026
FXUS63 KARX 270831
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
231 AM CST FRI FEB 27 2026
KEY MESSAGES
- WARM & WINDY TODAY WITH WEST-NORTHWEST GUSTS FROM 30 TO 35 MPHTHROUGH
THE AFTERNOON AND EVENING PRIMARILY ALONG AND NORTH OF
INTERSTATE 90.
- VERY NARROW, 50-75 MILE, BAND OF HEAVIER SNOWFALL REMAINS
POSSIBLE SATURDAY MORNING AND AFTERNOON. GIVEN VERY NARROW
FORCING, HIGHEST AMOUNTS AND EXACT LOCATION REMAINS MAIN
FORECAST CHALLENGE AS ANY SHIFT IN STORM TRACK SHIFTS THE BAND
100 MILES NORTH OR SOUTH, 1 TO 2 TIMES THE WIDTH.
DISCUSSION
ISSUED AT 142 AM CST FRI FEB 27 2026
WARM & WINDY TODAY:
SIMILAR TO PREVIOUS FORECASTS, HIGH (80%+) CONFIDENCE FOR ABOVE
NORMAL TEMPERATURES ACROSS THE FORECAST AREA TODAY WITH DAYTIME
HIGHS FROM THE UPPER 40S TO LOW 50S. PREEXISTING SNOWPACK WILL
INFLUENCE WEIGHT OF WARMEST TEMPERATURES BEING REALIZED AS A RESULT
OF HEAT SINK AND INCREASED ALBEDO.
A TIGHTENING LOW LEVEL ISOHEIGHT GRADIENT WITHIN THE WARM SECTOR OF
A STRENGTHENING EXTRATROPICAL CYCLONE SHIFTING SOUTHEAST THROUGH
SOUTHERN CANADA INCREASES WEST-NORTHWEST WINDS WITH GUSTS OF 30 TO
35 MPH LIKELY FOR MUCH OF THE AREA. HIGHER FIRE WEATHER CONCERNS ARE
MOSTLY SHUNTED SOUTH AND WEST OF THE LOCAL FORECAST AREA, WELL
WITHIN THE WARM SECTOR, ALSO LOCALLY INFLUENCED BY PREEXISTING
SNOWPACK.
NARROW BAND OF HEAVY SNOW REMAINS POSSIBLE SATURDAY:
MAIN FORECAST CONCERN CONTINUES TO BE A NARROW BAND OF HEAVY
SNOWFALL THROUGH SATURDAY MORNING. AS THE MAIN EXTRATROPICAL CYCLONE
SHIFTS EAST THROUGH ONTARIO, CANADA TONIGHT, IT'S ESTRANGED LOW
LEVEL BAROCLINIC BOUNDARY STREWN FROM THE MID-MISSISSIPPI RIVER
VALLEY THROUGH THE NORTHERN PLAINS INTO THE NORTHERN ROCKIES WILL
FOSTER THE AREA FOR SUBSEQUENT CYCLOGENESIS. HIGH RESOLUTION
DETERMINISTIC AND ENSEMBLE (HREF/REFS) MODEL DISAGREEMENT SEEMINGLY
STEMS FROM SOUTHERN EXTENT OF COLD FRONT PLUNGING THROUGH THE UPPER
MISSISSIPPI RIVER VALLEY THIS EVENING INTO TONIGHT AND SUBSEQUENT
LOCATION OF CYCLOGENESIS, LOW TRACK, AND ACCOMPANYING
FRONTOGENETICAL BAND.
COLLOCATION OF ACCOMPANYING ENHANCED FRONTOGENESIS WITH AN
EXTREMELY THICK, 10K FT, AND NARROW, 100 MI, DENDRITIC GROWTH
ZONE RAISES MUCH CONCERN FOR HEAVY SNOWFALL RATES PRODUCING
HIGHER SNOWFALL TOTALS IN A NARROW BAND ACROSS THE FORECAST
AREA. A MORE SOUTHERN SOLUTION SHUNTS HIGHER MOISTURE SOUTH OF
THE FORECAST AREA WHILST MEAGER FRONTOGENESIS GRAZES THE
SOUTHERN HALF OF THE FORECAST AREA. A MORE NORTHERN SOLUTION
INCREASES MOISTURE AVAILABILITY AND RESULTS IN HEAVY SNOWFALL
TOTALS LOCALLY. WHILE MOST RECENT HRRR RUN (27.06Z) WANED
(HALVED) COMPARED TO PREVIOUS RUN (HRRR 27.00Z), 0.4" PWATS
PROGRESSING THROUGH THE FORECAST AREA CONTINUE PROVIDING WETTEST
12 HOUR QPF VALUES NEAR 0.4". SIMILAR QPF VALUES SEEN IN THE
RAP ARE EXACERBATED BY COLLOCATION OF ENHANCED FRONTOGENESIS
WITH SUBSTANTIAL, 10K FT, DGZ HEIGHTS.
