057
FXUS63 KARX 252324
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
524 PM CST THU DEC 25 2025
KEY MESSAGES
- FREEZING PRECIPITATION MOSTLY NORTH OF I-94 TONIGHT INTO EARLY FRI
MORNING. ICING FROM A GLAZE TO AS MUCH AS 1/10" (NORTH OF HWY 29 IN
WI) EXPECTED. BE PREPARED FOR SLIPPERY TRAVEL.
- MORE DENSE FOG POSSIBLE TONIGHT ACROSS PORTIONS OF SOUTHEAST MN,
NORTHEAST IA INTO SOUTHWEST WI.
- RAW END TO THE HOLIDAY WEEKEND WITH FALLING TEMPS, BLUSTERY
WINDS SUN/SUN NIGHT (WIND GUSTS 35+ MPH POSSIBLE SE MN, NE IA).
DISCUSSION
ISSUED AT 145 PM CST THU DEC 25 2025
> TONIGHT: AREAS DRIZZLE, FREEZING DRIZZLE TONIGHT. LIGHT ICE
ACCUMULATIONS NORTH OF I-94. MORE DENSE FOG EXPECTED ACROSS PARTS OF
SE MN, NE IA INTO SOUTHWEST WI.
HEALTHY SWATH OF LOW LEVEL THERMODYNAMICS (EVIDENCED ON THE 280:295
K SFCS) PRECEDES AN UPPER LEVEL SHORTWAVE TROUGH ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY TONIGHT. THE DEEPER LIFT IS FAVORED ACROSS
NORTHERN PARTS OF MN/WI WHERE THE THERMODYNAMICS AND MORE STACKED QG
CONVERGENCE ARE SET TO LIE. AMPLE LIFT FOR PCPN PRODUCTION.
SATURATION IS THE KEY PLAYER IN WHAT FALLS THOUGH. NORTH-SOUTH
RUNNING TIME/HEIGHT X-SECTIONS AND BUFKIT SOUNDINGS SHOW A DISTINCT
LACK IN DEEP SATURATION. DEPTH RANGES FROM AROUND 4+ KFT DEEP NORTH
OF I-94, SHALLOWING TO 2 KFT (OF SUB) ACROSS PARTS OF NE IA. DEEP
ENOUGH FOR DRIZZLE PRODUCTION. HIGH/MID LEVEL CLOUDS WILL TOP THE
LOW DECK, BUT THE DEPTH OF DRY LAYER BETWEEN BOTH CLOUD LAYERS IS
EXPANSIVE IN THE RAP/HRRR - LIKELY TOO DEEP TO OVERCOME FOR A SEEDER-
FEEDER PROCESS (AT LEAST LOCALLY). THIS WILL KEEP THE PTYPE AS A
LIQUID - WITH SFC TEMPS DICTATES WHETHER THAT FREEZES OR NOT.
AS FOR THAT, FREEZING TEMPS STILL ON TAP MAINLY NORTH OF I-94 THIS
EVENING, BUT SLOWLY WARMING OVERNIGHT FROM SOUTHWEST TO NORTHEAST.
THEREFORE, HIGHER THREAT FOR ICING IMPACTS REMAINS ALONG/NORTH OF
HWY 29 IN NORTH-CENTRAL WI. WHILE IMPACTS MAY BE MINIMAL/IF ANY INTO
THE I-94 CORRIDOR, JUST A 1 TO 2 DEGREE DIFFERENCE IN EXPECTATIONS
COULD LEAD TO ICING ALONG I-94 - AND A LOT OF TRAVEL IMPACTS. WILL
CONTINUE THE CURRENT OUTLAY OF COUNTIES FOR THE WINTER WEATHER ADV,
WHICH INCLUDES I-94.
