132  
FXUS63 KDLH 100733  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
233 AM CDT WED SEP 10 2025  
   
KEY MESSAGES
 
 
- WIDESPREAD DENSE FOG THIS MORNING. A DENSE FOG ADVISORY IS IN  
EFFECT.  
 
- ADDITIONAL AREAS OF DENSE FOG EXPECTED TONIGHT INTO EARLY  
THURSDAY. ANOTHER DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR  
PORTIONS OF THE NORTHLAND.  
 
- ASIDE FROM VERY LIMITED COVERAGE OF LIGHT RAIN SHOWERS IN  
NORTH-CENTRAL WISCONSIN TODAY, HIGH PRESSURE WILL KEEP THE  
NORTHLAND DRY THROUGH THURSDAY.  
 
- A WARM FRONT WILL BRING CHANCES (30-50%) FOR SCATTERED SHOWERS  
AND THUNDERSTORMS TO PORTIONS OF THE NORTHLAND LATE THURSDAY  
NIGHT AND FRIDAY.  
 
- ON AND OFF CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN LATE  
SUNDAY INTO NEXT WEEK.  
 

 
   
DISCUSSION
 
 
ISSUED AT 233 AM CDT WED SEP 10 2025  
 
TODAY - THURSDAY:  
 
WIDESPREAD DENSE FOG HAS DEVELOPED DURING THE CURRENT OVERNIGHT  
HOURS ACROSS MUCH OF THE NORTHLAND ASIDE FROM NEAR INTERNATIONAL  
FALLS AND IN PORTIONS OF NORTHWEST WISCONSIN. EXPECT THIS FOG TO  
CONTINUE TO EXPAND INTO MUCH OF NORTHWEST WISCONSIN TOWARDS  
EARLY MORNING AS RAIN SHOWERS AND CLOUDS DEPART INTO NORTH-  
CENTRAL WISCONSIN. WHILE FOG COULD BRIEFLY BECOME DENSE IN  
KOOCHICHING COUNTY, CONFIDENCE WAS NOT HIGH ENOUGH IN WIDESPREAD  
DENSE FOG DEVELOPING THERE TO DO ANY EXPANSION TO THE DENSE FOG  
ADVISORY, BUT WILL CONTINUE TO MONITOR TRENDS IN CONDITIONS IN  
CASE THIS CHANGES. FOG/LOW STRATUS WILL BE SLOW TO BURN OFF THIS  
MORNING, SO DENSE FOG COULD LINGER INTO THE MID TO POSSIBLY LATE  
MORNING HOURS (GENERALLY IMPROVING TOWARDS AND AFTER 10 AM CDT).  
 
DESPITE SURFACE HIGH PRESSURE MOVING ACROSS NORTHERN ONTARIO AND  
FUELING RAIN-FREE CONDITIONS FOR MOST OF THE NORTHLAND TODAY,  
SOME LINGERING MID-LEVEL VORTICITY/WEAK SURFACE TROUGH IN  
NORTH-CENTRAL WISCONSIN COULD KEEP SOME SPORADIC LIGHT  
SHOWERS/SPRINKLES LINGERING THERE INTO EARLY THIS AFTERNOON.  
LITTLE TO NO ADDITIONAL RAIN ACCUMULATIONS ARE EXPECTED.  
GENERALLY SEASONAL TEMPERATURES ARE EXPECTED TODAY, WITH HIGHS  
RANGING FROM THE MID 60S NEAR LAKE SUPERIOR TO LOW TO MID 70S  
INLAND.  
 
HIGH RESOLUTION MODELS AND ENSEMBLES (HREF/REFS) SHOW A GOOD  
SIGNAL (50% TO LOCALLY 80% CHANCE) FOR DENSE FOG DEVELOPMENT  
AGAIN TONIGHT INTO THURSDAY MORNING FOR MUCH OF THE NORTHLAND  
ASIDE FROM NEAR THE INTERNATIONAL BORDER AND IN COUNTIES OF  
INLAND NORTHWEST WISCONSIN. ANOTHER ROUND OF DENSE FOG  
ADVISORIES WILL LIKELY BE NEEDED. HIGH TEMPERATURES ON THURSDAY  
WILL ALSO BE IN THE MID 60S TO MID 70S.  
 