REGARDLESS OF WHICH HIGH/LOW RESOLUTION ENSEMBLE MEMBER YOU CHOOSE,
ALL SOLUTIONS SUGGEST A NARROW (~50-75 MI) BAND OF ENHANCED SNOWFALL
RATES WITH MEASURABLE SNOWFALL FROM ENHANCED FRONTOGENESIS AND
STOUT, THICK DGZ FILAMENTS OF 7500'+ DRAPED ACROSS THE FORECAST
AREA. ON FACE VALUE, NEARLY ALL HREF MEMBERS ABSTAIN FROM WARNING
LEVEL CRITERIA SNOWFALL AMOUNTS WITH 10:1 SLR CALCULATIONS.
HOWEVER, ENHANCED FORCING WILL LIKELY PROVIDE CLOSER TO 20:1
SLRS, POTENTIALLY DOUBLING FACE-VALUE TOTALS.
HOWEVER, WHILE THESE CALCULATIONS THEN NEAR WARNING CRITERIA
LOCALLY, LACK OF SPATIAL CONFIDENCE COMBINED WITH THE VERY
TIGHT GRADIENT FOR EVEN /MEASURABLE/ SNOW AND DECREASED FORECAST
HOUR RESULTED IN COLLABORATION WITH NEIGHBORING FORECAST
OFFICES IN HOISTING A THIN WAFER WW.Y FROM SOUTHEAST MINNESOTA
INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN. VERY HIGH (90%)
CONFIDENCE IN THE ADVISORY REQUIRING A SPATIAL UPDATE AND
MODIFICATION DURING TODAY'S FORECAST PERIOD. SHOULD HREF
DPROG/DT TRENDS CONTINUE, A NORTHERN SHIFT INTO THE INTERSTATE
90 CORRIDOR IN CENTRAL WISCONSIN MAY ARISE, AGAIN.
SNOWFALL SUNDAY & PRECIPITATION CHANCES THROUGH NEXT WEEK:
ADDITIONAL PRECIPITATION CHANCES THROUGH SUNDAY HAVE MOSTLY
REMAINED SOUTH OF THE FORECAST AREA INTO THE MID MISSISSIPPI
RIVER VALLEY. CONFIDENCE WILL INCREASE WITH SATURDAY'S SYSTEM
PROGRESSION.
AS THE LOW LEVEL BAROCLINIC BOUNDARY LINGERS NEAR THE UPPER
MISSISSIPPI RIVER VALLEY THROUGH EARLY NEXT WEEK, SLIGHTLY ABOVE
NORMAL TEMPERATURES ARE ACCOMPANIED BY PRECIPITATION CHANCES.
EVENTUAL CYCLOGENESIS IN ENSEMBLES AND SELECT GLOBAL MODELS SUGGEST
HEAVY RAIN AND CONVECTION POTENTIALLY LATER NEXT WEEK.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1120 PM CST THU FEB 26 2026
INITIAL TEMPORARY VFR-MVFR BR AFFECTING SMALLER AIRPORTS WEST
OF THE MISSISSIPPI RIVER VALLEY LOCALLY IN NORTHEAST IOWA AND
SOUTHEAST MINNESOTA AT 26.06Z TAF ISSUANCE ISN'T EXPECTED TO
SINK DEEPER INTO LOWER CATEGORIES BUT REMAINS IMMEDIATE DETAIL
TO REMAIN COGNIZANT OF THROUGH THE OVERNIGHT HOURS.
SUBSEQUENT STRENGTHENING OF NOCTURNAL LOW LEVEL JET USHERS IN
LLWS CONCERNS FROM WEST TO EAST. WHILE STRONGER SURFACE WIND
SITES WEST OF THE MISSISSIPPI RIVER ARE LESS LIKELY TO REACH
CRITERIA, CORE OF STRONGEST LOW LEVEL WINDS EXPECTED TO REACH
THESE SITES. THEREFORE, HAVE CONTINUED SHORT WINDOW OF LLWS AT
KRST TAF SITE UNTIL SURFACE WINDS INCREASE THROUGH THE EARLY
MORNING HOURS. SURFACE WINDS INCREASE SLIGHTLY LATER AT KLSE TAF
SITE AND THEREFORE HAVE CONTINUED LLWS MENTION INTO THE MORNING
HOURS. STRONG SURFACE WINDS CONTINUE INTO FRIDAY NIGHT.
NARROW BAND OF HEAVY SNOWFALL EXPECTED SATURDAY MORNING. EXACT
LOCATION REMAINS INHERENT FORECAST DETAIL AFFECTING AVIATION
IMPACTS. LIFR-VLIFR POSSIBLE THROUGH SATURDAY MORNING WHERE
NARROW SNOW BAND SETS UP.
ARX WATCHES/WARNINGS/ADVISORIES
WI...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST SATURDAY FOR
WIZ053>055.
MN...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST SATURDAY FOR
MNZ086-087-094>096.
IA...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST SATURDAY FOR
IAZ009>011.
DISCUSSION...JAR
AVIATION...JAR
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