220  
FXUS63 KDLH 132334  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
634 PM CDT SUN JUL 13 2025  
   
KEY MESSAGES  
 
- A FEW SHOWERS OR STORMS ARE POSSIBLE ALONG A WEAK FRONT THAT  
MOVES THROUGH THE AREA THIS EVENING. SEVERE STORMS ARE NOT  
EXPECTED.  
 
- NORTHWESTERLY WINDS BEHIND THE FRONT WILL USHER ANOTHER PLUME  
OF CANADIAN WILDFIRE SMOKE INTO THE AREA TONIGHT THROUGH  
TOMORROW.  
 
- ADDITIONAL RAIN AND STORMS ARE POSSIBLE MONDAY NIGHT THROUGH  
WEDNESDAY AS A SLOW MOVING COLD FRONT MOVES THROUGH THE  
REGION, WITH COOLER TEMPERATURES TO FOLLOW.  
 
 
   
DISCUSSION  
 
ISSUED AT 124 PM CDT SUN JUL 13 2025  
 
THIS AFTERNOON AND TONIGHT:  
 
INCREASED SOUTHWESTERLY FLOW HAS PUSHED SMOKE CONCENTRATIONS OUT  
OF THE AREA THIS AFTERNOON, IMPROVING VISIBILITIES AND AIR  
QUALITY ACROSS THE NORTHLAND. THIS BREAK WILL BE SHORT-LIVED AS  
THE NEXT ROUND OF CANADIAN WILDFIRE SMOKE IS ALREADY ENTERING  
NORTHWEST MINNESOTA BEHIND AN APPROACHING FRONT. AS THIS FRONT  
PUSHES SOUTHWARD, ISOLATED SHOWERS AND STORMS ARE POSSIBLE, BUT  
EXPECT COVERAGE TO BE LOW. FORCING IS RATHER WEAK ALONG THE  
FRONT WITH A LIMITED CU FIELD SOUTH OF THE CANADIAN BORDER (PER  
LATEST SATELLITE IMAGERY) AS THE UPPER LEVEL TROUGH AXIS IS  
ALREADY EAST OF THE AREA. INSTABILITY PARAMETERS - SBCAPE  
AROUND 2000J/KG AND BULK SHEAR OF 30KTS - COULD BE ENOUGH TO  
OVERCOME THE POOR LAPSE RATES, DRIER MID LEVELS, AND WEAK MID  
LEVEL HEIGHT RAISES FOR A FEW STORMS TO DEVELOP THIS AFTERNOON  
AND EVENING. WILL CAP COVERAGE AT 20-25%. CANADIAN WILDFIRE  
SMOKE WILL RETURN TO THE NORTHLAND BEHIND THE FRONT, REDUCING  
AIR QUALITY THROUGH MONDAY.  
 
ZONAL FLOW ALOFT OVER THE AREA MONDAY KEEPS CONDITIONS WARM,  
WITH HIGHS IN THE 80S FOR MUCH OF THE AREA. A STRONGER MIDLEVEL  
TROUGH BEGINS TO CROSS THE ROCKIES, WITH A SURFACE LOW MOVING  
INTO THE CENTRAL PLAINS AND AN INVERTED TROUGH EXTENDING  
NORTHEASTWARD INTO THE NORTHLAND. THIS ESTABLISHES A LOW LEVEL  
CONVERGENCE ZONE TO OUR NORTHWEST AND A FOCUS FOR SHOWERS AND  
STORMS MONDAY, THAT EXPAND INTO NORTH CENTRAL MN DURING THE  
AFTERNOON. THIS INVERTED TROUGH/SURFACE CONVERGENCE BOUNDARY  
SHIFTS OVER THE AREA MONDAY NIGHT AND REMAINS AS A SERIES OF  
WAVES TRIP OVER THE BOUNDARY, FINALLY CLEARING NORTHWEST WI  
WEDNESDAY NIGHT. WAVES OF MODERATE TO HEAVY RAINFALL ARE POSSIBLE  
AS MOISTURE TRANSPORT ALONG THE BOUNDARY PUSHES PW VALUES TO  
NEAR 2 INCHES MONDAY NIGHT INTO TUESDAY. THERE IS SOME  
UNCERTAINTY ON WHERE EXACTLY THE BOUNDARY SETS UP, BEING THE  
FOCUS FOR TRAINING WAVES OF HEAVY RAINFALL. WHERE THIS DOES  
HAPPEN WILL RESULT IN AN INCREASED CHANCE OF LOCALIZED FLOODING,  
WITH 1-2 INCHES OF WIDESPREAD RAINFALL EXPECTED, AND LOCAL  
AMOUNTS OF 3-5 INCHES. THERE WILL ALSO BE A CHANCE OF STRONG TO  
SEVERE STORMS, MOST LIKELY TUESDAY INTO TUESDAY NIGHT, AS BETTER  
FORCING ALOFT ARRIVES AND LAPSE RATES IMPROVE. INSTABILITIES  
INCREASE DURING THE AFTERNOON, WITH MODEST BULK SHEAR VALUES.  
LIMITING FACTORS WOULD BE THE OVERALL MOIST PROFILES AND THE  
POSSIBILITY OF A WEAK CAP AROUND 700MB PREVENTING SIGNIFICANT  
CORE GROWTH.  
 
