portions of western Upper Michigan on the 20th.
Every event with a place to put it; 2 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 advancing from the Northern Plains brought periods of wet heavy snow to portions of western Upper Michigan on the 20th.
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 Mar 20, 2:28 AM CST, 32 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 428 AM EDT SUN MAR 20 2011 .DISCUSSION... GENERAL UPPER LEVEL OVERVIEW...CURRENTLY THE CWA IS UNDER A 250MB RIDGE CENTERED OVER THE CENTRAL CONUS. WE ARE ALSO UNDER THE RIGHT ENTRANCE REGION OF A 100KT+ JET...PRODUCING SOME HIGH CLOUDS. THERE IS A POS TILTED TROUGH OFF THE W COAST EXTENDING FROM A POLAR LOW...WITH A SHORTWAVE OVER UTAH. BY 06Z MON...THE SHORTWAVE WILL BE OVER THE AREA...WHILE THE TROUGH OVER THE W COAST BREAKS OFF THE POLAR TROUGH AND PIVOTS...BECOMES NEUTRALLY TILTED. THE TROUGH FROM THE POLAR LOW WILL EXTEND FROM GREENLAND TO HUDSON BAY...TO NORTHERN SASKATCHEWAN. BY 18Z MON...THE SHORTWAVE WILL BE OVER THE NE CONUS...WHILE THE POLAR TROUGH IS EXTENDED OVER ONTARIO. THE PRESSURE GRADIENT CREATED BY THE TROUGH AND A STRENGTHENING RIDGE OVER THE PLAINS STATES WILL CREATE A 100KT JET OVER THE EASTERN CWA. ALSO...THE TROUGH OVER THE W COAST WILL BE MORE NEG TILTED AND WILL LINK UP WITH A LOW CENTERED OVER FAR W RUSSIA. THE TROUGH OVER ONTARIO WILL MOVE OVER QUEBEC BY 06Z TUE...AND REMAIN THROUGH TUE NIGHT. HIGH PRESSURE WILL SLOWLY MOVE EAST TO UPPER MI BY 12Z WED. THE RESULTING PRESSURE GRADIENT WILL KEEP PARTS OF THE CWA IN THE RIGHT ENTRANCE REGION OF A 100-130KT JET FROM 00Z TUE THROUGH 06Z WED. IN THE MEANTIME BY 12Z WED...THE TROUGH THAT WAS OVER THE W COAST WILL BE QUITE NEG TILTED EXTENDING FROM THE NW CONUS TO IOWA. THEN BY 06Z THU...MODELS SHOW THAT THE TROUGH THAT WAS OVER QUEBEC HAS STRENGTHENED INTO A CLOSED LOW...AND MODELS SHOW THE NEG TILTED TROUGH THAT WAS CENTERED OVER IOWA HAS MERGED WITH THE LOW OVER QUEBEC...RESULTING IN A TROUGH EXTENDING OVER THE GREAT LAKES REGION AND HIGH PRESSURE TO THE WEST. MODELS AGREE WELL WITH LARGE SCALE DETAILS ON THE STRENGTH AND TIMING OF FEATURES THROUGH THIS TIME PERIOD. TODAY AND TONIGHT...PRECIP WILL MOVE IN FROM THE WEST THROUGH THE DAY AS WELL AS WAA AHEAD OF THE STORM SYSTEM THAT WILL EFFECT THE AREA. BY 00Z MON THE SHORTWAVE AND SFC LOW WILL BE OVER MN AND W WI. PAST MODEL RUNS DEEPENED THE SOUTHERN PORTIONS OF THE SFC LOW...BRINGING THE DOMINATING LOW OVER CENTRAL WI...BUT MODELS NOW SHOW A MORE COMPROMISED SOLUTION WITH THE SFC LOW MOVING OVER UPPER MI BY 06Z MON. MAIN FORECAST CHALLENGE WITH THIS SYSTEM WILL BE PRECIP TYPE AND AMOUNTS. LOW LEVEL TEMPS WILL BE ABOVE FREEZING BEFORE PRECIP STARTS...BUT VERY DRY LOW/MID LAYERS WILL ALLOW FOR COOLING AS PRECIP EVAPORATES THROUGH THESE LAYERS. THIS WILL RESULT IN A SHORT BURST OF SNOW BEFORE WAA BRING ABOVE FREEZING TEMPS AROUND 750MB JUST AHEAD OF THE LOW. KEPT MENTION OF THUNDER IN THE FORECAST WITH STEEPER LAPSE RATES IN THE MID LEVELS. THE DIVIDING LINE FOR PTYPE LOOKS TO BE OVER THE CENTRAL TO NORTHERN PARTS OF UPPER MI. SLR WILL BE LOW AS THE DGZ WILL BE VERY HIGH AND TEMPS WILL