616
FXUS63 KARX 012023
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
223 PM CST THU JAN 1 2026
KEY MESSAGES
- LOW SNOW CHANCES LATE FRIDAY NIGHT AND SATURDAY, MAINLY NORTH
OF INTERSTATE 90.
- ANOTHER WEATHER PRODUCER MOVES THROUGH THE REGION SUNDAY
AFTERNOON AND NIGHT AS TEMPERATURES CONTINUE TO WARM, WITH
HIGHER PROBABILITIES (40-55%) OF LIGHT SNOW FALLING NEAR/NORTH
OF INTERSTATE 94. THERE ARE SOME LOWER CHANCES (20-30%) THAT
THIS SYSTEM COULD HAVE A LIGHT WINTRY MIX IN THE I-90 TO I-94
CORRIDOR.
- ABOVE NORMAL TEMPERATURES EXPECTED NEXT WEEK WITH LITTLE TO
NO PRECIPITATION CHANCES AT THIS TIME.
DISCUSSION
ISSUED AT 223 PM CST THU JAN 1 2026
SATURDAY MORNING SMALL CHANCE FOR LIGHT SNOW NORTH OF I-90
A WEAK SYSTEM WILL BRUSH THE AREA IN NORTHWEST FLOW (AGAIN) WITH
VERY WEAK FORCING IT APPEARS AT THIS TIME. SOME VERY WEAK
FRONTOGENETIC SIGNAL IS SEEN...BUT THESE SYSTEMS ARE
OVERACHIEVING IN NORTHWEST FLOW AS OF LATE. WILL HAVE TO BE
READY TO AMP THIS ONE UP. 01.12Z CAMS / HREF HAVE SOME LOW
REFLECTIVITY SUGGESTIVE OF THE WEAK LIFT OVER THE AREA.
SOUNDINGS FROM 01.12Z DETERMINISTIC MODELS INDICATE MID-LEVEL
SATURATION WITH A 3-5KFT SURFACE-BASED DRY LAYER TO OVERCOME.
OVERALL I THINK THE LIFT WOULD BE MORE TIED TO THE SHORTWAVE
TROUGH SHIFTING THROUGH AND IF IT CAN ENHANCE FRONTOGENESIS LIKE
WE SAW TODAY. TODAY'S SNOW WAS VERY TIED TO THE APPARENT
SHORTWAVE TROUGH MOVING THROUGH THE NORTHWEST FLOW WITH A NICE
GOES WATER VAPOR DARKENING SIGNAL (OVER CENTRAL WI AT 18Z).
SUNDAY WINTRY MIX POSSIBLE, CHANCES NORTH OF I-90 CURRENTLY
LONGWAVE RIDGING CONTINUES TO BUILD ACROSS THE CENTRAL U.S THIS
WEEKEND AND CONFIDENCE PER THE 01.00Z LREF CLUSTER IS HIGH ON THIS
PATTERN. ON SUNDAY, A SHORTWAVE TROUGH, EJECTED FROM THE DEEP TROUGH
OFF THE WEST COAST, RIDES THE RIDGE THROUGH THE NORTHERN STATES.
