931
FXUS63 KARX 291047
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
547 AM CDT SUN MAR 29 2026
KEY MESSAGES
- WARMER TEMPERATURES FOR TODAY AND MONDAY WITH HIGHS IN THE 70S
NEAR AND SOUTH OF I-94 ON MONDAY. COOLER TEMPERATURES BY MID-
WEEK WITH HIGHS IN THE 40S AREAWIDE.
- ISOLATED STRONG TO SEVERE STORMS POSSIBLE ON MONDAY EVENING
AND OVERNIGHT WITH HAIL BEING THE PRIMARY THREAT.
- RAIN AND SNOW CHANCES (30-50%) FOR WEDNESDAY NIGHT INTO
THURSDAY.
DISCUSSION
ISSUED AT 1149 PM CDT SAT MAR 28 2026
TODAY - MONDAY: WARM, STORM CHANCES MONDAY NIGHT
UPPER-LEVEL RIDGING AND SOUTHERLY SURFACE FLOW WILL DOMINATE THE
SYNOPTIC FLOW PATTERN OVER THE NEXT TWO DAYS RESULTING IN ABUNDANT
WARM ADVECTION TO PUSH INTO THE REGION. CONSEQUENTLY, TEMPERATURES
WILL FEATURE A ROBUST WARMING TREND FOR SUNDAY AND ESPECIALLY ON
MONDAY WITH INTER-QUARTILE SPREAD IN THE NBM FOR HIGH TEMPERATURES
RANGING FROM THE UPPER 60S TO AROUND 80 SOUTH OF I-94 ON MONDAY
AFTERNOON. OVERALL, WHILE THE EC EXTREME FORECAST INDEX HAS FAIRLY
DECENT PROBABILITIES (50-70%) FOR EXCEEDING MODEL CLIMATOLOGY,
THE ABSENCE OF ANY SHIFT OF TAILS IN THE LOCAL AREA SUGGESTS
THAT ANY RECORD WARMTH IS LESS LIKELY. IN ANY CASE, WITH FAIRLY
DECENT MIXING IN RAP SOUNDINGS WITH A LOW-LEVEL DRY LAYER, COULD
CERTAINLY BE POSSIBLE FOR HIGHS TO TREND CLOSER TO THE HIGHER
PERCENTILES OF THE NBM ON MONDAY AFTERNOON.
AS WE HEAD INTO THE EVENING AND OVERNIGHT HOURS ON MONDAY, AN AXIS
OF 850MB MOISTURE TRANSPORT PUSHES NORTH INTO THE LOCAL AREA
ADVECTING IN HIGHER DEWPOINTS OVERNIGHT INTO THE 50S. AS THIS
OCCURS, INSTABILITY (MUCAPE VALUES OF AROUND 1000-1500 J/KG IN THE
NAM) INCREASES AS THIS MOISTURE TRANSPORT AXIS OVERRUNS A STATIONARY
BOUNDARY SITUATED NEAR I-90. THE LOW-LEVELS IN NAM/GFS SOUNDINGS ARE
FAIRLY CAPPED WITH THE BULK OF THE UNSTABLE LAYER BEING ABOVE 2KM.
HOWEVER, WITH STILL SOME ELONGATION TO MODEL HODOGRAPHS, WOULD
EXPECT SOME TENDENCY FOR ELEVATED STORMS TO BEGIN AS A SUPERCELLULAR
MODE PRIOR TO QUICKLY BECOMING MULTI-CELLUAR. GIVEN SOME STEEPER MID-
LEVEL LAPSE RATES TO AROUND 7-8 C/KM AND THE SUFFICIENT SHEAR,
THINKING THAT HAIL WILL BE THE PRIMARY THREAT WITH ANY STRONG TO
SEVERE STORMS THAT DO DEVELOP, CONTINGENT ON THE EXACT LOCATION OF
WHERE THIS STATIONARY BOUNDARY SETS UP.
