942  
FXUS63 KMQT 202053  
AFDMQT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MARQUETTE MI  
353 PM EST MON JAN 20 2025  
   
KEY MESSAGES  
 
- DANGEROUSLY COLD ARCTIC AIR CONTINUES THROUGH EARLY THIS WEEK,  
LEADING TO TEMPERATURES REMAINING SUBZERO PROBABLY THROUGH WED  
MORNING FOR MUCH OF UPPER MICHIGAN.  
 
- ENSURE YOUR WINTER CAR SURVIVAL KIT IS UP-TO-DATE. LIMIT TIME  
OUTDOORS FOR YOU AND YOUR PETS, AND CHECK ON VULNERABLE NEIGHBORS  
THROUGH THIS COLD SNAP.  
 
- FREQUENT WHITEOUTS ARE EXPECTED IN THE WEST WIND SNOW BELTS  
THROUGH TUESDAY MORNING DUE TO THE FALLING SNOW BEING A FINE,  
POWDERY TYPE SNOW THAT IS HIGHLY EFFECTIVE AT REDUCING  
VISIBILITY. EXPECT VERY HAZARDOUS DRIVING CONDITIONS IN THESE  
LAKE EFFECT SNOW AREAS.  
 
- NO WIDESPREAD, SIGNIFICANT SNOWFALLS FOR UPPER MI THROUGH THIS  
WEEK. NEARLY ALL OF THE SNOW THAT OCCURS WILL BE LAKE EFFECT  
DRIVEN.  
 
 
   
SHORT TERM /THROUGH TONIGHT/  
 
ISSUED AT 352 PM EST MON JAN 20 2025  
 
THE COLDEST PERIOD OF THIS ARCTIC STRETCH IS STILL AHEAD TONIGHT  
THROUGH TOMORROW. COLDEST OVERNIGHT LOWS TONIGHT WILL BE OVER THE  
INTERIOR WEST WHERE TEMPERATURES WILL SINK TO -25F. ELSEWHERE, THE  
REMAINDER OF UPPER MICHIGAN WILL BOTTOM OUT IN THE -10F TO -20F  
RANGE. THESE TEMPERATURES COUPLED WITH THE CONTINUED STRONG WNW  
WINDS WILL PUSH WIND CHILLS INTO THE -40F TO -45F RANGE. EXTREME  
COLD WARNINGS ARE ALREADY IN EFFECT ACROSS GOGEBIC AND IRON COUNTIES  
WHERE CURRENT TEMPERATURES ARE ALREADY IN THE -5 TO -10F RANGE. MOST  
OF THE REMAINING COUNTIES ACROSS THE U.P. WILL ALSO FALL UNDER  
EXTREME COLD WARNINGS THROUGH THE COURSE OF THE EVENING WITH ALL OF  
THE U.P. EXCEPT LUCE AND KEWEENAW COUNTIES UNDER AN EXTREME COLD  
WARNING BY TUESDAY MORNING. IF YOU MUST GO OUTSIDE TONIGHT, DRESS  
WARMLY IN LAYERS AND MAKE SURE TO HAVE A WINTER SURVIVAL KIT IN YOUR  
VEHICLE IN CASE OF EMERGENCY. LIMIT EXPOSURE OUTSIDE FOR YOU, YOUR  
FAMILY, AND YOUR PETS!  
 
ALSO OF NOTE, ONGOING WINTER WEATHER ADVISORIES REMAIN IN PLACE FOR  
ONTONAGON, NORTHERN HOUGHTON, ALGER, NORTHERN SCHOOLCRAFT, AND LUCE  
COUNTIES THROUGH THE SHORT TERM PERIOD. LAKE EFFECT SNOW SHOWERS  
WILL BACK TO THE WEST TONIGHT WITH ADDITIONAL SNOW TOTALS IN THE 3  
TO 5 INCH RANGE ACROSS ADVISORY AREAS AND LOCALIZED TOTALS UP TO 8  
TO 10 INCHES OVER THE NORTHEAST COUNTIES. THE M-28 CORRIDOR NEAR THE  
LAKE SUPERIOR SHORELINE WILL REMAIN ESPECIALLY TREACHEROUS DUE TO  
WHITEOUT CONDITIONS AT TIMES IN BLOWING, POWDERY SNOW (MUNISING  
EASTWARD TO PINE LAKE AND AS FAR SOUTH AS SENEY).  
 
