512
FXUS63 KARX 241135
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
635 AM CDT FRI JUL 24 2026
KEY MESSAGES
- THUNDERSTORM CHANCES RETURN THIS WEEKEND INTO EARLY NEXT WEEK WITH
THE POTENTIAL FOR SEVERE STORMS ON SUNDAY AND PERHAPS AGAIN
ON MONDAY.
- HEAT INDEX VALUES OF 100 OR HIGHER ON SUNDAY AND MONDAY COULD LEAD
TO HEAT RELATED ILLNESSES AND A HEAT ADVISORY MAY BE NEEDED FOR
PARTS OF THE AREA ON BOTH OF THOSE DAYS.
DISCUSSION
ISSUED AT 401 AM CDT FRI JUL 24 2026
THIS WEEKEND INTO NEXT WEEK: STORM CHANCES RETURN
UPPER LEVEL RIDGING WILL BECOME MORE PRONOUNCED THIS WEEKEND AS HIGH
PRESSURE STRENGTHENS OVER THE SOUTHERN ROCKIES. BEFORE THE RIDGE HAS
A STRONGER INFLUENCE OVER THE UPPER MIDWEST, ANOTHER VERY NICE DAY
IS EXPECTED FOR TODAY WITH HIGHS ONCE AGAIN IN THE 70S TO LOW 80S.
WITH NORTHWESTERLY FLOW ALOFT, SOME ELEVATED SMOKE FROM WILDFIRES IS
EXPECTED TO MOVE OVER THE AREA STARTING TONIGHT AND COULD LAST INTO
THE DAY ON SATURDAY. IMPACTS FROM THE SMOKE AT THE SURFACE ARE NOT
EXPECTED AS THE WIND SHOULD REMAIN OUT OF THE SOUTH TO SOUTHWEST.
RAIN SHOWERS OR THUNDERSTORMS ARE NOT EXPECTED DURING THE DAY, BUT A
SHOWER OR STORM MAY APPROACH TAYLOR/CLARK COUNTIES LATE TONIGHT INTO
SATURDAY MORNING.
HEIGHT RISES WILL OCCUR ON SATURDAY INTO SUNDAY AND STRONG WAA WILL
OCCUR IN THE LOW LEVELS THIS WEEKEND. MOISTURE THROUGHOUT THE COLUMN
WILL BE ON THE INCREASE THIS WEEKEND WHICH SHOULD RESULT IN OFF AND
ON CHANCES FOR SHOWERS AND THUNDERSTORMS, WITH THE HIGHEST CHANCES
ON SUNDAY AFTERNOON INTO THE EVENING. THE POTENTIAL IS STILL THERE
FOR STRONG TO SEVERE STORMS ACROSS PORTIONS OF THE AREA ON SUNDAY,
WITH THE BEST POTENTIAL ACROSS WISCONSIN AT THIS TIME. THE AXIS FOR
WHERE THE POTENTIAL FOR SEVERE STORMS WILL LIKELY CHANGE SOME SINCE
WE ARE STILL THREE DAYS OUT AND WILL BE HIGHLY DEPENDENT ON HOW FAR
NORTHEAST THE LOW LEVEL THERMAL RIDGE PROGRESSES. FOR AREAS THAT ARE
MORE UNDERNEATH THE THERMAL RIDGE, A CAPPING INVERSION AROUND H800
SHOULD LEAD TO MUCH LESSER THREAT FOR SEVERE STORMS WHEREAS AREAS
FURTHER NORTHEAST WILL HAVE LESS CAPPING. FOR THE AREAS IN THE MORE
UNCAPPED ENVIRONMENT, SUFFICIENT INSTABILITY AND SHEAR SHOULD BE IN
PLACE FOR SOME STORMS TO BECOME SEVERE. THE PRIMARY HAZARD SEEMS TO
BE DAMAGING WIND GUSTS, BUT LARGE HAIL AND TO A LESSER EXTENT A
TORNADO THREAT WILL ALSO BE POSSIBLE. THUNDERSTORMS MAY CONTINUE
INTO THE MORNING ON MONDAY BUT THE SEVERE STORM THREAT SHOULD
DECREASE OVERNIGHT.
SUNDAY AND MONDAY: SUMMER HEAT RETURN
HOT CONDITIONS ARE STILL LIKELY TO OCCUR ON SUNDAY AND MONDAY AS THE
AFOREMENTIONED RIDGE INFLUENCES THE WEATHER PATTERN ACROSS THE
CENTRAL CONUS. H850 TEMPERATURES SHOULD BE ABLE TO REACH THE MID 20S
CELSIUS ON BOTH OF THESE DAYS. THE INCREASE IN SURFACE MOISTURE WITH
FORECAST DEW POINTS IN THE UPPER 60S TO MID 70S WILL RESULT IN HEAT
INDEX VALUES UP TO 10 DEGREES WARMER THAN THE AIR TEMPERATURE.
CONFIDENCE CONTINUES TO INCREASE IN THE POTENTIAL FOR HEAT INDEX
VALUES TO REACH OR EXCEED 100 DEGREES ON BOTH SUNDAY AND MONDAY.
THERE IS STILL SOME UNCERTAINTY IN EXTENT OF HOTTEST
TEMPERATURES AS CLOUD COVER COMBINED WITH CONVECTION COULD LEAD
TO TEMPERATURES BEING A FEW DEGREES COOLER THAN CURRENTLY
ANTICIPATED. HAVE ISSUED AN EXTREME HEAT WATCH WHERE HIGHEST
DEWPOINT TEMPERATURES KEEP CONFIDENCE FOR REACHING EXTREME HEAT
WARNING AT LEAST 50% FOR PARTS OF SOUTHEAST MINNESOTA AND
NORTHEAST IOWA. WILL REQUIRE ADDITIONAL FINE TUNING AS FORECAST
HOUR NEARS AS WELL AS HEAT ADVISORY TO THE NORTHEAST IS LIKELY.
TROUGHING MAY BECOME MORE PRONOUNCED OVER THE GREAT LAKES REGION
DURING THE MIDDLE OF NEXT WEEK WHICH SHOULD WEAKEN THE RIDGE AND
PUSH IT A BACK FURTHER TO THE WEST. WARM SUMMER TIME CONDITIONS ARE
STILL EXPECTED THE REST OF THE WEEK EVEN THOUGH THE RIDGE MAY NOT
HAVE AS MUCH OF AN INFLUENCE OVER THE UPPER MISSISSIPPI RIVER
VALLEY.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 635 AM CDT FRI JUL 24 2026
PREDOMINANTLY VFR CONDITIONS THROUGH THE TAF PERIOD. CIGS STAY
AROUND 5KFT TO 10KFT THROUGH THE DAY THEN GRADUALLY LOWER THIS
EVENING AND OVERNIGHT. MVFR CIGS MOVE IN EARLY SATURDAY MORNING
AND ARE EXPECTED TO LINGER THROUGH MID-MORNING. SOUTHWEST WINDS
STAY IN THE 5 TO 15 MPH RANGE.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...EXTREME HEAT WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY
EVENING FOR MNZ094.
IA...EXTREME HEAT WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY
EVENING FOR IAZ008-009.
EXTREME HEAT WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
EVENING FOR IAZ010-018-019-029-030.
DISCUSSION...MUSCHA
AVIATION...CECAVA
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