912
FXUS63 KARX 202329
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
629 PM CDT WED MAY 20 2026
KEY MESSAGES
- FROST POTENTIAL CONTINUES TO LOOK LOW FOR TONIGHT.
- PERIODIC SHOWERS AND STORMS FROM THURSDAY NIGHT INTO SUNDAY
MORNING. CURRENTLY NOT EXPECTING ANY ORGANIZED SEVERE WEATHER.
- CONTINUING TO LOOK LIKELY THAT ABOVE- TO WELL-ABOVE NORMAL
TEMPERATURES WILL DEVELOP ACROSS THE REGION FROM MEMORIAL DAY
INTO WEDNESDAY.
DISCUSSION
ISSUED AT 1241 PM CDT WED MAY 20 2026
TONIGHT
A NORTHERN STREAM SHORTWAVE, CURRENTLY OVER NEBRASKA AND SOUTH
DAKOTA, WILL EAST NORTHEAST THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY TONIGHT. BUFKIT SOUNDINGS SHOW THAT A BROKEN TO OVERCAST MID-
AND HIGH DECK OF CLOUDS WILL MOVE INTO THE AREA TONIGHT. MUCH OF
THIS MOISTURE IS LOCATED ABOVE 600 MB AND THERE IS VERY DRY AIR IN
THE SUB-CLOUD LAYER. AS A RESULT, NOT ANTICIPATING ANY PRECIPITATION
FROM THIS WAVE. DURING THE EVENING, THERE IS A DEEP-LAYER OF LIGHT
WINDS. AS THE WAVE MOVES THROUGH THE AREA DURING THE OVERNIGHT, THE
NOCTURNAL, LOW-LEVEL JET INCREASES. THIS WILL RESULT IN THE BOUNDARY
LAYER STAYING WELL MIXED. THIS WILL HELP TO KEEP OUR TEMPERATURES
TONIGHT FROM BOTTOMING OUT OVERNIGHT. LOW TEMPERATURES ALONG AND
NORTH OF INTERSTATE 94 WILL BE IN THE MID- AND UPPER 30S, AND IN THE
LOWER AND MID-40S ELSEWHERE. FINALLY, THERE WILL BE LARGE
TEMPERATURE AND DEW POINT SEPARATION. THIS WILL RESULT IN LITTLE
FROST DEVELOPMENT. DUE TO THIS, WE DID NOT ISSUE A FROST ADVISORY
FOR TONIGHT.
FRIDAY NIGHT THROUGH SUNDAY MORNING
THERE WILL BE 2 NORTHERN STREAM SHORTWAVE TROUGHS WILL MOVING
THROUGH THE UPPER MISSISSIPPI RIVER VALLEY DURING THIS TIME FRAME.
THE FIRST WILL MOVE THROUGH THE REGION ON FRIDAY AND FRIDAY NIGHT
AND THE SECOND ONE WILL MOVE THROUGH THE REGION ON SATURDAY
NIGHT. THESE SYSTEMS WILL BRING PERIODIC SHOWERS AND STORMS. THE
INSTABILITY AHEAD OF BOTH WAVES ARE NOT THAT STRONG. IT IS UP
TO 250 J/KG FOR THE FIRST WAVE AND UP TO 750 J/KG WITH THE
SECOND WAVE. IN ADDITION, THE 0-3 AND 0-6 KM SHEAR IS ONLY UP TO
20 KNOTS. AS A RESULT, NOT EXPECTING ORGANIZED SEVERE WEATHER.
MEMORIAL DAY THROUGH WEDNESDAY
A 500 MB RIDGE WILL BUILD ACROSS THE AREA. THESE BUILDING HEIGHTS
WILL RESULT IN ABOVE- TO WELL-ABOVE NORMAL TEMPERATURES DEVELOPING
ACROSS THE REGION. THIS WILL POTENTIALLY RESULT IN TEMPERATURES
EXCEEDING THE 85TH PERCENTILE (MID- AND UPPER 80S). ONE CONCERN IS
WHETHER THE TROUGH SOUTH AND SOUTHWEST OF THIS UPPER LEVEL RIDGE
WILL MOVE NORTHWARD INTO THE AREA. IF THIS WAS TO OCCUR,
TEMPERATURES WOULD BE MORE IN THE 60S AND 70S AND THERE WOULD BE A
THREAT FOR SHOWERS AND STORMS.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 629 PM CDT WED MAY 20 2026
NO IMPACTS TO AVIATION ARE EXPECTED TONIGHT THROUGH THE TAF
PERIOD. MID CLOUDS AROUND 10KFT CONTINUE STREAMING INTO THE
REGION FROM THE SOUTHWEST THIS EVENING, LEADING TO VFR CEILINGS
THROUGH THURSDAY. WINDS BECOME SOMEWHAT VARIABLE THIS EVENING
AS THEY VEER TO THE EAST TO SOUTHEAST, BUT BECOME PREDOMINANTLY
FROM THE EAST TO SOUTHEAST BETWEEN 06Z-09Z. WIND SPEEDS INCREASE
THURSDAY MORNING, RESULTING IN GUSTS AROUND 15-20KT THROUGH THE
DAY.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...BOYNE
AVIATION...FALKINHAM
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