249  
FXUS63 KDLH 132300  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
600 PM CDT TUE MAY 13 2025  
   
KEY MESSAGES  
 
- CRITICAL FIRE WEATHER CONDITIONS WITH A RED FLAG WARNING IN  
EFFECT FOR ALL OF NORTHEAST MINNESOTA AND MUCH OF NORTHWEST  
WISCONSIN.  
 
- WIDESPREAD RAIN CHANCES RETURN THURSDAY THROUGH SATURDAY.  
 
- STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE THURSDAY  
AFTERNOON AND EVENING IN NORTHWEST WISCONSIN AND PORTIONS OF  
NORTHEAST MINNESOTA.  
 
 
   
DISCUSSION  
 
ISSUED AT 225 PM CDT TUE MAY 13 2025  
 
CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE ACROSS ALL OF  
NORTHEAST MINNESOTA AND MOST OF NORTHWEST WISCONSIN INTO THIS  
EVENING, AND A RED FLAG WARNING REMAINS IN EFFECT UNTIL 900 PM  
CDT. LATE TONIGHT INTO WEDNESDAY MORNING LOW LEVEL MOISTURE WILL  
FINALLY BE ON A SLOW INCREASE ACROSS NORTHWEST WISCONSIN AND  
INTO THE I-35 CORRIDOR AND OVER MUCH OF WESTERN LAKE SUPERIOR.  
THIS IS EXPECTED BE ASSOCIATED WITH A DECK OF LOW LEVEL  
STRATUS. WILL BE MONITORING FOR FOG DEVELOP ON AND NEAR LAKE  
SUPERIOR LATE TONIGHT INTO WEDNESDAY MORNING WITH INCREASING  
MOISTURE OVER THE COLD LAKE.  
 
WITH A RATHER SIMILAR SURFACE PATTERN ON WEDNESDAY AS HAS BEEN  
SEEN THE LAST COUPLE OF DAYS, ANOTHER WARM DAY IS EXPECTED WITH  
WIDESPREAD TEMPERATURES IN THE UPPER 70S TO THE MID 80S ON  
WEDNESDAY. A FEW READINGS NEAR 90 ARE POSSIBLE IN KOOCHICHING  
COUNTY WHERE DRIER AIR WILL BE IN PLACE. IN REGARDS TO FIRE  
WEATHER, NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ON  
WEDNESDAY ACROSS NORTHEAST MINNESOTA GIVEN THE WARM TEMPERATURES  
AND VERY DRY FUELS. THE MAIN LIMITING FACTOR TO REACHING  
CRITICAL LEVELS IS PRIMARILY HIGHER AFTERNOON RELATIVE HUMIDITY  
IN THE 30 TO 40 PERCENT RANGE FOR MOST AREAS, WITH HIGHER VALUES  
NEAR LAKE SUPERIOR. HIGHER RELATIVE HUMIDITY IN THE 40 TO 50  
PERCENT RANGE AND WEAKER WINDS ACROSS NORTHWEST WISCONSIN  
FURTHER REDUCE THE OVERALL FIRE WEATHER THREAT ACROSS NORTHWEST  
WISCONSIN ON WEDNESDAY. STILL FUELS ARE VERY DRY ACROSS THE  
AREA, AND VIGILANCE IS STILL A NECESSITY. SCATTERED DIURNALLY  
DRIVEN RAIN SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS  
NORTHWEST WISCONSIN INTO THE I-35 CORRIDOR OF NORTHEAST  
MINNESOTA ON WEDNESDAY WITH A FEW WEAK IMPULSES ALOFT AND  
INCREASING MOISTURE. SEVERE WEATHER IS NOT EXPECTED, HOWEVER  
LIGHTNING AND POSSIBLE FIRE STARTS WILL BE THE PRIMARY CONCERN.  
 
ON THURSDAY, A POTENT NEGATIVELY TILTED MID LEVEL SHORTWAVE IS  
FORECAST TO PROPAGATE INTO THE UPPER MIDWEST, SUPPORTING DEEPENING  
OF SURFACE LOW PRESSURE ACROSS NORTHWEST MINNESOTA AND EASTERN NORTH  
DAKOTA THROUGH THE DAY. THIS LOW PLACEMENT HAS MOVED FROM  
YESTERDAY ACROSS THE MAJOR ENSEMBLE FAMILIES, WHICH HAD A LOW  
PLACEMENT FURTHER TO THE SOUTH AND EAST ACROSS CENTRAL  
MINNESOTA. WITH A CENTRAL PRESSURE IN THE 980S MB RANGE, THIS  
LOW IS NEAR THE BOTTOM OF THE CLIMATOLOGY. AN OCCLUDED FRONT IS  
FORECAST TO LIFT NORTHEAST THROUGH DAY AS THE LOW DEEPENS,  
CROSSING THROUGH NORTHWEST WISCONSIN AND NORTHEAST MINNESOTA  
BETWEEN 18Z AND 24Z. BUOYANCY ON THE ORDER OF 1000-1500 J/KG IS  
EXPECTED TO ESTABLISH ITSELF ACROSS NORTHWEST WISCONSIN AND INTO  
THE I-35 CORRIDOR THURSDAY AFTERNOON AND INTO THE EARLY  
EVENING. GIVEN THE STRONG FORCING, UPSCALE GROWTH INTO A LINEAR  
MODE IS LIKELY ALONG THE OCCLUDED FRONT. GIVEN A LIKELY LINEAR  
MODE, DAMAGING WINDS WILL BE THE PRIMARY THREAT, FOLLOWED BY A  
QLCS TORNADO THREAT WITH A HIGHLY SHEARED LOW LEVEL ENVIRONMENT.  
FURTHER INTO NORTHEAST MINNESOTA, BUOYANCY IS EXPECTED TO BE  
LESS WITH A LOWER POTENTIAL FOR SEVERE THUNDERSTORMS. HOWEVER,  
WITH PRECIPITABLE WATER VALUES CLIMBING TO 1.25 TO 1.40 INCHES,  
A BROAD AREA OF PRECIPITATION WITH EMBEDDED THUNDERSTORMS WILL  
SPREAD ACROSS NORTHEAST MINNESOTA WITH THE PASSAGE OF THE  
OCCLUDED FRONT.  
 
