173
FXUS63 KARX 261103
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
603 AM CDT TUE MAY 26 2026
KEY MESSAGES
- PERIODIC STORM CHANCES INITIALLY THIS EVENING AND OVERNIGHT
INTO WEDNESDAY MORNING RETURNING FOR WEDNESDAY. LOW CONFIDENCE
IN STORMS ALTHOUGH DAMAGING WINDS DUE TO EVAPORATIVE COOLING
OF MOIST AIR INTO DRIER LOW LEVEL AIR REMAINS A CONCERN.
- ABOVE NORMAL TEMPERATURES CONTINUE THROUGH THE WEEKEND.
DISCUSSION
ISSUED AT 1257 AM CDT TUE MAY 26 2026
WARMER THAN NORMAL TEMPERATURES CONTINUE:
A PERSISTENCE FORECAST EXPECTED THROUGH MIDWEEK WITH HIGH CONFIDENCE
FOR ABOVE NORMAL TEMPERATURES DUE TO 90TH TO MAX PERCENTILE MID
LEVEL HEIGHTS OBSERVED IN 26.00Z SOUNDINGS ACROSS THE CENTRAL CONUS.
WHILE CONFIDENCE FOR WARMTH IS HIGH, LOCAL CONFIDENCE IN DEGREE OF
WARMTH IS LOWER, DUE TO INTERDEPENDENCE ON LOW CONFIDENCE
PRECIPITATION/STORM PROBABILITIES. HIGHEST CONFIDENCE FOR WARMEST
TEMPERATURES SEEN WELL WEST OF THE UPPER MISSISSIPPI RIVER VALLEY
THROUGH THE NORTHERN PLAINS INTO THE ROCKY MOUNTAIN WEST POTENTIALLY
SEEING TRIPLE DIGIT DAYTIME HIGHS TODAY THROUGH FRIDAY. LOCAL
CONFIDENCE FOR NEAR 90 DEGREE DAYTIME HIGH TEMPERATURES REMAINS
LOWER DUE TO BIAS CORRECTING MODELS CAUSING SIZABLE, 5-10 DEGREE
WARM TAILS, ON TOP OF LOW CONFIDENCE STORM CHANCES.
PERIODIC, LOW CONFIDENCE STORM CHANCES:
A LITTLE MOISTURE CONVERGENCE CURRENTLY PRESENT OVER NORTHERN
IOWA AND SOUTHERN MINNESOTA WILL SLOWLY SHIFT EAST EARLY THIS
MORNING. WITH MINIMAL SHEAR TO WORK WITH, THESE SHOWERS AND
STORMS WILL BE QUITE PULSEY. THERE IS SOME UNCERTAINTY ON HOW
FAR EAST THESE STORMS CAN GET, AS SOME MODEL GUIDANCE HAS THESE
STORMS GETTING INTO NORTHEAST IOWA AND PORTIONS OF SOUTHEAST
MINNESOTA OVER THE NEXT SEVERAL HOURS. WHILE CLOSER TO THE
FORECAST AREA, INCREASED LOW LEVEL MOISTURE IS ALSO EXPECTED TO
REMAIN SLIGHTLY UPSTREAM OF LOCAL FORECAST AREA, SOLIDIFIED BY A
SYNOPTIC LOW LEVEL STRETCHING AXIS EXTENDING FROM THE SOUTHERN
GREAT LAKES THROUGH SOUTHERN CANADA THROUGH MIDWEEK.
COMBINATION OF SUBSIDENCE ALONG THIS STRETCHING AXIS ATTEMPTING TO
SOLIDIFY DRIER, ANTICYCLONIC FLOW LOCALLY WITH INCOMING MOISTURE
ADVECTION ATTEMPTING TO ENTRAIN WITHIN THE ANTICYCLONIC FLOW AFFECTS
LOCAL PRECIPITATION CHANCES THIS EVENING INTO THE OVERNIGHT.
ALTHOUGH, DRIER AIR DOESN'T GO FAR, PROVIDING A POTENTIAL SHARP
CUTOFF IN STORMS/PRECIPITATION. THIS SYNOPTIC SETUP ALSO MEANS
SHEAR VALUES ARE NEARLY ABSENT, LIMITING STORM CONFIDENCE WHILE
STEEPER MID LEVEL LAPSE RATES SUGGEST SOME INSTABILITY FOR
STORMS TO INITIATE OFF THE SURFACE. THEREFORE, INVERTED V
SOUNDINGS DO SUGGEST STRONG WINDS FROM EVAPORATIVE COOLING WILL
BE POSSIBLE SHOULD/WHERE STORMS FORM THROUGH THIS EVENING AND
NIGHT.
WHILE SIMILAR LOW CONFIDENCE FOR STORMS WEDNESDAY EVENING AND NIGHT,
MORE, ALBEIT MINIMAL SHEAR VALUES SLIGHTLY INCREASE CONCERN FOR
DAMAGING WINDS WHERE STORMS FORM.
PERSISTENT FORECAST INTO THE WEEKEND:
THE AREA OF ANOMALOUS HEIGHTS INTENSIFIES THROUGH THE LOWER LEVELS
(SPC RAOB CLIMATOLOGY AT MPX) INTO THURSDAY, USHERING IN A BACKDOOR
COLD FRONT AND TIGHTENING A NEAR MERIDIONAL MOISTURE BOUNDARY ACROSS
THE FORECAST AREA. LONG TERM GLOBAL ENSEMBLES AND ACCOMPANYING
DETERMINISTIC MEMBERS SUGGEST AN OMEGA BLOCK SOLIDIFYING THIS
BOUNDARY POTENTIALLY THROUGH THE WEEKEND, KEEPING ANY CONFIDENCE IN
PRECIPITATION MINIMAL AND TEMPERATURES WARM.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 603 AM CDT TUE MAY 26 2026
A BAND OF SHOWERS AND STORMS IS CURRENTLY ALONG AND WEST OF
I-35. THE EXPECTATION WITH THESE SHOWERS AND STORMS IS THAT THEY
WILL SLOWLY PUSH EAST AND AND DISSIPATE OVER THE NEXT FEW HOURS.
THESE SHOWERS AND STORMS MAY IMPACT (15 TO 30%) PORTIONS OF
NORTHEAST IOWA AND SOUTHEAST MINNESOTA, BASICALLY WEST OF A
ROCHESTER TO NEW HAMPTON LINE. SCATTERED STORMS THEN DEVELOP
LATER THIS AFTERNOON AND CONTINUE INTO THE EARLY OVERNIGHT. THE
MAIN HAZARD WITH THESE STORMS WOULD BE GUSTY OUTFLOW WINDS. ALL
PRECIPITATION CHANCES DIMINISH BETWEEN 09Z AND 12Z. LIGHT
SOUTHWEST WINDS CONTINUE THROUGH THE AFTERNOON. ONCE STORMS GET
GOING AND PRODUCE OUTFLOWS, WINDS WILL BE VARIABLE AT MOST
LOCATIONS. CIGS MOSTLY STAY BETWEEN 6KFT AND 10KFT THIS
AFTERNOON AND INTO THE OVERNIGHT.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...JAR
AVIATION...CECAVA
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