423
FXUS63 KARX 121701
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1101 AM CST FRI DEC 12 2025
KEY MESSAGES
- LIGHT SNOW THIS MORNING AND AFTERNOON. ACCUMULATIONS
PRIMARILY LESS THAN 0.5". LIGHT SNOW FOR NORTHEAST IOWA
SATURDAY MORNING WITH MINIMAL ACCUMULATIONS EXPECTED.
- BITTER COLD THIS WEEKEND, WITH HIGHS ON SATURDAY AND SUNDAY IN
THE SINGLE DIGITS. WIND CHILLS OF -15F TO -35F ARE EXPECTED
SATURDAY AND SUNDAY MORNING. A COLD WEATHER ADVISORY IS IN
EFFECT FOR SOUTHEAST MINNESOTA AND WESTERN WISCONSIN SATURDAY
MORNING THROUGH SUNDAY MORNING.
- TRENDING TOWARDS MORE SEASONABLE TEMPERATURES AND DRIER
CONDITIONS FOR EARLY NEXT WEEK WITH HIGH TEMPERATURES
REBOUNDING INTO THE MID 30S.
UPDATE
ISSUED AT 954 AM CST FRI DEC 12 2025
SOUNDINGS ARE SHOWING A LACK OF ICE ALOFT DURING ONSET OF THE
PRECIPITATION THIS MORNING NEAR INTERSTATE 90 AND IN NORTHEAST
IOWA AND SOUTHWEST WISCONSIN DURING THE LATE MORNING AND EARLY
AFTERNOON. THIS WILL RESULT IN A BRIEF 1 TO MAYBE 2 HOUR PERIOD
OF FREEZING DRIZZLE AS THE BOUNDARY LAYER SATURATES. THE
BOUNDARY LAYER WILL THEN RAPIDLY COOL AND THIS WILL RESULT IN A
TRANSITION TO FLURRIES.
IN ADDITION, WE HAVE ADDED A COLD WEATHER ADVISORY FOR NORTHEAST
IOWA AND SOUTHWEST WISCONSIN FROM 6 PM SATURDAY THROUGH 10 AM
SUNDAY.
DISCUSSION
ISSUED AT 336 AM CST FRI DEC 12 2025
TODAY: LIGHT SNOW
AN UPPER LEVEL LOW OVER SOUTHERN MANITOBA AND WESTERN ONTARIO WILL
MOVE EAST DURING THE DAY AS IT IS APART OF THE LARGER LONGWAVE
TROUGH THAT IS SITUATED OVER THE UPPER MIDWEST TO NEW ENGLAND AREA.
WITH THE LOCAL AREA IN THE LEFT EXIT REGION OF AN APPROACHING JET
STREAK AND A BRIEF PERIOD OF POSITIVE VORTICITY ADVECTION DURING THE
AFTERNOON, ENOUGH LIFT WILL BE PRESENT FOR SOME LIGHT SNOW TO
DEVELOP ACROSS MUCH OF THE FORECAST AREA. THE RAP SHOWS A SLIGHT
INCREASE IN MOISTURE ADVECTION OVER THE REGION LATER THIS MORNING
AND THROUGH THE AFTERNOON TO ALSO AID IN SNOW DEVELOPMENT. SNOW
RATIOS WILL STAY ON THE HIGHER SIDE, 17 TO 20:1. THE SNOW WILL BE
AROUND FOR A SHORT TIME, AROUND 6 TO 8 HOURS. MINOR ACCUMULATION OF
UP TO 0.5" WILL BE POSSIBLE, WITH THE BEST CHANCE AT SEEING 0.5" UP
IN NORTH CENTRAL WISCONSIN.
