565
FXUS63 KARX 111959
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
159 PM CST THU DEC 11 2025
KEY MESSAGES
- ACCUMULATING SNOWFALL IS EXPECTED THIS AFTERNOON, PRIMARILY
OVER NORTHEAST IOWA WHERE 1-2 INCHES IS EXPECTED. ADDITIONAL
SNOWFALL IS POSSIBLE (10-60%) FRIDAY BRINING A FEW TENTHS UP
TO 1 INCH OF SNOW.
- TEMPERATURES ARE ON THE DECREASE THROUGH THE WEEKEND, WITH
HIGHS ON SATURDAY AND SUNDAY IN THE SINGLE DIGITS. WIND CHILLS
OF -25F TO -35F ARE EXPECTED SATURDAY AND SUNDAY MORNING. A
COLD WEATHER ADVISORY IS IN EFFECT FOR PORTIONS OF SOUTHEAST
MINNESOTA AND WEST-CENTRAL WISCONSIN SATURDAY MORNING.
- TRENDING TOWARDS MORE SEASONABLE TEMPERATURES AND DRIER
CONDITIONS FOR EARLY NEXT WEEK WITH HIGH TEMPERATURES
REBOUNDING INTO THE 30S.
DISCUSSION
ISSUED AT 158 PM CST THU DEC 11 2025
ACCUMULATING SNOWFALL THIS AFTERNOON AND FRIDAY
A WINTER SYSTEM DRIVEN BY A 700-500HPA SHORTWAVE TROUGH ONGOING
ACROSS THE CENTRAL GREAT PLAINS WILL CONTINUE TRUDGING
SOUTHEASTWARD THIS AFTERNOON INTO THE EVENING HOURS. A BAND OF
800-600HPA FRONTOGENESIS IS EXPECTED TO DRIVE SNOWFALL AND
SUBSEQUENT ACCUMULATIONS, BUT THE SOUTHWEST TREND NOTED BY THE
GLOBAL ENSEMBLE AND DETERMINISTIC GUIDANCE HAS NOW BEEN
REFLECTED WITHIN THE HIGH-RESOLUTION GUIDANCE, LEADING TO HIGH
CONFIDENCE IN THE MAJORITY OF SNOWFALL ACCUMULATIONS REMAINING
SOUTHWEST OF OUR AREA. ACCUMULATIONS AROUND 1 INCH ARE NOW
EXPECTED FOR PORTIONS OF NORTHEAST IOWA WITH A FEW TENTHS
POSSIBLE UP TO A LINE FROM ROCHESTER, MN TO PLATTEVILLE, WI.
DESPITE THE CONTINUED DECREASE IN SNOW AMOUNTS, EXPECT SOME
SLIPPERY TRAVEL DURING THE EVENING COMMUTE WHERE SNOW DOES
ACCUMULATE.
ANOTHER SHORTWAVE MOVES INTO THE REGION FRIDAY MORNING,
SHIFTING EASTWARD THROUGHOUT THE DAY. POSITIVE VORTICITY
ADVECTION, INFLUENCE FROM THE LEFT EXIT REGION OF AN APPROACHING
JET STREAK, AND WEAK 900-800HPA FRONTOGENESIS PER THE RAP
ASSOCIATED WITH THIS WAVE SHOULD PROVIDE ENOUGH UPWARD VERTICAL
MOTION TO ALLOW FOR SNOW DEVELOPMENT ACROSS THE REGION. A
SUBTLE MOISTURE TONGUE ALSO SHIFTS THROUGH THE AREA ALONG THE
WAVE, COINCIDING WITH A FAIRLY DEEP DGZ DEPICTED IN RAP/HRRR
SOUNDINGS. THIS COMBINED WITH THE ADEQUATE FORCING SHOULD
PROVIDE SOME HIGHER SNOW-LIQUID RATIOS, GENERALLY 15-20:1. ON
THE BACKSIDE OF THE PRIMARY WAVE, COLD AIR ADVECTION SHOULD
SUFFICIENTLY STEEPEN 0-1KM LAPSE RATES, GENERALLY 7-8C/KM,
WHICH COMBINED WITH LINGERING MOISTURE SHOULD LEAD TO SOME SNOW
SHOWERS FRIDAY AFTERNOON INTO THE EVENING, PRIMARILY ALONG AND
NORTH OF I-94. OVERALL, PROBABILITIES ARE HIGHEST ALONG AND
NORTH OF I-90 (30-60%) THROUGHOUT THE DAY, BUT SOME LOW
POTENTIAL EXISTS ACROSS THE WHOLE REGION (10-30%).
