736
FXUS63 KARX 011927
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
127 PM CST SUN FEB 1 2026
KEY MESSAGES
- ONE FINAL SNOW BAND MOVING THROUGH THIS AFTERNOON AND EARLY
EVENING (CENTRAL WI) WITH UP TO AN ADDITIONAL 1/2" EXPECTED.
IMPACTS SHOULD BE MINOR.
- WEAKER WEATHER SYSTEMS CONTINUE TO MOVE THROUGH NORTHWEST
FLOW WITH MORE LIMITED PREDICTABILITY. OVERALL IMPACTS FROM
WEATHER LOOK MINIMAL THROUGH 7 DAYS.
- TEMPERATURES WILL CONTINUE TO FLUCTUATE AROUND THE SEASONAL
NORMALS FOR EARLY FEBRUARY /HIGHS 20S, LOWS SINGLE DIGITS/
WITH A SLOW CREEP UPWARD LATE IN THE WEEK. WARMING ON THURSDAY
WILL LIKELY BRING HIGH TEMPERATURES ABOVE FREEZING FOR THE
FIRST TIME IN NEARLY 3 WEEKS!
DISCUSSION
ISSUED AT 127 PM CST SUN FEB 1 2026
SNOW ENDING LATER THIS AFTERNOON / EARLY EVENING
RADAR IS SHOWING ONE FINAL BAND OF SNOW TO MOVE THROUGH,
CURRENTLY POSITIONED OVER EASTERN MN AND EASTERN IA. THIS IS
ASSOCIATED WITH THE SECOND SHORTWAVE TROUGH/CURL CENTERED NEAR
MSP AT 19Z, WITH WARM ADVECTION CONTINUING IN THE LOW-LEVELS AND
LIFT AHEAD OF THIS WAVE. VISIBILITIES ARE LOWERING TO AROUND 2
MILES SO WITH THE PROGRESSIVE NATURE TO IT, A FEW TENTH OF
ACCUMULATION OF SNOW ARE EXPECTED. THE ROADS RECOVERED QUICKLY
ONCE THE FIRST ROUND OF SNOW ENDED THIS MORNING, SO WOULD THINK
IMPACTS WILL BE MINOR, A FEW SLICK SPOTS.
WEAKER WEATHER SYSTEMS MOVING THROUGH THIS WEEK - LITTLE IMPACT
LARGE SCALE NORTHWEST FLOW CONTINUES OVER THE UPPER MIDWEST BUT
SOME PROGRESSION IS SEEN IN THE PATTERN THIS WEEK ALLOWING
HEIGHTS TO RISE AND RIDGING TO BUILD IN. THIS WILL BRING A
GRADUAL WARM UP THROUGH THE WEEK WITH HIGHS IN THE 30S BY
THURSDAY. THIS TREND LOOKS TO CONTINUE INTO NEXT WEEKEND.
WEAK SYSTEMS IN NORTHWEST FLOW WILL CAUSE CHALLENGES TO
PREDICTABILITY THIS WEEK BUT OVERALL WHAT SHOULD BE LITTLE IMPACTFUL
WEATHER. TRANSIENT SYSTEMS BRING PERIOD OF CLOUDS AND DIFFERENT
SATURATION WHICH OCCASIONALLY TOYS WITH SUPERCOOLED LIQUID
SATURATED LAYER WITH LITTLE LIFT (FREEZING DRIZZLE?). SEEMS THE
PREDICTABILITY HORIZON WILL BE QUITE SHORT FOR THIS PATTERN.
ONE SYSTEM SHIFTS THROUGH IOWA ON MONDAY NIGHT PROVIDING A BAND OF
VERY LIGHT SNOW SOMEWHERE AROUND IOWA. THE 01.06Z ECMWF ENSEMBLE HAS
INCREASED MEASURABLE PRECIPITATION CHANCES TO 60-80% (24 HOUR)
ON A NW->SE SWATH JUST SOUTHWEST OF THE FORECAST AREA (MCW TO
NORTH OF DVN). HOWEVER, INDIVIDUAL MEMBER PLACEMENT OF THE BAND,
WHICH APPEARS FRONTOGENETICAL, VARIES FROM NEAR LA CROSSE TO
DES MOINES. SO, WEAK FORCING AND VARIOUS PLACEMENTS IN THE
NORTHWEST FLOW MAKE THIS A CHALLENGE BUT INTRODUCED SOME SNOW
CHANCES, BUT KEPT THEM LOW (20%). THIS LOOKS LIKE A LIGHT SNOW
OF A FEW TENTHS 03-15Z TUESDAY BUT WHERE IS THE QUESTION AS OF
RIGHT NOW.