THE WEEKEND: BITTER COLD TEMPERATURES
THAT SAME UPPER LEVEL LOW SHIFTS OVER THE NORTHERN GREAT LAKES AS
COLD AIR ADVECTION BEGINS TO MOVE INTO THE AREA ON THE BACK SIDE OF
THE LOW, TEMPERATURES WILL GET COLDER. THIS IN FACE WILL BE OUR
COLDEST TEMPERATURES OF THE SEASON SO FAR. IT BEGINS FRIDAY NIGHT
INTO SATURDAY MORNING WHERE WIND CHILLS OF -20 TO -30 WILL BE
POSSIBLE AND AS RESULT WE HAVE A COLD WEATHER ADVISORY IN PLACE FOR
SOUTHEAST MINNESOTA AND WESTERN WISCONSIN WHERE WIND CHILLS OF
AT LEAST -20 DEGREES ARE EXPECTED. NOT MUCH RELIEF FOR SATURDAY
AFTERNOON AND INTO THE EVENING WHERE WIND CHILLS REMAIN IN THE
-10 TO -20 RANGE. HIGHER CONFIDENCE IN EVEN COLDER TEMPERATURES
FOR SATURDAY NIGHT INTO SUNDAY MORNING WHERE AN EFI VALUE -0.8
TO -0.95 EXISTS OVER OUR FORECAST AREA. THESE VALUES INDICATE
THAT FORECASTED TEMPERATURES FOR SATURDAY NIGHT/SUNDAY MORNING
ARE ON THE LOWER SIDE OF CLIMATOLOGICAL NORMAL FOR THIS TIME OF
YEAR. ANOTHER IMPORTANT THING TO NOTE IS THAT ON SATURDAY WE ARE
UNDER CLOUDY SKIES AND BEGIN TO CLEAR OUT BY THE EVENING.
MOSTLY CLEAR SKIES ARE EXPECTED DURING THE OVERNIGHT AND THROUGH
SUNDAY MORNING HELPING TO LOWER TEMPERATURES EVEN MORE DUE TO
RADIATIONAL COOLING. FORECASTED LOW TEMPERATURES ARE BETWEEN -10
AND -17 DEGREES WITH WIND CHILLS OF -25 TO -35 DEGREES EXPECTED
FOR MOST LOCATIONS. THE ONLY DIFFERENCE IS HOW LONG A LOCATION
WILL BE BELOW -25 DEGREES FOR THE WIND CHILL. LOCATIONS IN FAR
SOUTHWESTERN WISCONSIN AND PORTIONS OF NORTHEAST IOWA WILL SEE
THESE WIND CHILLS AFTER MIDNIGHT SUNDAY MORNING. THERE EVEN IS A
LOW PROBABILITY (30 TO 50%), BASED ON THE 12Z LREF, OF WIND
CHILLS GETTING COLDER THAN
-35 DEGREES IN PORTIONS OF SOUTHEAST MINNESOTA AND NORTHEAST
IOWA. WITH THESE COLD WIND CHILLS, ANOTHER COLD WEATHER HEADLINE
WILL BE NEEDED IN THE NEXT DAY OR TWO.
IN ADDITION TO THE COLD TEMPERATURES, SHORTWAVE ENERGY COMES DOWN
FROM THE UPPER LEVEL LOW SITUATED OVER THE NORTHERN GREAT LAKES
AND IN DOING SO, A BAND OF 700MB FRONTOGENESIS DEVELOPS AND
MOVES OVER NORTHEAST IOWA SATURDAY MORNING INTO THE AFTERNOON.
THE TRACK OF THIS FRONTOGENESIS BAND IS VERY SIMILAR TO THE
PREVIOUS SNOW BAND THAT FELL ACROSS NORTHERN AND EASTERN IOWA ON
THURSDAY. WHILE SOME FLURRIES MAY BE POSSIBLE AS FAR NORTH AS
I-90, THE NORTHERN PORTION OF THE BAND LOOKS TO IMPACT AREAS
SOUTH OF A MASON CITY, IA TO GUTTENBERG, IA LINE. MOST LOCATIONS
FROM I-90 SOUTH TO THIS LINE WILL SEE FLURRIES TO MAYBE A
COUPLE TENTHS OF SNOW, WHILE SOUTH OF THE MASON CITY TO
GUTTENBERG LINE COULD SEE AROUND 0.5 TO 1" OF SNOW. NBM
PROBABILITIES FOR AT LEAST 1" OF SNOW ARE BETWEEN 20 AND 40%
WITH THE HIGHEST PERCENTAGES IN THE SOUTHERN PORTIONS OF FLOYD,
CHICKASAW, FAYETTE, AND CLAYTON COUNTIES.
