450
FXUS63 KARX 222356
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
656 PM CDT FRI MAY 22 2026
KEY MESSAGES
- PERIODIC SHOWERS AND THUNDERSTORMS ARE POSSIBLE (20-50%)
THROUGH MONDAY, MAINLY DURING THE LATE AFTERNOON AND EVENING
HOURS. CANNOT RULE OUT A SEVERE THUNDERSTORM FOR MONDAY BUT
THE CHANCE IS VERY LOW (<10%).
- THE CHANCE FOR PERIODIC SHOWERS AND THUNDERSTORMS DECREASES
(10-15%) FOR TUESDAY ONWARD AS A RIDGE BUILDS OVER OR NEAR THE
AREA.
- TEMPERATURES BEGIN WARMING THIS WEEKEND INTO NEXT WEEK WITH
ABOVE NORMAL TEMPERATURES FAVORED FROM SUNDAY ONWARD,
PARTICULARLY AS THE UPPER RIDGE BUILDS TUESDAY ONWARD.
DISCUSSION
ISSUED AT 151 PM CDT FRI MAY 22 2026
PERIODIC SHOWER AND THUNDERSTORM POTENTIAL THROUGH MONDAY
UPPER TROUGH, CURRENTLY LOCATED OVER THE NORTHERN PLAINS, WILL
SLOWLY CHURN NORTHEASTWARD THROUGH SUNDAY, WITH SOUTHWESTERLY FLOW
ALOFT BECOMING QUASI-ZONAL AS A RESULT. MULTIPLE PERTURBATIONS
WITHIN THIS FLOW WILL LEAD TO PERIODIC WINDOWS WITH POTENTIAL (20-
50%) FOR SHOWERS AND THUNDERSTORMS. WHILE UNCERTAINTY IN TIMING OF
THESE PERTURBATIONS IS HIGHEST SUNDAY AND MONDAY, ENOUGH
CONSISTENCY WAS SEEN ACROSS GUIDANCE TO RAISE POPS A BIT DURING
SATURDAY AFTERNOON AND EVENING.
AS FOR HAZARDS ASIDE FROM LIGHTNING, PROGGED CAPE PROFILES FOR
SATURDAY AND SUNDAY ARE SKINNY SO THINK THE CHANCE FOR SEVERE STORMS
IS REMOTE. HOWEVER, 22.15Z RAP AND 22.12Z HRRR SUGGEST A WELL-MIXED
BOUNDARY LAYER WILL BE PRESENT, SO CANNOT RULE OUT A STRONG WIND
GUST WITH ANY CONVECTION THAT DOES DEVELOP.
A BIT MORE INTRIGUE FOR MEMORIAL DAY AS 22.12Z GFS SOUNDINGS DEPICT
ROBUST CAPE PROFILES - AROUND 2000-2500 J/KG OF MLCAPE - AND MINIMAL
CAPPING, PARTICULARLY NORTH/WEST OF A CHARLES CITY TO BLACK RIVER
FALLS LINE DURING THE AFTERNOON. THAT SAID, WHILE DEEP SHEAR VALUES
ARE ENOUGH FOR SEVERE STORMS - AROUND 30-40 KNOTS - DISTRIBUTION OF
SAID SHEAR IN THE VERTICAL WITH LITTLE SHEAR ABOVE 3KM SUGGESTS
CONVECTION MAY HAVE TROUBLE ORGANIZING WITH HYDROMETEORS FAILING TO
VENT AWAY FROM THEIR UPDRAFTS. ADDITIONALLY, HEIGHTS ALOFT LOOK TO
BE RISING THROUGH THE DAY WHICH REDUCES ENTHUSIASM WITH REGARD TO
THE CAP BREAKING. FURTHERMORE, THIS OVERALL SCENARIO IS LARGELY
PRESENT ONLY WITHIN THE 22.12Z GFS AND 22.00Z GEFS, WITH ML-
BASED GUIDANCE USING ECENS KEEPING THIS POTENTIAL AWAY FROM OUR
FORECAST AREA. THUS, WHILE WE SHOULD CONTINUE TO MONITOR,
OVERALL THINKING IS THAT THE POTENTIAL FOR SEVERE STORMS IS
PRETTY LOW (<10%).
WARMER TEMPERATURES, LOW RAIN CHANCES TUESDAY ONWARD
RIDGE ALOFT BUILDS OVER THE UPPER MIDWEST TUESDAY ONWARD. THIS WILL
LEAD TO TEMPERATURES WELL ABOVE NORMAL WITH HIGHS MAINLY IN THE 80S.
HAVE TAMPED DOWN 22.11Z NBM HIGHS, WHICH INCLUDED VALUES IN THE LOW
90S ON TUESDAY, DUE TO SEASONAL BIAS CORRECTION ISSUES LEADING TO A
DISCREPANCY OF SEVERAL DEGREES VS. LREF TEMPERATURES.
AS FOR PRECIP, 22.12Z GUIDANCE SEEMS TO SHOW MORE CONSISTENCY IN THE
PLACEMENT AND MAGNITUDE OF THE UPPER RIDGE COMPARED TO PREVIOUS
CYCLES. HOWEVER, SOME ENSEMBLE MEMBERS AND 22.12Z GFS SHOW A RIDGE
DISPLACED A BIT TO THE WEST, ALLOWING FOR UPPER DISTURBANCES
ROTATING AROUND AN UPPER LOW OVER QUEBEC/NEW ENGLAND TO PASS OVER
THE CWA AND POTENTIALLY KICK OFF SOME CONVECTION. THEREFORE, WHILE
WARM AND DRY IS THE MOST PROBABLE OUTCOME (80%) TUESDAY THROUGH
FRIDAY, CANNOT TOTALLY RULE OUT SOME DISRUPTION TO OUTDOOR
ACTIVITIES AT THIS TIME.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 656 PM CDT FRI MAY 22 2026
CEILINGS GENERALLY 3-5KFT CONTINUE THIS EVENING INTO THE
OVERNIGHT HOURS WITH SOUTHEAST WINDS BEGINNING TO WANE TOWARDS
5-10KT. MVFR CEILINGS IN THE 2-3KFT RANGE MOVE INTO THE REGION
FROM THE WEST ALONG A COLD FRONT THAT SHIFTS EASTWARD THROUGHOUT
SATURDAY. THE 22.18Z REFS AND 22.19Z NBM ALSO SUGGEST SOME
PROBABILITIES FOR CEILINGS FALLING TO AROUND 1.5KFT WEST OF THE
MISSISSIPPI RIVER (10- 30%). ALSO CAN'T RULE OUT SOME SHOWERS
ALONG THIS FRONT, MOST FAVORABLE ALONG AND EAST OF THE
MISSISSIPPI RIVER (20-40%). HOWEVER, COVERAGE APPEARS VERY
ISOLATED AND IMPACTS SHOULD BE MINIMAL, BUT DID INCLUDE A PROB30
GROUP AT KLSE TO HIGHLIGHT THE POTENTIAL. WITH THE PASSAGE OF
THE COLD FRONT, CEILINGS BEGIN TO LIFT FROM WEST TO EAST AND
WINDS VEER TO THE NORTHWEST, RESULTING IN VFR CONDITIONS
RETURNING FOR MUCH OF THE REGION TOWARDS THE END OF THE TAF
PERIOD.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...FERGUSON
AVIATION...FALKINHAM
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