277
FXUS63 KARX 210345
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
945 PM CST SAT DEC 20 2025
KEY MESSAGES
- BREEZY TODAY WITH WIND GUSTS MOSTLY BETWEEN 25 AND 35 MPH
INTO THE EVENING.
- PRECIPITATION CHANCES INCREASE SUNDAY NIGHT INTO MONDAY
MORNING WITH POTENTIAL FOR MIXED PRECIPITATION, MAINLY ALONG
AND NORTH OF I- 90.
- ABOVE NORMAL TEMPERATURES FOR MUCH OF NEXT WEEK WITH HIGHS
GENERALLY IN THE 30S AND 40S THROUGH MIDWEEK AND POTENTIALLY
SOME 50S ON CHRISTMAS DAY FOR PORTIONS OF NORTHEAST IOWA AND
SOUTHWEST WISCONSIN.
DISCUSSION
ISSUED AT 119 PM CST SAT DEC 20 2025
TODAY-MONDAY: DRY WEEKEND, MIXED PRECIPITATION FOR MONDAY?
AS A COLD FRONT CONTINUES TO MOVE SOUTHEAST ACROSS THE REGION TODAY,
A SURFACE HIGH SITS OVER THE UPPER MIDWEST THROUGH THE WEEKEND.
THERE IS A LITTLE LAG IN THE COLDER AIR ARRIVING, AS IT MOVES INTO
THE FORECAST AREA THIS EVENING AND LINGER THROUGH THE OVERNIGHT.
HIGH TEMPERATURES FOR TODAY REMAIN IN THE UPPER 20S TO LOW 30S,
HOWEVER THAT HIGH WILL LIKELY BY THE EARLY AFTERNOON AS THE REST OF
THE AFTERNOON, TEMPERATURES GRADUALLY DECREASE. FOR THE REMAINDER OF
THE DAY, BETTER MIXING IS EXPECTED AS SUSTAINED WINDS OF 15 TO 25
MPH WITH GUSTS OF 25 TO 35 MPH WILL BE POSSIBLE INTO THE EVENING.
LOOKING AT RAP AND HRRR SOUNDINGS FOR POTENTIAL HIGH END WIND
GUSTS, AREAS TO THE NORTH OF I-94 HAVE THE BEST CHANCE AT SEEING
WIND GUSTS APPROACHING 40 MPH. THE STRONGER WINDS GRADUALLY
SHIFT EAST AS THE DAY PROGRESSES SO AREAS TO THE WEST WILL SEE
THEIR WINDS DIMINISH BEFORE AREAS NORTH OF I-94 AND EAST OF THE
MISSISSIPPI RIVER. BY THIS EVENING, THE AFOREMENTIONED COLDER
AIR ARRIVES, LOWERING OUR OVERNIGHT TEMPERATURES INTO THE SINGLE
DIGITS ABOVE AND BELOW ZERO. THE BELOW ZERO TEMPERATURES LIKELY
WILL STAY ALONG AND NORTH OF I-94. HEADING INTO SUNDAY, WE GET
A LITTLE WARM AIR ADVECTION WITH A SOUTHWEST WIND THAT INCREASES
OUR TEMPERATURES BACK INTO THE MID TO UPPER 20S FOR MOST.
