467  
FXUS63 KMPX 170005  
AFDMPX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN  
705 PM CDT SAT AUG 16 2025  
   
KEY MESSAGES  
 
- NARROW BAND OF HEAVY RAINFALL LIKELY TONIGHT FROM WEST-CENTRAL  
MINNESOTA THROUGH SOUTHWEST WISCONSIN. LOCALIZED FLASH  
FLOODING POSSIBLE.  
 
- MORE WIDESPREAD HEAVY RAIN, ALONG WITH A CHANCE FOR SEVERE  
WEATHER, IS EXPECTED SUNDAY EVENING INTO MONDAY MORNING.  
 
- SEASONABLE COOL & DRY AFTER MONDAY.  
 
 
   
DISCUSSION  
 
ISSUED AT 247 PM CDT SAT AUG 16 2025  
 
OUR EXPECTED MID-DAY SATURDAY LULL IN THE THUNDERSTORMS & HEAVY  
RAINFALL HAS COME TO FRUITION THIS AFTERNOON, OUTSIDE OF A FEW  
ISOLATED LIGHT SHOWERS ACROSS SOUTHERN MINNESOTA. THIS WILL  
CONTINUE INTO THE EVENING, BUT OUR NEXT ROUND OF HEAVY RAINFALL  
IS EXPECTED TO DEVELOP OVERNIGHT, AS FORCING FROM THE LOW LEVEL  
JET OVERNIGHT RUNS INTO A NEARLY STATIONARY BOUNDARY DRAPED  
ACROSS SOUTHERN MINNESOTA & WESTERN WISCONSIN. THIS IS A CLASSIC  
SETUP FOR A LINE OF STATIONARY TRAINING THUNDERSTORMS, BUT SOME  
QUESTIONS STILL EXIST REGARDING THE PLACEMENT & WIDTH OF THE  
BAND OF THUNDERSTORMS, & JUST HOW HEAVY THE RAINFALL AMOUNTS  
COULD BE. MOST HIGH-RESULTION MODELS ARE IN AGREEMENT WITH  
DEPICTING A VERY NARROW, ROUGHLY 20-50 MILE WIDE, BAND OF  
THUNDERSTORMS DEVELOPING AROUND MIDNIGHT. THE PLACEMENT OF THIS  
BAND VARIES DEPENDING ON INDIVIDUAL MODELS, BUT THE HIGH-  
RESOLUTION ENSEMBLES & THE AI GLOBAL ENSEMBLES ALL GENERALLY  
CONVERGE ON THE BEST CHANCES FOR HEAVY RAIN TONIGHT SETTING UP  
ALONG THE UPPER MINNESOTA RIVER VALLEY INTO SOUTHEAST MINNESOTA  
& SOUTHWEST WISCONSIN. THIS PLACEMENT WOULD ACTUALLY BE IDEAL  
IN HELPING TO MITIGATE THE FLOODING POTENTIAL, AS THE HEAVIEST  
RAIN OVER THE LAST 24 HOURS FELL FARTHER TO THE NORTH AND EAST  
OF THIS EXPECTED PLACEMENT. HIGH-RESOLUTAION MODELS ALSO VARY ON  
THE POTENTIAL RAINFALL AMOUNTS, BUT A FEW SHOW THE POTENTIAL  
FOR VERY HEAVY RAIN OF 4-6" OVER ONLY A FEW HOURS. THE GENERAL  
HIGH-RES MODEL CONSENSUS IS LOWER THAN THIS HOWEVER, MORE LIKE  
2-4", LARGELY OWING TO FORCING FROM THE LOW LEVEL JET ONLY BEING  
ON THE ORDER OF 20-30 KTS OVERNIGHT, AS OPPOSED TO 40+ KTS IN A  
"CLASSIC" FLASH FLOODING SET UP. DUE TO THE NARROWNESS OF THE  
SWATH OF HEAVY RAIN & UNCERTAINTY IN THE POTENTIAL AMOUNTS,  
WE'LL WAIT TO ANALYZE MORE AFTERNOON DATA BEFORE DECIDING ON A  
FLASH FLOOD WATCH OVERNIGHT. IF OUR CURRENT THINKING ON THE  
PLACEMENT OF THE BAND ACROSS SOUTHERN MN & POTENTIAL RAINFALL  
AMOUNTS OF 2-4" HOLDS, WE VERY WELL MAY ONLY SEE MINOR FLOODING  
ISSUES OUTSIDE OF URBAN AREAS & AREAS WITH STEEP TERRAIN.  
 
