862
FXUS63 KARX 110543
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1243 AM CDT TUE AUG 11 2026
KEY MESSAGES
- THUNDERSTORMS WILL MOVE IN ACROSS THE FORECAST AREA EARLY IN
THE MORNING AND SOME OF THE STORMS COULD BE SEVERE DUE TO
DAMAGING STRAIGHT LINE WIND GUSTS.
- PERIODIC STORM CHANCES ARE POSSIBLE THROUGHOUT THE REST OF THE
FORECAST PERIOD ALONG WITH COOLER TEMPERATURES BY THIS
UPCOMING WEEKEND.
DISCUSSION
ISSUED AT 1240 AM CDT TUE AUG 11 2026
NOW THROUGH THIS MORNING: STORMS AND SEVERE STORM POTENTIAL
A FEW SHOWERS AND STORMS DEVELOPED EARLIER ALONG A NEARLY STATIONARY
WEST TO EAST BOUNDARY JUST SOUTH OF THE FORECAST AREA. AS THE
BOUNDARY SLOWLY TRENDS NORTHWARD, CANNOT RULE OUT A COUPLE ATTEMPTS
AT CONVECTION OVER THE NEXT FEW HOURS ACROSS NORTHEASTERN IA INTO
SOUTHWESTERN WI. GIVEN HOW THE STORMS HAVE LARGELY STRUGGLED EVEN
WITH EXTREME BUOYANCY IN PLACE, THERE IS VERY LOW CONFIDENCE IN ANY
SEVERE STORM DEVELOPMENT THROUGH AT LEAST 3 AM. THE LACK OF SYNOPTIC
LIFT IS LIKELY LEADING TO THESE STORMS STRUGGLING TO BECOME
SUSTAINED.
THE HIGHER CHANCE FOR SEVERE STORMS IS CURRENTLY BEING FORECAST TO
OCCUR ACROSS AT LEAST THE SOUTHERN HALF OF THE CWA STARTING NEAR
SUNRISE AND LASTING THROUGH AT LEAST MID MORNING. A COMPLEX OF
THUNDERSTORMS IS ANTICIPATED TO DEVELOP OVER EASTERN SD INTO MN/IA
OVER THE NEXT COUPLE OF HOURS AND QUICKLY MOVE EAST AIDED BY UPPER
LEVEL FORCING. UNFORTUNATELY, TIMING AND LOCATION OF THIS POTENTIAL
SYSTEM REMAINS LOW CONFIDENCE AS CAMS HAVE ONCE AGAIN BEEN VERY
INCONSISTENT WITH THE EVOLUTION OF A POTENTIAL MCS. SUFFICIENT
INSTABILITY AND SHEAR WILL BE IN PLACE TO SUSTAIN CONVECTION AND
FORM SEVERE STORMS WITH THE PRIMARY HAZARD BEING DAMAGING STRAIGHT
LINE WIND GUSTS UP TO 70-80 MPH. HEAVY RAINFALL MAY ALSO LEAD TO A
THREAT FOR ISOLATED FLASH FLOODING, ESPECIALLY FOR AREAS THAT
RECEIVE RAINFALL BEFORE THE MAIN THUNDERSTORM LINE MOVES THROUGH.
TIMING OF THE SEVERE THREAT UNFORTUNATELY REMAINS UNCERTAIN, BUT IN
GENERAL STORMS SHOULD BEGIN TO MOVE OVER THE WESTERN COUNTIES BY 5-8
AM AND EXIT OFF TO THE EAST BY 10 AM TO 12 PM WITH SOME LINGERING
SHOWERS OR GENERAL THUNDERSTORMS INTO THE AFTERNOON HOURS.