AMOUNTS ON FRIDAY LOOK TO BE FAIRLY LIGHT GIVEN THE GENERAL
LACK OF MOISTURE AND OVERALL WEAK FORCING, BUT WITH THE
AFOREMENTIONED DEEP DGZ AND HIGHER EXPECTED SNOW-LIQUID RATIOS,
ACCUMULATIONS SHOULD BE ON THE ORDER OF A FEW TENTHS UP TO
AROUND 1 INCH PER THE 11.12Z HREF LPMM.
COLD TEMPERATURES THIS WEEKEND
STRONG HIGH PRESSURE SINKS SOUTHEASTWARD OUT OF CANADA THROUGH
THE WEEKEND, USHERING AN ARCTIC AIRMASS INTO THE UPPER MIDWEST.
THE FIRST BOUT OF COLD AIR COMES FRIDAY NIGHT INTO SATURDAY,
WITH WIND CHILLS FALLING INTO THE DOUBLE DIGITS BELOW ZERO, DOWN
TO -30F FOR LOCATIONS TOWARDS NORTH-CENTRAL WISCONSIN. HAVE
ISSUED THE SEASON'S FIRST COLD WEATHER ADVISORY FOR SATURDAY
MORNING FOR AREAS ALONG AND NORTH OF I-90 TO HIGHLIGHT TO
DANGEROUS COLD. THIS MAY NEED TO BE EXTENDED SOUTHWARD, BUT
GIVEN EXPECTED CLOUD COVER, NOT AS CONFIDENT IN THE ULTIMATE
WIND CHILL VALUES FURTHER SOUTH.
HIGHER CONFIDENCE IN DANGEROUS COLD COMES SATURDAY NIGHT INTO
SUNDAY MORNING AS THE HIGH PRESSURE BECOMES MORE INFLUENTIAL.
CLEARING SKIES OVERNIGHT SHOULD ALLOW FOR EFFICIENT RADIATIONAL
COOLING, RESULTING IN AMBIENT TEMPERATURES FALLING INTO THE
TEENS BELOW ZERO. WIND CHILL VALUES FALL TO -25F TO -35F DURING
THIS PERIOD WITH THE 11.00Z LREF HIGHLIGHTING A 20-40%
PROBABILITY TO FALL BELOW -35F WEST OF THE MISSISSIPPI RIVER.
THESE VERY COLD TEMPERATURES WILL LIKELY WARRANT ADDITIONAL COLD
WEATHER HEADLINES IN THE COMING DAYS.
BEFORE THE COLDEST AIR ARRIVES SUNDAY MORNING, A BAND OF 700HPA
FRONTOGENESIS DEVELOPS ON THE SOUTHERN EXTENT OF THE HIGH
PRESSURE, SPARKING ANOTHER RIBBON OF SNOWFALL ACROSS PORTIONS OF
MINNESOTA AND IOWA SATURDAY AFTERNOON. THIS BAND OF SNOW IS
CURRENTLY EXPECTED TO FOLLOW A VERY SIMILAR TRAJECTORY TO
TODAY'S SNOWBAND WITH A 20-50% PROBABILITY OF PRECIPITATION
ACROSS NORTHEAST IOWA. WITH THE SIMILAR TRAJECTORY, THE
GREATEST SNOWFALL AMOUNTS ARE EXPECTED SOUTHWEST OF OUR AREA.
GENERALLY A FEW TENTHS OF AN INCH OF SNOW IS EXPECTED AS THE
11.13Z NBM HIGHLIGHTS ONLY A 10-20% PROBABILITY FOR MORE THAN 1
INCH.
WARMER AND DRIER EARLY NEXT WEEK
AFTER THE WEEKEND, THE UPPER LEVEL PATTERN FINALLY BEGINS TO
SHIFT AS LONGWAVE RIDGING BUILDS INTO THE CENTRAL UNITED STATES.
