607
FXUS63 KARX 041941
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
141 PM CST WED MAR 4 2026
KEY MESSAGES
- RAIN CHANCES RETURN THURSDAY (15 TO 30%), MOSTLY IMPACTING
PORTIONS OF NORTHEAST IOWA AND SOUTHWESTERN WISCONSIN, HOWEVER
AMOUNTS REMAIN BELOW 0.1".
- RAIN LIKELY (95%) FOR FRIDAY MORNING AND THUNDERSTORMS FOR
FRIDAY EVENING, WITH POTENTIAL FOR SEVERE THUNDERSTORMS FRIDAY
EVENING. THERE IS A 40 TO 80% CHANCE FOR AT LEAST 1" OF RAIN
TO FALL FRIDAY INTO SATURDAY.
DISCUSSION
ISSUED AT 140 PM CST WED MAR 4 2026
TODAY-THURSDAY: MOSTLY DRY AND MILD
A LOW CURRENTLY SITTING OVER THE SOUTHERN PLAINS WILL MOVE INTO THE
MIDWEST THURSDAY MORNING. THIS INCREASES RAIN CHANCES MAINLY FOR
AREAS OUTSIDE OF OUR CWA. THE BETTER MOISTURE TRANSPORT REMAINS IN
NORTHERN ILLINOIS. THIS SYSTEM HAS ALSO SHIFTED SLIGHTLY SOUTHWARD
SO CURRENT POPS HAVE BEEN LOWERED TO 15 TO 30% FOR PORTIONS OF
NORTHEAST IOWA AND SOUTHWEST WISCONSIN. HREF PROBABILITIES FOR
MEASURABLE PRECIPITATION HAVE ALSO LOWERED AND ARE NOW BETWEEN 30
AND 60% IN PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWESTERN
WISCONSIN. YESTERDAY'S FORECAST HAD A LOW CHANCE OF RAIN
ACCUMULATIONS REACHING 0.1" IN GRANT COUNTY. THIS CHANCE HAS NO
DWINDLED TO ALMOST NOTHING BASED ON THE RECENT HREF PROBABILITIES.
ANOTHER SIGN THAT THE BETTER MOISTURE REMAINS OUT OF OUR FORECAST
AREA. TEMPERATURES FOR TODAY AND THURSDAY REMAIN IN THE UPPER 40S TO
LOW 50S.
FRIDAY: RAIN IN THE MORNING, POTENTIAL FOR SEVERE STORMS IN THE
EVENING/OVERNIGHT
HEADING INTO FRIDAY, A DEEPENING TROUGH AND RESULTANT SURFACE LOW
EJECT OUT OF THE CENTRAL ROCKIES AND INTO THE CENTRAL PLAINS. AHEAD
OF THIS LOW, STRONG MOISTURE ADVECTION PUSHES NORTHWARD INTO THE
UPPER MIDWEST. AS A RESULT, PWATS ARE FORECASTED TO BE IN THE 1 TO
1.25" RANGE WHICH IS IN THE 99 TO 99.5 PERCENTILE BASED ON THE
NAEFS. WIDESPREAD RAIN WITH MORE RAIN IN THE EVENING TO OVERNIGHT,
AS THE SURFACE LOW MOVES THROUGH THE REGION, WILL LEAD TO QUITE A
BIT OF RAIN OVER MUCH OF THE FORECAST AREA. ON THE EFI SIDE OF THE
THINGS, THERE IS A FOOTPRINT FOR 0.6 TO 0.7 ACROSS OUR FORECAST AREA
FOR QPF WHICH INDICATES THE AMOUNT OF RAIN IS ON THE HIGHER SIDE OF
CLIMATOLOGICAL NORMAL. CURRENT NBM PROBABILITIES FOR AT LEAST 1" OF
RAIN FALLING BETWEEN FRIDAY MORNING AND SATURDAY MORNING IS BETWEEN
40 AND 80% FOR LOCATIONS ALONG AND SOUTH OF I-94. CURRENT FORECASTED
AMOUNTS ARE GENERALLY BETWEEN 0.75 AND 1.25" ACROSS THE CWA. GIVEN
THAT THERE ARE AREAS THAT HAVE FROZEN GROUND, AROUND 6 TO 17 INCHES
OF FROST DEPTH, THIS AMOUNT OF RAIN MAY NOT BE ABLE TO ENTER THE
GROUND AND MUCH OF THE FALLING RAIN MAY END UP AS RUNOFF WHICH COULD
RESULT IN CREEK AND RIVER RISES. ONE THING THAT COULD HELP ALLEVIATE
THE AMOUNT OF RUNOFF IS THAT HIGHS ARE WELL ABOVE FREEZING, IN THE
UPPER 40S TO LOW 50S FOR TODAY AND THURSDAY AND UPPER 50S TO LOW 60S
FOR FRIDAY, WHICH WILL HELP WARM UP THE GROUND AND ALLOW FOR MORE
RAIN TO ENTER THE GROUND RATHER THAN END UP AS RUNOFF.