MEANWHILE, THE RECENT SPATE OF MILD DAYS HAS MELTED A LOT OF THE
SNOW PACK ACROSS THE AREA, MOISTENING THE NEAR SFC LAYER -
ESPECIALLY ACROSS IA INTO SOUTHERN MN. DENSE FOG WAS WIDESPREAD IN
THESE AREAS THIS MORNING, PERSISTING IN SPOTS THIS AFTERNOON, AND
EXPECT THE SAME LATER TONIGHT. HOW FAR EASTWARD THIS SPREADS IS A
QUESTION. RAP NEAR SFC WINDS ARE LIGHT SOUTH TO NORTHWESTERLY -
WHICH COULD PUSH THIS FOG PRODUCING LAYER ACROSS SE MN/NE IA. SREF
GUIDANCE IS IN FAVOR OF THIS, BUT SUGGEST THICK FOG WOULD SPREAD
INTO SOUTHWEST WI TOO. A DENSE FOG ADVISORY IS LIKELY FOR PORTIONS
OF THE FORECAST AREA - BUT UNCERTAINTY IN HOW WIDESPREAD. WILL HOLD
OFF ON ISSUING AT THIS TIME - MONITORING OBSERVATIONS/MODEL TRENDS
AS WE MOVE INTO THE EVENING AND ISSUE HEADLINES AS NEEDED.
> SUNDAY: LIGHT PCPN CHANCES, WINDY WITH FALLING TEMPERATURES.
UPPER LEVEL TROUGH DRIVES ACROSS THE PLAINS SAT, MAKING ITS WAY EAST
ACROSS THE MID MISSISSIPPI RIVER VALLEY SUN. VARIOUS PERTURBATIONS
ACCOMPANY/DROP INTO THE TROUGH WITH SFC CYCLOGENESIS IN THE LEE OF
THE TROUGH KICKING IN SAT WITH THE LOW THEN TRACKING NORTHEAST
ACROSS THE EASTERN GREAT LAKES BY 00Z MON.
WHILE THE TRACK OF THE STORM SYSTEM KEEPS THE BRUNT OF ITS PCPN
EAST/SOUTH OF THE LOCAL AREA, BITS OF UPPER LEVEL ENERGY RIDE
NORTHEAST ON THE BACKSIDE OF THE SFC FRONT ALONG WITH SOME ENERGY
DROPPING SOUTHEAST OUT OF CANADA. LIGHT PCPN WILL RESULT. COLDER AIR
IS FLOWING IN, SUGGESTING A WINTRY MIX CHANGING OVER TO SNOW.
HOWEVER, THERE ARE SATURATION CONCERNS HERE TOO, WITH DRYING MID
LEVELS POST THE SFC OLD FRONT. THIS MAKES DRIZZLE/FREEZING DRIZZLE A
POSSIBLITY. A SEEDER-FEEDER PROCESS COULD INTRODUCE ICE INTO THE
LOWER SATURATION, BUT THE DRIER LOOKS FAIRLY DEEP AND COULD/WOULD BE
TOUGH TO OVERCOME. NOT MUCH CLARITY AT THIS TIME - EXPECT REVISIONS
IN EXPECTATIONS AS WE MOVE THROUGH THE NEXT FEW DAYS. AMOUNTS OF ANY
PCPN TYPE LOOK MINOR AT THIS TIME.
PERHAPS THE "BIGGER" IMPACTS WITH THIS PASSING STORM SYSTEM IS
STRONGER/GUSTY WINDS AS IT EXITS, ALONG WITH FALLING TEMPS THROUGH
THE DAY. THE EPS PAINTS 40-60% CHANCES FOR 35 MPH GUSTS FOR SUN
AFTERNOON/NIGHT ALONG/WEST OF THE MISSISSIPPI RIVER.
COLDER AIR WILL BE FUNNELING IN FROM CANADA STARTING SUNDAY MORNING.
850 MB TEMPS PROGGED TO DROP FROM AROUND +5 C AT 12Z SUN TO -5 C BY
00Z SUN EVENING. THE HIGH TEMP SUNDAY WILL LIKELY BE WHATEVER IT IS
AT 1201 AM (UPPER 30S/LOW 40S) WITH TEMPS DROPPING INTO THE 20S BY
LATE AFTERNOON.
