662
FXUS63 KARX 081046
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
546 AM CDT WED JUL 8 2026
KEY MESSAGES
- ROUNDS OF THUNDERSTORMS ARE EXPECTED TODAY, ONE NORTH OF I-94
THIS MORNING AND A SECOND ACROSS MUCH OF THE AREA THIS
AFTERNOON AND EVENING. THESE STORMS WILL BE CAPABLE OF
PRODUCING HEAVY RAINFALL WITH MODEST PROBABILITIES (30-50%)
FOR OVER 1 INCH OF RAINFALL AND LOCALIZED SPOTS SEEING UPWARDS
OF 2 TO 4 INCHES.
- SOME STORMS THIS AFTERNOON AND EVENING MAY BE STRONG TO SEVERE
WITH DAMAGING WIND GUSTS BEING THE PRIMARY THREAT.
- SEASONABLE TEMPERATURES ARE EXPECTED THROUGHOUT MUCH OF THE
WEEK WITH HIGHS IN THE LOW TO MID 80S BEFORE WARMING THROUGH
THE WEEKEND AND INTO NEXT WEEK.
DISCUSSION
ISSUED AT 203 AM CDT WED JUL 8 2026
TODAY - THURSDAY: STORMS EXPECTED, SOME STRONG TO SEVERE WITH THE
POTENTIAL FOR HEAVY RAINFALL THIS AFTERNOON AND EVENING
STORMS ONGOING EARLY THIS MORNING ACROSS PORTIONS OF CENTRAL MN
WILL SHIFT INTO NORTH-CENTRAL WI THROUGHOUT THE EARLY MORNING
HOURS AS SUGGESTED THROUGHOUT MUCH OF THE CAMS AS A SHORTWAVE
IMPULSE SITUATED IN WESTERN MN PUSHES EASTWARD. NOTING SOME
GRAVITY WAVE SIGNATURES IN THE CONVECTION OVER WESTERN MN THAT
MIGHT TRY TO PROPAGATE SLIGHTLY MORE SOUTHWARD OF WHERE THE CAMS
CURRENTLY SUGGEST, OVERALL NOT CONFIDENT IN HOW THIS WOULD
MANIFEST BUT COULD SEE SOME STRONG WIND GUSTS WITH ANY ORGANIZED
CONVECTION NORTH OF I-94 EARLY THIS MORNING, ESPECIALLY
CONSIDERING THE RESPECTABLE 0-3KM SHEAR PROFILES IN THE RECENT
RAP.
OTHERWISE, AS THIS EARLY MORNING CONVECTION IN NORTH-CENTRAL WI
DEPARTS, THE KEY QUESTION IS EXACTLY WHERE THE RESULTANT BOUNDARY
LEFT BEHIND IS LOCATED TO INITIATE AFTERNOON CONVECTION. RUN-TO-RUN
CONSISTENCY IN MANY OF THE CAMS HAS NOT BEEN OVERLY CONSISTENT WITH
A VARIETY OF STORM MODES AND LOCATIONS BEING PRESENT KEEPING
FORECAST CONFIDENCE FOR THE AFTERNOON AND EVENING SOMEWHAT LOW. THAT
BEING SAID, THE ENVIRONMENT DEPICTED IN THE RAP SUGGESTS FAIRLY WEAK
DEEP-LAYER SHEAR PROFILES WITH RELATIVELY SKINNY INSTABILITY. AS A
RESULT, WOULD EXPECT ANY SUPERCELLULAR STRUCTURES THAT DO DEVELOP TO
STRUGGLE AS UPDRAFT/DOWNDRAFT SEPARATION WOULD NOT BE
MAINTAINED FOR VERY LONG. CONSEQUENTLY, WOULD EXPECT STORMS TO
TREND MULTI-CELLULAR OR LINEAR QUICKLY DEPENDING ON WHAT FORCING
IS PRESENT. OVERALL, THE HAIL THREAT WITH THESE STORMS APPEARS
SOMEWHAT LIMITED DUE TO THE DEEP WARM CLOUD DEPTHS, LACK OF
ROBUST DEEP LAYER SHEAR AND SKINNY INSTABILITY PROFILES.
HOWEVER, CERTAINLY COULD SEE SOME DAMAGING WIND GUSTS WITH
SIGNIFICANT PRECIPITATION LOADING IN STORMS AS WELL AS WITH ANY
LINEAR MODES.
IN ADDITION TO THE SEVERE POTENTIAL, THE PARAMETER SPACE FOR HEAVY
RAINFALL IS RESPECTABLE WITH PRECIPITABLE WATERS OF AROUND 1.75" AND
WARM CLOUD DEPTHS TO AROUND 3.5-4KM. CONSEQUENTLY, THE 00Z HREF HAS
MEDIUM PROBABILITIES (30-50%) FOR RAINFALL AMOUNTS OVER 1"
ACROSS MUCH OF THE LOCAL AREA. HOWEVER, CANNOT RULE OUT SOME
LOCALIZED RAINFALL AMOUNTS IN THE 2-4" RANGE AS THE 00Z HREF HAS
SOME AMOUNTS IN THIS RANGE IN THE HIGHER PERCENTILE MEMBERS.
