887  
FXUS63 KARX 180119  
AFDARX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LA CROSSE WI  
819 PM CDT SUN MAY 17 2026  
   
KEY MESSAGES
 
 
- SEVERE WEATHER POSSIBLE BETWEEN 7 PM AND 1 AM TONIGHT. ALL  
HAZARDS ARE POSSIBLE MAINLY WEST OF THE MISSISSIPPI RIVER.  
 
- ANOTHER ROUND OF SEVERE WEATHER POSSIBLE ON MONDAY NIGHT  
BETWEEN 9 PM AND 4 AM. THE MAIN THREAT WILL BE DAMAGING WINDS.  
WITH ISOLATED THREATS OF HAIL AND MAYBE A FEW QLCS TORNADOES.  
 

 
   
UPDATE
 
 
ISSUED AT 805 PM CDT SUN MAY 17 2026  
 
ONGOING NON-SEVERE SCATTERED STORMS ACROSS THE LOCAL AREA ARE  
INHIBITING NORTHWARD PROGRESSION OF WARM FRONT SEEN THROUGH  
NORTH-CENTRAL IOWA ON SURFACE OBSERVATIONS THIS EVENING, KEEPING  
LOCAL SEVERE THREAT CONDITIONAL, I.E., LOWER OVERALL CONFIDENCE.  
INTENSIFICATION OF THE LOW LEVEL JET, 45 KT SOUTH WIND ON DMX  
VWP, SUGGESTS A NORTHERN SHIFT IN WARM FRONT SURGING INSTABILITY  
FARTHER NORTH IN THE NEXT 1-2 HOURS. THEREFORE, INITIAL THREAT  
OF SURFACE BASED, SEMI-DISCRETE STORM MODE REMAINS A LOW  
CONFIDENCE SCENARIO TO REMAIN COGNIZANT OF UNTIL THE EVENTUAL  
MCS ON RADAR IMAGERY QUICKLY SHIFTING EAST THROUGH CENTRAL  
MINNESOTA ARRIVES IN 3+ HOURS. WHILE MAIN THREAT WITH THIS LINE  
WILL BE DAMAGING WINDS, SHOULD THE WARM FRONT REACH FARTHER  
NORTH, A QLCS TORNADO THREAT WOULD EXIST PRIMARILY ALONG THE  
FRONTAL BOUNDARY. THEREFORE, THE ONGOING TORNADO WATCH MAY  
REQUIRE A SWITCH TO SEVERE THUNDERSTORM WATCH.  
 

 
   
DISCUSSION
 
 
ISSUED AT 1257 PM CDT SUN MAY 17 2026  
 
THIS AFTERNOON  
 
THE REMNANT MCV WHICH BROUGHT RAIN MAINLY SOUTH OF INTERSTATE 94  
WILL CONTINUE TO MOVE NORTHEAST AWAY FROM THE AREA THIS AFTERNOON.  
AS IT DOES, THE SHOWERS AND ISOLATED STORMS CURRENTLY ALONG  
INTERSTATES 90 AND 94 WILL MOVE EAST NORTHEAST AWAY FROM THE AREA.  
ADDITIONAL RAINFALL AMOUNTS WILL BE UP TO A HALF INCH. AS A WARM  
FRONT GRADUALLY LIFTS NORTHWARD, TEMPERATURES ALONG AND SOUTH OF  
INTERSTATE 94 WILL WARM INTO THE 60S AND LOWER 70S, AND INTO 60S  
NORTH OF THIS INTERSTATE. THIS WILL RESULT IN SURFACE-BASED CAPES  
CLIMBING INTO THE 1000 TO 2500 J/KG ALONG AND SOUTH OF INTERSTATE 90  
BY 7 PM.  
 
TONIGHT  
 
LATE THIS AFTERNOON AND EVENING, 2-3K J/KG CAPES WILL DEVELOP AHEAD  
OF A SQUALL LINE MOVING EAST ACROSS EASTERN SOUTH DAKOTA, EASTERN  
NEBRASKA, NORTHERN IOWA, AND SOUTHERN MINNESOTA. WITH 0-6 KM  
SHEAR APPROACHING 40 KNOTS, THERE COULD POTENTIALLY BE SOME  
SUPERCELLS LOCATED ALONG THE LINE (THESE WOULD LIKELY STAY  
WEST OF THE UPPER MISSISSIPPI RIVER VALLY) AND ALONG THE WARM  
FRONT NEAR THE MINNESOTA AND IOWA BOARDER. IN ADDITION TO THE  
DEEP SHEAR, THERE IS 200-300 EHI ALONG THE MINNESOTA AND IOWA  
BOARDER AND DOWNDRAFT CAPES UP TO 1K J/KG. THE DISCRETE  
SUPERCELLS AHEAD OF THE SQUALL LINE WOULD BE CAPABLE OF  
PRODUCING WET MICROBURSTS, LARGE HAIL, AND ISOLATED TORNADOES  
BETWEEN 7 PM AND 10 PM IN SOUTHEAST MINNESOTA AND NORTHEAST  
IOWA. THE THREAT WILL THEN SHIFT TO MORE DAMAGING WINDS AND  
MAYBE A FEW QLCS TORNADOES AS THE SQUALL LINE MOVES INTO  
SOUTHEAST MINNESOTA AND NORTHEAST IOWA BETWEEN 10 PM AND 11 PM.  
THIS LINE WILL THEN GRADUALLY WEAKEN AS THE INSTABILITY WANES.  
THE SEVERE WEATHER THREAT WILL LIKELY WANE BY 1 AM MONDAY.  
 
