813
FXUS63 KARX 300608
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
108 AM CDT MON MAR 30 2026
KEY MESSAGES
- NEAR-RECORD WARMTH TODAY WITH HIGHS IN THE 70S TO NEAR 80
GIVES WAY TO COLDER THAN NORMAL TEMPERATURES BY MID-WEEK.
- ISOLATED STRONG TO SEVERE STORMS POSSIBLE OVERNIGHT AND INTO
TUESDAY MORNING. THE PRIMARY THREAT WITH ANY STRONG TO SEVERE
STORMS WILL BE LARGE HAIL.
- POTENTIAL FOR WINTRY MIX (40-70% CHANCE) WEDNESDAY NIGHT AND
INTO THURSDAY. SNOW AND ICE ACCUMULATIONS WILL BE POSSIBLE
DURING THIS PERIOD, HOWEVER CONFIDENCE IN EXACT AMOUNTS IS
VERY LOW AT THIS TIME.
DISCUSSION
ISSUED AT 1157 PM CDT SUN MAR 29 2026
TODAY - TUESDAY: NEAR-RECORD WARMTH TODAY, STORMS MONDAY EVENING
INTO TUESDAY MORNING
UPPER-LEVEL ZONAL FLOW AND WEAK RIDGING COMBINED WITH SOUTHERLY
SURFACE FLOW WILL BE THE DRIVERS FOR OUR VERY WARM TEMPERATURES
TODAY WITH THE NBM INTER-QUARTILE RANGE FOR HIGHS RANGING FROM THE
LOWER 70S TO LOWER 80S ACROSS MUCH OF THE AREA. FAIRLY DECENT MIXING
TO AROUND 850MB IN THE RECENT RAP/HRRR COUPLED WITH A DRY LAYER
ABOVE THIS WILL ALLOW FOR MINIMAL CLOUD COVER AND LARGER DEWPOINT
DEPRESSIONS NEAR THE SURFACE. AS A RESULT, WOULD NOT BE SURPRISED IF
WE TREND TOWARDS THE HIGHER PERCENTILES OF NBM AND KNOCK ON THE
DOOR OF SOME DAILY RECORDS IN SPOTS.
AS WE HEAD INTO THE LATE EVENING AND OVERNIGHT HOURS, THE
COMBINATION OF AN EML AT 700MB AND AN INCREASING AXIS OF 850MB
MOISTURE TRANSPORT HAS MUCH OF THE CAMS INSTIGATING A REGION OF
CONVECTION NEAR THE TRIPLE POINT OF IA/IL/WI AS THESE INGREDIENTS
INTERACT WITH A QUASI-STATIONARY BOUNDARY. OVERALL, RAP/HRRR
SOUNDINGS DEPICT A FAIRLY PRONOUNCED CAPPING INVERSION IN THIS
REGION WITH MUCAPE VALUES OF 1500-2500 J/KG AND FAIRLY DECENT MID-
LEVEL LAPSE RATES OF AROUND 8 C/KM. WHILE SHEAR PROFILES ARE NOT
OVERLY IMPRESSIVE IN THE UNSTABLE LAYER WITH ONLY SLIGHT HODOGRAPH
ELONGATION, THE MORE ROBUST THERMODYNAMICS WOULD CERTAINLY SUGGEST A
HAIL RISK WITH ANY STORMS THAT GET GOING IN THIS REGION. WILL NEED
TO WATCH ALONG THE CAPE GRADIENT AS WELL NEAR I-90 IF ANY STORMS CAN
DEVELOP ALONG THIS AS SHOWN IN THE HRRR/NAM NEST SOLUTIONS AS
THERE WOULD BE MORE SHEAR IN PLAY WHICH WOULD FAVOR ELEVATED
SUPERCELLS AT CONVECTIVE INITIATION WITH A SUBSEQUENT HAIL RISK.
OVERNIGHT THE AFOREMENTIONED QUASI-STATIONARY BOUNDARY LIFTS VERY
GRADUALLY NORTH AS A SURFACE LOW OVER THE GREAT PLAINS SHIFTS
TOWARDS THE REGION. THIS WILL ALLOW A MORE ROBUST AXIS OF MUCAPE TO
SHIFT NORTH TOWARDS I-90 CORRIDOR AHEAD OF AN APPROACHING COLD FRONT
FROM THE WEST ASSOCIATED WITH THE AFOREMENTIONED SURFACE LOW. AS
THIS COLD FRONT APPROACHES THE LOCAL AREA TOWARDS DAYBREAK, MUCH OF
THE CAMS AGREE ON INITIATING A SECONDARY ROUND OF CONVECTION WITH
THIS FRONTAL PASSAGE. OVERALL, HODOGRAPHS IN THE UNSTABLE LAYER ARE
LESS ELONGATED AS EARLIER IN THE NIGHT SO WOULD EXPECT MORE
TENDENCY FOR STORMS TO TREND MULTI-CELLULAR TO LINEAR IN THIS
REGIME WITH LARGE HAIL STILL BEING THE PREDOMINANT THREAT DUE TO
STEEP MID-LEVEL LAPSE RATES AND LARGER MUCAPE VALUES.
