788  
FXUS63 KMQT 200008  
AFDMQT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MARQUETTE MI  
708 PM EST THU DEC 19 2024  
   
KEY MESSAGES  
 
- LIGHT TO MODERATE SNOW WILL PERSIST THROUGH FRIDAY MORNING IN  
ASSOCIATION WITH A CLIPPER SYSTEM AS WELL AS LAKE ENHANCED  
SNOW OFF OF LAKE MICHIGAN AND ACROSS THE KEWEENAW PENINSULA.  
 
- A QUICK 1-2" OF HEAVY LAKE EFFECT SNOW IS LIKELY FRIDAY  
MORNING ACROSS MARQUETTE COUNTY, OTHERWISE LIGHT LAKE EFFECT  
SNOW WILL LINGER IN THE EAST-CENTRAL U.P. THROUGH SATURDAY.  
 
- ANOTHER SYSTEM COULD POTENTIALLY BRING A FEW INCHES OF SNOW  
ON MONDAY WITH LIKELY DRIER AND WARMER CONDITIONS BEHIND THE  
SYSTEM FOR CHRISTMAS EVE INTO CHRISTMAS DAY.  
 
 
   
SHORT TERM /THROUGH TONIGHT/  
 
ISSUED AT 355 PM EST THU DEC 19 2024  
 
FOCUS THIS AFTERNOON THROUGH TONIGHT CONTINUES TO BE ON A CLIPPER  
LOW PROGAGATING THROUGH THE REGION. LATEST WATER VAPOR  
IMAGERY/SURFACE ANALYSIS SHOWS THE SYSTEM POSITIONED ALONG THE  
MINNESOTA/IOWA BORDER WITH ASSOCIATED PRECIPITATION SHIELD  
CONCENTRATED OVER SOUTHEAST WI. DESPITE DWINDLING SNOW CHANCES  
ACROSS MENOMINEE COUNTY WITH THE CLIPPER SYSTEM, WILL CONTINUE TO  
TREND TOWARD POSSIBLE LAKE-ENHANCED UPSLOPE FLOW INTO TONIGHT. AS A  
RESULT, THE WARNING HAS BEEN DOWNGRADED TO ADVISORY LEVEL FOR  
MENOMINEE COUNTY TO BEST CAPTURE THIS TREND. MEANWHILE, ALSO  
IMPACTED BY THE N-S LAKE ENHANCED SNOW BAND WILL BE DELTA AND  
SCHOOLCRAFT COUNTIES. SO, THOSE WILL REMAIN UNDER ADVISORIES AS  
WELL. ELSEWHERE, SOME CAMS CONTINUE TO HINT AT LAKE ENHANCED  
BANDING, SOME WITH HEAVY SNOW AT TIMES, ACROSS THE KEWEENAW  
PENINSULA TONIGHT. SO, WINTER WEATHER ADVISORIES REMAIN IN EFFECT  
THROUGH THE NIGHT FOR THE PENSINSULA, TOO. SNOW AMOUNTS ACROSS  
ADVISORY LEVELS WILL GENERALLY TREND TOWARD AN ADDITIONAL 2-4 INCHES  
WITH POSSIBLE LOCALIZED AMOUNTS OF 3-5".  
 
 
   
