264
FXUS63 KARX 301843
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
143 PM CDT MON MAR 30 2026
KEY MESSAGES
- LOW STORM CHANCES ACROSS THE SOUTH THIS EVENING (7-10 PM)
BRING A SMALL CHANCE FOR HAIL TO QUARTER SIZE AND DAMAGING
WIND GUSTS. THIS IS A VERY CONDITIONAL THREAT BASED ON STORMS
BEING ABLE TO FORM IN NORTHEAST IOWA AND SOUTHWEST WI. STORM
CHANCES INCREASE AGAIN TUESDAY MORNING AROUND I-90 AND SOUTH
WITH A LARGE HAIL THREAT AGAIN.
- THE FIRST OF TWO STRONG WEATHER SYSTEMS MOVES THROUGH THE AREA
MIDWEEK AND PROBABILITIES ARE INCREASING FOR WINTRY IMPACTS
WEDNESDAY NIGHT INTO THURSDAY. CHANCES ARE INCREASING FOR SNOW
AND ICE ACCUMULATIONS JUST SOUTH OF I-90 AND NORTHWARD, WITH
RAIN SOUTH. THERE IS SOME POTENTIAL ICE ACCUMULATIONS TO REACH
1/4 INCH (30%) NORTHEAST OF I-94. UNCERTAINTY REMAINS
MODERATE.
- THE SECOND STRONG SYSTEM MOVES THROUGH THE MIDWEST LATE IN THE
WEEK AND INTO THE WEEKEND. THE AREA LOOKS TO BE ON MAINLY THE
WARMER SIDE OF THIS STORM WITH RAIN. THE STORM TRACK WILL
DETERMINE THE WINTRY WEATHER LOCATION, BUT RIGHT NOW THE
PROBABILITIES FOR ACCUMULATING SNOW APPEAR MORE TOWARD
CENTRAL MN AND NORTHERN WI, WITH SOME WINTRY MIX POSSIBLE
(30%) NORTH AND WEST OF LA CROSSE.
DISCUSSION
ISSUED AT 142 PM CDT MON MAR 30 2026
STORM CHANCES TONIGHT AND TUESDAY MORNING
A PREDOMINANT ZONAL FLOW CONTINUES ACROSS THE AREA INTO TUESDAY WITH
A NUMBER OF EMBEDDED SHORTWAVE TROUGHS SHIFTING THROUGH. A
STATIONARY FRONTAL BOUNDARY PARALLELS I-90 WITH SOUTHERLY FLOW
MOISTURE ADVECTING HIGHER DEWPOINT AIR IN, AND INSTABILITY IS
GROWING SLOWLY SOUTH OF THE FRONT. ONE OF THE LIMITING FACTORS
HOWEVER IS A VERY STRONG CAPPING INVERSION IN PLACE. THE LATEST
HRRR/NAM3KM CONVECTIVE INHIBITION ACROSS SOUTHWEST WI / NERN IA
MINIMIZES AT 125 J/KG PREVENTING SURFACE-BASED STORMS, FAVORING
MORE SOUTH OF THE FORECAST AREA CLOSER TO THE I-80 CORRIDOR.
STEEP, IMPRESSIVE LAPSE RATES ALOFT DUE TO AN ELEVATED MIXED
LAYER PRESENCE ALOFT IS FAVORABLE FOR UPDRAFT INTENSITY SHOULD
THE FORCING BE ENOUGH TO INITIATE ELEVATED STORMS. A WEAK LOW-
LEVEL MOISTURE TRANSPORT CONVERGENCE AREA DOES SHIFT THROUGH
NORTHEAST IA AND SOUTHWEST WI FROM 5-9 PM. SO, A CONDITIONAL
THREAT BASED ON THE FORCING SATURATING ALOFT AND LEVERAGING THE
STEEP LAPSE RATES. RIGHT NOW, IT SEEMS THERE IS A VERY SMALL
CHANCE (10-20%) FOR A STORM TO FORM. A QUARTER SIZED HAIL REPORT
AND DOWNBURST IN A VERY DRY SUBCLOUD LAYER CANNOT BE RULED OUT
(10-20%) FOR SWRN WI AND NERN IA THIS EARLY EVE BEFORE MOVING
EAST.