BY MONDAY, THE SURFACE HIGH IS INTO THE OHIO RIVER VALLEY AND THE
AREA GETS INTO ZONAL FLOW. THE WARM AIR ADVECTION CONTINUES SUNDAY
NIGHT INTO MONDAY AS THE SOUTHWEST WINDS REMAIN. MOISTURE TRANSPORT
BEGINS TO INCREASE LATE SUNDAY EVENING AS A WEAK WARM FRONT SHIFTS
NORTHWARD INTO OUR AREA. THIS WILL BE THE KICK STARTER FOR
PRECIPITATION IN EASTERN MINNESOTA AND WISCONSIN. AS PRECIPITATION
BEGINS, THE FURTHER NORTH YOU ARE THE MORE LIKELY THE PRECIPITATION
TYPE WILL BE SNOW AND GRADUALLY WARM UP TO RAIN. THE FURTHER SOUTH
YOU ARE, PRECIPITATION SHOULD BEGIN AS SNOW, HOWEVER BASED ON
FORECASTED SOUNDINGS BETWEEN I-90 AND I-94, A WELL-DEFINED WARM NOSE
IS PRESENT BETWEEN 1000 AND 3000FT. THE BEST LIFT IS ALSO WITHIN THE
CLOUD LAYER. THE RAP DOES A GOOD JOB SHOWING THIS LIFT USING THE
700MB VORTICITY. AT THE SAME TIME, DEWPOINTS REMAIN QUITE DRY IN THE
LOWEST 1500FT OR SO. DEWPOINTS WILL GRADUALLY INCREASE AS THE WARM
FRONT APPROACHES. THE POTENTIAL CONCERN HERE IS THAT THE
PRECIPITATION TYPE, BASED ON THESE PARAMETERS COULD BE FREEZING RAIN
FOR THE LOCATIONS BETWEEN I-90 AND I-94, AND COULD FINISH OFF AS
FREEZING RAIN FOR NORTHERN LOCATIONS. THERE IS STILL A BIT OF
UNCERTAINTY WITH A FEW THINGS REGARDING THE PRECIPITATION FOR
MONDAY. THE FIRST IS HOW FAR NORTH THE WARM FRONT GETS AND THE
ASSOCIATED MOISTURE TRANSPORT. EACH MODEL IS SHOWING THE
PRECIPITATION INITIATING SOMEWHERE IN OUR FORECAST, BUT SOME HAVE IT
CLOSER TO THE TWIN CITIES AND OTHERS NORTH OF I-94. ANOTHER
UNCERTAINTY IS WHILE TEMPERATURES GRADUALLY WARM DURING THIS
PRECIPITATION EVENT, IF THE ATMOSPHERE COOLS DOWN TO THE WET BULB,
THIS WOULD BE MOSTLY BE ALL SNOW EVERYWHERE, LOWERING THE CHANCE FOR
FREEZING RAIN. LASTLY, DO WE GET PRECIPITATION TO REACH THE SURFACE
BASED ON HOW DRY THE NEAR SURFACE ATMOSPHERE IS? OVERALL,
PRECIPITATION CHANCES INCREASE SUNDAY NIGHT INTO MONDAY MORNING BUT
AS FAR AS PRECIPITATION TYPE AND IF IT DOES PRECIPITATE, THOSE
VARIABLES ARE UNCERTAIN AT THIS TIME, ESPECIALLY THE FURTHER SOUTH
YOU GO. AREAS NORTH OF I-94 SHOULD SEE PRECIPITATION AND LIKELY SNOW
FOR A FEW HOURS BEFORE A POTENTIAL TRANSITION.
TUESDAY-FRIDAY: MOSTLY DRY AND WARMER TEMPERATURES
THE ZONAL FLOW BECOMES MORE SOUTHWESTERLY AS A RIDGE BUILDS IN AND
LINGERS THROUGH MUCH OF WEEK. GOOD WARM AIR ADVECTION HELPS TO
INCREASE TEMPERATURES INTO THE MID TO UPPER 30S FOR TUESDAY AND THE
UPPER 30S TO LOW 40S FOR CHRISTMAS EVE. SOME ENSEMBLE MEMBERS, ABOUT
30 TO 50%, SHOW LIGHT MEASURABLE PRECIPITATION ON WEDNESDAY INTO
THURSDAY AS A WAVE SNEAKS UNDER THE RIDGE. THE BETTER PRECIPITATION
CHANCES ARE SOUTH AND EAST OF OUR FORECAST AREA. ENSEMBLE GUIDANCE
ALSO FAVORS THE RIDGE AMPLIFYING WEDNESDAY AND THURSDAY, HOWEVER
THERE IS UNCERTAINTY ON HOW AMPLIFIED THE RIDGE GETS. THE
DETERMINISTIC GFS AND ABOUT 30% OF GEFS MEMBERS HAVE A COOLER
SOLUTION KEEPING TEMPERATURES COOLER THAN FORECASTED. THERE IS ALSO
ABOUT 70% OF EPS MEMBERS SUPPORTING THIS SOLUTION AS WELL, HOWEVER
BASED ON 06Z EPS MEMBERS, THEY HAVE WARMED UP A LITTLE BIT COMPARED
TO THE 00Z RUN. BASED ON 00Z LREF, THERE IS A 40% CHANCE THAT THE
RIDGE IS MORE AMPLIFIED, LEADING TO WARMER TEMPERATURES ACROSS THE
FORECAST AREA, ESPECIALLY FOR CHRISTMAS DAY. THE PROBABILITY FOR
SEEING 50 DEGREES IN THESE TWO CLUSTERS FOR CHRISTMAS IS BETWEEN 20
AND 50% FOR AREAS SOUTH OF I-90 IN ONE CLUSTER WHICH REPRESENTS 21%
OF ALL ENSEMBLE MEMBERS. THE OTHER CLUSTER REPRESENTS 19% OF ALL
ENSEMBLE MEMBERS AND IS THE WARMEST SOLUTION OF ALL OF THEM,
SUGGESTING A 40 TO 80% CHANCE OF AT LEAST 50 DEGREES, WITH THE
HIGHEST CHANCE IN NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN.