THIS UPPER RIDGING IS ANTICIPATED TO BRING A MUCH NEEDED
REPRIEVE FROM THE ACTIVE NORTHWEST FLOW OF THE PAST WEEK OR TWO,
ALTHOUGH THERE ARE A FEW SHORTWAVES THAT TRAVERSE THE MEAN FLOW
THROUGH THE BEGINNING OF THE NEW WEEK. HOWEVER, WITH THE RIDGE
THE DOMINANT FEATURE, THESE SHORTWAVES TEND TO STAY NORTH OF THE
LOCAL AREA ALONG WITH ANY PRECIPITATION POTENTIAL ASSOCIATED
WITH THEM, SO A FEW DRY DAYS ARE CURRENTLY EXPECTED THROUGH AT
LEAST THE MIDDLE OF THE NEW WEEK. TEMPERATURES ALSO BEING TO
WARM WITH THE RISING HEIGHTS AND WARM AIR ADVECTION UNDER
SOUTHWESTERLY LOW LEVEL FLOW, WITH THE 11.13Z NBM MEAN
SUGGESTING HIGH TEMPERATURES WILL BE FAR MORE SEASONABLE, RISING
INTO THE MID 30S THROUGH THE BEGINNING OF THE NEW WEEK. BY MID-
WEEK, ENSEMBLE GUIDANCE SUGGESTS THE NEXT WINTER SYSTEM COULD
MOVE THROUGH OUR AREA, BUT FAR TOO MUCH VARIABILITY EXISTS TO
GLEAN MUCH INFORMATION APART FROM THE POSSIBILITY.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1135 AM CST THU DEC 11 2025
MVFR TO LOW-VFR CONDITIONS LINGER THROUGHOUT MUCH OF THE TAF PERIOD
WITH LOW-LEVEL MOISTURE PERSISTING IN THE RAP/HRRR SOUNDINGS.
ADDITIONALLY, THE RECENT HREF KEEPS PROBABILITIES FAIRLY HIGH
(50-70%) FOR MVFR CIGS PAST 00Z FRIDAY AND INTO THE OVERNIGHT
WEST OF THE MISSISSIPPI RIVER WITH MUCH LOWER PROBABILITIES
(10-40%) EAST OF THE MISSISSIPPI RIVER. LIGHT SNOW WILL ATTEMPT
TO SNEAK INTO KRST THIS EVENING AS A BAND OF SNOW PUSHES TO THE
SOUTHEAST, HOWEVER CONFIDENCE IS ON THE LOWER END (20-40%
CHANCE) THAT THIS WOULD BRING CATEGORY REDUCING VSBYS AT THE
TERMINAL. A SECONDARY ROUND OF SNOW WILL PUSH FROM WEST TO EAST
ACROSS THE LOCAL AREA DURING THE MORNING HOURS ON FRIDAY
BRINGING SOME CHANCE (20-40%) FOR LIGHT SNOW AT EITHER KLSE OR
KRST FOR A FEW HOURS. IFR CIG PROBABILITIES INCREASE (60-80%) AT
KRST WITH THIS SYSTEM WITHIN THE HREF AND THUS HAVE INCLUDED
SOME MENTION TOWARDS THE END OF THE TAF PERIOD. WINDS WILL
GENERALLY REMAIN LIGHT AND VARIABLE UNTIL THE MORNING HOURS ON
FRIDAY WHERE WINDS WILL STEADILY INCREASE TO AROUND 10-15 KTS
FROM THE WEST-NORTHWEST BY 18Z ON FRIDAY.
ARX WATCHES/WARNINGS/ADVISORIES
WI...COLD WEATHER ADVISORY FROM MIDNIGHT FRIDAY NIGHT TO 10 AM CST
SATURDAY FOR WIZ017-029-032>034.
MN...COLD WEATHER ADVISORY FROM MIDNIGHT FRIDAY NIGHT TO 10 AM CST
SATURDAY FOR MNZ079-086>088.
IA...NONE.
DISCUSSION...FALKINHAM
AVIATION...NAYLOR
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