049  
FXUS63 KDLH 161038  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
438 AM CST MON DEC 16 2024  
   
KEY MESSAGES  
 
- DENSE FOG LINGERING FROM CLOQUET UP THE HIGHER TERRAIN OF THE  
NORTH SHORE THROUGH MID MORNING.  
 
- A CLIPPER SYSTEM WILL BRING AN INITIAL WINTRY MIX THIS  
MORNING, TRANSITIONING TO SNOW THROUGH THE REST OF TODAY AND  
EARLY EVENING BEFORE ENDING OVERNIGHT. LIGHT ACCUMULATIONS OF  
UP TO 2" FOR FAR NORTHERN MINNESOTA.  
 
- COLDER TEMPERATURES RETURN FOR TUESDAY THROUGH NEXT WEEKEND.  
 
- A MORE POTENT CLIPPER SYSTEM IS EXPECTED ON THURSDAY WITH  
ACCUMULATING SNOW INCREASINGLY LIKELY.  
 
 
   
DISCUSSION  
 
ISSUED AT 437 AM CST MON DEC 16 2024  
 
A BROAD AREA OF DRIZZLE/FREEZING DRIZZLE AND FOG UNDER STRATUS  
IS AFFECTING THE AREA THIS MORNING AS A LOW PRESSURE SYSTEM OVER  
SOUTHEAST MANITOBA MOVES EAST INTO ONTARIO TODAY. A COLD FRONT  
WHICH WILL FOLLOW THIS SYSTEM IS NOW MOVING ACROSS NORTH DAKOTA,  
WHICH SHOULD PUSH ACROSS THE FORECAST AREA TONIGHT. AS THIS  
SYSTEM MOVES EAST THE STRATUS, DRIZZLE AND FOG SHOULD ALSO PUSH  
EAST. AS COLDER AIR MOVES IN BEHIND THE LOW PRESSURE SYSTEM WE  
SHOULD SEE AN EVENTUAL SWITCH OVER TO LIGHT SNOW INSTEAD OF THE  
FREEZING DRIZZLE, AND THERE WILL BE SOME LIGHT ACCUMULATIONS  
TODAY AND THIS EVENING, MAINLY ALONG AND NORTH OF HWY 2. UP TO 2  
INCHES ARE POSSIBLE ALONG THE US/CANADA BORDER, THOUGH THESE  
AMOUNTS HAVE DECREASED SLIGHTLY WITH THIS SET OF MODEL RUNS.  
BACK AROUND MIDNIGHT AND EARLIER IN THE EVENING, THE SOUTHERLY  
WINDS WERE CAUSING SOME UPSLOPE FLOW ALONG THE NORTH SHORE,  
PRODUCING DENSE FOG ALONG THE HIGHER TERRAIN, WITH KDLH AND KCKC  
BOTH IN THE PEA SOUP OF FOG. HOWEVER, AS THE LOW HAS MOVED  
FARTHER EAST, THE WIND DIRECTIONS HAVE BEGUN VEERING MORE  
SOUTHWESTERLY, AND WE HAVE SEEN VISIBILITIES IMPROVE AT LEAST  
HERE AROUND THE TWIN PORTS, BUT VISIBILITIES REMAIN VERY POOR  
FARTHER NORTH ALONG THE NORTH SHORE. HAVE DECIDED TO LEAVE THE  
DENSE FOG ADVISORY IN PLACE AS IS, BUT WE MAY BE ABLE TO CANCEL  
ALL/PARTS OF THE ADVISORY EARLY AS THIS TREND CONTINUES.  
 
BEHIND THIS SYSTEM WE GET INTO A FAIRLY STRONG NORTHWEST FLOW  
REGIME, WITH GUSTY NORTHWEST WINDS EXPECTED ON TUESDAY AND  
TEMPERATURES COOLING OFF TOWARD NORMAL. A CLIPPER SYSTEM MOVES  
ACROSS SOUTHERN MN INTO WI ON TUESDAY, BUT MISSING THE NORTHLAND  
FOR THE MOST PART. I WOULD NOT BE TOO SURPRISED IF WE HAVE SOME  
LINGERING FLURRIES IN THE COLD AIR ADVECTION AND WITH STEEP LOW  
LEVEL LAPSE RATES, BUT WE MAY NOT HAVE ENOUGH MOISTURE AND HAVE  
LEFT THIS OUT FOR NOW. WE GET A TRAILING, WEAKER SHORTWAVE FOR  
WEDNESDAY, THAT TOGETHER WITH THE NORTHWEST FLOW SHOULD TURN ON  
THE LAKE EFFECT MACHINE FOR TUESDAY NIGHT INTO WEDNESDAY FOR THE  
SOUTH SHORE.  
 
