634  
FXUS63 KDLH 111132  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
632 AM CDT THU SEP 11 2025  
   
KEY MESSAGES  
 
- DENSE FOG THIS MORNING WILL DISSIPATE BY LATE MORNING. EXPECT  
ANOTHER ROUND OF DENSE FOG TONIGHT AND FRIDAY MORNING.  
 
- THERE IS A 10 TO 30 PERCENT CHANCE OF THUNDERSTORMS NORTH OF  
US-2 FRIDAY MORNING. THE RISK OF STORMS SHIFTS EAST INTO THE  
ARROWHEAD, WESTERN LAKE SUPERIOR AND NORTHWEST WISCONSIN BY  
LATE AFTERNOON THROUGH THE EVENING. A FEW STORMS MAY BE STRONG  
FRIDAY MORNING OVER NORTH-CENTRAL MINNESOTA.  
 
- ABOVE NORMAL, SUMMER-LIKE, TEMPERATURES THIS WEEKEND WITH  
HIGHS IN THE LOW 70S TO LOW 80S AWAY FROM LAKE SUPERIOR.  
 
- ON AND OFF CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN LATE  
SUNDAY AND CONTINUE THROUGH THE FIRST HALF OF THE WEEK.  
 
 
   
DISCUSSION  
 
ISSUED AT 430 AM CDT THU SEP 11 2025  
 
DENSE FOG SPREAD INLAND FROM LAKE SUPERIOR OVERNIGHT WITH  
RADIATIONAL FOG FOUND FARTHER INLAND. DENSE FOG ADVISORIES  
REMAIN IN EFFECT UNTIL 11 AM. ANTICIPATE VISIBILITY OF 1/4 MILE  
OR LESS. LIGHT DRIZZLE WAS FALLING NEAR LAKE SUPERIOR WHERE  
NORTHEASTERLY TO SOUTHEASTERLY WINDS WERE CREATING UPSLOPE FLOW.  
EXPECT THE DRIZZLE AND FOG TO DISSIPATE LATER THIS MORNING AND  
GIVE WAY TO MOSTLY SUNNY SKIES.  
 
HIGH PRESSURE OVER ONTARIO AND LOW PRESSURE OVER THE NORTHERN  
PLAINS WILL PROVIDE AN IDEAL PRESSURE GRADIENT ORIENTATION FOR  
STRONG NORTHEAST WINDS TO DEVELOP OVER THE SOUTHWEST ARM OF LAKE  
SUPERIOR. THE STRONG WINDS OF 15 TO 20 MPH WILL BUILD WAVES OF  
2 TO 4 FEET. THE WIND DIRECTION AND WAVE ACTION WILL CREATE A  
RISK OF RIP CURRENTS THIS AFTERNOON AND EVENING. A BEACH HAZARDS  
STATEMENT WAS ISSUED FROM 1 PM UNTIL 10 PM. WIND AND WAVES WILL  
LIKELY MAKE SWIMMING CONDITIONS CHALLENGING FRIDAY INTO NEXT  
WEEK.  
 
SHOWERS AND STORMS ARE FORECAST TO DEVELOP OVER THE NORTHERN  
PLAINS THIS AFTERNOON AND WILL BE CARRIED EASTWARD ON THE NOSE  
OF A NOCTURNAL LOW-LEVEL JET. THE STORMS ARE FORECAST TO MOVE  
ACROSS NORTHERN MINNESOTA FROM LATE TONIGHT THROUGH LATE MORNING  
FRIDAY. STORM CHANCES WILL BE HIGHEST ALONG THE CANADIAN BORDER  
FROM ABOUT 5 AM UNTIL 10 AM FRIDAY MORNING. THIS IS ALSO THE  
TIME OF THE GREATEST RISK OF STRONG TO SEVERE STORMS. HAIL AS  
LARGE AS QUARTERS AND WIND GUSTS AS STRONG AS 60 MPH ARE  
POSSIBLE FRIDAY MORNING.  
 
