035  
FXUS63 KDLH 221744  
AFDDLH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DULUTH MN  
1244 PM CDT TUE APR 22 2025  
   
KEY MESSAGES  
 
- ISOLATED SHOWERS LINGER IN PORTIONS OF THE ARROWHEAD AND  
NORTHWEST WISCONSIN TONIGHT INTO WEDNESDAY.  
 
- POTENTIAL FOR DENSE FOG OFF OF LAKE SUPERIOR AT THE HEAD OF  
THE LAKE AND FOR THE NORTH SHORE TONIGHT INTO EARLY WEDNESDAY  
MORNING.  
 
- ADDITIONAL ROUNDS OF RAIN THURSDAY INTO FRIDAY AND SUNDAY INTO  
EARLY NEXT WEEK.  
 
 
   
DISCUSSION  
 
ISSUED AT 337 AM CDT TUE APR 22 2025  
 
TODAY-WEDNESDAY:  
 
LOW PRESSURE LOCATED IN EAST-CENTRAL NORTH DAKOTA AS OF 3AM CDT  
WILL CONTINUE SHIFTING NORTHEAST THROUGHOUT TODAY AND TONIGHT  
INTO FAR SOUTHERN MANITOBA AND NORTHWESTERN ONTARIO. AS IT DOES  
SO, FRONTOGENESIS EXTENDING SOUTHEAST FROM THE LOW WILL CONTINUE  
TO PUSH A BAND OF LIGHT, SCATTERED SHOWERS CURRENTLY MOVING INTO  
THE BRAINERD LAKES NORTHEASTWARD THROUGH THE NORTHLAND TODAY AND  
THIS EVENING. WITH SOME WEAK INSTABILITY ALSO PRESENT ALOFT  
THROUGH AN HOUR OR TWO AFTER SUNRISE, HAVE ALSO INTRODUCED A  
SLIGHT CHANCE (15%) FOR AN EMBEDDED THUNDERSTORM OR TWO IN THE  
BRAINERD LAKES. WHILE HI-RES MODEL GUIDANCE DOES SHOW ADDITIONAL  
WEAK INSTABILITY DEVELOPING THIS AFTERNOON INTO EVENING, IT  
APPEARS TO BE IN LOCATIONS BEHIND THE BAND OF SHOWERS, SO DON'T  
EXPECT ADDITIONAL THUNDERSTORM DEVELOPMENT INTO THE REMAINDER OF  
TODAY. THE LOW PRESSURE THEN SLOWLY CHURNS EAST ACROSS NORTHERN  
ONTARIO TONIGHT INTO WEDNESDAY, LEAVING LINGERING ISOLATED RAIN  
SHOWER POTENTIAL (10-30%) IN THE ARROWHEAD AND NORTHWEST  
WISCONSIN, THOUGH MOST LOCATIONS IN THE NORTHLAND SHOULD REMAIN  
DRY FOR TONIGHT INTO WEDNESDAY. CAN'T RULE OUT A BRIEF MIX OF  
WET SNOW WITH THE RAIN IN THE TIP OF THE ARROWHEAD TONIGHT AS  
TEMPERATURES DROP TO AROUND OR JUST ABOVE FREEZING THERE, BUT  
DON'T EXPECT ANY ACCUMULATING SNOW. AS FOR RAINFALL AMOUNTS,  
MOST WILL COME WITH THE FRONTAL RAIN BAND, RANGING FROM AROUND  
ONE-QUARTER TO ONE-THIRD INCH IN NORTH-CENTRAL MN TO AROUND OR  
LESS THAN ONE-TENTH OF AN INCH FOR THE TWIN PORTS, ARROWHEAD,  
AND NORTHWEST WI.  
 
ANOTHER WEATHER NOTE FOR TODAY INTO EARLY WEDNESDAY WILL BE  
EASTERLY TO NORTHEASTERLY WINDS OFF OF LAKE SUPERIOR. THIS WILL  
KEEP THE NORTH SHORE, TWIN PORTS, AND EAST-FACING PORTIONS OF  
THE SOUTH SHORE COOLER TODAY. IT WILL ALSO INTRODUCE A POTENTIAL  
FOR DENSE FOG/VERY LOW CLOUDS TO PUSH INTO THE HEAD OF LAKE  
SUPERIOR AND THE NORTH SHORE TONIGHT INTO EARLY WEDNESDAY. WE  
WILL NEED TO MONITOR THIS FOG SIGNAL IN SUBSEQUENT FORECASTS AND  
MODEL TRENDS TO DETERMINE IF A DENSE FOG ADVISORY WILL BE  
NEEDED.  
 
THURSDAY-FRIDAY:  
 
THIS PERIOD WILL BE HIGHLIGHTED BY COOLER TEMPERATURES NEAR LAKE  
SUPERIOR DUE TO ONSHORE WINDS AND OTHERWISE WIDESPREAD HIGH  
TEMPERATURES IN THE 50S TO NEAR 60 DEGREES FOR THE REMAINDER OF  
THE NORTHLAND. THERE WILL ALSO BE A TIME FROM THURSDAY INTO  
THE FIRST HALF OF FRIDAY WHERE ADDITIONAL LIGHT RAIN SHOWERS  
ARE POSSIBLE (30-60% CHANCE) MAINLY SOUTH OF THE IRON RANGE AS A  
WEAKER LOW PRESSURE SYSTEM TRACKS SOUTH OF THE NORTHLAND, FROM  
THE CENTRAL PLAINS EAST INTO THE SOUTHERN GREAT LAKES. THE LOW-  
END THUNDERSTORM POTENTIAL FOR THURSDAY HAS DISAPPEARED WITH  
THIS UPDATE AS MID-RANGE MODEL GUIDANCE KEEPS INSTABILITY SOUTH  
OF THE NORTHLAND.  
 