MONDAY NIGHT  
 
A COLD FRONT WILL MOVE EAST THROUGH THE AREA. THERE WILL BE 1-2K  
J/KG CAPES AHEAD OF THIS FRONT. WITH MUCH OF THE DEEP (0-6 KM) SHEAR  
LOCATED POST FRONTAL, NOT ANTICIPATING ANY SUPERCELLS. AS A RESULT,  
IF THERE IS SEVERE WEATHER, IT WOULD BE LOCATED ALONG THE COLD FRONT  
AS A SQUALL LINE. THE PRIMARY THREAT WOULD BE DAMAGING WINDS WITH  
SECONDARY THREATS AS HAIL AND QLCS TORNADOES. TIMING LOOKS TO BE  
RATHER SIMILAR TONIGHT WITH THE SQUALL LINE MOVING INTO NORTHEAST  
IOWA AND SOUTHEAST MINNESOTA BETWEEN 9 PM AND 10 PM. IT WILL EXIT  
THE AREA BETWEEN 2 AM AND 4 AM. BY THIS TIME, THE WINDS WILL LIKELY  
BE SUB-SEVERE.  
 
FRIDAY INTO SATURDAY  
 
A SHORTWAVE TROUGH WILL MOVE EAST THROUGH THE AREA. THIS WILL RESULT  
IN ANOTHER ROUND OF SHOWERS AND ISOLATED STORMS. WITH CAPES LESS  
THAN 250 J/KG AND 0-3 KM AND 0-6 KM SHEAR LESS THAN 25 KNOTS, NOT  
ANTICIPATING ANY ORGANIZED SEVERE WEATHER AT THIS TIME.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
 
 
ISSUED AT 636 PM CDT SUN MAY 17 2026  
 
MVFR TO IFR CONDITIONS CURRENTLY PRESENT ACROSS THE REGION WITH  
SOME ISOLATED INSTANCES OF LIFR ALONG AND SOUTH OF THE I-90  
CORRIDOR. LOW CLOUDS ARE EXPECTED TO LINGER FOR MOST AREAS  
THROUGH LATER TONIGHT WITH SOME LOW PRECIP CHANCES. THE MAIN  
CHANCE FOR STORMS LOOKS TO PUSH EAST INTO THE REGION LATE THIS  
EVENING - LIKELY BETWEEN 04-08Z FOR THE TERMINALS. THE MAIN  
THREAT WITH THIS LINE OF STORMS WILL BE STRONG WINDS AND HEAVY  
RAINFALL SO HAVE CONTINUED WITH THE TEMPO GROUPS THAT BRING  
STRONGER WINDS IN FOR A SHORT TIME PERIOD. LOWER RAIN CHANCES  
WILL CONTINUE INTO TOMORROW MORNING BEHIND THE LINE OF STORMS  
WITH MOST LOCATIONS LIFTING BACK TO VFR CIGS THROUGH THE  
MORNING. SOME LOWER MVFR/IFR CIGS MAY LINGER ACROSS PORTIONS OF  
SE MINNESOTA AND WC WISCONSIN SO HAVE KEPT THEM AT THE KRST  
TERMINAL THROUGH THE END OF THE PERIOD.  
 

 
   
HYDROLOGY
 
 
ISSUED AT 106 AM CDT SUN MAY 17 2026  
 
ONE TO TWO INCH TOTALS ARE STILL FORECAST ACROSS THE AREA, WITH  
AREAS FURTHER WEST MORE FAVORED FOR THE 2 INCH TOTALS. THIS WILL  
LIKELY NOT CAUSE RIVER FLOODING, ONLY WITHIN BANK RISES.  
 

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

 
 

 
 
UPDATE...JAR  
DISCUSSION...BOYNE  
AVIATION...BARENDSE  
HYDROLOGY...BAUMGARDT  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab WI Page
The Nexlab IA Page
The Nexlab MN Page Main Text Page