COOLER TEMPERATURES ARRIVE BEHIND THE FRONT WITH HIGHS IN THE  
60S TO LOWER 70S FOR WEDNESDAY THROUGH THE END OF THE WEEK.  
LINGERING RAIN SHOWERS END THURSDAY MORNING AS SURFACE RIDGING  
BUILDS ACROSS THE AREA. RAIN CHANCES RETURN FOR FRIDAY AND  
SATURDAY, AS SOME WEAK SHORTWAVES MOVE THROUGH THE BROAD  
CYCLONIC FLOW ALOFT.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/  
 
ISSUED AT 634 PM CDT SUN JUL 13 2025  
 
ISOLATED SHOWERS OR A STORM OR TWO WILL ACCOMPANY A WEAK FRONT  
AS IT MOVES EASTWARD ACROSS NORTHEAST MINNESOTA AND NORTHWEST  
WISCONSIN TONIGHT. THE CHANCE A STORM WILL IMPACT ONE OF THE  
TERMINALS IS LOW, ABOUT 5%. SMOKE WILL FILTER INTO THE REGION  
BEHIND THE FRONT TONIGHT AND MAY LEAD TO MVFR VISIBILITY AT INL,  
HIB, AND DLH. A FEW SHOWERS OR STORMS ARE POSSIBLE FROM LATE  
MONDAY MORNING THROUGH THE AFTERNOON OVER NORTHERN MINNESOTA AND  
ADJACENT AREAS OF NORTHWEST ONTARIO. ADDED VCSH AT INL FOR THE  
MOMENT.  
 
 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/  
 
ISSUED AT 124 PM CDT SUN JUL 13 2025  
 
BREEZY SOUTHWEST WINDS ALONG THE NORTH SHORE AND HEAD OF THE  
LAKE DIMINISH THIS EVENING, AND GRADUALLY TURN TO THE SOUTH TO  
SOUTHWEST OVERNIGHT. SPEEDS INCREASE TO 5-7KTS MONDAY WITH GUSTS  
OF 20KTS, MAINLY FROM GRAND MARAIS AND GRAND PORTAGE. WINDS BECOME  
MORE VARIABLE IN DIRECTION WITH GENERALLY LIGHT SPEEDS MONDAY  
NIGHT INTO TUESDAY. ISOLATED STORMS ARE POSSIBLE THIS AFTERNOON  
AND EVENING WITH ADDITIONAL CHANCES FOR STORMS (30-40% CHANCE)  
MONDAY NIGHT INTO TUESDAY, INCREASING TO 70-80% DURING THE DAY  
TUESDAY.  
 
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 8 PM CDT THIS EVENING FOR  
LSZ140>146.  
 
 
 
 
 
DISCUSSION...HA  
AVIATION...HUYCK  
MARINE...HA  
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