788
FXUS63 KARX 311746
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1246 PM CDT FRI JUL 31 2026
KEY MESSAGES
- WIDESPREAD RAIN MOVES THROUGH THE REGION TODAY, RESULTING IN
RAINFALL TOTALS AROUND 1-3 INCHES, HIGHEST ACROSS SOUTHEAST
MINNESOTA, NORTHEAST IOWA, AND SOUTHWEST WISCONSIN. LOCALLY
HIGHER AMOUNTS OF 3-5 INCHES ARE POSSIBLE ACROSS THESE AREAS.
- RAINFALL MOVES EAST OF THE REGION THROUGHOUT THE DAY SATURDAY,
RESULTING IN DRY CONDITIONS SATURDAY NIGHT THROUGH MONDAY.
- SHOWERS AND STORMS RETURN TO THE REGION LATE MONDAY NIGHT
THROUGH WEDNESDAY (30-50%).
DISCUSSION
ISSUED AT 1251 AM CDT FRI JUL 31 2026
OVERNIGHT INTO TONIGHT
A SURFACE LOW WILL TRACK SOUTHEAST FROM SOUTHWEST MINNESOTA
INTO SOUTHEAST IOWA TODAY AND INTO NORTHERN ILLINOIS TONIGHT.
THE INITIAL BAND OF RAIN WILL BE NORTHWEST TO SOUTHEAST FROM
SOUTHWEST MINNESOTA INTO SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
AS LOW PRESSURE GRADUALLY DEEPENS THIS AFTERNOON AND TONIGHT, A
DEFORMATION BAND WILL DEVELOP OVER SOUTHERN MINNESOTA AND
NORTHERN IOWA. AS THIS OCCURS, THE BAND WILL BECOME MORE
ORIENTATED WEST TO EAST. WHERE THIS OCCURS, THE LONGEVITY OF THE
RAINFALL WILL INCREASE.
PRECIPITABLE WATER VALUES CLIMB INTO THE 1.75 TO 2.4 INCH RANGE
ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA, AND FROM 1.2 TO
1.75 INCHES THIS MORNING. THESE VALUES THEN DECREASE INTO THE
1.5 TO 2 INCH RANGE THIS AFTERNOON AND INTO THE 1 TO 2 INCH
RANGE TONIGHT. THE HIGHEST PRECIPITABLE WATER VALUES FOR THIS
AFTERNOON AND EVENING WILL BE SOUTH OF INTERSTATE 90.
A MESOSCALE CONVECTIVE COMPLEX CURRENTLY OVER WESTERN IOWA WILL
CONTINUE TO MOVE EAST SOUTHEAST OVERNIGHT AND THIS MORNING. AS
IT DOES, IT WILL KEEP MOST OF THE INSTABILITY WELL SOUTH OF THE
FORECAST AREA. THERE MIGHT BE SOME 0-1 KM MIXED-LAYER CAPES UP
TO 250 J/KG ACROSS FAYETTE AND CLAYTON COUNTIES.
THE 31.00Z HREF HAS A MEAN 24-HOUR RAINFALL TOTALS OF 1 TO 3
INCHES ACROSS SOUTHEAST MINNESOTA, NORTHEAST IOWA, AND SOUTHWEST
WISCONSIN. THE 24-HOUR LOCALIZED PROBABILITY-MATCHED MEAN HAS
GENERALLY A 4 TO 10 INCH ALONG THE BUFFALO RIDGE IN MINNESOTA.
THERE IS EVEN A VERY SMALL AREA IN THE 10-15 INCH RANGE. THIS
MAKES SENSE BECAUSE YOU HAVE AN OVERLAP OF THE INSTABILITY AND
HIGH PRECIPITABLE WATER VALUES (2-2.5 INCHES) IN THAT AREA.
FURTHER SOUTHEAST INTO SOUTHEAST MINNESOTA, NORTHEAST IOWA, AND
SOUTHWEST WISCONSIN THERE IS A NARROW POTENTIAL OF 3 TO 5
INCHES. THE QUESTION IS WHERE THIS MIGHT OCCUR. WITH THE GLOBAL
MODELS HAVING A TENDENCY OF BEING TOO FAR NORTH WITH THEIR QPF,
THERE IS CONCERN THAT THE MODELS MIGHT BE TOO FAR NORTH AND THIS
BAND MIGHT BE FURTHER SOUTH CLOSER TO THE BETTER INSTABILITY.
