919  
FXUS63 KDLH 160007  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
607 PM CST SUN DEC 15 2024  
   
KEY MESSAGES
 
 
- DENSE FOG LINGERING FROM CLOQUET UP THE HIGHER TERRAIN OF THE  
NORTH SHORE THROUGH EARLY TOMORROW MORNING.  
 
- A CLIPPER SYSTEM WILL BRING A BRIEF WINTRY MIX THIS EVENING IN  
FAR NORTHERN MINNESOTA AND THEN SNOW TO THE NORTHLAND TONIGHT  
THROUGH MONDAY. LIGHT ACCUMULATIONS OF UP TO 2" FOR FAR  
NORTHERN MINNESOTA.  
 
- COLDER TEMPERATURES TUESDAY AND BEYOND WITH OCCASIONAL SNOW  
CHANCES, INCLUDING A MORE POTENT CLIPPER SYSTEM ON THURSDAY  
WITH ACCUMULATING SNOW LIKELY.  
 

 
   
DISCUSSION
 
 
ISSUED AT 331 PM CST SUN DEC 15 2024  
 
REST OF TODAY THROUGH MONDAY:  
 
THE FREEZING DRIZZLE/PRECIPITATION THAT WAS HANGING AROUND THE  
NORTH SHORE THROUGH MUCH OF TODAY WILL COMES TO AN END BRIEFLY  
LATE THIS AFTERNOON INTO EARLY EVENING AS DRIER AIR ALOFT MOVES  
IN. TEMPERATURES HAVE ALSO WARMED TO AT OR JUST ABOVE FREEZING  
THIS AFTERNOON FOR THE NORTH SHORE AND MUCH OF THE NORTHLAND.  
WIDESPREAD FOG HAS BEEN PERSISTENT TODAY AND WILL CONTINUE INTO  
THE OVERNIGHT HOURS, AND LINGER ALONG THE NORTH SHORE INTO  
MONDAY MORNING. THE HIGHER TERRAIN OF THE TWIN PORTS INTO THE  
NORTH SHORE IS SEEING PARTICULARLY DENSE FOG DUE TO ONSHORE FLOW  
OFF OF LAKE SUPERIOR AND UP THE TERRAIN, WHERE A DENSE FOG  
ADVISORY REMAINS IN EFFECT INTO MONDAY MORNING. WILL NEED TO  
CONTINUE MONITORING OTHER PORTIONS OF CENTRAL INTO NORTHEASTERN  
MN FOR DENSE FOG POTENTIAL THIS EVENING INTO TONIGHT, BUT HREF  
PROBABILITIES ARE GENERALLY 50% OR LESS FOR THOSE AREAS AT THE  
MOMENT.  
 
ATTENTION THEN TURNS TO AN APPROACHING LOW PRESSURE SYSTEM  
CURRENTLY OVER CENTRAL NORTH DAKOTA THAT WILL TRACK INTO THE  
LAKE OF THE WOODS BY 6 AM MONDAY AND THEN INTO NORTHWESTERN  
ONTARIO DAYTIME MONDAY. PRECIPITATION WITH THIS SYSTEM STARTS AS  
MORE OF A WINTRY MIX IN NORTH-CENTRAL MN LATE THIS  
AFTERNOON/EVENING, BEFORE TRANSITIONING OVER TO SNOW  
TONIGHT/MONDAY MORNING AND CONTINUING AS SNOW THROUGH MONDAY AS  
PRECIPITATION SPREADS ACROSS THE NORTHLAND. LITTLE TO NO ICE  
ACCUMULATIONS ARE EXPECTED DURING THE WINTRY MIX PERIOD. SNOW  
AMOUNTS WILL BE LIGHT WITH THIS SYSTEM, WITH TOTALS RANGING FROM  
0.5-2" NORTH OF THE IRON RANGE, HIGHEST NEAR THE INTERNATIONAL  
BORDER. ACCUMULATIONS AROUND 0.5" INCHES ARE EXPECTED FOR THE  
IRON RANGE TO THE U.S. HWY 2 CORRIDOR, WITH LESSER ACCUMULATIONS  
FOR AREAS SOUTH OF HWY 2.  
 
ONE MORE DAY OF MILD TEMPERATURES ARE EXPECTED FOR MONDAY WITH  
HIGHS IN THE UPPER 20S TO AROUND FREEZING ON THE MN SIDE OF THE  
NORTHLAND AND LOW TO MID 30S IN NORTHWEST WI. WINDS WILL BECOME  
INCREASINGLY GUSTY OUT OF THE WEST TO NORTHWEST MONDAY AFTERNOON  
AND MONDAY NIGHT BEHIND A COLD FRONT, WITH GUSTS OF 20 TO 30 MPH  
EXPECTED. SOME LOCATIONS ALONG THE NORTH SHORE COULD SEE WINDS  
GUST TO 40 MPH MONDAY NIGHT GIVEN WINDS ACCELERATING DOWN THE  
TERRAIN OF THE NORTH SHORE.  
 
