195  
FXUS63 KMQT 191755  
AFDMQT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MARQUETTE MI  
1255 PM EST SUN JAN 19 2025  
   
KEY MESSAGES
 
 
- DANGEROUSLY COLD ARCTIC AIR SETTLES INTO THE AREA THIS WEEKEND  
INTO EARLY NEXT WEEK, LEADING TO TEMPERATURES REMAINING  
SUBZERO FROM TONIGHT THROUGH AT LEAST TUESDAY MORNING OVER THE  
INTERIOR WEST HALF OF UPPER MICHIGAN. MUCH OF WEST AND  
CENTRAL UPPER MICHIGAN MAY SEE TEMPERATURES FAIL TO RISE ABOVE  
ZERO ON MONDAY AND MAYBE TUESDAY.  
 
- HOMEOWNERS AND PROPERTY MANAGERS SHOULD TAKE ACTION NOW FOR  
THIS COLD PERIOD, ESPECIALLY IF PAST VERY COLD PERIODS HAVE  
YIELDED IMPACTS. ENSURE YOUR WINTER CAR SURVIVAL KIT IS UP-TO-  
DATE. THIS WEEKEND THROUGH TUESDAY, LIMIT TIME OUTDOORS FOR  
YOU AND YOUR PETS, AND CHECK ON VULNERABLE NEIGHBORS.  
 
- FREQUENT WHITEOUTS ARE EXPECTED IN THE NORTHWEST WIND SNOW  
BELTS TODAY 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 THE LAKE EFFECT SNOW AREAS.  
 
- NO WIDESPREAD, SIGNIFICANT SNOWFALLS FOR UPPER MI THROUGH NEXT  
WEEK. NEARLY ALL OF THE SNOW THAT OCCURS WILL BE LAKE EFFECT  
DRIVEN.  
 

 
   
SHORT TERM /THROUGH TONIGHT/
 
 
ISSUED AT 538 AM EST SUN JAN 19 2025  
 
HIGHLY AMPLIFIED FLOW ACROSS NORTH AMERICA HAS ALLOWED A BROAD MID-  
UPPER LEVEL TROUGH TO ENVELOP MUCH OF THE CONUS AND CENTRAL CANADA.  
AS A RESULT, VERY COLD ARCTIC AIR HAS BEEN ABLE TO PUSH INTO THE  
NORTHERN PLAINS AND UPPER GREAT LAKES THIS WEEKEND. 850 MB TEMPS  
AROUND -25C THIS MORNING WILL CONTINUE TO GET EVEN COLDER TODAY INTO  
TONIGHT REACHING FROM -26C EAST TO COLDER THAN -30C WEST BY 12Z  
MONDAY. THIS HAS RESULTED IN BITTER COLD SURFACE TEMPS ACROSS UPPER  
MICHIGAN EARLY THIS MORNING WITH TEMPS RANGING FROM NEAR 0F EAST AND  
NEAR LAKE SUPERIOR TO 5 BELOW TO NEARLY 20 BELOW OVER MUCH OF THE  
INTERIOR WEST HALF. HIGHS TODAY ARE ONLY EXPECTED TO GET IN THE  
SINGLE DIGITS ABOVE ZERO EAST HALF AND WILL ONLY BE IN THE SINGLE  
DIGITS BLO ZERO WEST HALF. LOWS TONIGHT WILL BE EVEN COLDER ACROSS  
THE INTERIOR WITH 10 BELOW TO 25 BELOW ZERO READINGS, COLDEST  
INTERIOR WEST, WHILE NEAR THE LAKE SUPERIOR SHORE READINGS WILL BE  
IN THE ZERO TO 10 BELOW ZERO RANGE. COLD ADVISORIES IN EFFECT OVER  
THE WEST TODAY WILL EXPAND ACROSS MOST OF THE CENTRAL COUNTIES LATER  
TONIGHT. IF YOU MUST GO OUTSIDE TODAY, 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!  
 