IN ADDITION TO THE RAIN, THERE IS A POTENTIAL FOR SEVERE
THUNDERSTORMS TO OCCUR FRIDAY EVENING AND INTO THE EARLY OVERNIGHT.
AS THE LOW SHIFTS INTO THE REGION, STRONG SOUTHWESTERLY FLOW ALOFT,
35 TO 50KTS AT 850MB, WILL BE IN PLACE AHEAD OF THIS LOW. COMBINING
THIS WITH THE SOUTH WINDS AT THE SURFACE, THERE WILL BE DECENT LOW
LEVEL SHEAR, HOWEVER THE INSTABILITY IS WHAT MAY BE LACKING FOR MORE
WIDESPREAD SEVERE WEATHER CHANCES. A COUPLE OF FACTORS WILL IMPACT
HOW UNSTABLE THE ATMOSPHERE CAN GET. THE FIRST IS HOW MUCH CAN WE
RECOVER GIVEN THE MORNING RAIN AND STORMS. WILL THIS BE ENOUGH TO
INHIBIT OUR TEMPERATURES FROM WARMING INTO THE UPPER 50S TO LOW 60S?
ANOTHER THING TO NOTE IS HOW FAR NORTH THE WARM AIR CAN GET. THERE
REMAINS QUITE A BIT OF UNCERTAINTY AMONGST MODELS ON HOW FAR NORTH
THE WARMER AIR CAN GET. THE GFS AND RAP ARE THE FURTHER NORTH
OUTLIERS WHILE THE NAM IS THE FURTHEST SOUTH SOLUTION. DEPENDING ON
WHICH SOLUTION PLAYS WILL DETERMINE THE EXTENT OF THE SEVERE WEATHER
POTENTIAL. ONE THING THAT IS FOR CERTAIN IS THAT THERE IS CURRENTLY
A FEW HUNDRED JOULES OF MUCAPE AVAILABLE TO GIVE US THUNDERSTORMS.
BASED ON THE AMOUNT OF SHEAR AND THE EXTENT OF THE WARM SECTOR,
THERE IS A SLIGHT RISK (LEVEL 2 OUT OF 5) FOR PORTIONS OF NORTHEAST
IOWA AND FAR SOUTHWESTERN WISCONSIN WITH A MARGINAL (LEVEL 1 OUT OF
5) FOR MAJORITY OF THE REST OF THE CWA. CSU ML PROBABILITIES ALSO
SHOW SOME SEVERE THREAT OVER THE ENTIRE CWA. WE WILL CONTINUE TO
MONITOR THIS AND HOPEFULLY MODELS HONE IN ON A SOLUTION OVER THE
NEXT DAY OR SO.
SATURDAY-MONDAY: COOLER SATURDAY, PLEASANT END OF WEEKEND AND EARLY
NEXT WEEK
A DRY WEEKEND IS EXPECTED AS WE ARE IN ZONAL TO SLIGHTLY SOUTHWEST
FLOW ALOFT. AFTER A COLD FRONT MOVES THROUGH EARLY SATURDAY MORNING,
HIGHS REMAIN IN THE 40S, BUT NORTHWEST WINDS AT 10 TO 15 MPH WILL
KEEP FEELS LIKE TEMPERATURES IN THE MID TO UPPER 30S. WARM,
SOUTHWEST FLOW RETURNS FOR SUNDAY AND MONDAY WHICH WILL HELP TO
INCREASE TEMPERATURES INTO THE UPPER 50S TO LOW 60S FOR SUNDAY AND
THE MID TO UPPER 60S FOR MONDAY.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1155 AM CST WED MAR 4 2026
LITTLE TO NO IMPACTS TO AVIATION ARE EXPECTED THROUGH THE
AFTERNOON AND EVENING. OVERNIGHT, THERE IS AN INCREASING SIGNAL
FOR ANOTHER ROUND OF DENSE FOG DEVELOPING WEST OF THE
MISSISSIPPI RIVER AFTER 06Z AS LOW LEVEL SATURATION INCREASES.
SOME UNCERTAINTY WHETHER OR NOT THIS IS REALIZED AS AN IFR/LIFR
STRATUS DECK INSTEAD EXISTS, BUT HAVE INTRODUCED VISIBILITY
REDUCTIONS TO THE KRST TAF TO ACCOUNT FOR THE POTENTIAL (30-60%
PER THE 04.12Z HREF/REFS). VISIBILITY RESTRICTIONS SHOULD
DISSIPATE AFTER 15Z, BUT LINGERING MVFR CEILINGS ARE EXPECTED
INTO THURSDAY AFTERNOON.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...CECAVA
AVIATION...FALKINHAM
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