WEDNESDAY - FRIDAY: MUCH COOLER, MID-WEEK WINTRY MIX POTENTIAL
AFTER THIS AFOREMENTIONED COLD FRONT PASSES THROUGH THE AREA ON
TUESDAY, TEMPERATURES TAKE A NOTICEABLE DIP INTO THE MIDDLE OF THE
WEEK WITH HIGHS GENERALLY IN THE 30S AND 40S FOR WEDNESDAY AND
THURSDAY. AS WE HEAD INTO WEDNESDAY NIGHT AND THURSDAY, THE NEXT
SYSTEM THAT WE WILL NEED TO MONITOR MOVES TOWARDS THE REGION IN THE
FORM OF A SHORTWAVE TROUGH COUPLED WITH A DEVELOPING SURFACE LOW IN
THE EXIT REGION OF THIS SHORTWAVE. COMPARED TO YESTERDAY, THERE
SEEMS TO BE MUCH MORE AGREEMENT AMONGST DETERMINISTIC MODELS FOR THE
PATH AND AMPLIFICATION OF THIS SHORTWAVE. OVERALL CONCEPTUAL MODEL
WITH THE SYSTEM WOULD HAVE A SURFACE LOW DEVELOPING SOUTH OF THE LOCAL
AREA WITH A ROBUST DEFORMATION BAND ON ITS NORTHWEST FLANK.
WITHIN THE DEFORMATION BAND BOTH THE NAM/GFS HAVE A DECENT AXIS
OF 700- 800MB FRONTOGENESIS INTO THURSDAY MORNING. PRETTY STRONG
WARM ADVECTION PUSHES INTO THE AREA ALOFT AHEAD OF THIS LOW
WHICH ESTABLISHES A DECENT WARM NOSE ALOFT IN THE NAM/GFS
SOUNDINGS. THE MAIN QUESTIONS WITH THIS IS 1) HOW STRONG IS THIS
SURFACE LOW AND NORTHERLY WARM PUSH AND 2) WHAT IS THE EXACT
LOCATION OF THIS SURFACE LOW. THESE QUESTIONS WILL DICTATE HOW
PRECIPITATION TYPES AND HOW AMOUNTS WILL MANIFEST AT ANY GIVEN
LOCATION.
WHEN LOOKING AT THE CLUSTER ANALYSIS OF THE GRAND ENSEMBLE
(GEFS/EC/CANADIAN ENSEMBLE) EACH CLUSTER GROUP ENCOMPASSING ALL
MEMBERS NOW HAVE RESPECTABLE PROBABILITIES (40-70% CHANCE) FOR AN
INCH OR GREATER OF SNOWFALL IN THE LOCAL AREA, WITH SOME QUESTION ON
THE SOUTHERN EXTENT. WHAT IS EQUALLY OF INTEREST IS NOW A FREEZING
RAIN FOOTPRINT WITH MEDIUM PROBABILITIES (30-60%) FOR A GLAZE OF ICE
IS PRESENT IN ALL CLUSTER GROUPS WITH AGAIN DEVIATIONS ON THE EXACT
LOCATION IN THE LOCAL AREA. SO EVEN IF THE DETERMINISTIC MODELS
(NAM/GFS) HAVE SOME EYE CATCHING FREEZING RAIN AMOUNTS IN THE
REGION, STILL QUITE A BIT OF UNCERTAINTY ON WHERE AND TO WHAT EXTENT
ANY ICING THREAT MATERIALIZES AT THIS POINT. IN ANY CASE, CERTAINLY
A SYSTEM TO WATCH WITH INCREASING CONFIDENCE THAT SOME LEVEL OF
WINTER PRECIPITATION WILL BE PRESENT IN THE REGION, HOWEVER
QUESTIONS REMAIN ON EXACTLY HOW IMPACTFUL. ALSO IMPORTANT TO NOTE
THAT REGARDLESS OF PRECIPITATION TYPE, THE EC EXTREME FORECAST INDEX
HAS A FAIRLY IMPRESSIVE FOOTPRINT FOR ANOMALOUS QPF WITH HIGH
CONFIDENCE (70-90%) TO EXCEED EC MODEL CLIMATOLOGY WITH A SHIFT OF
TAILS OF 0 TO 1 WHICH IS DRIVEN BY THE MOST EXTREME EC MEMBERS
HAVING BETWEEN 2 TO 3 INCHES OF QPF.
THIS WEEKEND:
AS WE HEAD INTO THIS WEEKEND, DETERMINISTIC GUIDANCE UNIFORMLY
AGREES ON SWINGING A DEEPER AND BROADER TROUGH THROUGH THE CENTRAL
CONUS AND TOWARDS THE UPPER MIDWEST. AS A RESULT, GRAND ENSEMBLE
(GEFS/EC/CANADIAN ENSEMBLE) HAS VERY HIGH PROBABILITIES (80-90%) FOR
MEASURABLE QPF DURING THIS PERIOD. GIVEN THAT THERE IS SOME UPPER-
LEVEL RIDGING THAT MOVES INTO THE AREA FOR FRIDAY, SOME MODERATION
IN TEMPERATURES WILL LIKELY OCCUR SO CURRENT INDICATION BASED ON
THIS AND CURRENT PROGGED TRACK WOULD FAVOR A MOSTLY RAIN SOLUTION
FOR THE LOCAL AREA AT THIS TIME.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 103 AM CDT MON MAR 30 2026
VFR EXPECTED THROUGH THE 30.06Z TAF PERIOD. MVFR-IFR MAY SHIFT
SOUTHWEST INTO CENTRAL AND WESTERN WISCONSIN NEAR THE END OF THE
PERIOD.
CLIMATE
ISSUED AT 1248 AM CDT MON MAR 30 2026
NEAR RECORD HIGHS TODAY (RECORD/FORECAST):
ROCHESTER, MN 77 (1967) / 74
LA CROSSE, WI 80 (1910) / 76
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...NAYLOR
AVIATION...JAR
CLIMATE...JAR
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