THE COLD AIR MOVING ACROSS LAKE SUPERIOR CONTINUES TO GENERATE LAKE  
EFFECT SNOW OVER THE NW WIND SNOW BELTS, BUT THE EXTREMELY COLD AIR  
MASS WILL RESULT IN POOR SNOW GROWTH AND FINE SNOW WHICH WILL LIMIT  
OVERALL ACCUMULATION. AT THE SAME TIME, THE FINE SNOW WILL GET BLOWN  
AROUND MORE CAUSING THE POTENTIAL FOR WHITEOUT CONDITIONS WITHIN THE  
SNOW BANDS. A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR ALGER,  
LUCE AND NORTHERN SCHOOLCRAFT THROUGH MONDAY WHERE A LONGER NW  
FETCH ACROSS LAKE SUPERIOR SHOULD BRING 4 TO 7 INCHES OF  
ADDITIONAL ACCUMULATION AND PERHAPS LOCALLY HIGHER AMOUNTS NEAR  
10 INCHES OVER EASTERN ALGER AND NORTHERN LUCE COUNTIES WHERE  
STRONG LOW-LEVEL CONVERGENCE WILL SET UP DUE TO ENHANCED LAKE-  
INDUCED TROUGHING FROM LAND BREEZES.  
 

 
   
LONG TERM /MONDAY THROUGH SATURDAY/
 
 
ISSUED AT 458 AM EST SUN JAN 19 2025  
 
BY 12Z MONDAY, 500MB RIDGING WILL HAVE SHIFTED OVER BRITISH  
COLUMBIA AND NORTHWEST TERRITORIES, CONTINUING AN EXTREMELY  
EFFICIENT SURGE OF FRIGID ARCTIC AIR IN THE FORM OF AN  
ANOMALOUSLY DEEP TROUGH CENTERED OVER THE UPPER GREAT LAKES,  
WITH THE GEFS SHOWING A -30 DAM 500MB HEIGHT ANOMALY OVER THE UP  
BY 12Z MONDAY, GOOD ENOUGH FOR BELOW THE 2.5TH PERCENTILE OF  
THE NAEFS CLIMATOLOGY. THE HREF MEAN 850MB TEMPERATURE WILL BE  
AROUND THE -30C MARK MONDAY (SLIGHTLY WARMER VALUES OVER THE  
EASTERN UP, SLIGHTLY COOLER OVER WESTERN LAKE SUPERIOR). THIS  
WILL TRANSLATE INTO SURFACE HIGH TEMPERATURES 50+% LIKELY TO  
REMAIN BELOW 0F ON MONDAY. SIMILAR IF NOT SLIGHTLY COOLER HIGH  
TEMPERATURES ARE EXPECTED TUESDAY AS 850MB TEMPERATURES WILL NOT  
CHANGE MUCH ACCORDING TO THE LREF MEAN. LOW TEMPERATURES WILL  
TAKE A TUMBLE, ESPECIALLY OVER THE INTERIOR WEST, WITH THE NBM  
CALLING FOR -22F FOR THE INTERIOR WEST TUESDAY MORNING AND  
VARIOUS MOS GUIDANCE CALLING FOR AS LOW AS -27F NEAR WATERSMEET.  
THE SURROUNDING MORNINGS WILL SEE LOWS IN THE NEGATIVE DOUBLE  
DIGITS IN THE INTERIOR WEST AND NEGATIVE SINGLE DIGITS  
ELSEWHERE, STILL COLD, BUT TUESDAY MORNING WILL BE THE COLDEST.  
WITH DOMINANT SURFACE PRESSURE FEATURES FAR FROM THE UP (A TRAIN  
OF 1040-1050MB SHORTWAVE HIGHS OVER THE PLAINS, 960S MB LOW  
OVER NEWFOUNDLAND AND LABRADOR), PERSISTENT WNW TO NW WINDS  
GUSTING TO AROUND 20 MPH ARE EXPECTED. WHILE THOSE WINDS ARE NOT  
UNUSUAL FOR THIS TIME OF YEAR, THE COMBINATION WITH THE FRIGID  
AIR TEMPERATURES WILL PROVIDE SOME OF THE MOST HAZARDOUS WIND  
CHILLS SINCE AT LEAST FEB. 2021, IF NOT JAN. 2019. AT THE LREF-  
MEAN WIND CHILL OF -44F IN THE IRONWOOD AREA TUESDAY MORNING,  
