802
FXUS63 KARX 131257
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
657 AM CST TUE JAN 13 2026
KEY MESSAGES
- ONE MORE MILD DAY TODAY WITH HIGHS IN THE 40S SOUTH OF I-94,
NEARING 50 FOR SOME SOUTH OF I-90. WINDS WILL INCREASE BY THE
AFTERNOON AND PERSIST INTO WEDNESDAY WITH PERIODIC GUSTS TO
AROUND 35 MPH, MAINLY WEST OF THE MISSISSIPPI RIVER.
- ACCUMULATING SNOW IS LIKELY BEGINNING THURSDAY AFTERNOON AND
CONTINUE INTO FRIDAY. PROBABILITIES FOR SNOWFALL AMOUNTS OF 2
INCHES OR GREATER ARE TRENDING HIGHER ACROSS THE LOCAL AREA
(50-90% CHANCE).
- BELOW NORMAL TEMPERATURES EXPECTED THIS WEEKEND WITH HIGHS
LIKELY IN THE SINGLE DIGITS AND TEENS.
UPDATE
ISSUED AT 653 AM CST TUE JAN 13 2026
HAVE NUDGED UP HIGH TEMPERATURES BY 3-5 DEGREES FOR TODAY GIVEN
THE CLEARING SKIES, AMPLE MIXING AND WARM MORNING TEMPERATURES
ALREADY IN THE UPPER 30S TO LOW 40S ALONG AND SOUTH OF I-90.
AREAS SOUTH OF I-90 COULD MAKE A RUN AT 50 DEGREES BEFORE THE
COLD FRONT AND CLOUDS ARRIVE LATER TODAY.
DISCUSSION
ISSUED AT 255 AM CST TUE JAN 13 2026
TODAY: ONE MORE MILD DAY WITH AFTERNOON & EVENING RAIN/SNOW SHOWERS
WE HAVE GOT ONE MORE MILD DAY IN STORE FOR TODAY AS A WEAK SHORTWAVE
EXITS TO OUR EAST THIS MORNING. WESTERLY FLOW DURING THE
DAYTIME HOURS WILL ALLOW OUR MILD AIRMASS TO REMAIN IN PLACE.
CONSEQUENTLY, EXPECTING HIGHS TO YET AGAIN REACH INTO THE 40S
FOR MUCH OF THE LOCAL AREA SOUTH OF I-94. WINDS WILL ALSO
INCREASE BY THE AFTERNOON AS THE COMBINATION OF A TIGHTENING
SURFACE PRESSURE GRADIENT AND MOMENTUM TRANSFER OF WINDS AROUND
30 KTS OFF THE DECK WILL ALLOW FOR GUSTS OF 25 TO 35 MPH THIS
AFTERNOON AND EVENING. AS WE HEAD INTO THE EVENING AND
OVERNIGHT, A COLD FRONTAL BOUNDARY WILL BEGIN TO PUSH INTO THE
AREA WHICH THE CAMS SUGGEST WILL INSTIGATE SOME ISOLATED TO
SCATTERED RAIN/SNOW SHOWERS WITH ITS PASSAGE. HOWEVER, NOT
EXPECTING MUCH IMPACT FROM THESE AT THIS TIME WITH LOW-LEVEL
LAPSE RATES NOT BEING ALL THAT STEEP.
WEDNESDAY - FRIDAY: SEASONABLY COLD WITH ACCUMULATING SNOW LIKELY
THURSDAY AFTERNOON THROUGH FRIDAY
WEDNESDAY WILL FEATURE A NOTICEABLE CHANGE IN TEMPERATURES AS
HIGHS RETURN TO SEASONABLE WITH MEDIAN HIGH TEMPERATURES IN THE
NBM RANGING FROM THE UPPER TEENS TO MIDDLE 20S AND LOWS
WEDNESDAY NIGHT LIKELY FALLING INTO THE SINGLE DIGITS FOR MOST
OF THE LOCAL AREA. ADDITIONALLY, WINDS WILL REMAIN BREEZY DURING
THE MORNING AND AFTERNOON WITH THE COLD ADVECTION BEHIND THE
AFOREMENTIONED SURFACE FRONTAL PASSAGE. CONSEQUENTLY, THE 13.00Z
HREF HAS RESPECTABLE PROBABILITIES (40-70% CHANCE) FOR WIND
GUSTS OVER 35 MPH CONTINUING INTO WEDNESDAY. HOWEVER,
PROBABILITIES FOR GUSTS HIGHER THAN THIS ARE QUITE LOW (UNDER
20% CHANCE). REGARDLESS, WILL CERTAINLY MAKE A COLD DAY FEEL
EVEN COLDER FOR WEDNESDAY.