THURSDAY NIGHT - FRIDAY:  
 
WHILE A MID/UPPER-LEVEL RIDGE WILL BE OVERHEAD FOR TONIGHT INTO  
FRIDAY, SOME WEAK SHORTWAVE ENERGY/VORTICITY ROUNDING THE TOP  
OF THE RIDGE AND SOUTHERLY RETURN FLOW OF MOISTURE/WARM AIR  
ADVECTION COMBINING WITH A WARM FRONTAL ZONE WILL BRING A 30-50%  
CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS TO PORTIONS OF  
THE NORTHLAND LATE THURSDAY NIGHT AND FRIDAY. THE HIGHEST  
PRECIPITATION POTENTIAL WILL BE ACROSS NORTH-CENTRAL AND  
NORTHEAST MINNESOTA. ANY SHOWERS AND STORMS THAT DEVELOP SHOULD  
REMAIN ELEVATED DUE TO A LOW-LEVEL (750-850 MB) CAPPING  
INVERSION. WHILE PROGGED BULK SHEAR WILL BE RATHER FAVORABLE  
(0-10 KM BULK SHEAR OF 45-55 KT), INSTABILITY WILL BE MODEST  
(200-600 J/KG MUCAPE), SO SEVERE WEATHER IS NOT ANTICIPATED.  
WHILE PWATS WILL ALSO BE ABOVE AVERAGE AT 1-1.5", THE SCATTERED  
NATURE OF SHOWERS AND STORMS SHOULD MITIGATE RAINFALL  
ACCUMULATIONS. FRIDAY WILL ALSO BE SLIGHTLY ABOVE AVERAGE UNDER  
THE RIDGE, WITH HIGH TEMPERATURES IN THE UPPER 60S TO AROUND  
80F, WARMEST AWAY FROM LAKE SUPERIOR.  
 
THIS WEEKEND:  
 
WHILE SOUTHERLY RETURN FLOW WILL KEEP ABOVE AVERAGE MOISTURE  
(PWATS OF 1-1.5"; SURFACE DEWPOINTS IN THE UPPER 50S TO 60S)  
CONTINUING INTO THE WEEKEND, A PSEUDO-OMEGA BLOCKING PATTERN  
ALOFT SETTING UP OVER THE UPPER MIDWEST FOR SATURDAY INTO EARLY  
SUNDAY SHOULD PREVENT PRECIPITATION CHANCES IN THE NORTHLAND  
UNTIL AT LEAST LATE SUNDAY. ABOVE AVERAGE TEMPERATURES PERSIST  
THIS WEEKEND WITH THE RIDGE, WITH HIGHS AROUND 70F NEAR LAKE  
SUPERIOR TO 70S/LOW 80S AWAY FROM THE LAKE.  
 
NEXT WEEK:  
 
ENSEMBLE GUIDANCE/CLUSTERS HAVE GENERAL AGREEMENT IN THE OMEGA  
BLOCKING PATTERN/RIDGE AXIS SHIFTING EAST OF THE NORTHLAND FOR  
LATE SUNDAY INTO NEXT WEEK AS THE UPPER-LEVEL PATTERN GRADUALLY  
BECOMES MORE ZONAL. THIS WILL ALLOW A SERIES OF SHORTWAVE  
TROUGHS TO TREK ACROSS THE UPPER MIDWEST VICINITY THROUGH MUCH  
OF NEXT WEEK, WITH PERIODIC CHANCES FOR SHOWERS AND  
THUNDERSTORMS AS SOUTHERLY LOW-LEVEL WINDS KEEP ABOVE AVERAGE  
MOISTURE AND TEMPERATURES PUMPING INTO THE AREA. WHILE  
CONFIDENCE IS MEDIUM TO HIGH IN A MORE ACTIVE PRECIPITATION  
PATTERN FOR NEXT WEEK, DIFFERENCES IN TIMING AND PLACEMENT OF  
THE SYNOPTIC/MESOSCALE FORCING MECHANISMS BETWEEN ENSEMBLE  
MEMBERS KEEP CONFIDENCE LOWER IN WHERE AND WHEN SHOWERS AND  
STORMS WILL EXACTLY DEVELOP AND MOVE THROUGH NEXT WEEK.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
 
