918
FXUS63 KARX 251201
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
601 AM CST THU DEC 25 2025
KEY MESSAGES
- RISK FOR A GLAZE OF ICE ALONG I-94 TO UPWARDS OF 0.10" OF ICE
NORTH OF HIGHWAY 29 CONTINUES TO INCREASE (60-80%) AND HAVE
ISSUED A WINTER WEATHER ADVISORY TO COVER THIS HAZARD.
- FOG ERODES FROM NORTH TO SOUTH EARLY THIS MORNING, BUT COULD
BUILD BACK NORTHWARD TODAY AND TONIGHT.
- HIGHS RUN 10-15 DEGREES ABOVE AVERAGE THROUGH SATURDAY, WITH
FALLING TEMPERATURES ON SUNDAY BEHIND A COLD FRONT AND
TEMPERATURES 20-30 DEGREES COLDER BY MONDAY MORNING.
- STRONG WINDS AND LIGHT SNOW ACCOMPANY THE PASSAGE OF THE COLD
FRONT ON SUNDAY, WHICH COULD NEGATIVELY IMPACT TRAVEL.
DISCUSSION
ISSUED AT 350 AM CST THU DEC 25 2025
TODAY: CLOUDY WITH DRIZZLE SPREADING NORTH
WIDESPREAD FOG DEVELOPED OVERNIGHT IN THE WAKE OF LAST NIGHT'S
DRIZZLE, BUT DRIER NORTHERLY FLOW HAS BEEN STEADILY ERODING THE
FOG AND LOW STRATUS THROUGH THE NIGHT AND AS OF 4 AM THE BULK OF
THE DENSE FOG HAD BEEN RELEGATED TO AREAS ALONG AND WEST OF
HIGHWAY 63. HOWEVER, WITH THE NEAR-SURFACE FLOW VEERING BACK TO
THE SOUTHEAST BY THIS AFTERNOON WITH THE PASSAGE OF A 700-500-MB
RIDGE AXIS AND INCREASING 290K ISENTROPIC ASCENT AHEAD OF THE
NEXT WARM FRONT, THE LOW CLOUDS AND FOG SPREAD BACK NORTHWARD
THROUGH THE AFTERNOON. THIS INCREASING UPGLIDE SHOULD AID IN THE
DEVELOPMENT OF DRIZZLE THAT SPREADS NORTHWARD WITH THIS
STRATUS, THOUGH WITH THE DEPTH OF THE BOUNDARY LAYER MOISTURE
FLIRTING WITH THE 1-KM THRESHOLD WE GENERALLY SEE FOR DRIZZLE
PRODUCTION, KEPT POPS ON THE LOWER SIDE THROUGH SUNSET.
TONIGHT - FRIDAY MORNING: ICING RISK ALONG AND NORTH OF I-94
TEMPERATURES ACROSS CENTRAL WISCONSIN HAVE FALLEN INTO THE LOW
TO MID-20S EARLY THIS MORNING AND WILL STRUGGLE TO REACH 30
DEGREES TODAY GIVEN THE INCREASING CLOUDS AND EASTERLY FLOW. BY
THE TIME THE AFOREMENTIONED DRIZZLE ARRIVES THIS EVENING, THE BELOW
FREEZING TEMPERATURES WILL RESULT IN ICING CONDITIONS ON
UNTREATED SURFACES. THE GREATEST RISK FOR TRAVEL IMPACTS LOOKS
TO BE ALONG AND NORTH OF HIGHWAY 10 WITH ICING AMOUNTS
APPROACHING 0.10" NORTH OF HIGHWAY 29 WERE THE MOISTURE PROFILES
ARE DEEPER.
HOWEVER, DID INCLUDE THE I-94 CORRIDOR IN THE ADVISORY GIVEN
THAT WET BULBS WILL BE BELOW FREEZING THROUGH AT LEAST MIDNIGHT
AND PRESENT A WINDOW FOR A LIGHT GLAZE OF ICE TO FORM. THE
FORECAST ALONG I-94 IS QUITE SENSITIVE TO SMALL CHANGES IN THE
TEMPERATURE/DEWPOINT THAT SHOULD BE MONITORED THROUGH THE DAY.
WITH INCREASING THETA-E ADVECTION THROUGH THE NIGHT, SURFACE
TEMPERATURES BEGIN TO WARM AFTER MIDNIGHT AND THE RISK FOR
FREEZING PRECIPITATION SHOULD END BEFORE MID-MORNING IN CENTRAL
WISCONSIN.
FRIDAY - SATURDAY: DRIER AND WARM
WITH THE OVERALL PATTERN AMPLIFYING IN THE WAKE OF TONIGHT'S
SYSTEM AND THE FLOW TURNING MORE TO THE SOUTHWEST, TOMORROW AND
SATURDAY FEATURE OUR WARMEST TEMPERATURES OF THE PERIOD WITH
MANY LOCALES CRACKING THE 40-45 DEGREE MARK. ROUGHLY 20-30% OF
THE NBM ENSEMBLE MEMBERS HAVE AREAS SOUTH OF HIGHWAY 18 CLOSING
IN ON 50 DEGREES TOMORROW, SPREADING AS FAR NORTH AS I-90 FOR
SATURDAY. SATURDAY NIGHT'S LOWS LOOK TO ONLY FALL INTO THE MID
TO UPPER 30S.
