802
FXUS63 KARX 292320
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
520 PM CST MON DEC 29 2025
KEY MESSAGES
- COLD TEMPERATURES THIS EVENING AND INTO TONIGHT WITH WIND
CHILLS RANGING FROM 10 TO 25 DEGREES BELOW ZERO.
- TWO CLIPPER SYSTEMS BRING SNOW CHANCES TO THE REGION ON
TUESDAY AND WEDNESDAY. MINOR ACCUMULATIONS OF AROUND A TRACE
TO A 1/2" ARE CURRENTLY EXPECTED WITH EACH SYSTEM.
- ADDITIONAL COLD AIR MOVES IN WEDNESDAY NIGHT AND THROUGH
FRIDAY WITH NEW YEARS DAY BEING VERY COLD WITH HIGHS IN SINGLE
DIGITS TO TEENS.
DISCUSSION
ISSUED AT 145 PM CST MON DEC 29 2025
REST OF TODAY - WEDNESDAY: COLD TONIGHT, SLIGHT WARM-UP
TUESDAY AND WEDNESDAY WITH PERIODIC SNOW CHANCES
WE CAN FIRMLY SAY GOODBYE TO OUR WINTER TROUBLEMAKER THIS AFTERNOON
AS THE SURFACE LOW ASSOCIATED WITH THIS SYSTEM GENERALLY PUSHES EAST
OF THE GREAT LAKES REGION TODAY. AS A RESULT, THE SURFACE PRESSURE
GRADIENT THAT HAS BEEN RESPONSIBLE FOR OUR BREEZY WINDS AND BLOWING
SNOW WILL CONTINUE TO WEAKEN AND THUS WE WILL CONTINUE TO SEE WIND
GUSTS DIMINISHING THROUGHOUT THE AFTERNOON AND EVENING. AS WE HEAD
INTO THE OVERNIGHT, NORTHWESTERLY FLOW WITH SURFACE HIGH PRESSURE
DEVELOPS INTO THE REGION WHICH IN TURN WILL ALLOW FOR MORE EFFICIENT
COOLING WITH SOME CLEARING IN SKY COVER AND RELATIVELY LIGHTER
WINDS. AS A RESULT, EXPECTING WIND CHILLS TO REMAIN IN THE 10 TO 25
DEGREES BELOW ZERO RANGE THIS EVENING AND INTO THE OVERNIGHT.
AS WE HEAD INTO TUESDAY, OUR ATTENTION THEN TURNS TO A WEAK CLIPPER
SYSTEM THAT PINWHEELS ITS WAY DOWN INTO THE REGION ASSOCIATED WITH A
WEAK PIECE OF WARM AIR ADVECTION. AS A RESULT, THE 29.12Z HREF HAS
HIGH PROBABILITIES (60-90% CHANCE) FOR MEASURABLE SNOWFALL ALONG AND
EAST OF THE MISSISSIPPI RIVER ON TUESDAY AFTERNOON AND EVENING AND
GRADUALLY DIMINISHING PROBABILITIES WEST OF THE MISSISSIPPI RIVER.
HOWEVER, GIVEN THE FAIRLY WEAK FORCING REGIME, NOT NOTING TOO MUCH
FOR MORE SUBSTANTIAL ACCUMULATIONS AS THE 29.12Z HREF HAS LOW
PROBABILITIES (20-30%) FOR AMOUNTS OF 0.5" OR GREATER. ONE THING
THAT WILL NEEDED TO BE WATCHED THOUGH GIVEN THE WEAKER FORCING
REGIME WILL BE IF LOSS OF SATURATION IN THE DENDRITIC GROWTH ZONE
WOULD OCCUR. WHEN LOOKING AT THE 29.12Z RAP/NAM SOUNDINGS AT KLSE
BOTH INDICATE SOME DEGREE OF SATURATION LOSS AT -10C SO CANNOT RULE
OUT A BRIEF PERIOD OF FREEZING DRIZZLE AS THIS SYSTEM EXITS LATER ON
TUESDAY AFTERNOON/EVENING. THE WARM ADVECTION ON TUESDAY WILL
ALLOW TEMPERATURES TO REMAIN IN THE MIDDLE TO UPPER 20S
THROUGHOUT MUCH OF THE DAY AND INTO THE OVERNIGHT AS LITTLE
MODIFICATION TO THIS AIRMASS WILL BE PRESENT.
BY WEDNESDAY MORNING, COLD AIR ADVECTION ASSOCIATED WITH A PASSING
UPPER-LEVEL SHORTWAVE TROUGH TO THE EAST WILL PUSH INTO THE AREA
RESULTING IN TEMPERATURES TRENDING COLDER DURING THE DAY ON
WEDNESDAY. ADDITIONALLY, THIS PROVIDED FORCING AND VERY WEAK
FRONTOGENETIC SIGNAL IN THE 29.12Z NAM WILL BE THE INSTIGATING
MECHANISM FOR SOME LIGHT SNOW CHANCES TO MEANDER THEIR WAY THROUGH
THE LOCAL AREA. OVERALL, THE GRAND ENSEMBLE (GEFS/EC/CANADIAN
ENSEMBLE) HAS MEDIUM PROBABILITIES (30-60%) FOR MEASURABLE SNOW
AND VERY LOW PROBABILITIES (10-20%) FOR 0.5" OR GREATER AT THIS
TIME SO REALLY NOT EXPECTING MUCH FOR ANY ACCUMULATIONS OR
IMPACTS AT THIS POINT.
