694
FXUS63 KARX 291056
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
556 AM CDT SAT AUG 29 2026
KEY MESSAGES
- SHOWERS AND SCATTERED STORMS THROUGH EARLY THIS AFTERNOON.
THE COOLEST TEMPERATURES FOR THE UPCOMING 7-DAYS WILL BE TODAY
WITH HIGH TEMPERATURES RANGING FROM THE UPPER 60S TO AROUND
80.
- SEVERE WEATHER THREAT LOOKS LOWER FOR SUNDAY AFTERNOON AND
NIGHT.
- ABOVE-NORMAL TEMPERATURES EXPECTED NEXT WEEK. THERE MAY BE
EVEN SOME RECORD WARM LOWS IN IOWA AND ILLINOIS EARLY NEXT
WEEK AND DURING THE LATE WEEK.
DISCUSSION
ISSUED AT 106 AM CDT SAT AUG 29 2026
THIS MORNING AND EARLY AFTERNOON
A SHORTWAVE TROUGH OVER SOUTHWEST MINNESOTA WILL MOVE EAST
OVERNIGHT AND THIS MORNING. AS THIS SYSTEM APPROACHES, THE 850
MB MOISTURE TRANSPORT WILL GRADUALLY INCREASE ON THE NOSE OF A
30-40 KNOT NOCTURNAL JET. SHOWERS AND MAYBE A FEW STORMS WILL
MOVE INTO NORTHEAST IOWA AND SOUTHEAST MINNESOTA AFTER 3 AM, AND
WESTERN WISCONSIN AROUND 6 AM. THESE SHOWERS AND STORMS WILL
MOVE OUT OF NORTHEAST IOWA AND SOUTHEAST MINNESOTA AROUND NOON
AND WESTERN WISCONSIN BY 3 PM.
THE 29.00Z HREF HAS A MEAN 24-HOUR RAINFALL OF A 0.25 TO 0.50
INCHES FROM NORTHEAST IOWA NORTHEAST INTO CENTRAL AND NORTH-
CENTRAL WISCONSIN, AND UP TO A QUARTER-INCH IN SOUTHWEST
WISCONSIN. THE ENSEMBLE LOCALIZED PROBABILITY-MATCHED MEAN
SUGGESTS THAT THERE COULD BE SOME LOCALIZED RAIN TOTALS OF A
HALF TO 1-INCH.
IN THE WAKE OF THIS SYSTEM, SOME OF THE CAMS ARE CONTINUING TO
SHOW THAT SUBSIDENCE IN THE WAKE OF THIS SYSTEM MIGHT BRING
STRONGER WINDS (UP TO 45 MPH) BETWEEN 925 AND 850 MB TO THE
SURFACE MAINLY WEST OF THE MISSISSIPPI RIVER. THE EVENING SHIFT
USED THE RAP TO RAISE THE ISSUED AT 106 AM CDT SAT AUG 29 2026WIND
GUSTS INTO THE 30 TO 40 MPH RANGE.
THERE IS A TRAILING SHORTWAVE TROUGH OVER CENTRAL SOUTH DAKOTA.
THERE IS AMPLE INSTABILITY AHEAD OF THIS WAVE AT THE APEX OF A
STRONG RIDGE. THIS HAS RESULTED IN SOME STRONG TO SEVERE STORMS.
THE CAMS ARE IN GENERAL AGREEMENT THAT THIS SHORTWAVE WILL MOVE
SOUTHEAST OF THE AREA LATE THIS MORNING AND AFTERNOON. THOUGHTS
ARE THAT THESE STORMS WILL GRADUALLY BECOME MORE ELEVATED AS THE
NIGHT PERSISTS AND THIS WOULD LIKELY CONTINUE THROUGH MUCH OF
THIS MORNING.
RAIN-COOLED AIR WILL SLOW THE WARMING THIS AFTERNOON. HIGH
TEMPERATURES WILL RANGE FROM THE UPPER 60S IN NORTH-CENTRAL
WISCONSIN TO AROUND 80 WEST OF THE MISSISSIPPI RIVER.
