344  
FXUS63 KDLH 180915  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
415 AM CDT MON AUG 18 2025  
   
KEY MESSAGES  
 
- A COUPLE WAVES OF RAIN AND THUNDERSTORMS MOVE THROUGH THE AREA TODAY,  
WITH RAIN CHANCES ENDING FROM WEST TO EAST THIS AFTERNOON.  
SEVERE STORMS ARE NOT EXPECTED.  
 
- HIGH PRESSURE AND DRIER CONDITIONS BUILD INTO THE AREA FOR TUESDAY  
INTO THURSDAY MORNING WITH INCREASING TEMPERATURES.  
 
- THE NEXT CHANCE FOR RAIN AND A FEW STORMS IS THURSDAY INTO  
FRIDAY, WITH COOLER WEEKEND TEMPERATURES.  
 
 
   
DISCUSSION  
 
ISSUED AT 403 AM CDT MON AUG 18 2025  
 
A STATIONARY FRONT REMAINS WELL TO OUR SOUTH THIS MORNING,  
STRETCHING FROM ACROSS THE MID MISSISSIPPI RIVER VALLEY INTO THE  
OHIO RIVER VALLEY. BROAD SURFACE HIGH PRESSURE CENTERED SOUTH OF  
HUDSON BAY IS ALLOWING FOR EAST TO SOUTHEAST WINDS ACROSS THE  
NORTHLAND, AND DESPITE DEWPOINTS MOSTLY IN THE 50S, THERE IS PLENTY  
OF LOW LEVEL MOISTURE AVAILABLE FOR CLOUDY SKIES. MESSY ZONAL FLOW  
ALOFT REMAINS ACROSS THE NORTHERN PLAINS INTO THE GREAT LAKES, WITH  
BROAD RIDGING OVER MUCH OF THE SOUTHERN CONUS.  
 
RIPPLES IN UPPER LEVEL FLOW ARE KICKING OFF A FEW AREAS OF SHOWERS  
AND STORMS THIS MORNING, AND EXPECT ADDITIONAL DEVELOPMENT AS OTHER  
WEAK SHORTWAVES CROSS THE REGION. THE BEST CHANCES FOR MORE RAIN  
REMAIN ACROSS NORTHWEST WISCONSIN, BUT CANNOT RULE OUT A  
PASSING SHOWER ANYWHERE IN THE NORTHLAND. BEING POST- FRONTAL  
AND WITH AN EASTERLY FETCH ACROSS THE LAKE, THE AIRMASS IS  
RATHER STABLE AND DO NOT EXPECT SEVERE STORMS. RAIN ACTIVITY  
ENDS FROM WEST TO EAST THROUGH THE AFTERNOON, AS UPPER LEVEL  
RIDGING AMPLIFIES UP THE SPINE OF THE ROCKIES AND WINDS ALOFT  
BECOME NORTHWESTERLY OVER THE NORTHLAND. THIS WILL BRING A  
RETURN TO DRIER CONDITIONS THROUGH MID WEEK AS SURFACE RIDGING  
SETTLES OVER THE AREA.  
 
RIDGING IS DAMPENED BY A TROUGH MOVING ACROSS SOUTHERN CANADA THAT  
WILL PUSH A COLD FRONT THROUGH THE NORTHLAND THURSDAY INTO FRIDAY.  
GOOD MOISTURE TRANSPORT AHEAD OF THE FRONT WILL PUSH PWS ABOVE 1.5  
INCHES. BULK SHEAR VALUES OF 40-50KTS AND LAPSE RATES OF 7DEGC/KM  
WOULD SUPPORT UPDRAFTS AND THE POTENTIAL FOR STRONG TO POSSIBLY A  
FEW SEVERE THUNDERSTORMS THURSDAY AFTERNOON INTO THE EVENING. BEHIND  
THE FRONT, A TASTE OF FALL, WITH HIGHS IN THE 60S AND LOWS IN THE  
40S.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/  
 
ISSUED AT 1238 AM CDT MON AUG 18 2025  
 
EAST TO SOUTHEAST BREEZY WINDS CONTINUE TONIGHT, WITH GUSTS UP  
TO 25KTS. OROGRAPHICALLY ENHANCED CLOUDS CONTINUE AT DLH, WITH A  
MIX OF MVFR/IFR HEIGHTS. AN APPROACHING TROUGH WILL BRING  
SHOWERS AND THUNDERSTORMS TO TERMINALS OVERNIGHT THROUGH MONDAY  
MORNING. CURRENTLY A BROKEN BAND OF SHOWERS IS MOVING EASTWARD  
THROUGH INL TO HIB TO DLH TO HYR. BEHIND THE LINE, IT IS  
POSSIBLE ADDITIONAL SHOWERS AND A COUPLE THUNDERSTORMS DEVELOP  
OVERNIGHT AND ALSO MOVE WEST TO EAST THROUGH THE AREA. GIVEN THE  
SCATTERED NATURE OF EXPECTED COVERAGE, HAVE INCLUDE VCSH/VCTS  
WITH PREVAILING SHRA AT TIMES. WITH INCREASING LOW LEVEL  
MOISTURE, CIGS WILL FALL TO IFR FOR ALL TERMINALS EXCEPT HYR,  
WHICH WILL REMAIN WITHIN THE MVFR CATEGORY. THESE LOW CIGS WILL  
PERSIST THROUGH MONDAY. WIND SPEEDS DECREASE THROUGH AFTERNOON  
MONDAY, BECOMING LESS THAN 5KTS MONDAY EVENING.  
 
 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/  
 
ISSUED AT 403 AM CDT MON AUG 18 2025  
 
EAST TO SOUTHEAST WINDS REMAIN ELEVATED THIS MORNING, RESULTING  
IN ELEVATED WAVE HEIGHTS AND HAZARDOUS CONDITIONS FOR SMALL  
CRAFT CONTINUING NEAR THE TWIN PORTS THROUGH MID MORNING, AND  
ALONG THE NORTH SHORE THROUGH THE AFTERNOON. WIND GUSTS OF  
25-30KTS REMAIN POSSIBLE WITH WAVE HEIGHTS UP TO 5FT. WINDS DO  
WEAKEN THROUGH THE DAY AND BEGIN A TURN TO THE NORTHEAST THIS  
EVENING.  
 
A FEW SHOWERS OR THUNDERSTORMS ARE POSSIBLE TODAY, WITH GENERAL  
THUNDERSTORM HAZARDS POSSIBLE. DRIER CONDITIONS RETURN TUESDAY  
AND WEDNESDAY.  
 
FOR THE OPEN WATER DISCUSSION, REFER TO THE NWS MARQUETTE AREA  
FORECAST DISCUSSION AT WEATHER.GOV/MQT.  
 
 
   
DLH WATCHES/WARNINGS/ADVISORIES  
 
MN...NONE.  
WI...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM CDT THIS AFTERNOON FOR LSZ140-  
141.  
SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ142-  
143.  
SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR LSZ144-  
145.  
 
 
 
 
 
DISCUSSION...HA  
AVIATION...HA  
MARINE...HA  
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