493
FXUS63 KARX 271143
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
543 AM CST SAT DEC 27 2025
KEY MESSAGES
- CONFIDENCE IS INCREASING FOR IMPACTFUL WINTER STORM SUNDAY
MORNING INTO MONDAY MORNING. HIGHEST SNOWFALL TOTALS OF 4" TO
6" FORECASTED ALONG AND NORTH OF INTERSTATE 90 FROM SOUTHEAST
MINNESOTA INTO WESTERN AND CENTRAL WISCONSIN. WINTER STORM
WATCHES FOR ACCUMULATING SNOWFALL AND BLIZZARD CONDITIONS HAVE
BEEN ISSUED.
- COLD TEMPERATURES THROUGH THE END OF THE WEEK MAY REACH COLD
WEATHER ADVISORY CRITERIA, OVERALL CONFIDENCE REMAINS DEPENDENT
ON EVOLUTION OF EARLY WEEK STORM SYSTEM.
DISCUSSION
ISSUED AT 337 AM CST SAT DEC 27 2025
PERSISTENT DRIZZLE & FOG TODAY:
THE LOW LEVEL MOISTURE OF THE HOLIDAY WEEK INCREASES THROUGH
TODAY AS THE LOW LEVEL RIDGE AXIS TRAVERSES THE FORECAST AREA
THIS MORNING AND RETURN FLOW ADVECTS A FILAMENT TIED TO GULF
MOISTURE TOWARDS THE UPPER MISSISSIPPI RIVER VALLEY. THEREFORE,
HAVE CONTINUED DRIZZLE/RAIN ADDITIONS OVER /MOST/ FORECAST
MODEL GUIDANCE TODAY AND TONIGHT. WHILE ISENTROPIC UPGLIDE WILL
BE A SUFFICIENT FORCING MECHANISM, THICKNESS OF LOW LEVEL
MOISTURE REALIZING FOG VS. DRIZZLE WILL BE DETERMINING FACTOR.
REGARDLESS, WHILE RECENT TEMPERATURE FORECASTS HAVE RUN A COUPLE
OF DEGREES WARMER THAN OBSERVATIONS, EXPECT ABOVE FREEZING
SURFACE TEMPERATURES ACROSS THE FORECAST AREA TO LIMIT OVERALL
IMPACTS.
WINTER STORM IMPACTS SUNDAY THROUGH MONDAY MORNING:
CONFIDENCE IN IMPACTFUL WINTER STORM CONTINUES TO INCREASE AS
CONFLUENCE WITHIN THE SYNOPTIC PATTERN CAUSES RAPID SURFACE
CYCLOGENESIS FROM THE MID MISSISSIPPI RIVER VALLEY SUNDAY
MORNING. DEEPER, SLIGHTLY MORE SOUTHERN SOLUTIONS TO THE SURFACE
LOW INCREASED LOCAL SNOWFALL IMPACTS FROM MORE ENHANCED LOW
LEVEL FRONTOGENESIS LINGERING THROUGH SUNDAY NIGHT OVER THE
FORECAST AREA. BESIDES ACCUMULATING SNOWFALL, THE RESULTANT
TIGHTENED PRESSURE GRADIENT WITH ENHANCED LOW LEVEL COLD AIR
ADVECTION WILL INCREASE NORTHWEST WINDS (25+KTS SUSTAINED HREF) EXACERBATING
VISIBILITY CONCERNS WITHIN AN ALREADY THICK DGZ RESIDENCE.
WINTER STORM HEADLINES ISSUANCES:
CURRENT CONFIDENCE FOR STRONGEST COLD AIR ADVECTION CAUSING FLASH
FREEZE CONCERNS COMBINED WITH HREF PROBABILITIES FOR INCREASED
WIND GUSTS PRIMARILY AFFECTS LOCALLY WESTERN MOST COUNTIES FROM
SOUTHEAST MINNESOTA INTO NORTHEAST IOWA. THEREFORE, HAVE ISSUED
WINTER STORM WATCH FOR BLIZZARD IN THESE COUNTIES IN
COLLABORATION WITH NEIGHBORING FORECASTS OFFICES (DMX/MPX). A
DEFAULT WINTER STORM WATCH WAS ISSUED ELSEWHERE, IN SOUTHEAST
MINNESOTA COUNTIES ADJACENT TO THE MISSISSIPPI RIVER AND WESTERN
INTO CENTRAL WISCONSIN, WHERE CONFIDENCE FOR 4"+ OF SNOWFALL
ALIGNS WITH FLASH FREEZE POTENTIAL AND STRONG WINDS ALONG
INTERSTATE CORRIDORS DURING THE HOLIDAY WEEKEND TRAVEL PERIOD.
