173
FXUS63 KARX 270534
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1234 AM CDT MON APR 27 2026
KEY MESSAGES
- PERIODIC PRECIPITATION IS EXPECTED THROUGH THIS EVENING.
POTENTIAL FOCUSES ON A ROUND OVERNIGHT, ANOTHER ROUND DURING
THE MORNING HOURS, AND A THIRD ROUND DURING THE AFTERNOON AND
EVENING. IF EVERYTHING COMES TOGETHER, THE THIRD ROUND MAY
FEATURE SEVERE THUNDERSTORMS WITH MAINLY A DAMAGING WIND RISK
AND A LOW TORNADO RISK. WHILE WE CANNOT YET DISMISS THIS
POSSIBILITY, THE PROBABILITY OF EVERYTHING COMING TOGETHER HAS
TRENDED DOWNWARD.
- QUICK PROGRESSION TO HEAVY RAINFALL KEEPS CONFIDENCE FOR RIVER
FLOODING LOW (<20%), HIGHEST ON FLASHIER RIVERS IN NORTHEAST
IOWA AND SOUTHWEST WISCONSIN.
- COLDER, SLIGHTLY BELOW NORMAL TEMPERATURES EXPECTED THROUGH
NEXT WEEK. A FROST OR FREEZE MAY OCCUR FRIDAY AND SATURDAY
MORNINGS.
DISCUSSION
ISSUED AT 1233 AM CDT MON APR 27 2026
SEVERE STORM POTENTIAL THIS AFTERNOON
OVERNIGHT INTO THIS MORNING, INITIAL ROUNDS OF PRECIP LOOK TO WORK
THEIR WAY NORTHEASTWARD TO OUR FORECAST AREA AHEAD OF A PAIR OF LEAD
DISTURBANCES EJECTING NORTHEAST OF AN UPPER TROUGH OVER E CO AS OF
05Z. AFTER THE MORNING ROUND, MUCH STRONGER FORCING FOR ASCENT
ARRIVES VIA THE MAIN BODY OF THE UPPER TROUGH, LEADING TO WIDESPREAD
SHOWERS AND, GIVEN COOLING TEMPERATURES ALOFT ABOVE INCREASINGLY
MOIST LOW LEVELS, SOME THUNDERSTORMS. THIS SETUP MAY YET PROVIDE
POTENTIAL FOR SEVERE STORMS - 27.00Z HREF JOINT PROBABILITIES
INDICATE A 40-90% CHANCE FOR SUFFICIENT INSTABILITY, SHEAR, AND A
LACK OF INHIBITION FOR SEVERE STORMS TO DEVELOP. THAT SAID, TREND
ACROSS GUIDANCE SUGGESTS MOST FAVORABLE CONDITIONS WILL BE DISPLACED
WELL TO OUR SOUTH WITH THE INFLUENCE OF MORNING SHOWERS AND MOSTLY
CLOUDY CONDITIONS LIMITING DESTABILIZATION. ADDITIONALLY, PROGGED
MID AND UPPER LEVEL SHEAR CHARACTERISTICS HAVE TRENDED TOWARD A LESS
FAVORABLE OUTCOME FOR SUPERCELLS TO MAINTAIN THEMSELVES WITH SHORT
HODOGRAPHS IN THE 3-6KM LAYER. IF ENOUGH SURFACE DESTABILIZATION
OCCURS, CANNOT RULE OUT A RISK FOR MAINLY DAMAGING WIND GIVEN
POTENTIAL FOR RAPID UPSCALE GROWTH DUE TO THE LARGE AMOUNT OF
FORCING AND, GIVEN SFC-3KM BULK SHEAR VALUES OF 35 KTS OR GREATER, A
STRAY QLCS TORNADO.
AS FOR RISKS FROM EXCESSIVE RAIN, FAST MOTION OF THUNDERSTORMS
SHOULD LIMIT FLASH FLOODING RISKS. CONCERNS MAINLY FOCUS ON FLASHIER
BASINS FOR EVENTUAL RIVER FLOODING BUT HEFS PROBABILITY FOR REACHING
MINOR IN THESE BASINS HAS TRENDED DOWNWARD, NOW GENERALLY 15% OR
LESS, AS PEAK RAIN AMOUNTS APPEAR VERY LIKELY (90%+ PER 27.00Z HREF)
TO REMAIN UNDER 2".
TURNING COOLER AFTER TODAY
UPPER TROUGHING BECOMES PREDOMINANT OVER THE EASTERN THIRD OF NORTH
AMERICA, INCLUDING THE UPPER MIDWEST. TEMPERATURES WILL RUN AROUND
OR A BIT COOLER THAN NORMAL AS A RESULT. FOCUS ON IMPACT CONTINUES
TO MAINLY LOOK AT FRIDAY AND SATURDAY MORNINGS IN THE WAKE OF
ANOTHER COLD FRONT. NBM CONTINUES TO POINT TOWARD THE POSSIBILITY
FOR A FROST (70-95%) OR FREEZE (25-70%) ON THESE MORNINGS,
PARTICULARLY IN CLARK/TAYLOR COUNTIES, WITH THE 27.01Z RUN.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1217 AM CDT MON APR 27 2026
VFR CONDITIONS WILL REDUCE TO MVFR CONDITIONS AS SHOWERS OVERSPREAD
THE AREA OVERNIGHT. THESE WILL PERSIST THROUGH MID-MORNING WITH MVFR
VSBY REDUCTIONS AND MVFR TO POTENTIALLY IFR CIG REDUCTIONS (40-70%
CHANCE IN THE RECENT HREF). WINDS WILL GENERALLY REMAIN FROM THE
SOUTHEAST FOR THE MORNING AND EARLY AFTERNOON AT AROUND 12-18 KTS.
AN ADDITIONAL ROUND OF STORMS DURING THE AFTERNOON WITH CONTINUED
LOW-MVFR TO IFR CIGS IS LIKELY. HOWEVER, WITH THE RECENT CAMS NOT
CONVECTING AS MUCH AS PREVIOUS RUNS, HAVE OPTED TO KEEP WITH A
PROB30 AT KRST DURING THE AFTERNOON AS CONFIDENCE IS LOW AT THIS
POINT HOW THIS WILL MANIFEST. REGARDLESS, AFTER THE FRONTAL PASSAGE
DURING THE LATE AFTERNOON AND EVENING THAT WILL INSTIGATE THIS
SECONDARY ROUND OF CONVECTION, WINDS WILL SHIFT TO
WEST/NORTHWESTERLY AT AROUND 15-20 KTS WITH GUSTS UP TO 30 KTS AND
CONTINUED LOW-MVFR TO IFR CIGS THROUGH 06Z TUESDAY.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...FERGUSON
AVIATION...NAYLOR
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