THE LOW-LEVEL JET WILL GRADUALLY WEAKEN THROUGH THE DAY.  
ISENTROPIC ASCENT IS WILL CONTINUE KEEPING A 10 TO 30 PERCENT  
CHANCE OF SHOWERS AND STORMS IN THE PICTURE OVER NORTHEAST  
MINNESOTA THROUGH THE DAY. THE VEERING LOW-LEVEL JET WILL SHIFT  
THE PRECIPITATION RISK INTO NORTHWEST WISCONSIN AND THE  
ARROWHEAD BY FRIDAY EVENING.  
 
A MID-LEVEL RIDGE WILL BUILD OVER THE UPPER MISSISSIPPI RIVER  
VALLEY REGION THIS WEEKEND INTO EARLY NEXT WEEK. SOUTHERLY  
THETA-E ADVECTION WILL PERSIST IN THE LOWER ALTITUDES. THUS A  
STRETCH OF ABOVE NORMAL TEMPERATURES ARE FORECAST THIS WEEKEND  
INTO EARLY NEXT WEEK. HIGHS ON FRIDAY WILL REACH THE MIDDLE 60S  
NEAR GRAND MARAIS TO AROUND 80 DEGREES FARTHER INLAND. SATURDAY  
AND SUNDAY WILL SEEM SUMMERY WITH HIGHS IN THE UPPER 60S TO LOW  
AND MIDDLE 80S. THOSE VALUES ARE NEAR NORMAL FOR PORTIONS OF  
THE NORTH SHORE TO AROUND 15 DEGREES ABOVE NORMAL FOR AREAS  
INLAND FROM LAKE SUPERIOR.  
 
SEVERAL ROUNDS OF SHOWERS AND STORMS ARE POSSIBLE SUNDAY  
THROUGH EARLY NEXT WEEK AS SEVERAL SHORTWAVE TROUGHS PROPAGATE  
NORTHWARD ALONG THE WESTERN PERIPHERY OF THE MID-LEVEL RIDGE. A  
FEW OF THESE STORMS COULD BE STRONG, ALTHOUGH THE OVERALL RISK  
OF SEVERE STORMS IS LOW (LESS THAN 5%).  
 
A PATTERN SHIFT IS FORECAST AROUND MIDWEEK AS A SUBSTANTIVE  
COLD FRONT MOVES SOUTHEASTWARD OUT OF THE CANADIAN PRAIRIES INTO  
THE PLAINS AND WESTERN GREAT LAKES. TEMPERATURES WILL TREND  
NEAR NORMAL FOR THE SECOND HALF OF NEXT WEEK. HIGHS THURSDAY ARE  
FORECAST IN THE MIDDLE 60S TO LOW 70S.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/  
 
ISSUED AT 632 AM CDT THU SEP 11 2025  
 
LOW VISIBILITY THIS MORNING IN FOG WILL IMPROVE GRADUALLY THIS  
MORNING. LOW CEILINGS WILL TAKE A LITTLE LONGER TO SCATTER OUT.  
UPSLOPE WINDS FROM THE EAST AND SOUTHEAST AT DLH OVERNIGHT WILL  
CONTINUE THIS MORNING. WITH WIDESPREAD DENSE FOG OVER LAKE  
SUPERIOR, THAT WIND DIRECTION HAS THE POTENTIAL TO KEEP LOW  
CEILINGS AND VISIBILITY LONGER THAN FORECAST. CONFIDENCE IN THE  
TIMING OF IMPROVEMENTS AT DLH IS ABOUT 70%. ONCE THE FOG AND LOW  
STRATUS LIFTS, EXPECT VFR CONDITIONS WITH SOUTHEAST WINDS UNTIL  
TONIGHT. FOG WILL LIKELY REDEVELOP UNDER MOSTLY CLEAR SKIES.  
THUNDERSTORM CHANCES INCREASE AT INL AFTER 10Z AS CONVECTION  
FROM THE DAKOTAS ON THE NOSE OF A LOW-LEVEL JET MOVE INTO NORTH-  
CENTRAL MINNESOTA. THE STORMS WILL PROGRESS FARTHER EAST AFTER  
12.12Z AND MAY AFFECT HIB.  
 