NEW YEARS DAY - FRIDAY: TRENDING COLDER
TEMPERATURES TAKE A TUMBLE TO WELCOME IN 2026 AS THE AFOREMENTIONED
COLD AIR ADVECTION AND EVER PRESENT NORTHWESTERLY SYNOPTIC FLOW KEEP
A STEADY INFLUX OF COLD AIR INTO THE REGION LATE THIS WEEK. AS A
RESULT, HIGHS ON THURSDAY WITHIN THE INTER-QUARTILE RANGE OF THE NBM
RANGE ANYWHERE FROM THE SINGLE DIGITS TO UPPER TEENS. ADDITIONALLY
WITH OVERNIGHT TEMPERATURES FALLING INTO THE SINGLE DIGITS ABOVE AND
BELOW ZERO NEW YEARS EVE (WEDNESDAY) NIGHT AND INTO NEW YEARS
(THURSDAY) MORNING, MINIMUM WIND CHILLS WILL LIKELY RANGE FROM 10 TO
25 DEGREES BELOW ZERO. AS A RESULT, IF YOU HAVE ANY PLANS TO HEAD
OUTDOORS FOR NEW YEARS EVE AND NEW YEARS, BE SURE TO DRESS
ACCORDINGLY.
AS FAR AS PRECIPITATION CHANCES ARE CONCERNED, LITTLE SIGNAL
REALLY STANDS OUT AFTER WEDNESDAY AS ENSEMBLE GUIDANCE DOES NOT
DEPICT ANY HIGHER MEASURABLE PRECIPITATION CHANCES THROUGH THIS
WEEKEND. THAT BEING SAID, GIVEN THE NORTHWESTERLY CYCLONIC FLOW
WITH A UPPER-LEVEL TROUGHING REGIME SITUATED TO OUR EAST, WOULD
NOT RULE OUT THE POTENTIAL FOR SOME SNOW SHOWERS ON DAYS WHERE
LOW-LEVEL LAPSE RATES ARE ABLE TO STEEPEN. EITHER WAY, HAVE HELD
WITH A DRY FORECAST FOR NOW AS ANY SNOW SHOWER POTENTIAL
REMAINS VERY UNCERTAIN AT THIS POINT AND LIKELY LOW IMPACT.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 518 PM CST MON DEC 29 2025
LARGELY MVFR TO VFR CONDITIONS CURRENTLY PRESENT ACROSS THE UPPER
MISSISSIPPI VALLEY WITH A FEW LOCATIONS ACROSS SE MINNESOTA STILL
REPORTING IFR CONDITIONS FROM BLOWING SNOW. AS WINDS BEGIN TO TAPER
OFF THIS EVENING AND OVERNIGHT TONIGHT, CONDITIONS WEST OF THE RIVER
SHOULD IMPROVE TO VFR. THE MVFR STRATUS CURRENTLY OVER WEST
CENTRAL/SOUTHWEST WISCONSIN WILL GRADUALLY SHIFT TO THE EAST WITH
ALL SITES RETURNING TO VFR OVERNIGHT.
ANOTHER QUICK WINTER SYSTEM IS EXPECTED TO MOVE IN FROM THE
NORTHWEST DURING THE DAY TOMORROW AND SHOULD BRING SOME IMPACTS
FOR THE TERMINALS. A BATCH OF MVFR STRATUS IS EXPECTED TO
OVERSPREAD THE REGION, IMPACTING BOTH KLSE AND KRST BY 15-18Z.
KLSE WILL SEE THE BETTER CHANCES FOR SNOW AND VISIBILITY IMPACTS
WITH PROBABILITIES DECREASING TO THE SOUTH AND WEST. AS SUCH,
HAVE ADDED PROB30S FOR SNOW AT KRST AS CONFIDENCE IN IMPACTS
DOES NOT CURRENTLY WARRANT A PREVAILING GROUP. SNOW WILL TAPER
OFF THROUGH THE AFTERNOON BUT THE MVFR CIGS WILL LINGER THROUGH
THE END OF THE PERIOD.
GUSTS OUT OF THE NORTHWEST HAVE ALREADY STARTED TO TAPER OFF EARLY
THIS EVENING WITH MOST SITES SEEING WINDS NEAR OR BELOW 15 KTS.
THESE WINDS WILL CONTINUE TO GRADUALLY DECREASE THROUGH THE
EVENING/OVERNIGHT HOURS, BECOMING MORE SOUTHWESTERLY BY
DAYBREAK. AS THE AFOREMENTIONED WINTER SYSTEM MOVES THROUGH THE
REGION, WINDS WILL SHIFT BACK TO THE NORTHWEST WITH SOME
AFTERNOON GUSTS BETWEEN 20-25 KTS POSSIBLE AT KRST.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...NAYLOR
AVIATION...BARENDSE
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