Area Forecast Discussion
Issued by NWS La Crosse, WI

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000
FXUS63 KARX 021638
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1135 AM CDT SUN AUG 2 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 247 AM CDT SUN AUG 2 2015

OH THE FUN OF PREDICTING SUMMER TIME CONVECTION. LACK OF ACTIVITY
ALONG WARM FRONT SATURDAY EVENING HAS ALLOWED WARM FRONT TO LIFT
FARTHER NORTHEAST THAN EXPECTED. WITH MODEST LOW LEVEL JET FORMING
OVERNIGHT...HAVE ALREADY SEEN ELEVATED STORMS FORM NORTH OF
INTERSTATE 94 WITH LARGE HAIL. THIS ACTIVITY LIKELY TO CONTINUE INTO
DAY BREAK WITH MODEST MIXED LAYER CAPE AND ENOUGH CONVERGENCE FOR
REGENERATION OF STORMS.

THIS WARM FRONT PLACEMENT DOES HAVE IMPLICATIONS ON WEATHER LATER
TODAY AS STRONGER SHORT WAVE TROUGH DROPS OUT OF CANADIAN PRAIRIES
INTO WESTERN GREAT LAKES BY TONIGHT. TEMPERATURES AND DEW POINTS
WILL BE HIGHER THAN PREVIOUSLY EXPECTED LEADING TO HIGHER MIXED
LAYER CAPE VALUES /2500-3500 J/KG/ AS ASSOCIATED COLD FRONT
APPROACHES. COMBINE THIS WITH MODEST SHEAR AND STRONGER MID LEVEL
WINDS...ORGANIZED CONVECTIVE COMPLEXES POSSIBLE ACROSS MAINLY
WISCONSIN THIS AFTERNOON.

SOME QUESTION ON WHERE MAIN DEVELOPMENT WILL OCCUR BUT WEAK
PERFORMING MESOSCALE MODELS TEND TO HINT AT STORMS FORMING EAST OF
AREA AND COULD BACK BUILD TO THE WEST INTO HIGHER CAPE REGION. THIS
LEADS TO VERY CONDITIONAL THREAT FOR OUR WISCONSIN COUNTIES...BUT
WORTH WATCHING CLOSELY THROUGH THE DAY.

UPSTREAM WAVE SHOULD KEEP CONVECTION VERY PROGRESSIVE...MOVING
THREAT AREA QUICKLY SOUTHEAST OF THE AREA THIS EVENING SO RAIN
THREATS DROP OFF QUICKLY TO MATCH.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 247 AM CDT SUN AUG 2 2015

SHIFT OF UPPER LOW FROM HUDSON BAY INTO ONTARIO WILL PUSH BOUNDARY
SOUTH OF THE AREA AND MAKE FOR A FEW QUIET DAYS TO START THE WEEK IN
NORTHWEST FLOW. THIS WILL ALSO MAKE FOR COOLER TEMPERATURES...BELOW
NORMAL FOR A FEW DAYS. DROPPED FAVORED COLD BOGS A FEW CATEGORIES AT
NIGHT AS WELL.

MEDIUM RANGE MODELS REMAIN RELATIVELY INCONSISTENT FROM RUN TO RUN
FROM MID WEEK ON. HINTS THAT AMPLIFICATION IN FLOW TO THE WEST COULD
BREAK DOWN AS SERIES OF SHORT WAVES MOVE ACROSS THE NORTHERN TIER OF
STATES. WITH FORECAST CONFIDENCE LOW...SMALL RAIN THREATS REMAIN
LITTERED IN OUTER FORECAST PERIODS. STRONGEST POTENTIAL WAVE APPEARS
TO BE WEDNESDAY NIGHT INTO THURSDAY WHICH COULD GENERATE A COMPLEX
OF STORMS WITH INSTABILITY RESIDING JUST SOUTHWEST OF THE AREA.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1135 AM CDT SUN AUG 2 2015

COLD FRONT WILL SWEEP SOUTHEAST ACROSS THE AREA THIS
AFTERNOON...SPARKING SHRA/TS MOSTLY ALONG ITS EASTERN FLANKS. MESO
MODELS FAVORING BRINGING IT THROUGH DRY FOR KRST...AND COULD MISS
KLSE ALSO. A LOT OF UNCERTAINTY AS ONGOING CONVECTION IS ELEVATED
POST THE FRONT...WHILE MORE WIDESPREAD SHRA/TS ARE EXPECT TO FIRE
ALONG/AHEAD OF THE FRONT LATER THIS AFTERNOON. THE FRONT WILL LIKELY
BE SOUTH OF THE TAF SITES BY THAT TIME...LIMITING THE THREAT. WILL
KEEP TAFS DRY FOR THE TIME BEING...BUT WILL MONITOR RADAR TRENDS
CLOSELY AND MAKE UPDATES AS NEEDED.

GUSTY/STRONG WINDS AHEAD AND POST THE FRONT...SETTLING DOWN A BIT
THIS EVENING.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...SHEA
LONG TERM...SHEA
AVIATION...RIECK


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