> NEXT WEEK: TRENDING MORE SEASONABLE, LIGHT PRECIPITATION CHANCES
HERE AND THERE
CHANGE IN THE UPPER LEVEL PATTERN AS WE MOVE INTO THE NEW WEEK.
FAIRLY PROGRESSIVE AND SOMEWHAT "DIRTY" FLOW WITH BITS OF SHORTWAVE
ENERGY SPINNING WEST TO EAST ACROSS THE REGION. BROAD SHORTWAVE
RIDGING, TROUGHING INFLUENCE THE REGION, EXCHANGING EVERY DAY OR
TWO.
THE SMALLER SCALE NATURE OF THE SHORTWAVES MAKES PINPOINTING
TIMES/LOCATIONS FOR PCPN CHANCES MORE CHALLENGING AND WILL RUN WITH
THE MODEL BLEND FOR NOW. PCPN WOULD GENERALLY BE LIGHT IN THIS
SCENARIO WITH NO "STRONGER" SYSTEM OF NOTE ON THE HORIZON.
UPS AND DOWNS IN THE TEMPS, DEPENDING IF RIDGE OR TROUGH IS
INFLUENCING THE REGION. ASIDE FROM THE COLDER START TO THE WEEK,
TEMPERATURES LIKELY TO FLUCTUATE AROUND/CLOSER TO THE LATE DEC/EARLY
JAN NORMALS.
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 520 PM CST THU DEC 25 2025
A WIDE VARIETY OF CONDITIONS ACROSS THE UPPER MISSISSIPPI VALLEY
CURRENTLY WITH CIGS RANGING FROM VFR ACROSS NORTH CENTRAL WISCONSIN
TO LIFR WEST OF THE RIVER. CONDITIONS WILL DETERIORATE AREAWIDE OVER
THE COMING HOURS WITH WIDESPREAD LIFR CIGS EXPECTED OVERNIGHT AND
INTO TOMORROW MORNING. DENSE FOG IS ALSO EXPECTED TO EXPAND
OVERNIGHT, LIKELY COVERING MUCH OF SOUTHEAST MINNESOTA AND NORTHEAST
IOWA (AND POTENTIALLY SOUTHWEST WISCONSIN AROUND DAYBREAK). ANYWHERE
THAT DOESN'T SEE DENSE FOG LATE OVERNIGHT AND INTO TOMORROW MORNING
WILL STILL LIKELY SEE VISIBILITIES AT OR LESS THAN 1 MILE DUE TO
LINGERING DRIZZLE. VISIBILITIES SHOULD IMPROVE TO VFR/MVFR BY 18Z
TOMORROW BUT CIGS WILL BE A BIT SLOWER TO ERODE. SOME PLACES
ALONG THE MISSISSIPPI COULD SEE IMPROVEMENT TO MVFR CIGS BY
LATE TOMORROW AFTERNOON BUT MOST PLACES WILL LIKELY STAY IN THE
IFR/LIFR RANGE THROUGH THE END OF THE PERIOD.
WINDS WILL DECREASE INTO THE EVENING BECOMING LIGHT AT LESS
THAN 10 KTS OVERNIGHT (GENERALLY REMAINING OUT OF THE
SOUTH/SOUTHEAST). WINDS WILL QUICKLY VEER TO THE NORTHWEST
THROUGH THE MORNING HOURS TOMORROW BUT SPEEDS SHOULD REMAIN AT
OR BELOW 10 KTS.
ARX WATCHES/WARNINGS/ADVISORIES
WI...WINTER WEATHER ADVISORY UNTIL 9 AM CST FRIDAY FOR WIZ017-029.
WINTER WEATHER ADVISORY UNTIL 6 AM CST FRIDAY FOR WIZ033-034-
042>044.
MN...NONE.
IA...NONE.
DISCUSSION...RIECK
AVIATION...BARENDSE
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