THE OVERNIGHT THUNDERSTORMS WILL BE AT THEIR PEAK BETWEEN  
MIDNIGHT & 6 AM, BUT THE HEAVY RAIN THREAT WILL STILL CONTINUE  
INTO THE MORNING AS THE STORMS BEGIN TO WANE & DISSIPATE. A  
BRIEF DRY SPELL MID-DAY LOOKS POSSIBLE AGAIN TOMORROW, BUT MORE  
WIDESPREAD THUNDERSTORMS & HEAVY RAIN ARE EXPECTED TO BE  
INCOMING OUT OF THE DAKOTAS BY MID-AFTERNOON. THIS ROUND OF  
THUNDERSTORMS WILL BE MORE WIDESPREAD, AND CONTINUE INTO MONDAY  
MORNING, AS THE LARGE SCALE FORCING IS MUCH STRONGER WITH AN  
UPPER LEVEL WAVE & SURFACE LOW MOVING THROUGH THE AREA. THE  
UPPER-END RAINFALL POTENTIAL IS PROBABLY LOWER WITH THIS ROUND  
OF STORMS AS OPPOSED TO TONIGHT'S, BUT WILL RESULT IN AT LEAST  
AN INCH OR TWO OF RAIN FALLING OVER A MUCH LARGER AREA. SEVERE  
WEATHER CAN'T BE RULED OUT WITH THE STRONGEST STORMS, MAINLY  
ACROSS SOUTHERN MINNESOTA TOMORROW AFTERNOON & EVENING, WITH  
DAMAGING WIND GUSTS & HAIL THE PRIMARY THREATS. A FLASH FLOOD  
WATCH MAY BE NEEDED SUNDAY NIGHT/MONDAY MORNING AS WELL, BUT  
WE'LL HAVE TO SEE WHERE THE HEAVY RAIN FROM TONIGHT FALLS & GET  
A FEW MORE RUNS OF MODEL DATA TO HAVE A BETTER IDEA OF WHERE THE  
FLOODING THREAT IS HIGHEST.  
 
BEYOND MONDAY, WE ACTUALLY ENTER AN EXTENDED STRETCH OF PLEASANT  
LATE SUMMER WEATHER WITH SEASONABLY COOL & DRY CONDITIONS  
EXTENDING INTO THE WEEKEND.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z MONDAY/  
 
ISSUED AT 646 PM CDT SAT AUG 16 2025  
 
VFR/MVFR CONDITIONS THIS EVENING WITH SOME PATCHY LOW STRATUS.  
AFTER MIDNIGHT, A NARROW AREA OF THUNDERSTORMS WILL DEVELOP AND  
COULD IMPACT KRWF AND KMKT. THESE WILL DIMINISH TOWARD SUNRISE,  
BUT THEN EXPECT SMALL CHANCES FOR THUNDERSTORMS MOST OF SUNDAY,  
WITH INCREASING CHANCES IN THE LATE AFTERNOON AND EVENING.  
 
KMSP...  
VFR CONDITIONS EXPECTED THIS EVENING AND OVERNIGHT AS THE STORMS  
ARE EXPECTED TO BE SOUTH AND WEST OF KMSP. LOW STRATUS WILL MOVE  
IN FOR SUNDAY, WITH THE NEXT CHANCE FOR THUNDERSTORMS SUNDAY  
EVENING, SO DID ADD A PROB30.  
 
/OUTLOOK FOR KMSP/  
MON...VFR, CHC MVFR/-TSRA. WIND S TO NW 5-15KTS.  
TUE...VFR. WIND NE 5-10KTS.  
WED...VFR. WIND NE 5KTS.  
 
 
   
MPX WATCHES/WARNINGS/ADVISORIES  
 
MN...NONE.  
WI...NONE.  
 
 
 
 
 
DISCUSSION...ETA  
AVIATION...JRB  
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