585
FXUS63 KARX 261103
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
603 AM CDT SAT SEP 26 2026
KEY MESSAGES
- LIGHT RAIN CHANCES INCREASE FOR EARLY THIS MORNING AND THEN
CONTINUE INTO THE AFTERNOON WITH THE HIGHEST CHANCES (40-100%)
FOR AREAS WEST OF THE MISSISSIPPI RIVER. SMALL RAIN CHANCES
(UP TO 20%) THEN CONTINUE FOR THE AREA INTO SUNDAY MORNING.
- AFTER A DRY SUNDAY NIGHT INTO MONDAY NIGHT, RAIN CHANCES
RETURN ON TUESDAY AND CONTINUE INTO WEDNESDAY.
- NEAR-NORMAL TEMPERATURES PERSIST INTO NEXT WEEK WITH HIGHS IN
THE 60S TO LOWER 70S.
DISCUSSION
ISSUED AT 1235 AM CDT SAT SEP 26 2026
TODAY
A SHORTWAVE TROUGH WILL EJECT NORTHEAST THROUGH THE UPPER
MISSISSIPPI RIVER VALLEY. THE STRONGEST FORCING AND MOISTURE
WILL BE LOCATED WEST OF THE MISSISSIPPI RIVER. WHILE THE CAMS
ARE SHOWING THAT THE SHOWERS WILL DECREASE THEIR COVERAGE AS
THEY MOVE EAST TOWARD THE MISSISSIPPI RIVER, THE SYNOPTIC
FORCING AND 850 MB MOISTURE TRANSPORT LOOK TO BE STRONG ENOUGH
TO PRODUCE AT LEAST SOME LIGHT RAINFALL TOTALS THROUGH THE
MORNING AND INTO THE MID-AFTERNOON. DUE TO THIS, INCREASED THE
RAIN CHANCES INTO THE 60-100% RANGE DURING THIS TIME FRAME.
HIGH TEMPERATURES WILL BE IN THE 60S. DUE TO THE RAIN AND CLOUD
COVER, THE COOLEST HIGH TEMPERATURES (LOWER 60S) WILL BE WEST
OF THE MISSISSIPPI RIVER. MEANWHILE, WESTERN AND CENTRAL
WISCONSIN WILL SEE HIGH TEMPERATURES IN THE MID- AND UPPER 60S.
TONIGHT AND SUNDAY
AS THE SHORTWAVE TROUGH CONTINUE TO MOVE NORTHEAST INTO A RIDGE
OF HIGH PRESSURE OVER THE GREAT LAKES, THERE WILL BE
FRONTOLYSIS ALONG THE SURFACE FRONT AND DRY SOUTHEAST WINDS WILL
ADVECT DRIER AIR INTO THE REGION FOR TONIGHT AND SUNDAY
MORNING. THIS SHOULD REDUCE THE SHOWER COVERAGE TO ISOLATED.
LOW TEMPERATURES TONIGHT WILL RANGE FROM THE MID-40S TO
MID-50S. HIGH TEMPERATURES ON SUNDAY WILL BE IN THE MID-60S.
SUNDAY NIGHT AND MONDAY NIGHT
HIGH PRESSURE OVER THE GREAT LAKES WILL KEEP THE AREA DRY FROM
SUNDAY NIGHT INTO MONDAY NIGHT.
LOW TEMPERATURES ON SUNDAY NIGHT AND MONDAY NIGHT WILL RANGE
FROM THE MID-40S TO MID-50S. THE COOLEST TEMPERATURES WILL BE IN
CENTRAL AND NORTH-CENTRAL WISCONSIN. HIGH TEMPERATURES ON
MONDAY WILL BE AROUND 70 DEGREES.
TUESDAY INTO WEDNESDAY
A NORTHERN STREAM SHORTWAVE TROUGH WILL MOVE THROUGH THE
REGION. THIS SYSTEM LOOKS TO BE RATHER PROGRESSIVE, SO THIS MAY
RESULT IN LESSER RAINFALL THAN PREVIOUSLY FORECAST. THERE IS A
50-80% PROBABILITY OF A HALF-INCH OR GREATER AND A 30-65%
PROBABILITY OF 1 INCH OR GREATER IN THE NBM.
HIGH TEMPERATURES ON TUESDAY AND WEDNESDAY WILL RANGE FROM
MID-60S TO AROUND 70. LOW TEMPERATURES ON TUESDAY NIGHT WILL BE
IN THE 50S.
THURSDAY INTO FRIDAY
STILL PLENTY OF UNCERTAINTY ON HOW FAR NORTH THE REMNANTS OF
POLO WILL GET. A FEW ENSEMBLE MEMBERS SUGGEST THAT THERE MIGHT
BE A PRE (PREDECESSOR RAINFALL EVENT) SOUTH OF INTERSTATE 90. A
THIRD OF MEMBERS SUGGEST THAT A WEAKENING SURFACE LOW AND ITS
ASSOCIATED WARM FRONT MAY MOVE INTO THE REGION. MEANWHILE, THE
OTHER MEMBERS KEEP THE AREA DRY. THE NBM CURRENTLY HAS THE
PROBABILITIES OF AN INCH OF RAIN OR GREATER UP TO 40%.
HIGH TEMPERATURES ON THURSDAY AND FRIDAY WILL BE IN THE
MID-60S. LOW TEMPERATURES ON THURSDAY NIGHT WILL RANGE FROM THE
MID-40S TO LOWER 50S.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 602 AM CDT SAT SEP 26 2026
SHOWERS HAVE BEGUN TO MOVE INTO NORTHEAST IOWA AND SOUTHEAST
MINNESOTA THIS MORNING. UPSTREAM OBSERVATIONS SUGGEST
VISIBILITIES ASSOCIATED WITH THESE SHOWERS ARE LARGELY VFR
THOUGH SOME SITES HAVE BEEN REPORTING REDUCTIONS OF 3-5SM ALONG
WITH MVFR TO IFR CEILINGS. WOULD EXPECT THIS TREND TO CONTINUE
AS THE SHOWERS CONTINUE EASTWARD, SO CAN'T RULE OUT SOME MVFR TO
POSSIBLY IFR RESTRICTIONS WEST OF THE MISSISSIPPI RIVER, MAINLY
WEST OF A KRST TO KCCY LINE THIS MORNING. DRIER AIR ACROSS
WISCONSIN SHOULD LARGELY HINDER SHOWERS, AND BY ASSOCIATION
MVFR/IFR RESTRICTIONS, EAST OF THE MISSISSIPPI RIVER WITH VFR
CONDITIONS EXPECTED TO PREVAIL THROUGH THE TAF PERIOD.
THAT SAID, RECENT HIGH-RESOLUTION GUIDANCE HAS BEGUN TO SUGGEST
SHOWERS COULD REDEVELOP OVERNIGHT MEANING THOSE EAST OF THE
MISSISSIPPI RIVER COULD HAVE A BETTER SHOT AT SEEING SOME LIGHT
RAIN THAN THEY DO DURING THE DAY. ALSO CAN'T RULE OUT A RUMBLE
OF THUNDER OVERNIGHT WEST OF THE MISSISSIPPI RIVER IF
REDEVELOPMENT DOES OCCUR, BUT THE POTENTIAL FOR LIGHTNING IS
VERY LOW (< 10%). OTHERWISE, SOUTHEAST WINDS OF 5-10KT CONTINUE
ACROSS THE REGION WITH GUSTS OF 15-20KT POSSIBLE THIS AFTERNOON,
STRONGEST WEST OF THE MISSISSIPPI RIVER.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...BOYNE
AVIATION...FALKINHAM
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