TUESDAY-WEDNESDAY:  
 
COLDER, BELOW-AVERAGE AIR ADVECTS INTO THE NORTHLAND FOR TUESDAY  
AND WEDNESDAY BEHIND THE COLD FRONT. A WEAK SHORTWAVE TROUGH  
PASSING OVER CENTRAL/SOUTHERN MINNESOTA ON TUESDAY INTO TUESDAY  
AFTERNOON AND EVENING COULD BRING SOME VERY LIGHT SNOW (QUICK  
DUSTING TO A COUPLE TENTHS OF AN INCH) TO EAST-CENTRAL MN AND  
NORTHWEST WI, THOUGH SOME LIGHT LAKE-EFFECT SNOW IN NORTHERN  
IRON COUNTY SHOULD PERSIST INTO WEDNESDAY. LOW TEMPERATURES  
TUESDAY NIGHT/WEDNESDAY MORNING SHOULD FALL INTO THE SINGLE  
DIGITS IN NORTHEAST MN AND LOW TO MID TEENS IN NORTHWEST WI.  
WIND CHILLS ARE FORECAST TO BE IN THE SINGLE DIGITS BELOW ZERO  
IN NORTHEAST MN AND SINGLE DIGITS ABOVE ZERO IN NORTHWEST WI.  
 
WEDNESDAY NIGHT-THURSDAY NIGHT CLIPPER SYSTEM:  
 
YET ANOTHER CLIPPER SYSTEM WILL QUICKLY CUT EASTWARDS ACROSS THE  
NORTHERN PLAINS BY LATE WEDNESDAY NIGHT AND INTO SOMEWHERE IN  
THE CENTRAL MN/NORTHERN IOWA/WESTERN WI VICINITY BY 12 PM  
THURSDAY AND THEN INTO THE CENTRAL GREAT LAKES BY EARLY FRIDAY AS  
HIGHLIGHTED IN THE LATEST GLOBAL ENSEMBLE SUITE OF MODELS.  
THIS PROGRESSION IS SEVERAL HOURS FASTER THAN THE PREVIOUS FEW  
MODEL RUNS, BUT THERE IS STILL SOME SPREAD IN THE EXACT TRACK OF  
THE LOW PRESSURE SYSTEM. HOWEVER, FORECAST MODEL SOUNDINGS  
SUGGEST THAT THE PRESENCE OF COLDER AIR COULD LEAD TO DEEPER  
SATURATION IN THE DENDRITIC GROWTH ZONE WITH THIS SYSTEM, WHICH  
WOULD RESULT IN HIGHER SNOW TO LIQUID RATIOS AND FLUFFIER SNOW  
WITH THIS SYSTEM. SYNOPTIC FORCING WITH THIS SYSTEM ALSO LOOKS A  
BIT MORE ROBUST THAT THE OTHER CLIPPERS WE HAVE SEEN RECENTLY,  
SO THERE IS A REAL POSSIBILITY THAT THIS SYSTEM COULD PRODUCE  
SHOVELABLE SNOWFALL IF THIS SYSTEM DOESN'T TRACK TOO FAR SOUTH  
OF THE NORTHLAND. NBM 24-HR SNOWFALL PROBABILITIES FOR >2" ON  
WEDNESDAY NIGHT TO THURSDAY NIGHT ARE CURRENTLY 30-50% FOR MOST  
OF THE NORTHLAND, AND LOCALLY HIGHER TO 60-70% ALONG THE NORTH  
SHORE WHERE SOUTHEAST WINDS OFF OF LAKE SUPERIOR SHOULD LEAD TO  
LAKE AND TERRAIN ENHANCEMENT TO SNOWFALL TOTALS. >4"  
PROBABILITIES ARE LOWER AT 15-30% FOR MOST OF THE NORTHLAND,  
WITH SOME LOCALLY HIGHER PROBABILITIES OF 30-45% ALONG THE NORTH  
SHORE AND PORTIONS OF THE SOUTH SHORE.  
 
TEMPERATURE-WISE, WEDNESDAY NIGHT AND THURSDAY NIGHT LOWS ARE  
FORECAST TO PRIMARILY BE IN THE SINGLE DIGITS ABOVE AND BELOW  
ZERO WITH WIND CHILLS AROUND ZERO INTO THE LOW TEENS BELOW ZERO.  
 
