470  
FXUS63 KARX 012222  
AFDARX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LA CROSSE WI  
520 PM CDT SAT APR 1 2023  
   
DISCUSSION
 
(THIS EVENING THROUGH SATURDAY)  
ISSUED AT 239 PM CDT SAT APR 1 2023  
 
KEY MESSAGES:  
 
- SYSTEM PASSING BY TO THE NORTH SUNDAY COULD BRING A LITTLE BIT  
OF RAIN OR SNOW TO PARTS OF NORTH-CENTRAL WISCONSIN.  
 
- ANOTHER POTENT EARLY SPRING SYSTEM LOOKS TO IMPACT THE REGION  
EARLY NEXT WEEK WITH ANOTHER ROUND OF RAIN, SOME SNOW, WIND AND  
POSSIBLY SOME SEVERE WEATHER. TUESDAY LOOKS TO BE THE MAIN DAY  
OF CONCERN, ESPECIALLY IN TERMS OF A SEVERE THREAT.  
 
TONIGHT - SUNDAY...  
 
INCREASED SURFACE WIND GUSTS CONTINUE INTO THE EARLY EVENING FOR  
MUCH OF THE FORECAST AREA AS THE UPPER LEVEL TROUGH, EVIDENT ON  
GOES WV IMAGERY, CONTINUES EAST INTO THE OHIO RIVER VALLEY. AN  
UPPER LEVEL RIDGE, LOCATED OVER THE NORTHERN PLAINS AT 18Z ON GOES  
WV IMAGERY, CONTINUES OVER THE FORECAST AREA TONIGHT. RETURN FLOW  
WITHIN THESE BUILDING HEIGHTS USHERS IN EXCITED WARM AIR  
ADVECTION TONIGHT INTO SUNDAY MORNING. INCREASED WINDS AND  
TEMPERATURES WILL BE THE STORY FOR SUNDAY WITHIN THIS TRANSIENT  
WARM SECTOR. THE LLJ AT 925 MB PEAKS ABOVE 50 KTS IN SOUTHEAST  
MINNESOTA SUNDAY MORNING, DISSIPATING THROUGH THE DAY. SOUTHERLY  
TO SOUTHWESTERLY GUSTS TO 40 MPH EXPECTED, PRIMARILY IN WIND PRONE  
AREAS WEST THE MISSISSIPPI RIVER. LIGHT, MIXED PRECIPITATION  
CHANCES AFFECT CENTRAL WISCONSIN COUNTIES AS AN UPSTREAM JET  
STREAK NOSES ACROSS THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI  
RIVER VALLEY SUNDAY AFTERNOON-EVENING. IMPACTS EXPECTED TO BE  
MINIMAL.  
 
MONDAY - WEDNESDAY...  
 
THE LATEST SET OF MEDIUM RANGE GUIDANCE CONTINUES TO POINT TO  
ANOTHER STRONG SYSTEM TO IMPACT THE UPPER MIDWEST FOR THE FIRST  
HALF OF THE NEW WEEK. A SHORT WAVE TROUGH IS EXPECTED TO COME IN  
OFF THE NORTHERN PACIFIC AND DROP INTO THE CENTRAL ROCKIES BY  
MONDAY NIGHT. THIS SYSTEM THEN EJECTS OUT TO THE NORTHEAST AND  
CROSSING THE UPPER MIDWEST TUESDAY NIGHT THROUGH WEDNESDAY. GOOD  
CONSENSUS RIGHT NOW THAT THE UPPER LEVEL LOW SHOULD PASS BY THE  
THE NORTHWEST OF THE LOCAL AREA. A POTENT SHORT WAVE TROUGH LOOKS  
TO BE ROTATING AROUND THE UPPER LEVEL LOW THAT SHOULD BE  
APPROACHING THE REGION AND THEN TRACK OVER THE AREA TUESDAY NIGHT.  
BOTH THE ECMWF AND GFS KEEP THE SURFACE LOW PRETTY TIGHT TO THE  
UPPER LEVEL LOW WHICH ALLOWS IT TO PASS BY TO THE NORTHWEST.  
INTERESTING THAT THE 01.12Z CMC HAS COME IN WITH A MUCH FURTHER  
EAST TRACK THAT WOULD SUGGEST A MUCH COLDER SOLUTION.  
 