BE NEAR 0C. HEAVIEST PRECIP LOOKS TO FALL LATE SUNDAY EVENING AS THE SHORTWAVE MOVES OVER AND WE ARE UNDER THE LEFT EXIT REGION OF A 100KT+ JET. PRECIP AMOUNT WILL BE HIGHLY PATH DEPENDENT...ESPECIALLY FOR SNOWFALL AMOUNTS. STORM TOTAL QPF OVER ONE INCH CANNOT BE RULED OUT...BUT THE MIX OF RAIN AND SNOW ALONG WITH SLR LESS THAN 10 TO 1 WOULD FAVOR LOW SNOW AMOUNTS. SNOW TOTALS LOOK TO BE HIGHEST OVER E UPPER MI...AS COOLER TEMPERATURES WILL FAVOR LESS CHANGE OVER TO SNOW IN THIS AREA. SNOW AMOUNTS IN THE FORECAST OVER THE E CWA WOULD FAVOR A WINTER WX ADV...BUT GIVEN UNCERTAINTY IN EXACT AMOUNTS WILL LET THE DAY SHIFT DECIDE ON HEADLINES. BY 12Z MON...THE SFC LOW WILL BE OVER GEORGIAN BAY AND MOST OF THE SYNOPTIC PRECIP WILL BE OUT OF THE CWA. MID LEVEL TEMPS BEHIND THE SYSTEM WILL NOT BE SUFFICIENT FOR LES...WITH 850MB TEMPS AROUND -4C. MONDAY...SFC RIDGE OF HIGH PRESSURE WILL MOVE OVER THE CWA BY 00Z TUE. UPSLOPE PRECIP IS POSSIBLE OVER W UPPER MI...WHICH SHOULD BE IN THE FORM OF DRIZZLE AS SATURATED LOW LEVELS WILL NOT REACH THE DGZ. TUESDAY...SFC LOW WILL MOVE INTO W IA BY 00Z WED...PUSHING HIGH PRESSURE TO OUR EAST. PRECIP ASSOCIATED WITH THIS SYSTEM WILL SKIRT AREAS ALONG THE WI BORDER MUCH OF THE DAY...MOVING FARTHER INTO W UPPER MI LATE IN THE DAY. PRECIP SHOULD BE ALL SNOW AS 850MB 0C LINE WILL BE OVER CENTRAL WI. WEDNESDAY...THE SFC LOW WILL MOVE FROM W IA AT 00Z WED TO N IL BY 12Z WED...TO W PA BY 00Z THU. AT THE SAME TIME...THE 500MB LOW WILL MOVE FROM S MN AT 12Z WED...TO W WI BY 18Z WED...THEN IT WILL MERGE WITH THE LOW OVER QUEBEC AND FORM A TROUGH OVER E UPPER MI INTO S WI BY 00Z THU. THIS WILL BRING THE NEXT CHANCE OF SIGNIFICANT PRECIP TO THE REGION AS MODEL QPF IS WELL OVER AN INCH OVER N WI AND CENTRAL AND SOUTHERN UPPER MI. LAKE ENHANCEMENT WILL ALSO BE A FACTOR TO CONSIDER AS 850MB TEMPS WILL COOL FROM -8C AT 12Z WED TO -11C AT 00Z THU OVER CENTRAL LAKE SUPERIOR. FUTURE SHIFTS WILL HAVE TO CLOSELY WATCH THE TRACK WITH THIS SYSTEM AS SMALL DIFFERENCES WILL MAKE FOR SIGNIFICANT CHANGES TO THE FORECAST. AS IT IS NOW...SNOW ACCUMULATIONS WELL OVER 12 INCHES ARE POSSIBLE...HIGHEST OVER THE SOUTHERN CWA. MODELS HAVE BEEN PRETTY CONSISTENT WITH THIS SYSTEM OVER THE LAST COUPLE OF RUNS...SO INCREASED POPS WERE WARRANTED FOR THIS TIME PERIOD. && .AVIATION /FOR THE 06Z TAF ISSUANCE/... CMX...EXPECT VFR CONDITIONS TNGT WITH LLVL DRY AIRMASS/DOWNSLOPING SLY FLOW. ALTHOUGH THE LACK OF A PRES FALL CENTER TO THE N BRINGS TO QUESTION EXTENT OF LLWS...MAINTAINED GOING FCST WITH AT LEAST SHARP DIRECTIONAL SHEAR ABV SHALLOW SFC ESE FLOW FUNNELED BY TERRAIN. ARRIVAL OF DEEPER MSTR/WINTRY MIX OF PCPN ON SUN WL RESULT IN DETERIORATING CONDITIONS TO IFR BY LATER IN THE DAY. SAW...AN AREA OF LO CLD HAS DVLPD TO THE S WITH VERY SHALLOW MSTR DEPICTED ON THE 00Z GRB RAOB UPSLOPING INTO SCNTRL UPR MI. STRENGTHENING SLY FLOW WL LIKELY ADVECT THIS CLD/IFR CIGS INTO SAW FOR AT LEAST A TIME EARLY THIS MRNG BEFORE INCRSG SSW FLOW THAT WL RESULT IN MARGINAL LLWS BRINGS DRIER AIR THAT IS PRESENT FARTHER S INTO NCENTRAL UPR MI. ARRIVAL OF DEEPER MSTR/WINTRY MIX OF PCPN ON SUN WL RESULT IN DETERIORATING