OVERALL, ABOVE NORMAL TEMPERATURES ARE LIKELY FOR THIS WEEK, HOW
WARM WE GET IS THE MAIN QUESTION AND ANOTHER THING TO NOTE IS THAT,
DEPENDING ON HOW MUCH SNOW COVER REMAINS ON WEDNESDAY AND THURSDAY
WILL ALSO IMPACT TEMPERATURES.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 945 PM CST SAT DEC 20 2025
CIGS: HIGHS PRESSURE WORKS OVERHEAD ON SUNDAY WITH SKC/SCT EXPECTED
TONIGHT THROUGH THE DAY ON SUNDAY. EXPECTING AN INCREASE IN CLOUDS
AND A MID LEVEL DECK TO PRESS IN FROM THE WEST SUNDAY EVENING,
STICKING AROUND THROUGH THE OVERNIGHT. LOOKING VFR AT THIS TIME.
WX/VSBY: NO IMPACTS EXPECTED THROUGH THE DAY SUNDAY. AN UPPER LEVEL
SHORTWAVE COULD PRODUCE AN AREA OF SNOW-WINTRY MIX AS IT MOVES
ACROSS CENTRAL MN/NORTHERN WI LATER SUNDAY NIGHT INTO MON MORNING.
LOW LEVEL TEMP PROFILE BRING PTYPE CONCERNS WHILE A RATHER DRY SUB
CLOUD LAYER SUGGESTS LIGHT PCPN WOULD NEVER MAKE IT TO THE SFC. A
LITTLE SHIFT SOUTHWARD IN SOME OF THE SHORT TERM GUIDANCE, BRINGING
HIGHER CHANCES (30-50%) INTO THE I-90 CORRIDOR FROM MID SUN EVENING
INTO THE EARLY OVERNIGHT. GOING TO KEEP THE FORECAST DRY FOR NOW
WITH A CLOSE EYE ON EVOLUTION/SHORT TERM TRENDS.
IN ADDITION, SOME SIGNALS THAT DRIZZLE COULD MANIFEST LATER MON
AFTERNOON-EVENING AS THE SYSTEM EXITS EAST - MOSTLY ACROSS WI.
CURRENT TEMPS WOULD KEEP IT AS A LIQUID. LOW END PROBABILITY (20-
40%) FOR NOW, BUT COULD INCREASE.
WINDS: WIND CONTINUE TO SLOWLY DECREASE MOVING INTO THE LATE EVENING
HOURS, AND THAT TREND WILL CONTINUE OVERNIGHT...LIGHTENING UP AND
BECOMING MORE VARIABLE TOWARD 12Z SUN.
WINDS TURN SOUTHERLY AS THE MORNING WEARS ON WITH AN UPTICK IN
SPEEDS (WITH SOME GUSTINESS) FROM THE AFTERNOON INTO THE NIGHT.
WINDS WILL STAY UP, PERHAPS INCREASE A BIT, WORKING THROUGH THE
OVERNIGHT HOURS AS A 50 KT LOW LEVEL JET (AROUND 2 KFT) WORKS
OVERHEAD.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...CECAVA
AVIATION.....RIECK
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