FORECAST CONFIDENCE & POTENTIAL IMPACTS:
WHILE CONFIDENCE FOR IMPACTFUL SNOW IS HIGH, THE RAPID EVOLUTION OF
THE PARENT EXTRATROPICAL CYCLONE OVER THE FORECAST AREA PERSISTS
/SOME/ UNCERTAINTY REGARDING LOCATION OF HIGHEST IMPACTS. THE SOUTH-
SOUTHWEST SHIFT IN LREF MEMBERS OVER PREVIOUS RUNS INCREASES LOCAL
FORECAST AND IMPACTS, SHOULD THE SOUTHWEST TREND CONTINUE THEN
HIGHER IMPACTS WILL LIKELY BE REALIZED.
FURTHER HEADLINE COMPLICATIONS ARISE REGARDING WIND SPEEDS AS
CURRENT HIGH RESOLUTION MODEL SOUNDINGS, HREF/LREF CONFIDENCE, AND
NDFD FORECAST WHICH WAS INCREASED FROM NBM IN COLLABORATION WITH
NEIGHBORING FORECAST OFFICES, SUPPORT ADVISORY SPEEDS ALONG AND WEST
OF THE MISSISSIPPI RIVER SUNDAY NIGHT INTO MONDAY MORNING.
SHOULD THE FATTER FLAKES, BROKEN UP BY THE STRONGER WINDS, BE
TOO WET TO BLOW AFTER REACHING THE GROUND AND NOT CAUSE
WIDESPREAD VISIBILITY CONCERNS (BLIZZARD), FURTHER HEADLINE
ASSESSMENT WILL BE REQUIRED.
COLDER THROUGH END OF THE WEEK:
THE POLAR AIRMASS SAGS SOUTHEAST ACROSS THE FORECAST AREA
THROUGH MIDWEEK WITH DAYTIME HIGHS BOTTOMING OUT IN THE SINGLE
DIGITS THURSDAY (LREF) AND SINGLE DIGITS OVERNIGHT LOWS
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/SATURDAY MORNING. WHILE
CURRENT CONFIDENCE IN TEMPERATURES IS MODERATE (30-50%), WIND
SPEEDS WILL REQUIRE ADDITIONAL CONFIDENCE REGARDING APPARENT
TEMPERATURES AND POTENTIAL COLD WEATHER HEADLINE CONCERNS MOSTLY
THURSDAY AND FRIDAY MORNINGS.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 532 AM CST SAT DEC 27 2025
FURTHER MOISTENING TO AN ALREADY SATURATED LOW LEVEL AIR MASS
PERPETUATES LIFR-VLIFR IMPACTS THROUGH MUCH OF THE 27.12Z TAF
PERIOD. CONFIDENCE IN CEILING IMPACTS REMAINS HIGH ACROSS THE
FORECAST AREA WHILE VISIBILITY IMPACTS ARE LESS CERTAIN. LOWER
ELEVATION SITES WITHIN RIVER VALLEYS (E.G., KLSE) HAVE MOSTLY
BEEN SPARED FROM LIFR VISIBILITIES. WHERE LIFR VISIBILITIES ARE
OCCURRING, INCREASING SURFACE WINDS MAY PROVIDE SUFFICIENT
MIXING FOR BETTER VISIBILITIES IN A SHORT WINDOW THIS AFTERNOON.
HAVE ACCOUNTED FOR THIS AT KRST TAF SITE FROM 19Z TO 23Z ALBEIT
IFR OR LIFR CEILINGS REMAIN LIKELY.
SUBSEQUENT IMPACTS FROM PRECIPITATION INITIALLY EXPECTED AT
27.12Z TAF PERIOD TERMINUS, LASTING THROUGH MONDAY MORNING
PRIMARILY IN CENTRAL WISCONSIN. INITIAL RAIN SWITCHES TO SNOW
FROM NORTHWEST TO SOUTHEAST THROUGH SUNDAY. A DEEPENING LOW
PRESSURE SYSTEM WILL RESULT IN STRONG NORTHWEST WINDS SUSTAINED
NEAR 30 KTS WEST OF THE MISSISSIPPI RIVER, GUSTING NEAR 40 KTS
AT TIMES. BLIZZARD CONDITIONS WILL BE POSSIBLE WEST OF THE
MISSISSIPPI RIVER. HIGHEST SNOWFALL AMOUNTS EXPECTED ALONG AND
NORTH OF INTERSTATE 90 LOCALLY IN SOUTHEAST MINNESOTA AND
WESTERN INTO CENTRAL WISCONSIN.
ARX WATCHES/WARNINGS/ADVISORIES
WI...WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR WIZ032-033.
WINTER WEATHER ADVISORY FROM 3 PM SUNDAY TO NOON CST MONDAY
FOR WIZ053>055.
WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
MORNING FOR WIZ017-029-034-041>044.
MN...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR MNZ079-086>088-
094>096.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR MNZ079-086>088-094-095.
WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
MORNING FOR MNZ096.
IA...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR IAZ008>011-018-019-
029-030.
WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR IAZ008-009-018-019.
WINTER WEATHER ADVISORY FROM 3 PM SUNDAY TO NOON CST MONDAY
FOR IAZ010-011.
DISCUSSION...JAR
AVIATION...JAR
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