FROSTBITE CAN TAKE PLACE IN 10 MINUTES, HALF AN HOUR OR LESS FOR  
MUCH OF THE UP THAT IS EXPECTED TO SEE -20F OR LOWER WIND  
CHILLS THROUGH WEDNESDAY MORNING. ADDITIONALLY, SUCH COLD AIR  
MOVING OVER PARTICULARLY SHALLOW SNOWPACKS (OR IN THE CASE OF  
THE SOUTHERN UP, NO SNOW PACK) COULD DRIVE A DEEP FROST DEPTH,  
WHICH WOULD INCREASE THE THREAT OF DAMAGE TO PIPES/ETC THAT ARE  
NOT BURIED PARTICULARLY DEEPLY, THOUGH FROST DEPTH FORECASTING  
IS CHALLENGING, SO TO WHAT DEPTH WOULD BE CONSIDERED "SAFE" IS  
UNCERTAIN. ONE IMPORTANT NOTE WITH THIS HAZARDOUS WIND CHILL IS  
THAT FOR MULTIPLE DAYS, THE DAYTIME WIND CHILL VALUES WILL STILL  
BE IN THE NEGATIVE TEENS TO NEGATIVE 20S, SO NO REPRIEVE IS  
EXPECTED WHEN THE SUN COMES UP, PUTTING SOME VULNERABLE  
POPULATIONS EVEN FURTHER AT RISK AS IT BECOMES MUCH MORE  
DIFFICULT TO JUST "RIDE IT OUT". IMPACTS TO PEOPLE, PETS, PIPES,  
AND PLANTS ARE EXPECTED, SO TAKE PRECAUTIONS IF ANY OF THE  
ABOVE APPLY. DUE TO CONTINUED HIGH CONFIDENCE IN WIND CHILLS AS  
LOW AS -45 IN THE INTERIOR WEST BY TUESDAY MORNING, EXTREME COLD  
WARNINGS WILL BE ISSUED WITH THIS FORECAST PACKAGE IN ADDITION  
TO THE ONGOING COLD WEATHER ADVISORIES.  
 
OF COURSE, WITH SUCH FRIGID TEMPERATURES ALOFT AND A WIDE-OPEN LAKE  
SUPERIOR (ONLY 3-4% ICE COVER PER GLERL AND MOST OF IT IN BLACK BAY,  
NIPIGON BAY, THE BAYS NORTH OF SAULT STE MARIE, AND THE APOSTLE  
ISLANDS REGION), LAKE EFFECT SNOW WILL BE PRESENT. SUCH FRIGID  
AIRMASSES WILL SUPPORT TINY CRYSTALS AS EVEN THE BOUNDARY LAYER WILL  
BE COLDER THAN THE DGZ, BRINGING EXPECTED QPF TO NEAR 10:1. QPF  
VALUES ARE NOT EXPECTED TO BE EXTREME WITH SUCH A COLD AIRMASS NOT  
BEING ABLE TO HOLD MUCH WATER CONTENT, AS THE HREF MEAN ONLY SHOWS  
ABOUT 0.07"-0.12"/24-HR QPF RATES. SLIGHTLY BETTER QPF RATES MIGHT  
LOCALLY BE REALIZED OVER THE EAST WHERE CAMS SHOW A REMNANT "SURFACE  
INVERTED TROUGH"-LIKE FEATURE THAT IS EXPECTED TO BRING BETTER  
CONVERGENCE FOR THE BANDS. THIS RESULTS IN SNOWFALL RATES OF AROUND  
1"/6 HR BROADLY ALONG THE SPINE OF THE KEWEENAW AND 2-3"/6HR RATES  
OVER THE EASTERN LAKE SUPERIOR SHORES. AS SUCH, A WINTER WEATHER  
ADVISORY CONTINUES FOR A PORTION OF THE EASTERN UP THROUGH MONDAY.  
EXTENSIONS IN TIME AND EXPANSIONS TO THE WEST MAY BECOME NECESSARY  
IF A BLSN THREAT IS REALIZED WITH SUCH A DRY SNOW WITH TINY  
PARTICLES THAT ARE EXTREMELY EFFICIENT AT REDUCING VISIBILITY. THE  
EURO ENSEMBLE IS CALLING FOR 70+% CHANCE OF SUB-QUARTER MILE  
VISIBILITY THROUGH MONDAY AND INTO TUESDAY FOR THE KEWEENAW WITH  
LESSER VIS RESTRICTIONS EXPECTED ELSEWHERE.  
 