LONG TERM /FRIDAY THROUGH WEDNESDAY/  
 
ISSUED AT 252 PM EST THU DEC 19 2024  
 
BY 12Z FRIDAY, A WEAKENING SURFACE LOW PRESSURE WILL HAVE TRACKED  
INTO THE OHIO RIVER VALLEY WHILE 1040MB HIGH PRESSURE DESCENDS  
SOUTHEAST INTO THE NORTHERN PLAINS. THIS WILL WORK TO BACK THE FLOW  
ACROSS LAKE SUPERIOR FROM NE TO NNW AND SHIFT A DOMINANT LES BAND  
FROM THE KEWEENAW INTO THE CENTRAL UP. RECENT HREF GUIDANCE HINTS AT  
A 20-40% CHANCE FOR 0.5"/HOUR RATES DURING THE MORNING COMMUTE HOURS  
IN MARQUETTE COUNTY AS IT TRANSLATES EASTWARD. A QUICK 1-2" OF SNOW  
IS POSSIBLE WHEREVER THE HEAVIEST RATES MANIFEST. LES WILL BE  
WEAKENING THROUGH THE AFTERNOON HOURS AS DRY AIR AND SUBSIDENCE WORK  
ITS WAY ACROSS LAKE SUPERIOR. LAND BREEZES SETUP OVERNIGHT INTO  
SATURDAY AND FOCUS A MORE DOMINANT BAND INTO THE EAST-CENTRAL.  
THERMODYNAMICS ARE FAVORABLE FOR HEAVY LES WITH DELTA-TS PUSHING 20-  
2 5C, HOWEVER, THE LIMITING FACTOR WILL BE VERY DRY AIR LOWERING  
INVERSION HEIGHTS DOWN TO 4-6 KFT. AT THE SAME TIME, THE SURFACE  
HIGH WILL BE SOLIDLY OVERTOP THE UPPER GREAT LAKES AND BOUNDARY  
LAYER WIND WILL BE DECREASING INTO THE AFTERNOON, LIKELY BREAKING UP  
ALREADY WEAK LES BANDS TO MORE SHOWERY SEGMENTS. ALL OF THIS IS TO  
SAY THAT THE EAST AND CENTRAL COULD SQUEEZE OUT ANOTHER INCH OR SO  
THROUGH SATURDAY MORNING.  
 
LINGERING LES SHOWERS OFF OF LAKE MICHIGAN IN THE FAR EAST UP ARE  
LIKELY ON SUNDAY AS HIGH PRESSURE SLIDES EAST, CREATING A S-SW FETCH  
ACROSS THE LONG AXIS OF THE LAKE. THERE ARE STILL SOME UNCERTAINTIES  
ON SNOW ACCUMULATIONS GIVEN A NARROW WINDOW FOR LIFT WITHIN THE DGZ  
AND WAA RAMPING UP SUNDAY AFTERNOON. FOR NOW, AT LEAST AN INCH OR  
TWO OF SNOW IN SCHOOLCRAFT AND LUCE COUNTIES IS ON THE TABLE SUNDAY.  
OTHERWISE, LOW TEMPERATURES THIS WEEKEND WILL BE ON THE COLD SIDE,  
DIPPING AROUND 10-15F NEAR THE LAKESHORES AND 0-10F INLAND, WITH A  
FEW SPOTS IN THE INTERIOR WEST POTENTIALLY REACHING JUST BELOW ZERO.  
 
THE TREND FOR A WHITE CHRISTMAS STILL HOLDS ON AS A WEAK SHORTWAVE  
IS PROGGED TO DEVELOP IN THE NORTHERN PLAINS AND MEANDER INTO THE  
UPPER GREAT LAKES MONDAY INTO TUESDAY. THE CURRENT DETERMINISTIC  
MODEL SUITE IS STILL WORKING OUT THE KINKS ON THE TIMING AND  
PLACEMENT OF SURFACE FEATURES, HOWEVER, LREF GUIDANCE SUGGESTS A  
WET 1-2" OF SNOW ACROSS THE UP, POSSIBLY UPWARDS OF 3" IN THE  
EAST COINCIDING ENHANCEMENT VIA LAKE MICHIGAN. BEHIND MONDAY'S  
WEAK SYSTEM, ENSEMBLES ARE IN GOOD AGREEMENT ON A PERIOD OF  
WARMTH CHARACTERIZED BY 850MB TEMP ANOMALIES UPWARDS OF +5-10  
THROUGH THE REST OF 2024 AND INTO EARLY JANUARY. YOOPER WINTER  
WEATHER RECREATIONISTS SHOULD PREPARE FOR A DWINDLING SNOWPACK  
AS WE ROUND OUT THE YEAR.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/  
 