STRONGER WARM ADVECTION KICKS IN THURSDAY AND WARMS HIGHS INTO
THE 30S FOR MUCH OF THE AREA. AT THE SAME TIME, STRONGER FORCING
WITH A SHORTWAVE TROUGH IN NORTHWEST FLOW SHIFTS MAINLY THROUGH
WI/GREAT LAKES. THE WARM AIR MOVING IN LOOKS TO BE ISOTHERMAL
IN THE LOW-LEVELS IN THE ENSEMBLE SOUNDING PROFILES REVIEWED (NO
LARGE WARM NOSE ALOFT) AND SUGGESTS RA/SN. THE 01.00Z ECMWF
ENSEMBLE PTYPE NOMOGRAMS ALSO INDICATE VERY LOW CHANCES (<10%)
OF MIXED PRECIPITATION IN THIS SYSTEM, AND MAINLY A RA/SN TYPE.
NBM HAS RESOLVED THIS WELL FOR THE FORECAST. PRECIPITATION
CHANCES ARE HIGHEST (40% IN CENTRAL WI) AND AMOUNTS LOOK VERY
LIGHT AGAIN (<0.10").
WEEKEND OUTLOOK AND TEMPERATURES
PREDICTABILITY TAKES A HIT ON THE WEEKEND FOR TEMPERATURE
FORECASTING WITH DIFFERENCES IN THE MAGNITUDE OF THE
PROGRESSIVE RIDGE BUILDING. LARGE INTERQUARTILE /25-75TH
PERCENTILE/ RANGES OF OVER 12F EXIST...WITH MIN/MAX VALUES FROM
THE TEENS TO LOW 40S FOR HIGHS. THURSDAYS SAME INTERQUARTILE
DIFFERENCE IF ONLY 4F, SO DIFFERENCE STARTING FRIDAY AND MAINLY
THE GEFS DEEPER AND COLDER WITH THE EASTERN NORTH AMERICAN
TROUGH...WHICH THE LOCAL AREA IS INFLUENCED BY. FOR NOW, MINOR
TO NO PRECIPITATION CHANCES ARE IN THE FORECAST AND STUCK WITH
THE NATIONAL BLENDED GUIDANCE WITH NEAR NORMAL, OR SLIGHTLY
ABOVE, TEMPERATURES. BUT, THERE IS BIG BOOM TEMPERATURE
POTENTIAL SHOULD THE RIDGE BUILD IN STRONGER (40S FOR HIGHS).
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1127 AM CST SUN FEB 1 2026
LIGHT SNOW AND ASSOCIATED MVFR/IFR CONDITIONS REMAIN THE PRIMARY
CONCERN IN THE AVIATION FORECAST. INITIAL ROUND OF SNOW IS
EAST OF THE MISSISSIPPI WITH SPORADIC FLURRIES ONGOING ACROSS
THE AREA. NEXT ROUND SWEEPS WEST TO EAST THROUGH THE REGION
AFTER 19Z WITH MVFR TO IFR EXPECTED TO RETURN AT RST/LSE FOR A
SHORT PERIOD. AFTER SNOW DEPARTS, LINGERING MVFR CEILINGS IN THE
1-2 KFT RANGE ARE EXPECTED. UNCERTAINTY FOCUSES ON WHEN THIS
CLOUD DECK BREAKS UP ENOUGH TO NO LONGER CONSTITUTE A CEILING
BUT CURRENT THINKING IS THAT THIS WILL OCCUR DURING THE 06Z TO
12Z TIME FRAME. ONCE THIS OCCURS, VFR SHOULD BECOME PREDOMINANT
THROUGH THE END OF THE PERIOD AND BEYOND (POTENTIALLY A FEW DAYS
BEYOND).
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...BAUMGARDT
AVIATION...FERGUSON
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