SUNDAY: COLD FRONT ARRIVES
THOSE 30 DEGREE READINGS AT SUNRISE ON SUNDAY WILL BE THE
WARMEST WE SEE THROUGH AT LEAST THE FIRST HALF OF THE NEW WEEK.
THE TIMING OF THE COLD FRONT HAS BEEN SLIDING LATER IN TIME BY
ABOUT 6-12 HOURS LATER OVER THE LAST FEW DAYS, BUT IT DOESN'T
CHANGE THE FORECAST MUCH FOR SUNDAY WITH FALLING TEMPERATURES
THROUGH THE DAY.
WITH THE FORECAST LOW TRACK AND RESULTANT DEFORMATION ZONE
SLIDING SOUTHWARD AND MORE INTO THE FORECAST AREA, THE RISK FOR
ACCUMULATING SNOW WITH ITS PASSAGE IS ON THE INCREASE. AMOUNTS
DON'T LOOK TO BE TOO HIGH AT THIS TIME GIVEN THE PROGRESSIVE
NATURE OF THE SYSTEM, BUT 10-20% OF THE NBM ENSEMBLE MEMBERS
HAVE SNOW AMOUNTS IN EXCESS OF 2" AND A FEW OUTLIERS EXCEED 4".
STRONG WINDS WILL ACCOMPANY THE POST-FRONTAL AIRMASS WITH AT
LEAST 60-70% OF THE NBM MEMBERSHIP SHOWING WIND GUSTS OF 35-45
MPH. COMBINED WITH THE LIGHT/BLOWABLE SNOW AND FALLING
TEMPERATURES, WE WILL NEED TO MONITOR TRENDS FOR TRAVEL IMPACTS
AS WE GET CLOSER TO THIS EVENT.
MONDAY - WEDNESDAY: COOL START TO THE WEEK, DRIER
THE COLDER AIR FLOODS SOUTH FOR SUNDAY NIGHT WITH LOWS IN THE
SINGLE DIGITS AND WIND CHILLS IN THE TEENS BELOW ZERO MONDAY
MORNING. HIGHS LOOK TO STAY BELOW 20 FOR THE DAY ON MONDAY AS A
TRANSIENT SURFACE RIDGE SLIDES THROUGH.
MODERATING TEMPERATURES DO ARRIVE BY TUESDAY AND WEDNESDAY AS
HIGHS RETURN CLOSER TO AVERAGE. TO WHAT EXTENT TEMPERATURES
REBOUND IS SOMEWHAT UNCERTAIN GIVEN HOW THE REGION WILL RESIDE
ALONG THE DOWNSTREAM FLANK OF A SHARPER RIDGE THAT COULD FUNNEL
COLDER AIR INTO THE REGION. IN FACT, THE NBM HAS A NEARLY 30
DEGREE SPREAD IN THE HIGH TEMPERATURE FORECAST BY MIDWEEK,
INDICATIVE OF HOW WE WILL RESIDE ALONG THE TRANSITION ZONE
BETWEEN TWO AIRMASSES. THERE ARE A FEW TOKEN SHOTS OF SNOW THAT
COULD MOVE THROUGH, BUT NOTHING TO HANG ONES AT ON AT THIS RANGE
IN THE FORECAST.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 535 AM CST THU DEC 25 2025
POOL OF MOIST LOW LEVEL AIR SITUATED ALONG OUR WESTERN
PERIPHERAL COUNTIES FROM SOUTHEAST MINNESOTA INTO NORTHEAST IOWA
LEAVES MUCH UNCERTAINTY IN AVIATION IMPACTS PRIMARILY AT KRST
TAF SITE THROUGH THE 25.12Z TAF PERIOD. THE EDGE OF MVFR-IFR
VISIBILITIES AND IFR-LIFR CEILINGS EXPECTED TO LIE NEAR AND JUST
WEST OF KRST THROUGH THE LATE MORNING BUT MAY LINGER THROUGH THE
DAY.
MOISTURE POOL SLOSHES NORTHEAST AGAIN THROUGH THE AFTERNOON
INCREASING AND SPREADING IMPACTS ACROSS THE LOCAL FORECAST AREA.
RESULTANT IFR-LIFR LIKELY OVERNIGHT. LOW CONFIDENCE IN IFR
LIFTING FRIDAY EVENING FOR SOME WITH MVFR CEILINGS LIKELY
HOLDING ON THROUGH SATURDAY MORNING, LINGERING IN CENTRAL
WISCONSIN.
ARX WATCHES/WARNINGS/ADVISORIES
WI...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM CST
FRIDAY FOR WIZ017-029.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
FRIDAY FOR WIZ033-034-042>044.
MN...NONE.
IA...NONE.
DISCUSSION...SKOW
AVIATION...JAR
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