THE NEXT SYSTEM OF FOCUS MOVES INTO THE REGION ON THURSDAY IN
FORM OF A PRONOUNCED SHORTWAVE TROUGHING REGIME ON THURSDAY
AFTERNOON. AS THIS INITIAL SHORTWAVE MOVES INTO THE AREA,
STRONG QG CONVERGENCE WILL BE THE MAIN FORCING MECHANISM WITH
THIS AS THE NAM/GFS DO NOT SHOW ANY OVERTLY STRONG SIGNAL FOR
FRONTOGENESIS WITH THIS FEATURE. CONSEQUENTLY, EXPECTING A
PERIOD OF LIGHT TO MODERATE SNOW BEGINNING THURSDAY EVENING AND
CONTINUING INTO FRIDAY. THE KEY QUESTION WITH THIS, THAT HAS
SOME VARIANCE IN DETERMINISTIC GUIDANCE, IS IF ANY ADDITIONAL
SUBTLE SHORTWAVE PERTURBATIONS WILL MOVE THROUGH THE BROADER
TROUGHING REGIME INTO THE LOCAL AREA. CURRENTLY, ENSEMBLE
GUIDANCE GENERALLY FAVORS THIS SOLUTION WHICH WOULD SUGGEST
KEEPING PERIODS OF SNOW GOING THROUGHOUT THE DAY ON FRIDAY.
AS FAR AS SNOWFALL AMOUNTS ARE CONCERNED, PROBABILITIES ARE FAIRLY
HIGH (50-90% CHANCE) IN THE GRAND ENSEMBLE (GEFS/EC/CANADIAN
ENSEMBLE) FOR ACCUMULATIONS IN EXCESS OF 2 INCHES ACROSS MUCH OF THE
LOCAL AREA WITH THE HIGHEST PROBABILITIES (70-90%) NEAR AND
NORTH OF I-90. THIS IS ASSUMING A SNOW TO LIQUID RATIO OF AROUND
15 TO 1 WHICH IS NBM MEAN SLR FOR THIS EVENT. THE EXACT CEILING
FOR SNOWFALL AMOUNTS REMAINS CONTINGENT ON HOW THE FORCING
MECHANISMS EVOLVE, PARTICULARLY INTO FRIDAY. CONFIDENCE IS VERY
HIGH THAT WE WILL SEE A PERIOD OF ACCUMULATING SNOW WITH THE
INITIAL SHORTWAVE THURSDAY AFTERNOON AND INTO FRIDAY MORNING.
HOWEVER, ADDITIONAL FORCING MECHANISMS BEHIND THE INITIAL
SHORTWAVE PASSAGE WILL BE KEY TO DETERMINING HOW ACCUMULATING
SNOW WOULD TREND LATER INTO THE DAY ON FRIDAY. IN ANY CASE, IT
IS VERY LIKELY WE WILL SEE A PERIOD OF ACCUMULATING SNOW
BEGINNING ON THURSDAY AFTERNOON AND CONTINUING INTO FRIDAY.
THERE ARE SOME INCREASING PROBABILITIES (20-50%) FOR SLIGHTLY
HIGHER SNOWFALL AMOUNTS IN EXCESS OF 4 INCHES IN THE GRAND
ENSEMBLE (GEFS/EC/CANADIAN ENSEMBLE) FROM THURSDAY AFTERNOON
THROUGH FRIDAY NIGHT. HOWEVER AGAIN, THIS WOULD BE CONTINGENT ON
HOW SUBSEQUENT FORCING MECHANISMS MANIFEST WITHIN THE BROADER
TROUGHING REGIME.