THIS AFTERNOON THROUGH WEDNESDAY: PERIODIC STORM CHANCES
THE AREA SHOULD BE SUPPRESSED FROM ANY STORM DEVELOPMENT THIS
AFTERNOON THROUGH THE EVENING IN THE WAKE OF THE MORNING SHOWERS AND
STORMS. CLOUD COVER SHOULD CLEAR OUT AND TEMPERATURES ARE FORECAST
TO RISE INTO THE LOW TO MID 80S THIS AFTERNOON WHICH ARE RIGHT AT
AVERAGE FOR MID AUGUST. A RINSE AND REPEAT SCENARIO MAY OCCUR FOR
TUESDAY NIGHT INTO WEDNESDAY MORNING AS ANOTHER SHORTWAVE TROUGH
QUICKLY PROPAGATES EAST/SOUTHEAST FROM THE DAKOTAS TOWARDS THE
MIDWEST. THE SHORTWAVE SHOULD TRIGGER ANOTHER ROUND OF SHOWERS OR
STORMS OUT OF THE DAKOTAS INTO NEBRASKA AND THEY SHOULD QUICKLY MOVE
EAST, POTENTIALLY FORMING ANOTHER MCS. JUST HOW FAR EAST THE STORMS
CAN GET REMAINS UNCERTAIN AT THIS TIME AND MAY HIGHLY BE DEPENDENT
ON HOW THE STORMS PAN OUT LATER THIS MORNING. SOME OUTLIER SOLUTIONS
DO HAVE ANOTHER ROUND OF STORMS MOVING ACROSS MN/IA ON WEDNESDAY
MORNING BUT CONFIDENCE IN THE STORMS BEING SEVERE OR EVEN REACHING
THE AREA IS EXTREMELY LOW AT THIS POINT. ANOTHER WARM DAY IS LIKELY
ON WEDNESDAY ALONG WITH MOSTLY DRY CONDITIONS. A SURFACE BOUNDARY
HAS THE POTENTIAL TO SET UP OVER WEST CENTRAL WISCONSIN INTO CENTRAL
MINNESOTA WHICH COULD BECOME A FOCAL POINT FOR AFTERNOON INTO THE
EVENING STORM DEVELOPMENT. INGREDIENTS COULD BE IN PLACE FOR SEVERE
STORMS SHOULD ANY STORMS DEVELOP ALONG THE BOUNDARY ON WEDNESDAY.
THURSDAY INTO NEXT WEEK: TRENDING COOLER WITH CONTINUED RAIN CHANCES
THE CENTER OF THE H500 HIGH PRESSURE IS FORECAST TO SHIFT EAST OVER
THE GULF COAST STATES LATE THIS WEEK INTO THIS WEEKEND. THE MAIN
RIDGE AXIS APPEARS TO STAY SOUTH OF THE FORECAST AREA DURING THIS
TIME FRAME WHICH WILL KEEP THE REGION UNDERNEATH WESTERLY FLOW ALOFT.
THIS PATTERN SHOULD LEAD TO COOLER CONDITIONS FRIDAY INTO NEXT WEEK
WITH HIGH TEMPERATURES A FEW DEGREES BELOW AVERAGE. OFF AND ON
CHANCES FOR SHOWERS AND STORMS IS LIKELY AS SHORTWAVES EMBEDDED IN
THE UPPER LEVEL FLOW MOVE OVER THE UPPER MISSISSIPPI VALLEY DURING
THIS TIME FRAME. THE HIGHEST CHANCES (50-70 PERCENT) FOR WIDESPREAD
RAIN ARE MOST NOTABLE ON SATURDAY INTO SUNDAY AS MID LEVEL MOISTURE
TRANSPORT PEAKS AS A STRONGER WAVE ROUNDS THE TOP OF THE RIDGE.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1240 AM CDT TUE AUG 11 2026
VFR CONDITIONS CURRENTLY PRESENT ACROSS THE REGION. AN AREA OF
THUNDERSTORMS IS EXPECTED TO MOVE IN FROM THE WEST/NORTHWEST DURING
THE EARLY MORNING HOURS AFTER 10Z. WHILE THE BULK OF THE
POTENTIALLY SEVERE ACTIVITY SHOULD STAY TO THE SOUTH OF THE
TERMINALS IN NE IOWA AND SW WISCONSIN, BOTH THE TERMINALS WILL
SEE A FEW HOURS OF THUNDERSTORM POTENTIAL. AS SUCH, HAVE
TRANSITIONED THE PROB30S FROM THE EARLIER PACKAGE TO TEMPOS AS
CONFIDENCE IS NOW HIGH ENOUGH THAT THEY WILL SEE THIS ACTIVITY.
THIS CLUSTER OF STORMS WILL MOVE THROUGH DURING THE MORNING
HOURS WITH VFR CONDITIONS PREVAILING FOR THE DURATION OF THE
PERIOD AFTERWARDS. WINDS THROUGH THE DAY WILL REMAIN LIGHT AND
VARIABLE.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...MUSCHA
AVIATION...BARENDSE
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