TUESDAY - FRIDAY: TURNING COOLER, ADDITIONAL PRECIPITATION CHANCES
AS WE HEAD INTO TUESDAY, A COLD FRONTAL PASSAGE DURING THE DAYTIME
HOURS ON TUESDAY WILL BRING ADDITIONAL SHOWER AND ISOLATED STORM
POTENTIAL IN ADDITION TO USHERING MUCH COOLER TEMPERATURES BEHIND
THE FRONTAL PASSAGE. AS A RESULT, INTER-QUARTILE HIGH TEMPERATURES
IN THE NBM RANGE FROM THE LOWER 40S TO LOWER 50S ACROSS THE AREA,
LIKELY UNIFORMLY BELOW CLIMATOLOGICAL NORMALS FOR MOST. TEMPERATURES
FOR THURSDAY MAY TREND EVEN COOLER WITH THE LOWER PERCENTILES IN THE
NBM HAVING HIGHS IN THE 30S FOR SOME.
THE NEXT FEATURE THAT BEARS MONITORING COMES DURING THE LATE
WEDNESDAY AND INTO THURSDAY TIMEFRAME AS A 500MB SHORTWAVE EJECTS
FROM THE CENTRAL ROCKIES AND INTO THE CENTRAL PLAINS ON THURSDAY.
CURRENTLY, THERE REMAINS SOME DEVIATIONS IN THE EXACT PLACEMENT
OF THIS SHORTWAVE AS THE EC SOLUTION TENDS TO FAVOR A SLOWER
AND WEAKER TROUGH AS OPPOSED TO THE GEFS SOLUTIONS WHICH HAS
SHOWN A FASTER AND MORE AMPLIFIED TROUGH. THIS HAS FAIRLY
PROMINENT IMPLICATIONS AS A FASTER AND MORE AMPLIFIED TROUGH
FAVORS A STRONGER AND DEEPER SURFACE LOW THAT PASSES CLOSER TO
THE REGION UNLIKE THE EC COUNTERPART. OVERALL, CLUSTER ANALYSIS
OF THE GRAND ENSEMBLE (GEFS/EC/CANADIAN ENSEMBLE) HAS HIGHER
PROBABILITIES (40-70% CHANCE) FOR MEASURABLE SNOW IN THE GEFS
FAVORED CLUSTERS (ROUGHLY 1/3 OF MEMBERS) COMPARED TO THE EC
DOMINATED CLUSTERS (ROUGHLY 2/3 OF MEMBERS) WHICH HAS LOW
PROBABILITIES (10-30%) FOR MEASURABLE SNOW. OVERALL, GIVEN THAT
WE ARE GETTING INTO APRIL AS WELL, THERMAL PROFILES WOULD BE A
QUESTION SO CONFIDENCE OF HOW IF ANY WINTRY PRECIPITATION WILL
MANIFEST WITH THIS SYSTEM AS IT MOVES INTO THE AREA IS VERY LOW.
IN ANY CASE, THE GRAND ENSEMBLE (GEFS/EC/CANADIAN ENSEMBLE) HAS
HIGH PROBABILITIES (70-90%) FOR MEASURABLE QPF DURING THIS
PERIOD, SO CONFIDENCE IS HIGH WE WILL SEE SOME PRECIPITATION
MID-WEEK, JUST A MATTER OF IF ANY SNOW WILL CREEP ITS WAY IN.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 545 AM CDT SUN MAR 29 2026
VFR EXPECTED THROUGH THE 29.12Z TAF PERIOD. OFF SURFACE WINDS
THAT WARRANTED LLWS MENTION AT KLSE OVERNIGHT HAVE WEAKENED
ENOUGH TO LEAVE OUT AT 29.12Z TAF ISSUANCE. SIMILAR
STRENGTHENING TO NOCTURNAL LOW LEVEL JET TONIGHT RAISES LLWS
CONCERNS AT CALMER SURFACE WIND SUSCEPTIBLE LOCATIONS. CURRENT
CONFIDENCE AND STRENGTH DOESN'T MEET CRITERIA OR WARRANT
INCLUSION AT KLSE TAF SITE BUT WILL REQUIRE FURTHER ADDRESSING
IN SUBSEQUENT TAF ISSUANCES.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...NAYLOR
AVIATION...JAR
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page