 
   
LONG TERM /TUESDAY THROUGH SUNDAY/  
 
ISSUED AT 438 AM EST MON JAN 20 2025  
 
AFTER A FEW DAYS OF THE SAME WEATHER PATTERN (STEEP RIDGING OVER  
WESTERN CANADA, DEEP TROUGHING OVER THE GREAT LAKES), AN ACTIVE  
PATTERN LOOKS TO SET UP BEYOND THE MIDWEEK AS THE FIRST IN A SERIES  
OF SHORTWAVES TRANSITS THROUGH THE MIDWEST REGION. THIS SHORTWAVE  
MIGHT NOT HAVE MASSIVE PRECIPITATION POTENTIAL DUE TO WEAKENING  
SYNOPTIC SUPPORT AS IT ARRIVES AND OTHER SYNOPTIC FEATURES ROBBING  
IT OF NEEDED MOISTURE TRANSPORT, BUT THE SHIFT IN THE PATTERN WILL  
BRING AT LEAST MORE SEASONAL AIR OVER THE UP IN CONTRAST TO THE  
CURRENTLY ONGOING DANGEROUS COLD AIR. WHILE DETAILS IN TIMING AND  
INTENSITY OF THE FOLLOWING SHORTWAVES IS STILL HIGH, THE GEFS SHOWS  
ONLY A BRIEF PERIOD OF LOCAL RIDGING THURSDAY BEFORE ANOTHER  
SHORTWAVE PASSES FRIDAY. FROM THERE, MORE SHORTWAVES ARE EXPECTED,  
BUT THE UNCERTAINTY IS HIGH IN ANY DETAILS BEYOND THE GENERAL  
PATTERN. IN A LONGWAVE PERSPECTIVE, BY SUNDAY, A SPLIT FLOW PATTERN  
SETS UP AS A CUTOFF LOW WILL BE OVER THE DESERT SOUTHWEST, PUTTING  
THE UPPER GREAT LAKES IN A PERSISTENT NORTHWESTERLY FLOW (ASIDE FROM  
PASSING SHORTWAVES).  
 
HAZARDOUS COLD AND WIND CHILLS WILL BE ONGOING TUESDAY MORNING. HIGH  
TEMPERATURES ARE NOT EXPECTED TO BREAK THE 0 F MARK FOR ALL EXCEPT  
KEWEENAW COUNTY AND THE EASTERN THIRD OF THE UP, AND EVEN THEN, ONLY  
LOW SINGLE DIGITS ARE EXPECTED. WHILE LARGE-SCALE SURFACE FEATURES  
ARE FAR DISPLACED FROM THE UP (GEFS MEAN LOW OF 961MB OVER THE  
LABRADOR SEA AND 1050MB HIGH OVER COLORADO), THE GRADIENT WILL BE  
TIGHT ENOUGH TO FORCE 10-20 MPH WINDS WITH GUSTS TO AROUND 25 MPH.  
THIS WILL ONLY ALLOW WIND CHILLS TO "WARM" FROM THE -30S AND -40S TO  
THE -20S AND NEGATIVE TEENS. THIS WILL CONTINUE TO THREATEN  
VULNERABLE LIFE AND PROPERTY WITH LITTLE TO NO REPRIEVE FROM THE  
BRUTAL COLD AND WIND CHILL. CURRENT COLD WEATHER HEADLINES WILL BE  
KEPT AS IS, AS THERE IS SOME UNCERTAINTY AROUND WHETHER OR NOT  
CONDITIONS WILL REMAIN IN WARNING CRITERIA OR WILL SIMPLY BE  
ADVISORY-LEVEL DURING THE DAYTIME HOURS OF TUESDAY AND TUESDAY  
NIGHT. WHILE THE TEMPERATURES AND WIND CHILLS WILL CONTINUE AS THEY  
WERE, ONE THING THAT WILL CHANGE WILL BE THE ONGOING LAKE EFFECT  
SNOW, AS SURFACE RIDGING PUSHING OVER THE SOUTHWEST PORTION OF THE  
MIDWEST WILL FORCE WINDS TO BE MORE WESTERLY TO SOUTHWESTERLY,  
PUSHING LAKE EFFECT TO THE KEWEENAW PENINSULA AND ONLY THE  
SHORELINES EAST OF MUNISING, EVENTUALLY COMPLETELY OFFSHORE. HREF  
MEAN 6-HOURLY PRECIP OF 0.1" OR MORE WILL BE LIMITED ALMOST ENTIRELY  
TO NORTH OF THE PORTAGE CANAL. WITH TOTAL SNOWFALL ON TUESDAY  
EXPECTED TO BE BELOW 2 INCHES UP-WIDE, EXTENSIONS IN ANY ONGOING  
WINTER WEATHER ADVISORIES ARE NOT EXPECTED.  
 
