857
FXUS63 KARX 051804
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
104 PM CDT SUN JUL 5 2026
KEY MESSAGES
- NEAR TO SLIGHTLY ABOVE NORMAL HIGHS IN THE LOW TO MID 80S NEAR
90 FOR TUESDAY. POTENTIAL FOR BELOW NORMAL TEMPERATURES FOR
LATTER HALF OF THE WEEK INTO THE WEEKEND.
- WIDESPREAD PRECIPITATION CHANCES TUESDAY NIGHT THROUGH
THURSDAY. OVERALL CONFIDENCE FOR SEVERE STORMS IS LOW,
DEPENDENT ON DIURNAL TIMING OF LOCAL FRONTAL PASSAGE
WEDNESDAY.
DISCUSSION
ISSUED AT 1255 PM CDT SUN JUL 5 2026
TODAY:
AGGRAVATED CUMULUS CAN BE SEEN BURBLING ON SATELLITE IMAGERY
EARLY THIS AFTERNOON AS DAYTIME HEATING PERMITS PARCELS TO
REACH THEIR CONVECTIVE TEMPERATURES. A THICK LOW LEVEL CALM WIND
PROFILE LIMITS DURATION OR EXTENT OF PRECIPITATION OR STORMS,
SEEN ON RADAR IMAGERY POPPING UP FOR 1 OR 2 SCANS BEFORE COOLER
RAIN-COOLED AIR OVERCOMES ANY ATTEMPTS AT ADDITIONAL RISING
UPDRAFTS.
THROUGH TUESDAY:
A RELATIVELY STAGNANT UPPER LEVEL PATTERN KEEPS A MOSTLY PERSISTENT
FORECAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY FOR THE
START OF THE WEEK WITH DAYTIME HIGHS IN THE LOW TO MID 80S AND
LOW AFTERNOON PRECIPITATION POTENTIAL PRIMARILY ALONG OUR
WESTERN PERIPHERY. THE RESPONSIBLE MID-UPPER LEVEL LOW SEEN ON
EARLY AFTERNOON SATELLITE WATER VAPOR IMAGERY LOOPS PROGRESSING
FROM IOWA INTO MISSOURI EXPECTED TO SIT OVER THE SOUTHERN GREAT
LAKES CAUSING EAST WIND OVER THE GREAT LAKES. RETURN FLOW
AMPLIFIES FROM THE CENTRAL THROUGH NORTHERN PLAINS, EVENTUALLY
ADVECTING EAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY
TUESDAY NIGHT THROUGH WEDNESDAY.
MIDWEEK PRECIPITATION POTENTIAL:
ACCOMPANYING PRECIPITATION POTENTIAL INCREASES HEAVY RAIN THREAT AS
THE PERSISTENT UPSTREAM RETURN FLOW ALLOWS PWATS TO PUSH 1.5" TO 2"
ACCORDING TO HIGHEST (70-100%) LREF PROBABILITIES. DIURNAL TIMING OF
THE PASSING WAVE WILL DETERMINE LOCAL STORM AND SEVERE CHANCES AS
LREF INTERMEMBER AND INTRAMEMBER VARIATION EXHIBITS LOWEST SB/MU
CAPE UP TO 1000 J/KG WITH OVERNIGHT PASSAGE AND HIGHEST INSTABILITY
OF 2500 J/KG+. WHILE OVERALL CONFIDENCE FOR STORMS AND SEVERE
WEATHER REMAINS LOW, WEDNESDAY SHOWS LOCALLY HIGHEST POTENTIAL FOR
UNSTABLE AIRMASS OVER THE FORECAST AREA WHICH CAUSES MORE
UNCERTAINTY DUE TO SKY COVER LIMITING DIURNAL HEATING INFLUENCE AS
PRECIPITATION POTENTIAL INCREASES INITIALLY TUESDAY NIGHT.
REGARDLESS, LIMITED AVAILABLE SHEAR LIMITS STORM STRENGTH, HINGING
ON FRONTAL PASSAGE PRIMARILY IN THE LOWEST LEVELS DUE TO THE
INHERENT WIND SHIFT.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1214 PM CDT SUN JUL 5 2026
GOOD SIGNAL FOR VALLEY FOG TONIGHT WITH LIGHT WINDS, MOIST
SURFACE CONDITIONS FROM RECENT RAIN, AND CLEARING SKIES. HAVE
THEREFORE ADDED LIFR TO LSE TONIGHT INTO THE TAF. OTHER CONCERN
IS THE POTENTIAL FOR SCATTERED THUNDERSTORMS THIS AFTERNOON.
WHILE THE CHANCE IS LOW, CONGESTED CUMULUS ON SATELLITE
SUGGESTS PROB30 MENTIONS OF TSRA ARE PRUDENT AND HAVE INCLUDED
SCT DECKS WITHIN THE MVFR RANGE (2-3 KFT). OTHERWISE, GENERALLY
LIGHT WINDS ARE EXPECTED OVER THE NEXT 24 HOURS.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...JAR
AVIATION...FERGUSON
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