NEXT WEEKEND-EARLY NEXT WEEK:  
 
AREAS AWAY FROM LAKE SUPERIOR WILL ONCE AGAIN SEE A WARMING  
TREND FOR SATURDAY INTO EARLY NEXT WEEK WITH HIGHS IN THE UPPER  
50S TO WIDESPREAD 60S FOR LOCATIONS AWAY FROM LAKE SUPERIOR.  
THIS WILL BE DUE TO HIGH PRESSURE ON SATURDAY SHIFTING EAST OF  
THE REGION AND SURFACE WINDS TURNING SOUTHEASTERLY AHEAD OF  
WHAT GLOBAL MODEL ENSEMBLES GENERALLY AGREE ON BEING A  
DEVELOPING COLORADO LOW LATER SUNDAY THAT IS THEN FORECAST TO  
EJECT NORTHEAST TO SOMEWHERE ACROSS THE UPPER MIDWEST THROUGH  
THE FIRST HALF OF NEXT WEEK. THERE IS STILL A FAIRLY LARGE  
AMOUNT OF SPREAD AND UNCERTAINTY REGARDING THE TRACK AND TIMING  
OF THE LOW PRESSURE, SO CONFIDENCE IN RAINFALL AMOUNTS AND  
THUNDERSTORM/SEVERE WEATHER AT THIS TIME RANGE ARE CURRENTLY  
LOW. WITH THAT SAID, NAEFS AND ECMWF ENSEMBLE SITUATIONAL  
AWARENESS TABLES POINT TO A SURGE OF 90+ PERCENTILE PWATS FOR  
THIS TIME OF YEAR AT AROUND OR JUST OVER 1" WITH TRAJECTORIES  
OF WESTERN GULF MOISTURE SURGING NORTHWARD AHEAD OF THE COLORADO  
LOW. THEREFORE, THERE SHOULD BE PLENTY OF MOISTURE PRESENT FOR  
A BETTER SOAKING RAIN POTENTIAL TO HOPEFULLY ALLEVIATE SOME OF  
THE MODERATE TO SEVERE DROUGHT CONDITIONS THAT HAVE DEVELOPED  
ACROSS PARTS OF NORTHWEST WI AND NORTH-CENTRAL/NORTHEAST MN.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/  
 
ISSUED AT 1244 PM CDT TUE APR 22 2025  
 
A BAND OF LIGHT RAIN IN FAR NORTHERN MINNESOTA EARLY THIS  
AFTERNOON ENTERS ONTARIO THROUGH THE NEXT FEW HOURS, LEAVING  
BEHIND LINGERING RAIN SHOWERS INTO THE OVERNIGHT HOURS. MVFR  
CEILINGS TRAIL BEHIND THE RAIN BAND AND ARE EXPECTED TO CLEAR  
OUT OF MOST TERMINALS 22-02Z. FOG IS LIKELY TO FORM TONIGHT  
ALONG AND WEST OF THE BAYFIELD PENINSULA INTO THE TWIN PORTS AND  
ALONG THE NORTH SHORE. THERE IS 50-60% CHANCE OF DENSE FOG  
AFFECTING SOME TERMINALS IN THE TWIN PORTS AND ALONG THE NORTH  
SHORE. AT THIS POINT, LIFR CONDITIONS ARE EXPECTED AND ARE IN  
THE DLH TAF. SKIES CLEAR AND VISIBILITIES IMPROVE WITHIN A  
COUPLE HOURS EITHER SIDE OF 12Z.  
 
 
   
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/  
 
ISSUED AT 337 AM CDT TUE APR 22 2025  
 
NORTHEAST WINDS DEVELOP TODAY, GUSTING INTO THE LOW-20 KNOTS  
RANGE BRIEFLY THIS AFTERNOON INTO EARLY EVENING IN THE  
SOUTHWESTERN ARM OF THE LAKE. A SMALL CRAFT ADVISORY MAY (30-50%  
CHANCE) BE NEEDED AT THE HEAD OF THE LAKE THIS AFTERNOON AND  
EVENING, BUT THE POTENTIAL WAS TOO LOW AT THIS TIME TO ISSUE  
ONE. THERE IS POTENTIAL FOR DENSE FOG TO DEVELOP, MAINLY AT THE  
HEAD OF THE LAKE TONIGHT INTO EARLY WEDNESDAY MORNING DUE TO  
MOISTURE IN THE MARINE BOUNDARY LAYER DUE TO RAINFALL MOVING  
THROUGH TODAY.  
 
A WIND SHIFT TO SOUTHWESTERLY OCCURS WEDNESDAY, BUT WINDS  
REMAIN BELOW 20 KNOTS UNDER A STABLE LAKE WARM AIR ADVECTION  
REGIME, WITH WINDS THEN LIGHTENING AND VEERING NORTHERLY  
WEDNESDAY NIGHT. WINDS VEER BACK TO NORTHEASTERLY FOR THURSDAY,  
WITH GUSTS GENERALLY REMAINING AROUND 15 KNOTS, THOUGH SOME  
FUNNELING OF WINDS INTO THE HEAD OF THE LAKE COULD PUSH GUSTS TO  
AROUND 20 KNOTS.  
 
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...NONE.  
 
 
 
 
 
DISCUSSION...ROTHSTEIN  
AVIATION...NLY  
MARINE...ROTHSTEIN  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab MN Page
The Nexlab WI Page
Main Text Page