CONDITIONS TO IFR BY LATER IN THE DAY WITH UPSLOPE SE FLOW. CONDITIONS MAY FALL TO LIFR LATE THIS EVNG UNDER SOME DRYING ALF THAT WL TEND TO DIMINISH PCPN. && .MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/... A LOW PRESSURE SYSTEM WILL MOVE OVER THE AREA BY LATE TODAY...BRINGING STRONG SE WINDS UP TO 30 KNOTS AHEAD OF THE LOW. STRONG WINDS ARE EXPECTED TUESDAY INTO WED AS A TIGHT PRES GRADIENT DEVELOPS BETWEEN LOW PRES MOVING FROM THE PLAINS TOWARD NORTHERN IL AND HIGH PRES OVER NRN ONTARIO. ENE WINDS GALES WILL BE POSSIBLE FROM TUE AFTERNOON INTO WED...ESPECIALLY ACROSS THE WRN PORTION OF THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && DISCUSSION...TITUS AVIATION...KC MARINE...JLB
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MARQUETTE MI 431 PM EDT SAT MAR 19 2011 MIZ001>007-009>014-084-085-201200- KEWEENAW-ONTONAGON-NORTHERN HOUGHTON-BARAGA-MARQUETTE-ALGER-LUCE- GOGEBIC-IRON-DICKINSON-MENOMINEE-DELTA-SOUTHERN SCHOOLCRAFT- SOUTHERN HOUGHTON-NORTHERN SCHOOLCRAFT- 431 PM EDT SAT MAR 19 2011 /331 PM CDT SAT MAR 19 2011/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WESTERN UPPER MICHIGAN AND CENTRAL UPPER MICHIGAN. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THERE IS A SLIGHT CHANCE OF THUNDERSTORMS SUNDAY AFTERNOON INTO SUNDAY EVENING OVER THE WEST HALF OF UPPER MICHIGAN. SEVERAL INCHES OF WET SNOW ARE POSSIBLE SUNDAY NIGHT EAST OF A LINE FROM MUNISING TO MANISTIQUE. .SPOTTER INFORMATION STATEMENT... THE NEED FOR WEATHER SPOTTER REPORTS IS NOT ANTICIPATED AT THIS TIME. LSZ162-240>251-263>267-201200- 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- 431 PM EDT SAT MAR 19 2011 /331 PM CDT SAT MAR 19 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...SUNDAY THROUGH FRIDAY SOUTHEAST GALE FORCE GUSTS TO 35 KNOTS ARE POSSIBLE SUNDAY AFTERNOON OVER NORTH CENTRAL LAKE SUPERIOR. EAST GALE FORCE WINDS OF 35 TO 40 KNOTS ARE EXPECTED LATE TUESDAY AFTERNOON THROUGH WEDNESDAY OVER THE WESTERN HALF LAKE SUPERIOR. HEAVY FREEZING SPRAY IS ALSO POSSIBLE TUESDAY NIGHT. .SPOTTER INFORMATION STATEMENT... THE NEED FOR WEATHER SPOTTER REPORTS IS NOT ANTICIPATED AT THIS TIME. LMZ221-248-250-201200- 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- 431 PM EDT SAT MAR 19 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...SUNDAY THROUGH FRIDAY EAST GALE FORCE WINDS TO 35 KNOTS ARE EXPECTED TUESDAY NIGHT AND WEDNESDAY. .SPOTTER INFORMATION STATEMENT... THE NEED FOR WEATHER SPOTTER REPORTS IS NOT ANTICIPATED AT THIS TIME. JLA
The national radar mosaic for the moment the first event began.
2 winter weather. Local standard time, as filed.
Spotters near Marenisco measured four to five inches of wet snow in the early morning hours of the 20th. Greater than one inch per-hour snowfall rates occurred over a three-hour period.
There was a report of three inches of wet snow in Calumet during the late afternoon and evening hours of the 20th. The Houghton County Airport also reported lowered visibility in moderate to heavy snow during the event.
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, March 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: 290998, 290999.