TUESDAY MORNING SEEMS TO HAVE A BIT BETTER ELEVATED INSTABILITY
ACROSS THE AREA SOUTH OF I-90 AS THE STATIONARY FRONT BECOMES A COLD
FRONT AND MOVES SOUTHEAST THROUGH THE AREA. THE ELEVATED INSTABILITY
IS OVER 1000 J/KG WITH STEEP 400-700 MB LAPSE RATES (>8C/KM) SHOULD
SATURDATION OCCUR ALOFT AND STORMS BE REALIZED. THIS SEEMS TO BE A
BETTER CHANCE FOR LARGE HAIL, WITH 30 KTS OF BULK SHEAR IN THE 2-7KM
LAYER, BUT AGAIN CONDITIONAL ON THE SATURATION OCCURRING. RECENT
RAP RUNS INDICATE A SLIGHTLY INCREASING MOISTURE CONVERGENCE
SIGNAL BUT MOST CONVERGENCE OVER CENTRAL/EAST WI. THE 30.12Z
CAMS ARE QUIET, SANS THE LATEST HRRR RUNS THAT SUGGEST SOME I-90
STORMS. THE MAIN WINDOW FOR THIS WOULD BE ABOUT 4-9 AM. WITH
THE CONDITIONAL NATURE AGAIN, HAVE RAIN CHANCES AT 30%.
IMPACTFUL LATE WINTER STORM POSSIBLE MIDWEEK
CONFIDENCE IS PRETTY HIGH THAT THE AREA WILL BE IN THE STORM TRACK
OF A STRONGER LOW PRESSURE AREA EJECTING NORTHEAST FROM THE TEXAS
PANHANDLE. PRECIPITATION LOOKS TO BE A SURE BET WEDNESDAY NIGHT
THROUGH THURSDAY. THE COLD AIR USHERED IN BY TUESDAYS COLD
FRONT WILL SET THE STAGE FOR WINTRY PRECIPITATION INCLUDING ICE
AND SNOW ACCUMULATIONS. A VERY WARM LAYER ALOFT IS COMING IN
WED NIGHT WITH MAXT ALOFT GETTING TO 5-6C. SURFACE TEMPERATURES
LOOK LIKE THEY WILL BE RIGHT NEAR FREEZING FOR MUCH OF THE AREA
SOUTH OF I-94 WHICH WILL HAVE A HUGE IMPACT ON RAIN VERSUS
FREEZING RAIN / ICING AND SNOW AREAS - AND THEIR ACCUMULATIONS.
HEADING INTO APRIL, TEMPERATURES NEAR FREEZING CAUSE A PAUSE FOR
GOING TOO BONKERS WITH ICE ACCUMULATIONS. A CLEAR SIGNAL IS
THAT THE RIVER VALLEYS WILL BE WARMER AND ANY ICING WOULD BE
MUCH REDUCED THERE. BUT THE TRACK OF THIS SYSTEM WILL GOVERN THE
PRECIPITATION TYPES...AND MODERATE UNCERTAINTY EXISTS IN THE
TRACK AND SURFACE TEMPERATURES.
THE CURRENT CONSENSUS IN THE WINTRY MIX AND ICING PROBABILITIES
ARE IN A WIDE BAND ALONG I-90, SLIGHTLY INTO NERN IA AND
SOUTHWEST WI (RICHLAND/CRAWFORD) AND NORTH. RAIN WOULD FALL
SOUTH OF THAT AREA. NBM PROBABILITIES FROM THE 30.06Z NBM RUN
SUGGEST A 40-70% CHANCE OF ONE-TENTH OF AN INCH OF ICE IN THAT
REGION, WITH THE HIGHER PROBABILITIES NORTHEAST OF I-94 WHERE
THE COLDEST TEMPERATURES BELOW FREEZING WOULD RESIDE. THIS AREA
COULD HAVE THE HIGHEST ACCUMULATION OF ICE DUE TO FAVORABLE
SURFACE TEMPERATURES WITH THE NBM PROBABILITIES AROUND 30%
FOR ONE-QUARTER INCH OF ICE FOR CLARK AND TAYLOR COUNTIES.
THERE COULD ALSO BE A FEW INCHES OF SNOW WEDNESDAY NIGHT THERE
PRIOR TO THE ICING.