 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/  
 
ISSUED AT 430 AM CDT THU SEP 11 2025  
 
HIGH PRESSURE NEAR HUDSON BAY AND LOW PRESSURE OVER THE  
NORTHERN PLAINS WILL WORK TOGETHER TO CREATE STRONG NORTHEAST  
WINDS OVER THE SOUTHWEST ARM OF LAKE SUPERIOR THIS AFTERNOON AND  
TONIGHT. WINDS WILL BE STRONGEST NEAR THE TWIN PORTS AT AROUND  
15 TO 20 KNOTS. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR THIS  
AFTERNOON AND TONIGHT. WINDS WILL BE FROM THE NORTHEAST OVER THE  
REST OF LAKE SUPERIOR THOUGH WIND SPEEDS WILL BE LOWER, AROUND  
5 TO 10 KNOTS. WAVES NEAR THE TWIN PORTS WILL BUILD TO 2 TO 4  
FEET. WINDS WILL GRADUALLY WEAKEN TONIGHT BEFORE STRENGTHENING  
AGAIN FRIDAY. A FEW THUNDERSTORMS ARE FORECAST OVER WESTERN LAKE  
SUPERIOR FRIDAY AND FRIDAY NIGHT. THE GREATEST RISK OF STORMS  
WILL BE FROM SILVER BAY TO GRAND PORTAGE AND EASTWARD OVER THE  
OPEN WATERS. A FEW STORMS MAY BE STRONG WITH HAIL TO PENNY SIZE,  
WIND GUSTS TO 30 KNOTS, AND OCCASIONAL CLOUD-TO-WATER  
LIGHTNING.  
 
NORTHEAST WINDS PERSIST INTO THE WEEKEND. GENERALLY LOWER  
PRESSURE WILL REMAIN OVER THE PLAINS AND HIGHER PRESSURE WILL BE  
FOUND OVER ONTARIO. SATURDAY INTO EARLY NEXT WEEK IS SHAPING UP  
TO BE QUITE WARM OVER NORTHERN MINNESOTA AND NORTHWEST  
WISCONSIN, WHICH WILL CREATE A STRONG THERMAL GRADIENT ALONG THE  
SHORE DURING THE DAY. THUNDERSTORMS OVER THE NORTHERN PLAINS  
WILL STRENGTHEN THE LOW PRESSURE OVER THAT AREA, WHICH WILL  
TIGHTEN THE PRESSURE GRADIENT OVER LAKE SUPERIOR AND LEAD TO  
STRONG NORTHEAST WINDS SATURDAY INTO NEXT WEEK. SMALL CRAFT  
ADVISORIES MAY BECOME NECESSARY.  
 
ADDITIONAL ROUNDS OF STORMS ARE FORECAST SUNDAY THROUGH MUCH OF  
NEXT WEEK.  
 
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 11 AM CDT THIS MORNING FOR MNZ010>012-  
018>021-025-026-033>038.  
BEACH HAZARDS STATEMENT FROM 1 PM CDT THIS AFTERNOON THROUGH  
THIS EVENING FOR MNZ037.  
WI...DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR WIZ001>004-  
006>009.  
BEACH HAZARDS STATEMENT FROM 1 PM CDT THIS AFTERNOON THROUGH  
THIS EVENING FOR WIZ001.  
MARINE...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR LSZ121-  
140>148-150.  
 
 
 
 
 
DISCUSSION...HUYCK  
AVIATION...HUYCK  
MARINE...HUYCK  
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