304  
FXUS63 KDLH 172000  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
300 PM CDT SUN AUG 17 2025  
   
KEY MESSAGES
 
 
- ANOTHER ROUND OF RAIN AND THUNDERSTORMS BEGINS THIS AFTERNOON  
AND CONTINUES OVERNIGHT INTO MONDAY MORNING.  
 
- HIGH PRESSURE AND DRIER CONDITIONS BUILD INTO THE AREA FOR  
TUESDAY INTO THURSDAY MORNING WITH NEAR NORMAL TEMPERATURES.  
 
- THE NEXT CHANCE FOR PRECIPITATION IS LATE IN THE WORK WEEK.  
 

 
   
DISCUSSION
 
 
ISSUED AT 258 PM CDT SUN AUG 17 2025  
 
TODAY HAS BEEN ALMOST FALL LIKE, WITH STRONG EASTERLY WINDS,  
STRATUS CLOUDS STREAMING OFF LAKE SUPERIOR, AND COOL  
TEMPERATURES. A LOW PRESSURE SYSTEM DEVELOPING OVER SOUTH DAKOTA  
WITH A WARM FRONT EXTENDING EAST OVER CENTRAL MINNESOTA AND  
INTO WISCONSIN. THIS SYSTEM WILL PUSH EAST-NORTHEAST TODAY  
THROUGH TOMORROW, WITH THE LOW CENTER AND WARM FRONT STAYING  
JUST SOUTH OF THE FORECAST AREA. THIS WILL CAUSE A SURGE OF  
WARM, MOIST AIR UP OVER THE FRONT, AND IS CURRENTLY PRODUCING A  
LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER EASTERN NORTH AND  
SOUTH DAKOTA AND WESTERN MINNESOTA. THESE WILL PUSH INTO THE  
FORECAST AREA THIS AFTERNOON AND TONIGHT IN WAVES OF SHOWERS AND  
EMBEDDED THUNDERSTORMS TONIGHT AND MONDAY MORNING BEFORE  
EXITING OFF TO THE EAST MONDAY AFTERNOON AND EVENING. THE  
PROBABILITY OF GETTING MORE THAN A HALF INCH OF RAINFALL BY  
MONDAY EVENING IS OVER 50 PERCENT FOR NORTHERN MINNESOTA AND  
MOST OF NORTHWEST WISCONSIN. THE MOST RAIN SHOULD FALL IN A  
CORRIDOR FROM THE BRAINERD AND MILLE LACS LAKES AREA EAST  
THROUGH THE TWIN PORTS AND BAYFIELD PENINSULA, WHERE RAINFALL  
AMOUNTS OF OVER AN INCH AND A HALF ARE POSSIBLE.  
 
A RIDGE OF HIGH PRESSURE NOSES INTO THE AREA MONDAY NIGHT INTO  
TUESDAY AND LINGERS OVER THE AREA THROUGH WEDNESDAY NIGHT,  
GIVING US A PERIOD OF QUIETER AND DRIER WEATHER WITH NEAR NORMAL  
TEMPERATURES.  
 
ACTIVE WEATHER WITH SEVERAL PRECIPITATION CHANCES RETURNS  
THURSDAY INTO FRIDAY WITH A STRONG UPPER LOW THAT MOVES ACROSS  
THE CANADIAN PRAIRIES, ACROSS ONTARIO AND INTO QUEBEC THURSDAY  
THROUGH SATURDAY. CONFIDENCE IS INCREASING IN THIS GENERAL  
SCENARIO, BUT THE DETAILS OF THE STRENGTH OF THE SYSTEM AS WELL  
AS TIMING HAVE YET TO BE NARROWED DOWN. FOR NOW, PRECIPITATION  
CHANCES HAVE INCREASED FOR THURSDAY NIGHT INTO FRIDAY. WE SHOULD  
HAVE SOME WARMER THAN NORMAL TEMPERATURES THURSDAY AND FRIDAY,  
SHIFTING TO COOLER THAN NORMAL FOR NEXT WEEKEND.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
 
 
ISSUED AT 1254 PM CDT SUN AUG 17 2025  
 
CURRENT VFR CONDITIONS TO BE SLOWLY OVERCOME BY MVFR CEILINGS AS  
WAVES OF SHOWERS AND THUNDERSTORMS SPREAD IN FROM THE SOUTHWEST  
LATER TODAY AND THIS EVENING. ALL TERMINALS TO EVENTUALLY  
DETERIORATE THIS EVENING TO PREDOMINANTLY MVFR CONDITIONS, THEN  
TO IFR CEILINGS AND MVFR VISIBILITIES AFTER 05Z/MIDNIGHT AS  
WIDESPREAD RAIN WITH EMBEDDED THUNDER SPREADS IN. PERIODS OF  
LIFR CEILINGS ARE ALSO POSSIBLE, BUT HAVE ONLY INCLUDED THAT FOR  
KBRD AND KINL FOR NOW. EXPECT A GRADUAL IMPROVEMENT BEGINNING  
LATE MORNING/EARLY AFTERNOON, BUT CONFIDENCE IS LOW AND HAVE NOT  
INCLUDED FOR NOW.
 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
 