WINDS IN THE LOW-LEVELS BACK TO SOUTHWESTERLY AND WARM ADVECTION
KICKS IN AHEAD OF THE TROUGH. THE 01.00Z LREF IS IN GOOD AGREEMENT
ON AN ELEVATED WARM LAYER ABOVE 0C MOVING NORTHEAST INTO THE
AREA SUNDAY AFTERNOON WITH PROBABILITIES INCREASING (FOR >0C
WARM LAYER MAXT) SOUTHWEST OF I-94. SURFACE T AND TW LAG AND
REMAIN BELOW FREEZING MAKING FOR THE POSSIBILITY OF A WINTRY MIX
OF PRECIPITATION AS THE TROUGH MOVES CLOSER. RIGHT NOW NORTHERN
WI, DOWN TO I-94 HAS HIGHER PROBABILITIES FOR SNOW, WITH A MIX
SOUTH OF THERE. THE LREF PROBABILITIES SUGGEST ABOUT A 30% (<10%)
CHANCE OF 0.01" (0.05") OF PRECIPITATION ON I-90, INCREASING
NORTHWARD. NORTH OF I-90, PRECIPITATION PROBABILITIES INCREASE,
AND THERE ARE CLUSTERS TAKING THE PRECIPITATION COMPLETELY
NORTH OF THE AREA (ABOUT 50% OF THE LREF MEMBERS). THE SOUTHERN
EDGE OF THE PRECIPITATION WOULD NEED TO BE INTO THE WARM LAYER
FOR NON-ZERO PROBABILITIES OF A WINTRY MIX INCLUDING ICE PELLETS
OR POSSIBLY FREEZING RAIN. PREDICTABILITY IS STILL LOW ON THESE
DETAILS, BUT SOMETHING TO WATCH. THE MODEL TREND OVER THE PAST
12 HOURS OF THE ECMWF ENSEMBLE IS SOUTHWESTWARD AND IT LOOKS
LIKE THE SYSTEM HAS LIGHT AMOUNTS (<0.10") FOR THE AREA. TIMING
WOULD BE SUNDAY AFTERNOON AND EVENING RIGHT NOW, BUT FIGURE
THAT WILL CHANGE. NBM HAS TRENDED TOWARD LOW CHANCES FOR
FREEZING RAIN IN THE FORECAST AS WELL IN THAT I-90 TO I-94
CORRIDOR AREA AND THUS HAVE ADDED THAT TO THE DETERMINISTIC
GRIDDED FORECAST.
TEMPERATURES WARMING INTO NEXT WEEK
THE LARGE SCALE FLOW WILL TRANSITION FROM NORTHWEST TO ZONAL OR
SLIGHTLY SOUTHWEST WITH MID-CONUS RIDGING LOOKING LIKELY BY NEXT
WEEK. THIS WILL CAUSE A WARMING TREND ACROSS THE AREA WITH
PROBABILITIES FOR ABOVE NORMAL TEMPERATURES QUITE HIGH (90%).
INTERQUARTILE MAX TEMPERATURE SPREADS ARE AROUND 5 DEGREES NEXT
WEEK IN THE 01.00Z LREF WHICH IS MODERATE PREDICTABILITY. A
MAJORITY OF THE GUIDANCE HAS A WEATHER SYSTEM MOVING THROUGH
THE NORTHERN STATES ON TUESDAY, WHICH WOULD BE JUST WEST OF THE
AREA. OVERALL, FAIRLY QUIET.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1127 AM CST THU JAN 1 2026
MAIN AVIATION IMPACT FOR 01.18Z TAF PERIOD IS A BAND OF
MODERATE SNOWFALL CAUSING IFR-MVFR VISIBILITIES ALONG AND EAST
OF THE MISSISSIPPI RIVER AT TAF ISSUANCE. HIGHEST IMPACTS SEEN
LIFTING AT KLSE SHORTLY AFTER 01.18Z TAF ISSUANCE, FROM LIFR TO
IFR VISIBILITIES, ARE EXPECTED TO CONTINUE THROUGH THE
AFTERNOON. NORTHWESTERN PERIPHERY OF RADAR RETURNS SEEN JUST
UPSTREAM OF KMSP WITH MVFR-IFR VISIBILITIES BETWEEN THERE AND
KLSE. THEREFORE, TIMED LIFTING OF IMPACTS AT KLSE BY 20Z BUT
WILL NEED TO CLOSELY MONITORED.
MVFR CEILINGS MAY SHIFT EAST THROUGH MINNESOTA AND IOWA
TONIGHT, AFFECTING KRST AS WELL AS POTENTIALLY ALL LOCAL SITES.
HAVE INCLUDED MENTIONED AT KRST BUT WILL BE SUBSEQUENT FORECAST
DETAIL TO KEEP AN EYE ON.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...BAUMGARDT
AVIATION...JAR
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