HIGH PRESSURE SLIDING TO THE SOUTH AND EAST OF THE UP BY WEDNESDAY  
WILL SHIFT THE BOUNDARY LAYER WIND PATTERN TO BE MORE SOUTHWESTERLY,  
PROVIDING A 1-2 COMBINATION OF SHIFTING LAKE EFFECT BANDS OFFSHORE  
AND ADVECTING WARMER SOUTHERN AIR OVER THE UP, GIVING SOME REPRIEVE  
TO THE HAZARDOUS CONDITIONS AHEAD TO END THE WEEKEND AND BEGIN THE  
WORK WEEK. GRANTED, CHANCES OF HIGH TEMPERATURES REACHING THE  
"NORMAL" MARK (AROUND 20) FOR THIS TIME OF YEAR ARE BELOW 30% BEFORE  
FRIDAY, BUT AFTER 48-72 HOURS OF SUBZERO TEMPERATURES, WEDNESDAY'S  
HIGHS IN THE 11-16 DEGREE RANGE MIGHT JUST FEEL TROPICAL. ENSEMBLES  
ARE INCREASING IN CONFIDENCE IN A SHORTWAVE PIVOTING FROM THE JUNEAU  
VICINITY MONDAY AFTERNOON TO THE DAKOTAS BY WEDNESDAY MORNING, WITH  
THE GEFS SHOWING A CLUSTER OF WEAKENING CLIPPER SURFACE LOWS LATE  
WEDNESDAY INTO THURSDAY OVER THE UP. WHILE SYNOPTIC PRECIPITATION IS  
POSSIBLE WITH THAT POTENTIAL SYSTEM, BLOCKING FROM VARIOUS SYNOPTIC  
SYSTEMS FAR TO THE SOUTH AND EAST WILL BLOCK MOISTURE TRANSPORT FROM  
EFFECTIVELY REACHING THE UP, LIMITING QPF POTENTIAL. REGARDLESS OF  
EXACT SOLUTION, THE LREF SHOWS 925MB FLOW BECOMING 85% LIKELY TO BE  
WITHIN 30 DEGREES OF NWERLY BY LATE THURSDAY INTO FRIDAY WITH  
GREATER THAN 75% CHANCES OF 850MB TEMPERATURES SUPPORTIVE OF AN LES  
PATTERN, A RETURN TO COOLER (BUT NOT FRIGID) TEMPERATURES AND LES IS  
EXPECTED TO END THE WORK WEEK. MOVING INTO NEXT WEEKEND, SOME EARLY  
INDICATIONS IN THE ENSEMBLES SHOW ANOTHER POTENTIAL CLIPPER LOW  
AROUND SATURDAY MORNING, BUT UNCERTAINTY IS UNDERSTANDABLY HIGH. THE  
GENERAL PATTERN REMAINS LARGELY UNCHANGED FROM PRIOR EXPECTATIONS  
WITH CONTINUED COOL AIR ALOFT SUPPORTING FAVORABLE CONDITIONS FOR  
POST-CLIPPER LES.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
 
