749
FXUS63 KARX 300952
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
352 AM CST TUE DEC 30 2025
KEY MESSAGES
- POTENTIAL FOR LIGHT SNOW TODAY (40-80%) AND AGAIN WEDNESDAY
(30-70%). TOTAL SNOW ACCUMULATIONS GENERALLY AROUND 1 INCH OR
LESS ARE EXPECTED. PATCHY FREEZING DRIZZLE MAY DEVELOP
(10-20%) BEHIND THE SNOWFALL THIS AFTERNOON/EVENING.
- COLD AIR MOVES IN WEDNESDAY NIGHT THROUGH FRIDAY, RESULTING IN
A COLD START TO THE NEW YEAR. NEW YEAR'S DAY WILL BE THE
COLDEST AS MORNING WIND CHILLS 10 TO 25 DEGREES BELOW ZERO AND
HIGHS TOPPING OUT IN THE TEENS ARE EXPECTED.
DISCUSSION
ISSUED AT 352 AM CST TUE DEC 30 2025
SNOW POTENTIAL TODAY AND WEDNESDAY
TWO QUICK HITTING SYSTEMS MOVE THROUGH THE UPPER MISSISSIPPI
RIVER VALLEY TODAY AND WEDNESDAY, ALLOWING FOR PERIODS OF LIGHT
SNOWFALL BETWEEN THE TWO DAYS.
TODAY'S SYSTEM MOVES INTO THE REGION BY THE LATE MORNING,
BRINGING LIGHT SNOWFALL THROUGH THE AFTERNOON AND EVENING HOURS
(40-80%) ASSOCIATED WITH A WING OF 850HPA WARM AIR ADVECTION AND
BROAD QG FORCING. SNOWFALL RATES SHOULD BE LIGHT, WITH THE
30.00Z HREF SUGGESTING UP TO 1/4" PER HOUR ACROSS OUR AREA WHILE
AMOUNTS AROUND 1 INCH OR LESS ARE EXPECTED, HIGHEST ALONG AND
EAST OF THE MISSISSIPPI RIVER.
LOW POTENTIAL (10-20%) EXISTS FOR A FEW HOURS OF PATCHY
FREEZING DRIZZLE IN THE WAKE OF THE SNOWFALL THIS AFTERNOON AND
EVENING AS MODEL SOUNDINGS DEPICT DRYING WITHIN AND ABOVE THE
DGZ, WHILE SATURATION REMAINS IN THE LOWEST ~6KFT, ABOVE -10C.
THE MAIN QUESTION IS IF ADEQUATE FORCING REMAINS PRESENT WHEN
SAID ICE LOSS OCCURS TO ALLOW DRIZZLE TO DEVELOP. THE 30.03Z RAP
SUGGESTS THE PRIMARY WARM ADVECTION WING SHIFTS EASTWARD BY THE
TIME ICE LOSS OCCURS, LIMITING THE OVERALL FORCING EXPECTED AND
THUS DRIZZLE POTENTIAL. HOWEVER, SOME LINGERING WEAK WARM
ADVECTION ALONG WITH THE PASSAGE OF A WEAK LOW LEVEL TROUGH
COULD PROVE TO BE ENOUGH TO SUPPORT THIS FREEZING DRIZZLE
SCENARIO. REGARDLESS, EXPECT SLIPPERY SPOTS ON THE ROADWAYS
DURING THE EVENING COMMUTE VIA SNOWFALL AND/OR FREEZING DRIZZLE.
FOR WEDNESDAY, AN UPPER LEVEL SHORTWAVE TROUGH AND ASSOCIATED POSITIVE
VORTICITY ADVECTION IS DEPICTED OVER THE GREAT LAKES REGION,
RESULTING IN FAR WEAKER SYNOPTIC SCALE FORCING ACROSS OUR AREA
AS COMPARED TO TODAY. HOWEVER, 800-700HPA FRONTOGENESIS IS
EXPECTED TO DEVELOP ACROSS THE UPPER MISSISSIPPI RIVER VALLEY
ASSOCIATED WITH A WEAK COLD FRONT MOVING SOUTHWARD, WHICH WILL
SUPPORT ADDITIONAL LIGHT SNOWFALL DURING THE AFTERNOON HOURS
(30-70%). ACCUMULATIONS ARE EXPECTED TO BE LESS THAN 1 INCH,
WITH THE 30.00Z LREF SUGGESTING PROBABILITIES FOR GREATER THAN
0.5 INCHES ARE 20-40%.
COLDER TEMPERATURES FOR THE NEW YEAR
TEMPERATURES FALL QUICKLY NEW YEAR'S EVE INTO NEW YEAR'S DAY IN
THE WAKE OF THE AFOREMENTIONED COLD FRONT, RESULTING IN
OVERNIGHT LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.
FORTUNATELY, THE LOW LEVEL WIND FIELD IS EXPECTED TO BE ON THE
DECREASE DURING THIS TIME AS A LOW LEVEL RIDGE BUILDS INTO THE
REGION, LIMITING THE EXTENT WIND CHILLS CAN FALL. THIS IS
SUPPORTED BY A DECREASING TREND IN LREF PROBABILITIES FOR WIND
CHILLS LESS THAN -25 DEGREES. HOWEVER, WIND CHILLS NEW YEAR'S
EVE INTO THE MORNING OF NEW YEAR'S DAY ARE STILL EXPECTED TO BE
COLD, GENERALLY 10 TO 25 DEGREES BELOW ZERO DESPITE THE
WEAKENING WIND FIELD, SO ENSURE YOU ARE PREPARED IF YOU HAVE
PLANS OUTDOORS.
UPPER LEVEL RIDGING CONTINUES BUILDING ACROSS THE UNITED STATES TO
FINISH OUT THE WEEK, SUPPORTING SURFACE HIGH PRESSURE. THESE
FEATURES ARE CURRENTLY EXPECTED TO SHIFT EASTWARD THROUGH THE
WEEKEND, ALLOWING FOR WARMING TEMPERATURES AND MINIMAL THREAT OF
IMPACTFUL WEATHER, ALTHOUGH WILL NEED TO MONITOR FOR ANY SHORTWAVES
THAT ARE ABLE TO TRAVERSE THE MEAN NORTHWEST FLOW DURING THIS PERIOD
AS VARIATION EXISTS AMONGST THE VARIOUS ENSEMBLE MEMBERS.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1139 PM CST MON DEC 29 2025
VFR CONDITIONS ARE EXPECTED THROUGH THE OVERNIGHT PERIOD INTO
TUESDAY MORNING ACROSS THE AREA. A QUICK-MOVING SYSTEM
APPROACHES THE AREA FROM THE NW LATE TUESDAY MORNING THROUGH THE
AFTERNOON, WHICH WILL BRING A RETURN OF MVFR CEILINGS AND
SCATTERED SNOW SHOWERS. THE BEST CHANCES (50-80%) FOR THESE SNOW
SHOWERS WILL BE ALONG AND EAST OF THE MISSISSIPPI RIVER AND WILL
BRING A 50-60% CHANCE OF IFR VISIBILITIES AND 20-30% CHANCE OF
IFR CEILINGS WITH THEM.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...FALKINHAM
AVIATION...JAW
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