ISSUED AT 707 PM EST THU DEC 19 2024  
 
LIGHT SNOW ASSOCIATED WITH LOW PRES PASSING BY WELL TO THE S OF  
UPPER MI WILL CONTINUE THIS EVENING. A SFC TROF WILL THEN DROP  
ACROSS UPPER MI OVERNIGHT, INITIATING LAKE EFFECT SHSN. AT IWD,  
EXPECT CONDITIONS VARYING BTWN VFR AND MVFR TO BECOME PREVAILING IFR  
BY LATE EVENING WITH -SHSN CONTINUING THRU THE NIGHT. IMPROVEMENT TO  
MVFR WILL OCCUR EARLY FRI MORNING. OCNL FLURRIES ARE EXPECTED ON FRI  
AT IWD, BUT NO VIS RESTRICTION OUT OF VFR WILL OCCUR. AT CMX, EXPECT  
VFR TO FALL TO MVFR THIS EVENING AND THEN PERSIST THRU FRI. SOME  
BRIEF PERIODS OF IFR ARE POSSIBLE DURING THE NIGHT. OCNL FLURRIES  
ARE POSSIBLE AT CMX ON FRI. AT SAW, EXPECT CONDITIONS FLUCTUATING  
BTWN MVFR AND IFR INTO FRI MORNING. PASSAGE OF TROF FRI MORNING WILL  
BE ACCOMPANIED BY HEAVIER SHSN, AND NOT OUT OF THE QUESTION THAT  
BRIEF LIFR COULD OCCUR. MVFR CIGS AND OCNL FLURRIES ARE THEN  
EXPECTED AT SAW THRU THE END OF THE FCST PERIOD. AFTER THE TROF  
PASSAGE, NORTHERLY WINDS AT CMX/SAW WILL GUST TO AROUND 20KT.  
 
 
   
MARINE  
 
ISSUED AT 252 PM EST THU DEC 19 2024  
 
NORTHEAST WINDS INCREASE TO 30 KNOTS TONIGHT OVER THE WEST HALF ON  
THE BACKSIDE OF A CLIPPER LOW MOVING THROUGH THE LOWER GREAT  
LAKES/OHIO VALLEY. CURRENTLY, NOT EXPECTING ANY GALE FORCE GUSTS,  
HOWEVER AN ISOLATED GUST TO 35 KNOTS CAN'T BE COMPLETELY RULED OUT  
TONIGHT(<20% CHANCE). WAVE HEIGHTS WILL BUILD TO 4-7 FEET TONIGHT IN  
THE WEST HALF, WITH THE HIGHEST WAVES EAST OF THE APOSTLE ISLANDS.  
AS THE SURFACE LOW PRESSURE CONTINUES PULLING FURTHER SOUTHEAST AND  
HIGH PRESSURE BEGINS TO BUILD IN FROM THE HIGH PLAINS, WINDS WILL  
TURN OUT OF THE NORTH-NORTHWEST THROUGH FRIDAY EVENING, GUSTING  
UPWARDS OF 20-30 KNOTS ACROSS THE EAST AND CENTRAL LAKE, WITH AN  
ISOLATED GALE TO 35 KNOTS POSSIBLE (<20% CHANCE). WAVE HEIGHTS BUILD  
TO 4-7 FEET LATE FRIDAY INTO EARLY SATURDAY MORNING.  
 
WINDS AND WAVES THEN SUBSIDE QUICKLY ON SATURDAY AND REMAIN CALM  
THROUGH SUNDAY MORNING. LOW PRESSURE MOVING THROUGH THE UPPER  
MIDWEST COULD INCREASE SOUTHERLY WINDS TO 20-30 KNOTS SUNDAY  
AFTERNOON INTO MONDAY, HIGHEST EAST HALF. ENSEMBLE GUIDANCE PRESENTS  
A 30-40% CHANCE FOR GALE FORCE GUSTS ACROSS THE EAST-CENTRAL LAKE  
EARLY MONDAY THROUGH THE EVENING.  
 
 
   
MQT WATCHES/WARNINGS/ADVISORIES  
 
UPPER MICHIGAN...  
WINTER WEATHER ADVISORY UNTIL 7 AM EST /6 AM CST/ FRIDAY FOR  
MIZ001-003-012>014.  
 
WINTER WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ FRIDAY FOR  
MIZ002-009.  
 
WINTER WEATHER ADVISORY UNTIL 3 AM CST FRIDAY FOR MIZ010-011.  
 
LAKE SUPERIOR...  
NONE.  
LAKE MICHIGAN...  
NONE.  
 
 
 
 
 
SHORT TERM...TDUD  
LONG TERM...BW  
AVIATION...ROLFSON  
MARINE...BW  
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