THE KEY POINT OF UNCERTAINTY THAT REMAINS IS AGAIN RELATED TO
WHERE STORMS MAY FREQUENT THE SAME LOCATIONS AS MUCH OF THE CAMS
HAVE CONFLICTING OPINIONS ON WHERE CONVECTION MAY TREK EARLIER
IN THE AFTERNOON. THAT BEING SAID, THERE HAS BEEN SOME
INCREASING SIGNAL DURING THE LATE AFTERNOON AND EVENING FOR A
MORE PRONOUNCED FRONTAL PASSAGE TO INTERACT WITH CONVECTION IN
THE LOCAL AREA AND FORCE IT UPSCALE, MOST NOTABLY SEEN IN THE
RECENT HRRR AND NAM NEST RUNS. THIS WOULD LIKELY COINCIDE WITH
A SHORTWAVE, CURRENTLY SITUATED OVER SOUTH DAKOTA, PUSHING
THROUGH THE AREA DURING THE EVENING AND OVERNIGHT. IN THIS
SCENARIO, MORE ORGANIZATION OF COLD POOLS COULD LEAD TO A
DAMAGING WIND RISK AS WELL. ADDITIONAL STORMS CANNOT BE RULED
OUT OVERNIGHT AND INTO THE EARLY MORNING HOURS WITH ANY
DIFFERENTIAL HEATING BOUNDARIES, BUT GIVEN THE DEGREE OF SURFACE
STABILITY OVERNIGHT AND INTO THE EARLY MORNING HOURS ON
THURSDAY, THE SEVERE POTENTIAL WITH THESE SHOULD BE MINIMAL.
FRIDAY - EARLY NEXT WEEK: WARMER TEMPERATURES RETURN
OVER THE WEEKEND, MID TO UPPER LEVEL RIDGING BEGINS TO BUILD ACROSS
THE UNITED STATES WHICH IS NOTED IN MOST/ALL OF THE DETERMINISTIC
AND ENSEMBLE GUIDANCE. HEIGHTS ASSOCIATED WITH THIS RIDGE ARE
EXPECTED TO BE FAIRLY IMPRESSIVE, REACHING 594-600DAM AT 500HPA,
WHICH THE 07.00Z NAEFS HIGHLIGHTS AS NEAR OR EXCEEDING THE MAXIMUM
HEIGHTS WITHIN CLIMATOLOGY. SURFACE TEMPERATURES TREND WARMER THIS
WEEKEND INTO NEXT WEEK IN RESPONSE TO THESE RISING HEIGHTS. THERE'S
STILL QUITE A BIT OF SPREAD WITHIN THE VARIOUS ENSEMBLE SUITES
REGARDING WHAT THE TEMPERATURES WILL ULTIMATELY BE, BUT
INTERQUARTILE SPREADS SUGGEST HIGHS IN THE UPPER 80S ARE FAVORED,
BUT POSSIBLY REACH INTO THE LOW 90S. DEWPOINT TEMPERATURES ALSO
INCREASE DURING THIS PERIOD AS THE 07.07Z NBM SUGGESTS A 30-60%
PROBABILITY TO EXCEED 70 DEGREES HIGHEST OVER NORTHEAST IOWA,
TRANSLATING TO APPARENT TEMPERATURES IN THE 90S. WILL NEED TO
CONTINUE MONITORING TRENDS, BUT A RETURN TO WARM AND MUGGY
CONDITIONS LOOKS TO BE ON THE HORIZON
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 546 AM CDT WED JUL 8 2026
VFR CONDITIONS ACROSS MUCH OF THE AREA THIS MORNING GIVES WAY TO
INCREASING COVERAGE OF STORMS BY AFTERNOON WITH CORRESPONDING MVFR
AND IFR REDUCTIONS. STORMS WILL BEGIN TO DEVELOP DURING THE MID-
AFTERNOON AND WILL FORM INTO A BROKEN LINE WHILE GRADUALLY PUSHING
SOUTH WITH TIME. THESE STORMS MAY BE STRONG TO SEVERE WITH DAMAGING
WIND GUSTS BEING THE PRIMARY HAZARD. STORMS WILL EVENTUALLY PUSH
SOUTH OF I-90 IN THE 00Z TO 03Z TIMEFRAME LEAVING BEHIND LOW-VFR
CIGS IN THEIR WAKE. AS WE HEAD INTO THE OVERNIGHT, LOW-LEVEL
MOISTURE STUCK UNDER THE INVERSION WILL AID IN DEVELOPING LIKELY (70-
90% CHANCE IN THE RECENT HREF) MVFR STRATUS WITH EVEN THE POTENTIAL
FOR IFR STRATUS (40-70% CHANCE IN THE RECENT HREF) AT KRST AFTER
09Z. WINDS WILL BE FROM THE SOUTHWEST DURING THE DAYTIME HOURS TODAY
BUT WILL GRADUALLY SHIFT TO NORTHERLY OVERNIGHT IN THE WAKE OF A
FRONTAL PASSAGE.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...FALKINHAM/NAYLOR
AVIATION...NAYLOR
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