313  
FXUS63 KARX 071150  
AFDARX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LA CROSSE WI  
550 AM CST FRI FEB 7 2025  
   
KEY MESSAGES  
 
- IMPACTFUL SNOW LIKELY TONIGHT THROUGH SATURDAY AFTERNOON.  
CURRENT FORECAST IS FOR AN INCH OR LESS ACROSS NORTHEAST IOWA  
AND FAR SOUTHWESTERN WISCONSIN, 2 TO 4 INCHES BETWEEN I-90 AND  
I-94 WITH THE HIGHEST TOTALS CLOSER TO I-94. TAYLOR AND CLARK  
SNOW TOTALS RANGE FROM 5 TO 7 INCHES. A WINTER WEATHER  
ADVISORY HAS BEEN ISSUED FOR MOST AREAS ALONG AND NORTH OF  
I-90 WITH A WINTER STORM WATCH CONTINUING FOR TAYLOR AND CLARK  
COUNTIES. THE AMOUNT OF DRY AIR AND TRACK OF THE STORM WILL  
IMPACT SNOW TOTALS.  
 
- COLDER AIR RETURNS EARLY NEXT WEEK WITH WIND CHILLS MAINLY  
BETWEEN -5 AND -20 DEGREES.  
 
 
   
DISCUSSION  
 
ISSUED AT 427 AM CST FRI FEB 7 2025  
 
TONIGHT-SATURDAY: IMPACTFUL SNOW EXPECTED  
 
LOOKING AT CURRENT WATER VAPOR IMAGERY, A WAVE IS OVER THE NORTHERN  
ROCKIES PRODUCING SNOW IN IDAHO AND WESTERN MONTANA. THIS SYSTEM  
WILL WORK ITS WAY EASTWARD ACROSS THE NORTHERN PLAINS AND INTO THE  
UPPER MIDWEST THROUGHOUT THE DAY. AT THIS SAME TIME, A COLORADO LOW  
WILL MOVE NORTHEAST ACROSS THE CENTRAL PLAINS TOWARDS THE OHIO RIVER  
VALLEY. THESE TWO SYSTEMS WILL PHASE WITH ONE ANOTHER ONCE THEY GET  
INTO THE OHIO RIVER VALLEY AREA LATER SATURDAY EVENING. SO FOR THE  
TIME-BEING WE WILL FOCUS ON THE NORTHERN WAVE AS THIS WILL BRING  
ACCUMULATING SNOW TO THE FORECAST AREA. IN ADDITION TO THIS NORTHERN  
WAVE, THE UPPER MIDWEST WILL BE IN THE LEFT EXIT REGION OF A JET  
STREAK AND FRONTOGENESIS AT THE 500-600MB LEVEL LOOKS GOOD AS THE  
WAVE MOVES THROUGH THE AREA. COMPARED TO PREVIOUS FORECASTS, THE  
700MB FRONTOGENESIS IS NOT AS IMPRESSIVE AND WIDESPREAD AS IT ONCE  
WAS. THE BEST LIFT AT THIS LEVEL OCCURS FOR SEVERAL HOURS IN NORTH  
CENTRAL WISCONSIN, THEN A DECENT 700MB FRONTOGENESIS BAND MOVES  
THROUGH THE AREA, ROUGHLY FROM I-90 NORTHWARDS BETWEEN 17 AND 20Z.  
 