TONIGHT AND SUNDAY MORNING
THE 500 MB LONGWAVE RIDGE AXIS WILL MOVE EAST INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THE NOSE 30-40 KNOT 850 MB JET WILL
DEVELOP DURING THE EVENING AHEAD OF ANOTHER SHORTWAVE TROUGH
MOVING EAST ON THE NORTH SIDE OF THE 500 MB RIDGE. IT CONTINUES
TO LOOK LIKE THE BETTER CHANCES OF SHOWERS AND STORMS WILL BE
ALONG AND NORTH OF INTERSTATE 90. AS THE THE NOCTURNAL JET
GRADUALLY VEERS OVERNIGHT, THE SHOWERS AND STORMS WILL MOVE OUT
OF THE AREA ON SUNDAY MORNING.
WHILE THE 0-6 KM SHEAR IS GREATER THAN 40 KNOTS NORTH OF
INTERSTATE 94 TONIGHT, THE MOST-UNSTABLE CAPES ARE LESS THAN 500
J/KG, SO THE CHANCES OF ORGANIZED SEVERE WEATHER LOOKS LOW.
LOW TEMPERATURES TONIGHT WILL BE AROUND 60 NORTH OF INTERSTATE
94 AND IN THE 60S ACROSS THE REMAINDER OF THE AREA.
SUNDAY AFTERNOON AND NIGHT
ON SUNDAY AFTERNOON AND NIGHT, THE RIDGE AXIS WILL BUILD NORTH
ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. A FRONTAL BOUNDARY
WILL BE INITIALLY NEAR INTERSTATE 90 IN THE MORNING AND THEN
MOVE GRADUALLY NORTH DURING THE DAY. AS THIS OCCURS, THE STRONG
WESTERLIES WILL SHIFT NORTHWARD INTO NORTHERN MINNESOTA AND
NORTHERN WISCONSIN. THIS SHOULD RESULT IN LESSER 0-3 KM AND 0-6
KM SHEAR ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THUS,
THINKING THE MARGINAL RISK OF SEVERE WEATHER SHOULD BE SHIFTED
FURTHER NORTH.
HIGH TEMPERATURES ON SUNDAY WILL RANGE FROM THE UPPER 70S TO
MID-80S. LOW TEMPERATURES ON SUNDAY NIGHT WILL RANGE FROM THE
MID-60S TO LOWER 70S.
MONDAY THROUGH FRIDAY
A NORTHERN STREAM SHORTWAVE TROUGH WILL GRADUALLY FLATTEN THE
RIDGE ON MONDAY NIGHT AND TUESDAY. THIS WILL LEAVE THE UPPER
MISSISSIPPI RIVER VALLEY ON THE NORTHERN PERIPHERY OF THIS RIDGE
THROUGH MID-WEEK AND THEN THERE ARE SOME INDICATIONS THAT THIS
RIDGE MAY BUILD NORTHWARD ACROSS THE REGION FOR LATE IN THE
WEEK. PERIODIC SHOWERS AND STORMS LOOK POSSIBLE DURING THE MID-
WEEK.
TEMPERATURES WILL BE LIKELY ABOVE NORMAL THROUGH THIS TIME
PERIOD. HIGH TEMPERATURES WILL BE MAINLY IN THE 80S. THERE MAY
BE EVEN A FEW LOWER 90S. LOW TEMPERATURES WILL BE IN THE 60S AND
LOWER 70S. THERE WILL BE A POSSIBILITY OF NEAR RECORD WARM LOWS
ACROSS IOWA AND ILLINOIS EARLY IN THE WEEK AND AGAIN DURING THE
LATE WEEK.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 555 AM CDT SAT AUG 29 2026
A SHORTWAVE TROUGH WILL BRING SHOWERS AND SCATTERED STORMS TO
THE AREA THROUGH MID-AFTERNOON. THE RAIN WILL AFFECT KRST
THROUGH 29.18Z AND KLSE THROUGH 29.20Z. THIS RAIN MAY RESULT IN
MVFR CEILINGS AND VISIBILITIES AT TIMES. IN ADDITION, THERE
COULD BE PREVAILING MVFR CEILINGS NORTH OF INTERSTATE 94 THIS
AFTERNOON. ADDITIONAL SHOWERS AND STORMS WILL BE POSSIBLE NORTH
OF INTERSTATE 94 TONIGHT.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...BOYNE
AVIATION...BOYNE
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