THE LATEST ENSEMBLE DATA HAS REALLY BACKED OFF ON THE POTENTIAL  
SNOW IN THE LOCAL AREA FROM THIS SYSTEM, WHICH MAKES SENSE GIVEN  
THE EXPECTED TRACK. HOWEVER, SOME SNOW MAY STILL OCCUR AS IT LOOKS  
LIKE A WARM FRONT WILL DEVELOP MONDAY NIGHT AND THEN TRY TO LIFT  
NORTH TUESDAY. THE ECMWF IS THE MOST AGGRESSIVE WITH BLASTING THE  
WARM FRONT THROUGH THE AREA WHILE THE GFS WANTS TO HOLD IT BACK  
OVER THE AREA. THIS COULD BE A MORE PROBABLE OUTCOME, ESPECIALLY  
IF OVERRUNNING RAIN FORMS TO THE NORTH OF THE WARM FRONT AND HELPS  
TO REINFORCE THE COLD AIR AND PIN THE FRONT, SIMILAR TO WHAT  
HAPPENED FRIDAY. WITH THIS IDEA, THE ENSEMBLES STILL SUGGEST THERE  
IS A 30 TO 40 PERCENT CHANCE FOR SOME MEASURABLE SNOW OVER  
PORTIONS OF SOUTHEAST MINNESOTA INTO NORTH-CENTRAL WISCONSIN. THE  
PROBABILITIES DROP TO 20 PERCENT OR LESS FOR ONE INCH AMOUNTS,  
REFLECTING THE OVERALL WARMER SOLUTION.  
 
WITH THE WARMER SOLUTION, THERE DOES LOOK TO BE A SEVERE THREAT  
FOR THE LOCAL AREA. WITH THE DIFFERENCES IN WHAT HAPPENS TO THE  
WARM FRONT, THE MEAN ENSEMBLE SOLUTIONS WOULD SUGGEST SOME SURFACE  
BASED CAPE SPREADING OVER ALL OF THE LOCAL AREA WITH THE HIGHEST  
VALUES TUESDAY AFTERNOON ACROSS THE SOUTHERN SECTIONS. THE  
DIFFERENCES WITH THE WARM FRONT CAN BE CLEARLY SEEN IN THE  
INDIVIDUAL CAPE FIELDS WITH THE CMC MEMBERS KEEPING THE CAPE SOUTH  
OF THE IOWA/MINNESOTA BORDER, THE GEFS BRINGS IT UP TO ABOUT  
INTERSTATE 90 WITH THE EPS GOING ALL THE WAY TO LAKE SUPERIOR. THE  
SEVERE OUTLOOKS ARE HAVING BEEN PICKING UP ON THE SIGNAL FOR A  
POTENTIAL OUTBREAK FOR A COUPLE OF DAYS NOW WITH THE LATEST  
OUTLOOKS SHOWING AN INCREASE IN THE POTENTIAL ALONG WITH A BIT OF  
A NORTHWARD SHIFT. THE CSU ML OUTLOOKS BASED OFF THE GEFS HAS AT  
LEAST A 15% PROBABILITY WHERE IT HAS THE SURFACE CAPE AND 30%  
PERCENT PROBABILITIES SOUTH OF INTERSTATE 90. THE INCREASE IN  
PROBABILITIES IS SHOWN NOT FAR TO THE SOUTH OF THE AREA WHERE AN  
AREA OF UP TO 60 PERCENT RESIDES OVER SOUTHEAST IOWA, ILLINOIS AND  
MISSOURI. THE DAY 4 OUTLOOK FROM SPC HAS ALSO SHIFTED A BIT  
FARTHER NORTH WITH 15% SHOWN ACROSS NORTHEAST IOWA AND ACROSS  
SOUTHERN WISCONSIN WITH THE 30% PROBABILITIES TO THE SOUTH ACROSS  
SOUTHERN IOWA INTO ILLINOIS AND MISSOURI. IF THESE TRENDS CONTINUE  
WITH LATER MODEL RUNS, WOULD EXPECT TO START SOME MESSAGING ON  
THE SEVERE THREAT SUNDAY.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)  
ISSUED AT 520 PM CDT SAT APR 1 2023  
 
CIGS: SKC/SCT TONIGHT WITH MID CLOUDS MOVING IN WITH AN UPPER LEVEL  
SHORTWAVE TROUGH NEAR 12Z SUN. THE MID/VFR DECK LOOKS TO CLEAR  
EARLY/MID AFTERNOON SUN, BUT HIGH CIRRUS COULD LINGER INTO EARLY  
EVENING.  
 
WX/VSBY: THE SHORTWAVE TROUGH WILL BRING SOME PCPN WITH IT, BUT NEAR  
TERM/MEDIUM RANGE GUIDANCE KEEPS ANY THREAT WELL NORTH OF THE TAF  
SITES.  
 
WINDS: BECOMING LIGHT SOUTH/SOUTHEAST THIS EVENING, INCREASING  
TOWARD 12Z SUN AND BECOMING FAIRLY BREEZY DURING THE DAY. GUSTS  
PUSHING INTO THE LOW 30KTS POSSIBLE AT KRST.  
 

 
   
ARX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
MN...NONE.  
IA...NONE.  

 
 

 
 
DISCUSSION...04/JAR  
AVIATION.....RIECK  
 
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