FRIDAY-NEXT WEEKEND:  
 
SEASONABLY COLD WEATHER IN NORTHWEST FLOW SHOULD KEEP BELOW-  
AVERAGE TEMPERATURES GOING FOR FRIDAY INTO NEXT WEEKEND, WITH  
MORNING LOWS IN THE -10F TO 5F RANGE AND MORNING WIND CHILLS  
POTENTIALLY AS COLD AS -5F TO -20F DEPENDING ON HOW STRONG WINDS  
WILL BE NEXT WEEKEND.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
 
 
ISSUED AT 543 PM CST SUN DEC 15 2024  
 
LIFR TO IFR CONDITIONS PERSIST ACROSS THE NORTHLAND THIS  
EVENING, WITH CIGS AT 200 TO 400FT. EXPECT DRIZZLE AND/OR  
FREEZING DRIZZLE AS TEMPERATURES FALL, BRINGING VIS DOWN TO  
LESS THAN 1 MILE AT TIMES. LIGHT SNOW WILL MOVE INTO THE AREA  
TONIGHT, IMPACTING TERMINALS THROUGH MONDAY. BEST COVERAGE WILL  
BE NEAR THE INTERNATIONAL BORDER, WITH AMOUNTS UP TO 2 INCHES.  
VIS SHOULD IMPROVE WITH THE SNOW, BUT CIGS WILL REMAIN IN THE  
LIFR RANGE. SOUTHEASTERLY WINDS TO START THE FORECAST PERIOD  
WILL VEER TO THE SOUTH TONIGHT AND THEN SOUTHWEST MONDAY AS COLD  
FRONT MOVES THROUGH THE AREA. GUSTS OF 18KTS ARE POSSIBLE  
OVERNIGHT, AND INCREASE TO 20-25KTS MONDAY AFTERNOON.  
 

 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
 
 
ISSUED AT 331 PM CST SUN DEC 15 2024  
 
LIGHT SOUTHEAST WINDS PERSIST THROUGH TONIGHT. SOME PATCHY FOG  
IS POSSIBLE ALONG THE NORTH SHORE, AS WELL, BUT IS NOT EXPECTED  
TO BE DENSE. FOR MONDAY, AHEAD OF A CLIPPER SYSTEM, WINDS ARE  
EXPECTED TO SWITCH TO SOUTHWESTERLY AND THEN WESTERLY TO  
NORTHWESTERLY LATE MONDAY INTO EARLY TUESDAY. WIND GUSTS UP TO  
25 TO 30 KT ARE EXPECTED TO DEVELOP, AND SOME GALES TO 35 KT ARE  
POSSIBLE IN THE OUTER APOSTLE ISLANDS AND ROUGHLY FROM PORT  
WING TO BAYFIELD ALONG THE PENINSULA MONDAY AFTERNOON INTO  
MONDAY NIGHT. ADDITIONALLY, WINDS ARE FORECAST TO PICK UP TO  
GALES OF 35 KNOTS ALONG THE NORTH SHORE MONDAY EVENING INTO  
EARLY TUESDAY MORNING DUE TO ACCELERATING WINDS DOWN THE SLOPES  
OF THE NORTH SHORE TERRAIN. GALE WARNINGS ARE IN EFFECT MONDAY  
EVENING INTO EARLY TUESDAY WHERE WIND GUSTS TO 35 KNOTS ARE  
FORECAST. WAVE HEIGHTS AROUND 4 TO 8 FEET ARE ALSO EXPECTED IN  
THIS TIME PERIOD ALONG WITH LIGHT/RAIN SNOW CHANGING TO SNOW  
MONDAY NIGHT. AFTER THE CLIPPER SYSTEM PASSES THROUGH ON  
TUESDAY, WINDS AND WAVES ARE EXPECTED TO DECREASE OUT OF THE  
NORTHWEST ON TUESDAY AFTERNOON.  
 
FOR THE OPEN WATER DISCUSSION, REFER TO THE NWS MARQUETTE AREA  
FORECAST DISCUSSION AT WEATHER.GOV/MQT.  
 

 
   
DLH WATCHES/WARNINGS/ADVISORIES
 
 
MN...DENSE FOG ADVISORY UNTIL 9 AM CST MONDAY FOR MNZ020-021-037.  
WI...NONE.  
MARINE...SMALL CRAFT ADVISORY FROM 4 AM MONDAY TO 9 AM CST TUESDAY FOR  
LSZ121-143>145-148.  
SMALL CRAFT ADVISORY FROM 4 AM TO 9 PM CST MONDAY FOR  
LSZ140>142.  
GALE WARNING FROM 9 PM MONDAY TO 9 AM CST TUESDAY FOR  
LSZ140>142.  
SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM CST MONDAY FOR LSZ146-  
147-150.  
GALE WARNING FROM 4 PM MONDAY TO 9 AM CST TUESDAY FOR LSZ146-  
147-150.  
 

 
 

 
 
DISCUSSION...ROTHSTEIN  
AVIATION...HA  
MARINE...ROTHSTEIN  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MN Page
The Nexlab WI Page Main Text Page