300
FXUS63 KARX 272343
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
643 PM CDT MON APR 27 2026
KEY MESSAGES
- WHILE THE LOCAL SEVERE WEATHER THREAT IS DECREASING, STILL
CANNOT FULLY RULE OUT AN ISOLATED SEVERE STORM BEFORE 8PM THIS
AFTERNOON. THE TORNADO THREAT IS QUITE CONDITIONAL BUT STILL
NON-ZERO.
- COOLER AND DRIER FOR THE REMAINDER OF THE WORK WEEK WITH HIGHS
IN THE 50S AND LOWS IN THE 30S. WARMING UP NEXT WEEKEND.
DISCUSSION
ISSUED AT 1247 PM CDT MON APR 27 2026
THIS AFTERNOON: CONVECTIVE EVOLUTION DETAILS
A 998-MB QUASI-BARBELL SURFACE LOW STRUCTURE WAS NOTED ALONG A
COLD FRONT ADVANCING THROUGH SOUTHWESTERN MN AND NORTHWESTERN IA
EARLY THIS AFTERNOON, WITH BROAD EAST TO SOUTHEAST FLOW AHEAD
OF THESE LOW CENTROIDS AND VEERING FLOW ON THE SOUTH SIDE OF
THESE LOWS BEHIND A WARM FRONT. A CORRIDOR OF CLEARING DEVELOPED
WITHIN THE DRY SLOT AHEAD OF THE COLD FRONT, ALLOWING FOR SOME
AIRMASS RECOVERY IN THE WAKE OF OUR MORNING CONVECTION. WHILE
ONLY A FEW DEGREES, THIS INSOLATION WAS ENOUGH TO TRIGGER
CONVECTIVE INITIATION ALONG THE FRONT SHORTLY BEFORE MIDDAY IN
NORTHWESTERN IOWA. WITH THE 850-MB JET ALREADY DISPLACED TO THE
EAST AND SURFACE FLOW VEERED TO THE SSW AHEAD OF THE FRONT, THE
STORMS ARE ENCOUNTERING A VERTICAL WIND PROFILE UNFAVORABLE FOR
SUSTAINED UPDRAFT LONGEVITY, FEATURING COMPRESSED AND COMPLEX
HODOGRAPHS PER HRRR/RAP PROFILES.
AN ADDITIONAL LINE OF CONVERGENCE ALONG THE DE-FACTO WARM FRONT
LIFTING INTO NORTHEASTERN IOWA COULD ALSO SPARK SHOWERS AND
STORMS OVER THE NEXT FEW HOURS. WHILE THESE STORMS WILL DEVELOP
IN A MORE FAVORABLE WIND PROFILE FEATURING LOOPED AND ELONGATED
HODOGRAPHS, THE LACK OF DAYTIME HEATING AHEAD OF THE LINE WILL
RESULT IN STRUGGLING UPDRAFTS IF ANY DO MANAGE TO GET GOING AT
ALL. THUS IS THE STORY OF OUR CURRENT WEATHER SETUP--TWO
POTENTIAL AREAS OF CONVECTIVE DEVELOPMENT, BUT NEITHER HAS BOTH
THE FAVORABLE THERMODYNAMIC AND KINEMATIC PROFILES IN PLACE TO
SUPPORT AN ORGANIZED SEVERE WEATHER THREAT.
WHILE A VERY LOW PROBABILITY (< 10%) GIVEN THE RELATIVELY
PROGRESSIVE NATURE OF THE LOW/FRONT, SHOULD SUFFICIENT CLEARING
TAKE PLACE AHEAD OF THE FRONT, THERE COULD BE ENOUGH 0-3-KM
MLCAPE AND SURFACE VORTICITY POOLED ALONG THE FRONT TO GENERATE
LANDSPOUT TORNADOES WITH ANY CONVECTION ROOTED ALONG THE
BOUNDARY. HOWEVER, THE DEGREE OF RECOVERY AHEAD OF THE FRONT
WILL BE KEY AND THE WINDOW OF OPPORTUNITY FOR SUCH A SETUP WILL
BE ONLY AN HOUR OR TWO AT ANY GIVEN LOCATION.
THE THREAT FOR SEVERE WEATHER DEPARTS ONCE THE COLD FRONT
PASSES, WHICH LOOKS TO BE BETWEEN 3PM AND 8PM TONIGHT.
REST OF THE WEEK: COOLER AND DRIER
BROAD LONGWAVE TROUGHING WITH MULTIPLE EMBEDDED SHORTWAVES RESIDES
OVER THE NORTH-CENTRAL U.S. THROUGH THE REMAINDER OF THE WEEK,
KEEPING A CONTINUED FETCH OF POLAR AIR IN PLACE AND TEMPERATURES
ROUGHLY 10 DEGREES BELOW NORMAL. SEVERAL OF THESE AFOREMENTIONED
UNDULATIONS BRING PERIODS OF CLOUDS AND POSSIBLY LIGHT SHOWERS
FROM TUESDAY THROUGH THURSDAY, BUT THE PROBABILITIES FOR
MEASURABLE PRECIPITATION IS QUITE LOW AND IMPACTS SHOULD BE
MINIMAL. LOWS WILL BE DICTATED BY CLOUD COVER AND WINDS WITH THE
SURFACE HIGH PRESSURE CENTROID REMAINING UPSTREAM, BUT THE NEED
FOR FROST/FREEZE HEADLINES WILL INCREASE FROM TUESDAY THROUGH
FRIDAY NIGHTS. THE PATTERN SHIFTS FOR NEXT WEEKEND AS RIDGING
BUILDS IN, ALLOWING FOR MORE SEASONAL TEMPERATURES TO CREEP
NORTHWARD.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 636 PM CDT MON APR 27 2026
AREA OF TSRA FROM EAU TO DBQ IS MOVING EAST AS OF ISSUANCE TIME.
EXPECT THESE TO CLEAR EAST OF A AUW TO DLL LINE DURING THE 02Z
TO 03Z HOUR. LINGERING MVFR TO POTENTIALLY (20%) IFR STRATUS
WILL CONTINUE IN THE WAKE OF A COLD FRONTAL PASSAGE THROUGH
TUESDAY MORNING. NORTHWESTERLY WINDS WITH GUSTS TO 20-30 KNOTS
WILL ALSO BE PREDOMINANT BEHIND THE FRONT.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...SKOW
AVIATION...FERGUSON
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