A DRY SLOT ASSOCIATED WITH THE DEEP LOW IS LIKELY TO OVERTAKE MOST  
OF THE NORTHLAND THURSDAY NIGHT, WITH A LULL IN PRECIPITATION BEFORE  
WRAP AROUND MOISTURE AND PRECIPITATION EXPANDS ACROSS THE AREA  
THROUGH THE DAY ON FRIDAY. WITH AFTERNOON HEATING A FEW EMBEDDED  
THUNDERSTORMS ARE POSSIBLE ON FRIDAY. RAIN SHOWERS IN WRAP  
AROUND MOISTURE WILL DECREASE THROUGH THE DAY ON SATURDAY AS THE  
LOW EXITS TO THE EAST.  
 
IN REGARDS TO PRECIPITATION TOTALS, WIDESPREAD AMOUNTS OF ONE-HALF  
TO THREE-QAURTERS OF AN INCH ARE EXPECTED ACROSS MOST OF THE  
NORTHLAND THURSDAY THROUGH SATURDAY. GIVEN THE FURTHER NORTHWEST LOW  
LOCATION THURSDAY INTO FRIDAY, THE HEAVY DEFORMATION ZONE  
PRECIPITATION WILL ALSO BE DISPLACED INTO NORTH DAKOTA, RESULTING IN  
A REDUCTION IN THE RAINFALL FORECAST FROM YESTERDAY FOR THE BRAINERD  
LAKES THROUGH LAKE OF THE WOODS AREAS.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/  
 
ISSUED AT 600 PM CDT TUE MAY 13 2025  
 
PRIMARY AVIATION CONCERN IS THE DEVELOPMENT OF FOG NEAR LAKE  
SUPERIOR THAT MAY CAUSE IFR CONDITIONS AT DLH LATE TONIGHT INTO  
EARLY WEDNESDAY MORNING. AT THIS POINT THE GUIDANCE SEEMS WEAK AND  
CURRENT OBS DO NOT LEND ENOUGH CONFIDENCE TO INCLUDE IFR AT DLH AT  
THIS POINT, BUT DEW POINT TRENDS WILL NEED TO BE MONITORED AS RICHER  
LOW LEVEL MOISTURE ADVECTS IN FROM THE SOUTH, CAUSING FOG TO DEVELOP  
ON LAKE SUPERIOR AND SPREADING INLAND NEAR THE LAKE. OTHERWISE VFR  
CONDITIONS WILL PERSIST AT ALL SITES WITH CLEAR SKIES, EXCEPT  
INCREASING CLOUDS IMPACT HYR AND DLH ON WEDNESDAY. SOUTH-  
SOUTHEASTERLY WINDS TONIGHT AROUND 5 KNOTS OR LESS, INCREASING TO 5  
TO 10 KNOTS WEDNESDAY AFTERNOON. A FEW SCATTERED SHOWERS AND A  
THUNDERSTORM OR TWO ARE POSSIBLE ACROSS NORTHWEST WISCONSIN INTO  
PARTS OF EASTERN MN THAT WILL IMPACT HYR OFF AND ON AND MAY IMPACT  
DLH. INCLUDED PROB30 GROUPS FOR CONVECTION AT BOTH, THOUGH  
CONFIDENCE IS HIGHEST AT HYR.  
 
 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/  
 
ISSUED AT 225 PM CDT TUE MAY 13 2025  
 
NORTHEAST WINDS AROUND 10 KTS THIS AFTERNOON AND INTO THE EARLY  
EVENING. AS MOISTURE INCREASES OVER LAKE SUPERIOR LATE TONIGHT  
INTO WEDNESDAY, AREAS OF FOG MAY DEVELOP (40-60 PERCENT  
CHANCE). NORTHEAST WINDS WILL INCREASE TO 10 TO 15KTS WITH GUSTS  
TO 20 KTS ON WEDNESDAY, AND FURTHER INCREASE TO SUSTAINED AT 15 TO  
20KTS WITH GUSTS OF 25 TO 30KTS ON THURSDAY AS STRONG LOW  
PRESSURE APPROACHES THE AREA. WAVES HEIGHTS WILL INCREASE TO 3-6  
FEET ON THURSDAY. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED ON  
THURSDAY. THUNDERSTORMS, SOME WITH WIND GUSTS OVER 34KTS, ARE  
LIKELY THURSDAY AFTERNOON AND EVENING.  
 
FOR THE OPEN WATER DISCUSSION, REFER TO THE NWS MARQUETTE AREA  
FORECAST DISCUSSION AT WEATHER.GOV/MQT.  
 
 
   
DLH WATCHES/WARNINGS/ADVISORIES  
 
MN...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR MNZ010>012-  
018-019-025-026-033>038.  
WI...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR WIZ001-002-  
006>008.  
MARINE...NONE.  
 
 
 
 
 
DISCUSSION...PA  
AVIATION...JJM  
MARINE...PA  
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