THIS SYSTEM WILL BE A FAST MOVER AS SNOW IS NOT EXPECTED TO START  
MOVING INTO THE CWA UNTIL AFTER 06Z AND THEN LEAVING THE EASTERN  
PORTIONS OF THE CWA BY ~00Z. WITH HOW FAST THIS SYSTEM IS, QPF  
TOTALS HAVE CONTINUED TO COME DOWN FROM THE PREVIOUS FORECAST, WITH  
ROUGHLY 0.05 TO 0.20 INCHES ACROSS MOST OF THE CWA AND 0.2 TO 0.4  
INCHES FOR TAYLOR AND CLARK COUNTIES. SNOW RATIOS CONTINUE TO RANGE  
FROM 15:1 TO 20:1 SO THIS SNOW WILL BE ON THE DRIER AND FLUFFIER  
SIDE. DRY LOW-LEVELS CONTINUE TO BE IN THE FORECAST SOUNDINGS. WHILE  
THERE WILL BE GOOD LIFT IN THE DGZ, THE LOW LEVELS REMAIN DRY, THUS  
SNOW WOULD NOT REACH THE GROUND INITIALLY UNTIL SATURATION OCCURS.  
WITH THIS DRY AIR TO START, SNOW TOTALS HAVE GONE DOWN ACROSS  
PORTIONS OF SOUTHWESTERN WISCONSIN AND SOUTHEAST MINNESOTA.  
GENERALLY SPEAKING, ROUGHLY 1 TO 3 INCHES IS FORECASTED FOR MOST  
AREAS ALONG AND SOUTH OF I-90 WITH 2 TO 4 INCHES BETWEEN I-90 AND  
CLARK COUNTY. SOMETHING TO NOTE IS THAT THE 03Z RAP AND 06Z HRRR  
BOTH SHOW A SECONDARY BAND OF HEAVIER SNOW IMPACTING SOUTHEASTERN  
MINNESOTA. IF THIS HOLDS TRUE THEN TOTALS THERE WOULD INCREASE A  
COUPLE INCHES. ANOTHER SCENARIO THAT COULD HAPPEN IS THAT IF  
SATURATION OCCURS RIGHT AWAY OR SOONER, THEN TOTALS ACROSS THE AREA  
COULD INCREASE. CURRENT SNOWFALL RATES ARE MOSTLY BETWEEN 0.25 AND  
.75 INCHES/HOUR ACROSS MOST OF THE FORECAST WITH HIGHER RATES IN  
TAYLOR AND CLARK COUNTIES. IF THESE RATES INCREASE WHERE THE DRY AIR  
IS INITIALLY IN PLACE, THIS COULD ALSO HELP BRING SATURATION TO THE  
AREA SOONER AND THUS RAISE SNOW TOTALS. CURRENTLY THE HIGHEST SNOW  
TOTALS ARE ACROSS TAYLOR AND CLARK COUNTIES WHERE 5 TO 7 INCHES IS  
FORECASTED. CURRENT NBM PROBABILITIES HAVE ALSO REDUCED SHOWING A 50  
TO 70% CHANCE OF GREATER THAN 3 INCHES BETWEEN I-90 AND I-94. THE  
CHANCE FOR GREATER THAN 6 INCHES TO OCCUR CONTINUES TO BE HIGHEST  
ALONG AND NORTH OF I-94 WHERE A 40 TO 65% CHANCE EXISTS. AN ADDITION  
TO THIS FORECAST IS WE ENDED UP PUTTING SOME LOW POTENTIAL (15%) FOR  
FREEZING DRIZZLE TO MIX IN WITH LIGHT SNOW ACROSS THE SOUTHERN  
PORTIONS OF FAYETTE, CLAYTON, AND GRANT COUNTIES. THE 07Z NBM  
PROBABILITIES FOR FREEZING RAIN ARE BETWEEN 15 AND 20% FROM 6AM TO  
11AM FOR THESE LOCATIONS. SOUNDINGS FOR THIS AREA SUPPORT THE LOW  
CHANCE FOR FREEZING DRIZZLE AS THEY SHOW A COUPLE DRY LAYERS WITH  
LITTLE TO NO ICE ALOFT. WITH THESE NEW SNOW TOTALS, HAVE ISSUED A  
WINTER WEATHER ADVISORY FOR MOST AREAS ALONG AND NORTH OF I-90 AND  
KEPT THE WINTER STORM WATCH FOR TAYLOR AND CLARK COUNTIES.  
 
SUNDAY-THURSDAY: COOLER TEMPERATURES  
 
A LONGWAVE TROUGH SETS UP OVER THE NORTHERN PORTIONS OF THE CONUS.  
SURFACE HIGH PRESSURE GRADUALLY BUILDS IN OVER THE AREA EARLY NEXT  
WEEK. THIS WILL RESULT IN COLDER CANADIAN AIR SINKING DOWN INTO THE  
NORTHERN PLAINS AND UPPER MIDWEST. LOW TEMPERATURES FOR EARLY NEXT  
WEEK ARE FORECASTED TO BE IN THE SINGLE DIGITS BOTH ABOVE AND BELOW  
ZERO. THE GOOD NEWS FOR NEXT WEEK IS THAT WINDS APPEAR RELATIVELY  
LIGHT. THE COLDEST DAY IS CURRENTLY FORECASTED TO BE TUESDAY AND  
TUESDAY NIGHT WHERE HIGH TEMPERATURES ARE IN THE SINGLE DIGITS TO  
MID TEENS AND LOWS ARE ROUGHLY -15 TO 0 DEGREES. MINIMUM APPARENT  
TEMPERATURES FOR TUESDAY THROUGH THURSDAY ARE EXPECTED TO MOSTLY  
RANGE FROM -5 TO -20 DEGREES WITH SOME SPOTS GETTING AS LOW AS -25  
DEGREES.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/  
 
ISSUED AT 538 AM CST FRI FEB 7 2025  
 
VFR CONDITIONS TODAY WITH INCREASING MID AND HIGH LEVEL CLOUDS  
MOSTLY FL100-250. DETERIORATING CONDITIONS NORTH OF I94 TONIGHT  
AFTER 04Z WITH SOME MVFR CONDITIONS POSSIBLE FOR TAYLOR COUNTY.  
 
 
   
ARX WATCHES/WARNINGS/ADVISORIES  
 
WI...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST  
SATURDAY FOR WIZ032>034-043-044.  
WINTER STORM WATCH FROM LATE TONIGHT THROUGH SATURDAY EVENING  
FOR WIZ017-029.  
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST  
SATURDAY FOR MNZ079-086-087.  
IA...NONE.  
 
 
 
 
 
DISCUSSION...CECAVA  
AVIATION...ZAPOTOCNY  
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