ATTENTION TURNS UPSTREAM TO A WEAKENING CLIPPER LOW WHICH WILL BE  
APPROACHING THE REGION WEDNESDAY MORNING. A BELT OF HIGH PRESSURE  
DRAPED FROM THE VIRGINIAS TO TEXAS WILL KEEP ANY OCEANIC MOISTURE  
TRANSPORT SOURCES FROM CONTRIBUTING TO THIS SYSTEM, AND GIVEN PRIOR  
SIMILAR SETUPS IN MOISTURE-STARVED CLIPPERS THIS SEASON, ONLY A  
COUPLE TO A FEW TENTHS OF SNOWFALL ARE EXPECTED WITH THIS SYSTEM AS  
IT PASSES WEDNESDAY. THE CHANGING OF THE FLOW WITH THE CLIPPER  
SHORTWAVE WILL ALLOW FOR ENOUGH POTENT WARM ADVECTION TO BRING HIGH  
TEMPERATURES WEDNESDAY INTO THE TEENS ABOVE ZERO. WHILE THIS IS  
STILL A HANDFUL OF DEGREES BELOW NORMAL (AT LEAST), THIS WILL BE A  
WELCOME BREAK FROM THE SUBZERO CONDITIONS, THOUGH OVERNIGHT LOWS MAY  
DIP BELOW ZERO IN THE INTERIOR WEST THROUGHOUT THE REMAINDER OF THE  
WEEK. WEDNESDAY MORNING WIND CHILLS WILL STILL BE AROUND THE COLD  
WEATHER ADVISORY THRESHOLD BUT WILL CERTAINLY WARM ABOVE THEN  
THROUGHOUT THE MORNING AND SHOULD BE AROUND THE 0 DEGREE MARK BY THE  
EARLY AFTERNOON (40-70% CHANCE OF ABOVE 0 WIND CHILLS ACCORDING TO  
THE LREF FOR WEDNESDAY AFTERNOON).  
 
MORE SEASONABLE AIR IS EXPECTED TO RETURN TO THE AREA AS NBM HIGHS  
IN THE LOW 20S FRIDAY ONWARDS ARE MORE REFLECTIVE OF THE NORMAL  
HIGHS FOR THIS TIME OF YEAR. AS LONG AS LAKE SUPERIOR REMAINS IN ITS  
CURRENT MAINLY ICE-FREE STATE, TEMPERATURES ALOFT CONTINUE TO  
SUPPORT LAKE EFFECT SNOW IN THE WAKE OF ANY PASSING SHORTWAVES, AND  
FOR THE WEEKEND AND BEYOND, THE MOST COMMON 925MB WIND DIRECTION  
REMAINS NWERLY, SO THAT WILL CONTINUE TO BE THE EXPECTED REGIME FOR  
LES BANDS TO SET UP IN FOLLOWING ANY CLIPPERS.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/  
 
ISSUED AT 137 PM EST MON JAN 20 2025  
 
LAKE EFFECT SNOW SHOWERS/CLOUDS WILL CONTINUE TO IMPACT IWD AND CMX  
THROUGH THE TAF PERIOD. MOST AFFECTED WILL BE CMX WHERE HEAVIER LAKE  
EFFECT SNOW SHOWERS WILL CREATE IFR/LIFR CONDITIONS. IWD, ON THE  
OTHER HAND, WILL TREND MORE TOWARD MVFR WITH SOME IMPROVEMENT TO VFR  
AT TIMES. ELSEWHERE, SAW HAS RETURNED TO VFR WHERE IT IS EXPECTED TO  
STAY. MEANWHILE, STRONG NORTHWEST WINDS WILL CONTINUE TO GUST TO 25  
KTS AT ALL SITES, RESULTING IN BLOWING SNOW/VISIBILITY THREATS AT  
CMX.  
 