MONDAY-WEDNESDAY: WARMER AND DRIER
AS THE BACK SIDE OF THE LONGWAVE TROUGH CONTINUES ITS TREK EASTWARD,
UPPER LEVEL RIDGING FINALLY BREAKS THROUGH AND COVERS THE UPPER
MIDWEST FOR EARLY NEXT WEEK. WITH SOUTHWEST WINDS, GOOD WARM AIR
ADVECTION WILL BE IN PLACE AND HELP TO INCREASE TEMPERATURES INTO
THE LOW TO MID 30S FOR TUESDAY AND THE MID 30S TO POTENTIALLY 40
DEGREES FOR SOME LOCATIONS! THE MOST RECENT NBM GIVES A PROBABILITY
FOR AT LEAST 40 DEGREES OF 30 TO 50% FOR PORTIONS OF SOUTHWEST
WISCONSIN AND NORTHEAST IOWA, ESPECIALLY RIVER VALLEYS IN THESE
AREAS. WHILE UNDER THE RIDGE, SHORTWAVE WILL PASS TO OUR NORTH AND
LEAVE OUR LOCAL AREA DRY FOR THE FIRST PART OF NEXT WEEK. THIS WILL
BE A NICE BREAK FROM THE ACTIVE PATTERN THAT WE HAVE SEEN OVER THE
PAST COUPLE OF WEEKS. ONCE THURSDAY ROLES AROUND, THE RIDGE BREAKS
DOWN AND THE FLOW BECOMES ZONAL OR SLIGHTLY NORTHWEST, WHICH
TRANSLATES TO A POTENTIAL FLIP BACK TO AN ACTIVE PATTERN FOR THE
SECOND HALF OF NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1101 AM CST FRI DEC 12 2025
IFR TO MVFR CIGS WILL PREVAIL ACROSS THE LOCAL AREA OVER THE COURSE
OF THE AFTERNOON WITH ABUNDANT LOW-LEVEL MOISTURE IN PLACE. IN
ADDITION, A BAND OF LIGHT SNOW CONTINUES TO MOVE THROUGH THE LOCAL
AREA BRINGING MVFR TO IFR VSBY REDUCTIONS ALONG WITH THEM AS THEY
QUICKLY MOVE FROM WEST TO EAST. CANNOT RULE OUT SOME FREEZING
DRIZZLE FOR A BRIEF PERIOD DURING PRECIPITATION ONSET ACROSS WESTERN
WI, HOWEVER THIS WILL LIKELY ONLY LAST FOR ABOUT AN HOUR AT THE MOST
BEFORE SWITCHING TO SNOW AS COLD AIR ADVECTION PUSHES SATURATION
INTO THE DENDRITIC GROWTH ZONE. CIGS WILL IMPROVE TO VFR AS COLD AIR
ADVECTION WORKS IN THIS EVENING WITH WINDS ALSO INCREASING DURING
THE LATE AFTERNOON FROM THE WEST-NORTHWEST AT AROUND 15 KTS WITH
GUSTS UP TO AROUND 25 KTS.
ARX WATCHES/WARNINGS/ADVISORIES
WI...COLD WEATHER ADVISORY FROM 6 PM SATURDAY TO 10 AM CST SUNDAY
FOR WIZ054-055-061.
COLD WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CST
SUNDAY FOR WIZ017-029-032>034-041>044-053.
MN...COLD WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CST
SUNDAY FOR MNZ079-086>088-094>096.
IA...COLD WEATHER ADVISORY FROM 6 PM SATURDAY TO 10 AM CST SUNDAY
FOR IAZ008>011-018-019-029-030.
UPDATE...BOYNE
DISCUSSION...CECAVA
AVIATION...NAYLOR
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