804
FXUS63 KARX 020539
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1239 AM CDT SUN AUG 2 2026
KEY MESSAGES
- ISOLATED SHOWERS POSSIBLE (15-25% CHANCE) THIS AFTERNOON AND
EVENING.
- NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES THIS WEEKEND INTO
EARLY NEXT WEEK WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
- SHOWER AND STORM CHANCES (30-60%) RETURN TUESDAY INTO
WEDNESDAY.
DISCUSSION
ISSUED AT 1205 PM CDT SAT AUG 1 2026
REST OF TODAY - SUNDAY: ISOLATED SHOWERS THIS AFTERNOON AND EVENING
COOLING TEMPERATURES ALOFT WITH NORTHERLY FLOW IN PLACE WILL
ALLOW FOR SOME INSTABILITY (AROUND 500-750 J/KG OF MUCAPE) TO BE
PRESENT ACROSS THE REGION THIS AFTERNOON AND EVENING ALLOWING
FOR THE DEVELOPMENT OF SOME ISOLATED SHOWERS DURING THIS
TIMEFRAME AS HINTED AT IN SOME OF THE CAMS. OVERALL, GIVEN THE
FAIRLY SKINNY INSTABILITY PROFILES AND LACK OF DEEP-LAYER SHEAR,
WOULD THINK THAT ROBUST CONVECTIVE DEVELOPMENT IS VERY
UNLIKELY. IN ANY CASE, CANNOT RULE OUT (15-25% CHANCE) SOME
ISOLATED SHOWERS LATE THIS AFTERNOON AND INTO THE EVENING.
OTHERWISE, UPPER-LEVEL RIDGING WITH ACCOMPANYING SURFACE HIGH
PRESSURE WILL MOVE INTO THE REGION OVERNIGHT AND INTO SUNDAY
RESULTING IN CLEARING SKIES AND LIGHT WINDS NEAR THE SURFACE.
CONSEQUENTLY, CANNOT FULLY RULE OUT SOME FOG FORMATION IN RIVER
VALLEYS, HOWEVER THE STRONGER WINDS PERSISTING OFF THE SURFACE WILL
LIKELY MITIGATE THIS. TEMPERATURES WILL LIKELY REMAIN SEASONABLE
WITH NORTHEASTERLY SURFACE FLOW KEEPING TEMPERATURES SLIGHTLY COOLER
THAN NORMAL WITH HIGHS GENERALLY IN THE UPPER 70S TO AROUND 80
DEGREES FOR SUNDAY.
MONDAY - WEDNESDAY: INCREASING RAIN CHANCES TUESDAY/WEDNESDAY
FAIRLY DRY CONDITIONS ARE EXPECTED TO BEGIN THE WORK WEEK WITH THE
AFOREMENTIONED UPPER-LEVEL RIDGING AND SURFACE HIGH PRESSURE IN
PLACE FOR MONDAY. CONSEQUENTLY, A RELATIVELY PERSISTENCE FORECAST IS
EXPECTED FOR MONDAY WITH HIGHS GENERALLY IN THE UPPER 70S TO LOWER
80S WITH MINIMAL SKY COVER. HOWEVER, THE PATTERN CHANGES AS WE HEAD
INTO TUESDAY AS A SHORTWAVE TROUGH PUSHES THROUGH THE DAKOTAS BY
TUESDAY MORNING, SWITCHING OUR FLOW ALOFT TO MORE ZONAL. AS THIS
OCCURS, A WEAK SURFACE BOUNDARY ASSOCIATED WITH THE AFOREMENTIONED
SHORTWAVE TROUGH PUSHES THROUGH THE AREA LATE TUESDAY AFTERNOON
THROUGH WEDNESDAY WITH THE GRAND ENSEMBLE (GEFS/EC/CANADIAN
ENSEMBLE) HAVING INCREASED PROBABILITIES (50-80%) FOR MEASURABLE
PRECIPITATION DURING THIS PERIOD. OVERALL, NOT OVERLY IMPRESSED WITH
INSTABILITY AND SHEAR PROFILES IN THE DETERMINISTIC GFS DURING THIS
PERIOD AS A FAIRLY SUBSTANTIAL LOW-LEVEL EML KEEPS SOUNDING
PROFILES FAIRLY CAPPED. THIS LIMITED POTENTIAL FOR SEVERE
WEATHER IS HIGHLIGHTED IN THE JOINT PROBABILITIES FOR SBCAPE AND
BULK SHEAR IN THE GRAND ENSEMBLE (GEFS/EC/CANADIAN ENSEMBLE)
HAVING EXTREMELY LOW (UNDER 5%) FOR HAVING FAVORED SHEAR AND
INSTABILITY DURING THIS PERIOD. CONSEQUENTLY, THINKING THAT
WHILE THIS IS OUR NEXT PERIOD FOR WIDESPREAD RAIN ACROSS THE
AREA, THE PROBABILITY FOR ORGANIZED SEVERE WEATHER IS VERY LOW
AT THIS TIME.
THURSDAY - FRIDAY: SEASONABLE, SMALL CHANCES FOR SHOWERS AND STORMS
AS WE HEAD INTO THE LATER HALF OF NEXT WEEK, CONTINUED ZONAL TO
NORTHWESTERLY MID-LEVEL FLOW WILL PERPETUATE THE RISK FOR ANY
SHOWERS AND STORMS IF ANY SHORTWAVE PERTURBATIONS CAN SNEAK
THEIR WAY INTO THE AREA. THERE ARE SOME PROBABILITIES (20-40%)
IN THE GRAND ENSEMBLE (GEFS/EC/CANADIAN) FOR FAVORABLE
INSTABILITY (OVER 1000 J/KG OF SBCAPE) AND BULK SHEAR (OVER 30
KTS) FOR SEVERE WEATHER ACROSS THE AREA DURING THIS PERIOD.
HOWEVER, CONFIDENCE ACROSS DETERMINISTIC AND ENSEMBLE GUIDANCE
IS FAIRLY LOW WITH HOW THESE FEATURES WOULD BE RESOLVED SO
THINKING THE SMALL PRECIPITATION CHANCES IN THE NBM (15-25%) ARE
APPROPRIATE AT THIS TIME. ADDITIONALLY, WITH CONTINUED ZONAL TO
NORTHWESTERLY FLOW, THINKING TEMPERATURES WILL REMAIN
RELATIVELY SEASONABLE WITH THE NBM KEEPING THE INTER-DECILE
RANGE FOR HIGH TEMPERATURES IN THE MIDDLE 70S TO UPPER 80S
THROUGH FRIDAY.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1234 AM CDT SUN AUG 2 2026
VFR EXPECTED AT BOTH TAF SITES THROUGH THE 02.06Z TAF PERIOD.
VFR CLOUD DECK ADVECTING SOUTHWEST THROUGH CENTRAL WISCONSIN
EXPECTED TO REMAIN EAST OF KLSE TAF SITE OVERNIGHT. LIGHT WINDS
EXPECTED THROUGH SUNDAY.
LIFR FG BUILDING IN WISCONSIN RIVER VALLEY AFFECTING KOVS NOT
EXPECTED TO SPREAD AND AFFECT OTHER SMALLER AIRPORTS. WHILE
PATCHY FG IS POSSIBLE IN UPPER MISSISSIPPI RIVER VALLEY (KLSE),
CURRENT DEWPOINT TO TEMPERATURE SEPARATION SUGGESTS SATURATION
IS UNLIKELY AND THEREFORE HAVE ABSTAINED FROM INCLUSION IN TAF.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
DISCUSSION...NAYLOR
AVIATION...JAR
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