757
FXUS63 KARX 111836
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
136 PM CDT TUE AUG 11 2026
KEY MESSAGES
- PERIODIC STORM CHANCES THROUGH THE WEEKEND. ANY SEVERE
POTENTIAL LOOKS LOW AT THIS TIME.
- TEMPERATURES REMAIN NEAR NORMAL WITH HIGHS IN THE MID 70S TO
MID 80S THROUGH THURSDAY, THEN COOL SLIGHTLY FOR THE WEEKEND.
DISCUSSION
ISSUED AT 135 PM CDT TUE AUG 11 2026
THIS AFTERNOON - THURSDAY: STORM POTENTIAL WITH SEASONABLE
TEMPERATURES
STORMS FROM THIS MORNING SHOT OFF A BOUNDARY THAT WENT NORTHEAST
THROUGH THE CWA. THIS BOUNDARY HELPED TO INITIATE SOME SHOWERS ACROSS
WESTERN AND CENTRAL WISCONSIN AND CONTINUED TO MOVE NORTHWARD. MORE
SHOWERS AND STORMS ARE POSSIBLE THIS AFTERNOON AND EVENING ALONG
THIS BOUNDARY, HOWEVER THE CHANCES ARE LOW (<15%). AS WE HEAD INTO
TONIGHT AND WEDNESDAY MORNING, ANOTHER MCS OR LINE OF STORMS IS
EXPECTED TO FORM AS A SHORTWAVE SHIFTS DOWN FROM THE NORTHERN PLAINS
INTO PORTIONS OF THE UPPER MIDWEST. DUE TO THIS MORNING'S MCS, THE
PATH FOR TONIGHT'S STORMS SHOULD STAY MOSTLY SOUTH OF THE FORECAST
AREA WITH OUR SOUTHERN TIER OF COUNTIES SEEING THE HIGHEST POTENTIAL
FOR SHOWERS/STORMS (20 TO 40%). THE RRFS SOLUTION HAS ONE OF THE
MORE DEFINED STORM COMPLEXES AND IT IMPACTS NORTHEAST IOWA. IT IS
ALSO ONE OF THE MORE NORTHERN SOLUTIONS. NOT TO RULE OUT THE
POSSIBILITY OF THIS HAPPENING, BUT THIS MORNING'S MCS WENT A LITTLE
FURTHER SOUTH THAN ANTICIPATED SO THE THINKING IS THAT WEDNESDAY
MORNING'S WOULD FOLLOW SUIT. IN ADDITION, A BOUNDARY SHOULD FORM TO
THE NORTH OF THE STORM COMPLEX AFTER IT MOVES THROUGH, LEAVING A LOW
POTENTIAL (15 TO 25%) FOR SCATTERED SHOWERS AND STORMS MOSTLY NORTH
OF I-90 DURING THE AFTERNOON AND EVENING.
BY EARLY THURSDAY MORNING ANOTHER SHORTWAVE MOVES DOWN INTO THE
REGION. AT THE SAME TIME, A LOW FORMS IN THE CENTRAL PLAINS. THIS
LOW WILL SHIFT TOWARDS THE NORTHEAST AS SOUTHWEST FLOW INCREASES
ALOFT AND THE SHORTWAVE WILL MOVE SOUTHEASTWARD. THIS TWO SYSTEMS
LOOK TO MEET SOMEWHERE BETWEEN CENTRAL IOWA AND SOUTHERN MINNESOTA.
THIS AREA WOULD HAVE THE HIGHEST CHANCE FOR SHOWERS AND STORMS TO
OCCUR. CURRENTLY THERE IS STILL A BIT OF UNCERTAINTY ON WHERE
EXACTLY SHOWERS AND STORMS PASS THROUGH FOR THURSDAY MORNING. WILL
GET BETTER DETAILS AS WE GET CLOSER. WITH ZONAL FLOW ANTICIPATED
THROUGH THURSDAY, HIGH TEMPERATURES SHOULD STAY CLOSE TO NORMAL,
WITH HIGHS IN THE MID 70S TO MID 80S.
FRIDAY - EARLY NEXT WEEK: PERIODIC STORM CHANCES
HEADING INTO THE WEEKEND GUIDANCE IS IN GOOD AGREEMENT ON THE RIDGE
SHIFTING OVER THE EASTERN US. THIS IN TURN WILL PUT OUR REGION IN
WEST TO SOUTHWEST FLOW AS THE RIDGE AXIS SHOULD STAY TO OUR
SOUTHEAST. THE POSITION OF THIS RIDGE WILL HELP KEEP OUR
TEMPERATURES SLIGHTLY BELOW NORMAL WITH HIGHS IN THE LOW 70S TO LOW
80S THROUGH THE WEEKEND. WITH A GOOD SOUTHWEST FETCH OF MOISTURE
FROM THE GULF FROM FRIDAY INTO SUNDAY AND PWATS IN THE 97.5 TO 99TH
PERCENTILES (1.75 TO 2.25") THERE IS A HEAVY RAIN POTENTIAL DURING
THE PERIOD. BOTH THE GFS AND ECMWF HAVE A WARM FRONT THAT BRINGS AN
INITIAL BAND OF SHOWERS AND STORMS ON FRIDAY NIGHT/SATURDAY MORNING
FOLLOWED BY ANOTHER SHORTWAVE FOR SATURDAY EVENING. THERE IS ALREADY
AN EFI SIGNAL OF 0.5 TO 0.65 INDICATING THAT THIS RAIN EVENT WOULD
LEAN ON THE HIGHER SIDE OF CLIMATOLOGY. WPC HAS GONE AHEAD AND
ISSUED A SLIGHT RISK FOR EXCESSIVE RAINFALL FOR SATURDAY DUE TO
THESE PARAMETERS.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1225 PM CDT TUE AUG 11 2026
A FEW POCKETS OF MVFR CEILINGS HAVE LINGERED THROUGHOUT THE
MORNING HOURS, BUT HAVE BEGUN TO DISSIPATE WITH HEATING WHICH
WILL RESULT IN VFR CONDITIONS PREVAILING THROUGH THE REST OF THE
AFTERNOON. A FEW ISOLATED SHOWERS AND PERHAPS A STORM COULD
DEVELOP NORTH OF I-94 THIS AFTERNOON AND EVENING, BUT THIS
POTENTIAL IS LOW, ONLY 10-20% PER THE 11.12Z HREF/REFS.
OVERNIGHT, SOME CONCERN FOR FOG EXISTS GIVEN HUMID CONDITIONS
AND RAINFALL FROM THIS MORNING, BUT INCREASING MID-HIGH CLOUD
COVER AROUND 12-15KFT COULD LIMIT THE AMOUNT OF COOLING SEEN
ACROSS THE REGION. THIS WOULD ACT TO KEEP FOG POTENTIAL CONFINED
TO LOWER LYING AREAS AND TO THOSE CLOSER TO AND EAST OF THE
MISSISSIPPI RIVER, THOUGH IF CLOUD COVER REMAINS AT BAY, FOG
POTENTIAL WOULD BECOME MORE WIDESPREAD. THERE'S ALSO SOME
INDICATION OF ADDITIONAL SHOWERS/STORMS ALONG/SOUTH OF HIGHWAY
18 ACROSS NORTHERN IOWA/SOUTHWEST WISCONSIN WEDNESDAY MORNING
THOUGH PROBABILITIES OF THIS ARE ALSO ON THE LOWER END (20-30%).
OTHERWISE, WINDS REMAIN LIGHT AND VARIABLE OVER THE NEXT 24
HOURS.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...CECAVA
AVIATION...FALKINHAM
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