THIS SYSTEM HAS VERY ANOMALOUS MOISTURE INFLOW OF OVER AN INCH OF
PRECIPITABLE WATER (1-1.25") WHICH IS NEAR THE DAILY MAX AT KDVN PER
SPC CLIMATOLOGY. LIQUID EQUIVALENT AMOUNTS ACROSS THE SOUTH LOOK TO
BE IN THE 1.50-2.0" RANGE WITH THE LATEST GEFS AND ECMWF ENSEMBLES
SHOWING 10-25% CHANCES OF 2" NEAR DUBUQUE. THIS WOULD FALL
MOSTLY AS RAIN AND CAUSE RIVER RISES ON THE KICKAPOO RIVER.
THESE PRECIPITATION TOTALS DECREASE NORTHWESTWARD, WITH 50-70%
CHANCES OF 1+ INCHES AT LA CROSSE (IN MIXED PRECIPITATION). SO,
A WET SYSTEM.
WILL BEGIN TO RAMP UP THE MESSAGING ON THIS STORM USING
PROBABILITIES AS THEY PROVIDE A NICE WAY TO DESCRIBE THE POSSIBLE
IMPACTS YET TEMPER IT WITH UNCERTAINTY BOTH IN SURFACE
TEMPERATURE AND STORM TRACK. THE NBM PROBABILITIES OF ONE-TENTH
OF AN INCH OF ICE ALSO HIGHLIGHT THE LESSER ACCUMULATIONS IN
THE RIVER VALLEYS.
ANOTHER WEATHER SYSTEM NEXT WEEKEND
GENERAL CONSENSUS EXISTS ON ANOTHER STRONG SYSTEM EJECTING OUT
OF A LONGWAVE TROUGH DEVELOPING OVER THE WESTERN U.S. THIS
WEEK. THE SYSTEM IS CURRENTLY OVER ALASKA, FAR AWAY, BUT MANY OF
THE ENSEMBLES OF THE 30.00Z LREF HAVE A STRONGER CYCLONE MOVING
THROUGH FRIDAY AND SATURDAY. THE AREA LOOKS TO BE ON MAINLY THE
WARMER SIDE OF THIS STORM WITH RAIN. THE STORM TRACK WILL
DETERMINE THE WINTRY WEATHER LOCATION, BUT RIGHT NOW THE
PROBABILITIES FOR ACCUMULATING SNOW APPEAR MORE TOWARD CENTRAL
MN AND NORTHERN WI, WITH SOME WINTRY MIX POSSIBLE (30%) NORTH
AND WEST OF LA CROSSE. IT IS WAY OUT IN THE TIMING AND THERE IS
A MODERATE AMOUNT OF SPREAD ON THE TRACK...BUT SOMETHING TO KEEP
AN EYE ON.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1229 PM CDT MON MAR 30 2026
VFR CONDITIONS SHOULD PREVAIL FOR THE NEXT 12-15 HOURS BEFORE
STRATUS POTENTIALLY DEVELOPS IN CENTRAL WI AND SPREADS SOUTHWEST
ACROSS THE AREA. GUIDANCE SUGGESTS STRATUS WILL BE IN THE
500-1500 FOOT LAYER SO HAVE GONE WITH LOW END MFVR MENTIONS WITH
THIS UPDATE AND CAN MOVE TO IFR LATER IF NEEDED. A THUNDERSTORM
OR TWO MAY (25%) OCCUR IN FAR SW WI THIS AFTERNOON AND SOME
SHOWERS MAY (30%) OCCUR IN THE 12Z-18Z TUESDAY TIME FRAME ACROSS
MUCH OF THE AREA BUT CONFIDENCE ON TS IS TOO LOW TO ADD A
MENTION TO THE DEFINITE MVFR CONDITIONS ALREADY INCLUDED DUE TO
STRATUS.
HYDROLOGY
ISSUED AT 142 PM CDT MON MAR 30 2026
RAIN AMOUNTS WEDNESDAY NIGHT AND THURSDAY COULD APPROACH 2
INCHES IN SOUTHWEST WISCONSIN. SHOULD THIS OCCUR, AND THE
PRECIPITATION TYPE REMAIN AS ALL RAIN, STREAM AND RIVER RISES
ARE POSSIBLE ON THE KICKAPOO RIVER LATE IN THE WEEK.
CLIMATE
ISSUED AT 1248 AM CDT MON MAR 30 2026
NEAR RECORD HIGHS TODAY (RECORD/FORECAST):
ROCHESTER, MN 77 (1967) / FCST: 74
LA CROSSE, WI 80 (1910) / FCST: 76
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...BAUMGARDT
AVIATION...FERGUSON
HYDROLOGY...BAUMGARDT
CLIMATE...BOYNE
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