 
   
MARINE  
 
ISSUED AT 438 AM EST MON JAN 20 2025  
 
TO BEGIN THE WEEK, STRONG LOW PRESSURE OVER THE LABRADOR SEA AND  
STRONG HIGH PRESSURE JUST EAST OF THE ROCKIES WILL KEEP  
NORTHWESTERLY WINDS GUSTING TO AROUND 25 KT TODAY, SHIFTING TO BE  
MORE WESTERLY BY TUESDAY AS LOCAL HIGH PRESSURE PUSHES INTO  
WISCONSIN. WHILE A LOCALIZED GALE FORCE GUST CAN'T BE RULED OUT  
(~20% CHANCE) IN SOUTHEASTERN LAKE SUPERIOR, WIDESPREAD GALES ARE  
NOT EXPECTED FOR MONDAY AND TUESDAY. AN APPROACHING CLIPPER LOW ON  
WEDNESDAY WILL BRING SOUTHWESTERLY WIND GUSTS UP TO NEAR 30 KT, WITH  
CHANCES OF GALES OF AROUND 40% FOR EARLY WEDNESDAY. AS THE CLIPPER  
DEPARTS, WINDS FALL TO AROUND 20 KT OUT OF PRIMARILY THE NORTHWEST  
THROUGH THURSDAY. FOR FRIDAY INTO THE WEEKEND, PRIMARILY WESTERLY  
AND SOUTHWESTERLY WINDS AROUND 25 KT ARE EXPECTED, WITH GALES NOT  
EXPECTED UNTIL AT LEAST MONDAY (30% CHANCE) DEPENDENT ON THE  
POTENTIAL PASSAGE OF ANOTHER LOW PRESSURE SYSTEM. WITH SOME OF THE  
MOST FRIGID AIR OF THE LAST FEW YEARS OVER LAKE SUPERIOR, HEAVY  
FREEZING SPRAY WARNINGS ARE IN EFFECT THROUGH AT LEAST WEDNESDAY  
MORNING AS WAVES OF 3-8 FEET WILL ALLOW FOR SUPERCOOLED SPRAY TO  
FORM.  
 
 
   
MQT WATCHES/WARNINGS/ADVISORIES  
 
UPPER MICHIGAN...  
COLD WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ001-007.  
 
WINTER WEATHER ADVISORY FROM 7 AM TO 7 PM EST TUESDAY FOR  
MIZ001.  
 
COLD WEATHER ADVISORY UNTIL 10 PM EST /9 PM CST/ THIS EVENING  
FOR MIZ002-004-005-011>013-084.  
 
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ002-006-  
007-085.  
 
EXTREME COLD WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO  
1 PM EST /NOON CST/ TUESDAY FOR MIZ002-004-005-011>013-  
084.  
 
COLD WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR MIZ003.  
 
WINTER WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ003.  
 
EXTREME COLD WARNING FROM 4 AM TO 1 PM EST TUESDAY FOR MIZ003.  
 
COLD WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR MIZ006-014-  
085.  
 
EXTREME COLD WARNING FROM 1 AM TO 1 PM EST TUESDAY FOR MIZ006-  
014-085.  
 
EXTREME COLD WARNING UNTIL NOON CST TUESDAY FOR MIZ009-010.  
 
LAKE SUPERIOR...  
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/  
WEDNESDAY FOR LSZ162-240>251-263>267.  
 
LAKE MICHIGAN...  
NONE.  
 
 
 
 
 
SHORT TERM...TDUD  
LONG TERM...GS  
AVIATION...TDUD  
MARINE...GS  
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