WE HAVE ALREADY SEEN A SLIGHT SOUTH IN THE CAMS THIS EVENING.
EARLIER IN THE EVENING, THEY WERE EITHER ALONG OR NORTH OF
INTERSTATE 90. THEY ARE NOW MORE SOUTH OF INTERSTATE 90. WILL
THERE BE MORE OF SOUTHERN SHIFT AS WE PROGRESS THROUGH THE
OVERNIGHT AND INTO FRIDAY MORNING?
HIGH TEMPERATURES TODAY WILL RANGE FROM THE UPPER 60S TO
MID-70S. LOW TEMPERATURES WILL BE AROUND 60 FOR TONIGHT.
SATURDAY
THE SURFACE LOW WILL SLOWLY MOVE SOUTHEAST ACROSS NORTHERN
ILLINOIS. THERE IS GENERAL CONSENSUS IN THE GLOBAL MODELS AND
THEIR ENSEMBLE MEMBERS FOR A DEFORMATION BAND TO ORIENTATE
ITSELF FROM NORTHEAST TO SOUTHWEST JUST SOUTHEAST OF THE
SOUTHWEST AND CENTRAL WISCONSIN. THEY WILL LIKELY SEE SOME MORE
RAIN, BUT IT WOULD LIKELY BE ON THE LIGHT SIDE (UP TO A TENTH OF
AN INCH). HIGH TEMPERATURES WILL RANGE FROM THE MID-70S
(SOUTHWEST AND CENTRAL WISCONSIN TO AROUND 80 ELSEWHERE.
SATURDAY NIGHT INTO MONDAY
HIGH PRESSURE WILL KEEP THE AREA DRY FROM SATURDAY NIGHT INTO
MONDAY. HIGH TEMPERATURES WILL RANGE FROM AROUND 80 TO THE
MID-80S. LOW TEMPERATURES WILL RANGE FROM THE LOWER 50S TO LOWER
60S.
MONDAY NIGHT INTO WEDNESDAY
A COLD FRONT WILL MOVE INTO THE AREA ON MONDAY NIGHT AND THEN
LINGER ACROSS THE AREA INTO WEDNESDAY. WHILE THE 0-1 KM MIXED-
LAYER CAPES WILL OCCASIONALLY CLIMB UP TO 1000 J/KG AT TIMES,
BOTH THE 0-3 AND 0- 6 KM SHEAR REMAINS WEAK. AS A RESULT NOT
SEEING ANY ORGANIZED SEVERE WEATHER AT THIS TIME. HIGH
TEMPERATURES WILL RANGE FROM THE MID-70S TO MID-80S. LOW
TEMPERATURES WILL RANGE FROM THE MID-50S TO MID-60S.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1246 PM CDT FRI JUL 31 2026
RAIN WILL CONTINUE TO ROTATE ACROSS THE REGION THIS AFTERNOON
AND EVENING AS AN AREA OF LOW PRESSURE PASSES BY JUST TO OUR
SOUTH. RATHER LOW PROBABILITY (15%) FOR A STRIKE OR TWO OF
LIGHTNING IN THE VICINITY OF RST/LSE, SO HAVE KEPT THUNDER
MENTION OUT OF TAFS. SLIGHTLY HIGHER CHANCES FOR A THUNDERSTORM
WILL BE FURTHER SOUTH OF I-90. MVFR VISIBILITY WITH ANY AREAS
OF HEAVIER RAIN. CEILINGS WILL LIKELY RANGE FROM MVFR TO IFR
THROUGH TONIGHT, LOWEST TO THE SOUTH OF INTERSTATE 90, BEFORE
EVENTUALLY RETURNING TO VFR AFTER DAYBREAK SATURDAY.
INCREASING WINDS THIS AFTERNOON OUT OF THE NORTHEAST WITH GUSTS
OF 20-30 KNOTS AS THE LOW PASSES BY, THEN DIMINISHING OUT OF
THE NORTH TONIGHT.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...BOYNE
AVIATION...KURZ
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