 
ISSUED AT 1254 PM EST SUN JAN 19 2025  
 
FLIGHT RESTRICTIONS CONTINUE AT ALL TAF SITES DUE TO LAKE EFFECT  
SNOW AND BLOWING SNOW, BUT WORST CONDITIONS REMAIN AT IWD AND CMX.  
IWD WILL MAINLY TREND TOWARD MVFR WITH PERIODS OF IFR, WHILE CMX  
WILL PREVAIL AT IFR AND FURTHER DETERIORATE TO LIFR AT TIMES.  
MEANWHILE, MVFR CONDITIONS AT SAW SHOULD IMPROVE TO VFR LATER  
TODAY WHERE THE LAKE EFFECT IS NOT AS PREDOMINANT. STRONG  
NORTHWEST WINDS GUSTING TO 20-25 KTS WILL CONTINUE THE BLOWING  
SNOW/REDUCED VISIBILITY THREAT AT IWD AND CMX.  
 

 
   
MARINE
 
 
ISSUED AT 458 AM EST SUN JAN 19 2025  
 
WITH LARGE-SCALE SURFACE PRESSURE FEATURES FAR AWAY FROM LAKE  
SUPERIOR, NORTHWEST WINDS GUSTING TO AROUND 25 KT WILL BE THE NORM  
THROUGH TUESDAY. FRIGID ARCTIC AIR WILL CAUSE PERIODS OF HEAVY  
FREEZING SPRAY THROUGHOUT THE WEEKEND AND EARLY PORTION OF NEXT  
WEEK. HIGH PRESSURE SLIDING TO THE SOUTH AND EAST WILL CAUSE WINDS  
TO BECOME MORE SOUTHWESTERLY WEDNESDAY, REMAINING AROUND 25 KT,  
THOUGH WARMING TEMPERATURES AND A CHANGE IN WIND DIRECTION REDUCING  
WAVE HEIGHTS SHOULD REDUCE THE FREEZING SPRAY TO LIGHT-TO-MODERATE.  
BEYOND THEN, GALES WILL DEPEND ON WHETHER OR NOT A CLIPPER LOW  
MATERIALIZES IN THE MID-TO-LATE WEEK PERIOD AND AGAIN OVER THE  
WEEKEND, IN WHICH CASE GALES TO 35 KNOTS BECOME POSSIBLE, BUT  
PROBABILITIES AT THIS TIME ARE ONLY AROUND 20-30%.  
 

 
   
MQT WATCHES/WARNINGS/ADVISORIES
 
 
UPPER MICHIGAN...  
COLD WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ001-003.  
 
COLD WEATHER ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING  
TO 10 PM EST /9 PM CST/ MONDAY FOR MIZ002-004-005-007-011-  
084.  
 
EXTREME COLD WARNING FROM 10 PM EST /9 PM CST/ MONDAY TO 1 PM  
EST /NOON CST/ TUESDAY FOR MIZ002-004-005-011-084.  
 
WINTER WEATHER ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ006-007-  
085.  
 
COLD WEATHER ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING  
TO 1 PM EST /NOON CST/ TUESDAY FOR MIZ006-012>014-085.  
 
COLD WEATHER ADVISORY UNTIL 4 AM CST MONDAY FOR MIZ009-010.  
 
EXTREME COLD WARNING FROM 4 AM MONDAY TO NOON CST TUESDAY FOR  
MIZ009-010.  
 
LAKE SUPERIOR...  
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ TUESDAY  
FOR LSZ162-240>251-263>267.  
 
LAKE MICHIGAN...  
NONE.  
 

 
 

 
 
SHORT TERM...VOSS  
LONG TERM...GS  
AVIATION...TDUD  
MARINE...GS  
 
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