ATTENTION THEN TURNS TO THE MUCH STRONGER CLIPPER THAT SHOULD  
MOVE THROUGH THE AREA ON THURSDAY. WE STILL HAVE A LOT OF SPREAD  
ON THE TRACK OF THIS SYSTEM, WHICH OF COURSE IS PRODUCING QUITE  
THE SPREAD IN POTENTIAL SNOWFALL AMOUONTS. SCARILY ENOUGH, THERE  
ARE MEMBERS IN BOTH THE ECMWF AND GEFS ENSEMBLE SUITES WHICH  
PRODUCE SEVERAL INCHES OF SNOWFALL FOR THE SOUTHERN HALF OF THE  
FORECAST AREA, BUT THERE ARE ALSO MEMBERS WHICH ARE DRY. FOR  
NOW, CONFIDENCE REMAINS LOW, BUT IF THE MEANS WORK OUT, WE ARE  
LOOKING AT A BAND OF SNOW THAT WILL NEED TO BE SHOVELED/PLOWED  
ON THURSDAY SOMEWHERE IN THE NORTHLAND. THIS SYSTEM SHOULD ALSO  
HAVE A PERIOD OF LAKE EFFECT SNOW WHICH LINGERS INTO AT LEAST  
FRIDAY.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/  
 
ISSUED AT 1144 PM CST SUN DEC 15 2024  
 
DENSE FOG WILL PERSIST AT DLH THROUGH AROUND 15Z, THEN GRADUAL  
IMPROVEMENT AFTER THAT AS WINDS GRADUALLY SWITCH TO WESTERLY.  
ELSEWHERE, IFR CEILINGS WITH VARYING VISIBILITIES DUE TO FOG,  
THOUGH DENSE FOG IS NOT EXPECTED MOST OF THE TIME. AREAS OF  
LIGHT RAIN OR DRIZZLE ARE EXPECTED TO TRANSITION OVER TO LIGHT  
SNOW MONDAY MORNING. SNOW IS MOST LIKELY TO REDUCE VISIBILITIES  
TO MVFR AT INL/HIB. SNOW CONSISTENCY WILL START OFF HEAVY AND  
WET IN THE MORNING, BUT BECOME CLOSER TO LIGHT AND FLUFFY BY THE  
AFTERNOON. VISIBILITIES TREND TOWARDS VFR AT BRD/HYR IN THE  
MORNING, AND SLOWER TO IMPROVE AT DLH WITH LINGERING FOG.  
WESTERLY WINDS ARE EXPECTED TO GRADUALLY INCREASE IN SPEED WITH  
GUSTS 15 TO 20 KT WITH COLD AIR MOVING IN.  
 
 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/  
 
ISSUED AT 437 AM CST MON DEC 16 2024  
 
A CLIPPER SYSTEM MOVING THROUGH THE AREA TODAY WILL TAKE THE  
CURRENT SOUTH-SOUTHWEST WINDS OVER THE LAKE AND CAUSE THEM TO  
GRADUALLY VEER THROUGH THE WEST TODAY TO NORTHWEST TONIGHT INTO  
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 THIS AFTERNOON INTO TONIGHT. ADDITIONALLY, WINDS ARE  
FORECAST TO PICK UP TO GALES OF 35 KNOTS ALONG THE NORTH SHORE  
LATE THIS EVENING INTO EARLY TUESDAY MORNING DUE TO ACCELERATING  
WINDS DOWN THE SLOPES OF THE NORTH SHORE TERRAIN. GALE WARNINGS  
ARE IN EFFECT THIS 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, NORTHWEST WINDS AND WAVES ARE EXPECTED TO  
DECREASE 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 THIS MORNING FOR MNZ020-021-  
037.  
WI...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM CST TUESDAY FOR LSZ121-143>145-  
148.  
SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR  
LSZ140>142.  
GALE WARNING FROM 9 PM THIS EVENING TO 9 AM CST TUESDAY FOR  
LSZ140>142.  
SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ146-  
147-150.  
GALE WARNING FROM 4 PM THIS AFTERNOON TO 9 AM CST TUESDAY FOR  
LSZ146-147-150.  
 
 
 
 
 
DISCUSSION...LE  
AVIATION...JDS  
MARINE...LE  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab MN Page
The Nexlab WI Page
Main Text Page