 
ISSUED AT 1254 PM CDT SUN AUG 17 2025  
 
NORTHEAST WINDS ARE STRENGTHENING SO FAR TODAY, WITH GUSTS SO  
FAR STAYING UNDER 33 KTS, BUT I DO NOT EXPECT THAT TO LAST LONG,  
AND WINDS SHOULD BE STRONGEST BETWEEN THE 2PM TO 8PM. THIS IS  
BEING CAUSED BY A TIGHTENING PRESSURE GRADIENT OVER WESTERN LAKE  
SUPERIOR BETWEEN HIGH PRESSURE OVER ONTARIO AND INCOMING LOW  
PRESSURE PASSING THROUGH SOUTH DAKOTA AND SOUTHERN MINNESOTA  
LATER TODAY. SUSTAINED WIND SPEEDS AROUND 20 KNOTS WITH GALE  
FORCE GUSTS, MAINLY FOR THE SOUTHWEST TIP OF THE LAKE. THESE  
WINDS WILL BUILD LARGE WAVE HEIGHTS, WHICH IS UNUSUAL FOR THIS  
TIME OF YEAR, ACROSS ALL WATERS RANGING FROM 3 TO 6 FEET. EXPECT  
DANGEROUS CONDITIONS FOR SMALL CRAFT AND VESSELS THROUGH TODAY  
WITH ADVISORIES IN EFFECT. THE GALE WARNING HAS BEEN EXPANDED TO  
THE DULUTH TO PORT WING ZONE, FOR NOW THROUGH 10 PM. WHILE THE  
CURRENT ADVISORIES EXPIRE THIS EVENING CURRENTLY, AN EXTENSION  
IN TIME CAN BE EXPECTED FOR MOST ZONES IS LIKELY INTO MONDAY AS  
ELEVATED SWELL LINGERS. THE NEXT ROUND OF THUNDERSTORMS BUILDS  
WEST TO EAST THIS EVENING AND GENERAL THUNDERSTORM HAZARDS ARE  
LIKELY TONIGHT INTO MONDAY MID- DAY.  
 
FOR THE OPEN WATER DISCUSSION, REFER TO THE NWS MARQUETTE AREA  
FORECAST DISCUSSION AT WEATHER.GOV/MQT.  
 

 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
 
 
ISSUED AT 258 PM CDT SUN AUG 17 2025  
 
NORTHEAST WINDS CONTINUING TO BLOW HARD, WITH GUSTS OF UP TO 36  
KNOTS SO FAR. WIND GUSTS SHOULD BE STRONGEST NOW THROUGH 8PM.  
THIS IS BEING CAUSED BY A TIGHTENING PRESSURE GRADIENT OVER  
WESTERN LAKE SUPERIOR BETWEEN HIGH PRESSURE OVER ONTARIO AND  
INCOMING LOW PRESSURE PASSING THROUGH SOUTH DAKOTA AND SOUTHERN  
MINNESOTA LATER TODAY. SUSTAINED WIND SPEEDS AROUND 20 KNOTS  
WITH GALE FORCE GUSTS, MAINLY FOR THE SOUTHWEST TIP OF THE LAKE.  
THESE WINDS WILL BUILD LARGE WAVE HEIGHTS, WHICH IS UNUSUAL FOR  
THIS TIME OF YEAR, ACROSS ALL WATERS RANGING FROM 3 TO 6 FEET.  
EXPECT DANGEROUS CONDITIONS FOR SMALL CRAFT AND VESSELS THROUGH  
TODAY WITH ADVISORIES IN EFFECT. THE GALE WARNING HAS BEEN  
EXPANDED TO THE DULUTH TO PORT WING ZONE, FOR NOW THROUGH 10 PM.  
WHILE THE CURRENT ADVISORIES EXPIRE LATER THIS EVENING  
CURRENTLY, AND AN EXTENSION IN TIME CAN BE EXPECTED FOR MOST  
ZONES IS LIKELY INTO MONDAY AS ELEVATED SWELL LINGERS. THE NEXT  
ROUND OF THUNDERSTORMS BUILDS WEST TO EAST THIS EVENING AND  
GENERAL THUNDERSTORM HAZARDS ARE LIKELY TONIGHT INTO MONDAY MID-  
DAY. AFTER MONDAY NIGHT, WE CAN ANTICIPATE A FEW DAYS OF  
QUIETER WEATHER ON THE LAKE.  
 
FOR THE OPEN WATER DISCUSSION, REFER TO THE NWS MARQUETTE AREA  
FORECAST DISCUSSION AT WEATHER.GOV/MQT.  
 

 
   
DLH WATCHES/WARNINGS/ADVISORIES
 
 
MN...BEACH HAZARDS STATEMENT UNTIL 10 PM CDT THIS EVENING FOR  
MNZ037.  
WI...BEACH HAZARDS STATEMENT UNTIL 10 PM CDT THIS EVENING FOR  
WIZ001.  
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ121-  
140-141-146>148-150.  
GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR LSZ142>145.  
 

 
 

 
 
DISCUSSION...LE  
AVIATION...LE  
MARINE...LE  
 
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