THIS WEEKEND: BELOW NORMAL TEMPERATURES LIKELY WITH SOME SNOW CHANCES
BY THE TIME THIS WEEKEND ROLLS AROUND, COLD ADVECTION WITH A SURFACE
COLD FRONT ASSOCIATED WITH THE AFOREMENTIONED SHORTWAVE WILL PUSH
THROUGH THE AREA RESULTING IN WELL BELOW NORMAL TEMPERATURES FOR THE
DAY ON SATURDAY. STILL SOME UNCERTAINTY WITH EXACTLY HOW COLD WE GET
AS DETERMINISTIC AND ENSEMBLE GUIDANCE HAS NOT YET RESOLVED EXACTLY
WHERE THE CORE OF THIS ARCTIC AIRMASS ENDS UP. CONSEQUENTLY, THE
INTER-QUARTILE RANGE FOR HIGHS ON BOTH SATURDAY AND SUNDAY RANGES
ANYWHERE FROM THE SINGLE DIGITS ABOVE ZERO TO AROUND 20 FOR HIGHS.
OVERNIGHT LOWS DURING THIS PERIOD HAVE A SIMILAR DEGREE OF VARIANCE
WITH INTER-QUARTILE RANGE OF THE NBM, RANGING FROM THE TEENS BELOW
ZERO TO SINGLE DIGITS ABOVE ZERO. SO FAIRLY HIGH CONFIDENCE THAT WE
WILL BE BELOW CLIMATOLOGICAL NORMALS FOR THE WEEKEND, QUESTIONS JUST
LINGER ON EXACTLY HOW COLD.
AS FAR AS PRECIPITATION CHANCES ARE CONCERNED FOR THE WEEKEND, SOME
POST-FRONTAL SNOW SHOWERS WILL BE POSSIBLE DURING THE DAY ON
SATURDAY. THIS IS GENERALLY AS A RESULT OF THE AFOREMENTIONED LOW-
LEVEL COLD ADVECTION STEEPENING LOW-LEVEL LAPSE RATES ALONG WITH THE
CYCLONIC FLOW IN PLACE WITHIN THE NORTHWESTERLY FLOW REGIME. OVERALL
FAIRLY STRONG PROBABILITIES (50-80%) IN THE GRAND ENSEMBLE
(GEFS/EC/CANADIAN ENSEMBLE) FOR MEASURABLE SNOW ON SATURDAY.
HOWEVER, PROBABILITIES FOR AMOUNTS OF AN INCH OR GREATER ARE
LOW (10-20% CHANCE). GIVEN THAT WE WILL BE IN NORTHWEST FLOW ON
SUNDAY AND INTO EARLY NEXT WEEK, WILL HAVE TO WATCH TO SEE IF
WE CAN GET ANY SHORTWAVES TO PROGRESS INTO THE REGION WITHIN THE
NORTHWESTERLY FLOW. HOWEVER, DETERMINISTIC AND ENSEMBLE
GUIDANCE HAVE LOW PREDICTABILITY ON HOW ANY SYSTEMS DURING THAT
PERIOD WOULD EVOLVE AT THIS POINT.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 445 AM CST TUE JAN 13 2026
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MUCH OF THE MORNING
WITH INCREASING WINDS INTO THE EARLY AFTERNOON TO AROUND 15-20 KTS.
WINDS GUSTS UP TO AROUND 25-30 KTS WILL BE POSSIBLE FROM THIS
AFTERNOON INTO WEDNESDAY WITH HIGHEST GUSTS WEST OF THE MISSISSIPPI
RIVER IN UNSHELTERED LOCATIONS. LLWS WILL CONTINUE TO BE A
CONSIDERATION AT KLSE THIS MORNING, HOWEVER BY MID TO LATE MORNING
INCREASING WIND GUSTS WILL REDUCE ANY LLWS CONCERNS. VFR CIGS THIS
MORNING WILL GIVE WAY TO MVFR CIGS THIS AFTERNOON WITH THE RECENT
HREF HAVING HIGH PROBABILITIES (60-90% CHANCE) FOR CEILINGS BELOW
2000FT. THESE WILL LIKELY PERSIST THROUGH THE OVERNIGHT WITH SOME
CHANCE FOR IMPROVEMENT BACK TO VFR TOWARDS 12Z ON WEDNESDAY. A STRAY
RAIN/SNOW SHOWER WILL BE POSSIBLE (15-20% CHANCE) LATER THIS
AFTERNOON AND EVENING AT KLSE HOWEVER CONFIDENCE WAS NOT HIGH ENOUGH
TO INCLUDE IN THIS TAF ISSUANCE.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
UPDATE...SKOW
DISCUSSION...NAYLOR
AVIATION...NAYLOR
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