 
ISSUED AT 1227 AM CDT WED SEP 10 2025  
 
STILL SOME INTERMITTENT SHOWERS IN THE VICINITY OF HYR THROUGH  
ROUGHLY 07-08Z. DENSE FOG HAS ALREADY DEVELOPED FOR MUCH OF  
CENTRAL AND NORTHEAST MINNESOTA AND IS EXPECTED TO EXPAND ACROSS  
MUCH OF THE REMAINDER OF THE AREA OVERNIGHT, WITH INL PERHAPS  
BEING THE ONE EXCEPTION TO AVOID THE DENSE FOG FOR MOST OF THE  
NIGHT. HOWEVER, SOME BRIEF DENSE FOG COULD DEVELOP THERE, AS  
WELL. EXPECT LIFR TO VLIFR CONDITIONS IN THE FOG TONIGHT INTO  
EARLY/MID MORNING TODAY BEFORE CONDITIONS START TO IMPROVE WITH  
DAYTIME SUNLIGHT ERODING THE FOG AND SCATTERING OUT CONDITIONS  
BACK TO VFR THIS AFTERNOON. HYR/NORTHWEST WISCONSIN COULD SEE  
MVFR CEILINGS HANG AROUND THROUGH MUCH OF TODAY, THOUGH.  
ADDITIONAL FOG TO DENSE FOG DEVELOPMENT APPEARS LIKELY AGAIN  
TONIGHT FOR A GOOD PORTION OF THE AREA, THOUGH MOSTLY LOOKS TO  
DEVELOP TOWARDS THE VERY END OR AFTER THE CURRENT TAF PERIOD.  
 

 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
 
 
ISSUED AT 233 AM CDT WED SEP 10 2025  
 
MAIN MARINE HAZARD OVER THE NEXT 48 HOURS IS PERIODS OF DENSE  
FOG ACROSS MUCH OF WESTERN LAKE SUPERIOR. A MARINE DENSE FOG  
ADVISORY IS CURRENTLY IN EFFECT UNTIL 10 AM, BUT THERE IS A  
POSSIBILITY THAT DENSE FOG (VISIBILITY LESS THAN 1 NM) PERSISTS  
FOR PORTIONS OF THE SOUTH SHORE THROUGH MUCH OF TODAY. MORE  
WIDESPREAD DENSE FOG IS EXPECTED TO DEVELOP AGAIN TONIGHT INTO  
THURSDAY MORNING, SO AN ADDITIONAL DENSE FOG ADVISORY LOOKS  
LIKELY.  
 
OUTSIDE OF FOG, EXPECT PERSISTENT NORTHEAST WINDS TODAY THROUGH  
AT LEAST FRIDAY AT 5-15 KT, STRONGEST FOR THE SOUTH SHORE AND  
SOUTHWESTERN ARM OF LAKE SUPERIOR WHERE WINDS WILL GET FUNNELED.  
THE NEXT CHANCE FOR SCATTERED THUNDERSTORMS (30-50% CHANCE)  
RETURNS TO WESTERN LAKE SUPERIOR ON FRIDAY.  
 
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 10 AM CDT THIS MORNING FOR MNZ011-012-  
018>021-025-026-033>038.  
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001>003-  
006>008.  
MARINE...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ121-  
140>148-150.  
 

 
 

 
 
DISCUSSION...ROTHSTEIN  
AVIATION...ROTHSTEIN  
MARINE...ROTHSTEIN  
 
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