212
FXUS63 KARX 131150
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
650 AM CDT THU AUG 13 2020
SHORT TERM
(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT THU AUG 13 2020
SKIES WERE PARTLY TO MOSTLY CLOUDY EARLY THIS MORNING, WITH
TEMPERATURES RANGING FROM THE MID 50S TO UPPER 60S. A FEW SHOWERS
AND ISOLATED STORMS ASSOCIATED WITH AN AREA OF STRONGER 925 MB
MOISTURE TRANSPORT WERE MOVING ACROSS TAYLOR AND CLARK COUNTIES
IN FAR NORTH-CENTRAL WISCONSIN.
SHOWERS/STORMS ACROSS NORTH-CENTRAL WISCONSIN SHOULD DIMINISH THIS
MORNING AS MOISTURE TRANSPORT JUST TO OUR NORTHWEST DECREASES. FOR
THE REST OF THE DAY, STRONGER MOISTURE TRANSPORT, INSTABILITY, AND
SHORTWAVE ENERGY STAY TO OUR NORTHWEST, AS DO HIGHER PRECIPITATION
CHANCES. LOCALLY, MODELED SOUNDINGS SHOW A BIT OF CAPPING
DEVELOPING, SO WITHOUT STRONGER FORCING THIS WOULD TEND TO FAVOR DRY
WEATHER. A STRAY SHOWER OR STORM COULD PERHAPS INTRUDE FROM THE
WEST, BUT RIGHT NOW THIS THREAT LOOKS LOW AND HAVE TRENDED THINGS
DRY. CURRENT CLOUD COVER MIGHT THIN LATER THIS MORNING AND ALLOW FOR
SOME SUNSHINE, BUT ADDITIONAL CUMULUS COULD FORM THIS AFTERNOON
GIVEN STEEPENING LAPSE RATES. HIGHS ARE EXPECTED TO REACH THE 80S,
THOUGH MORE PERSISTENT CLOUD COVER COULD KEEP SOME AREAS IN THE
UPPER 70S.
LONG TERM
(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU AUG 13 2020
NEXT TIME PERIOD TO WATCH FOR PRECIPITATION LOOKS TO BE FRIDAY
MORNING, AS A WEAKENING LINE OF SHOWERS/STORMS PROGRESSES ACROSS
MINNESOTA. GUIDANCE REALLY DIMINISHES THIS BEFORE REACHING OUR AREA,
LIKELY DUE TO THE LESS FAVORABLE INSTABILITY AND LACK OF STRONG
MOISTURE TRANSPORT COMPARED TO LOCATIONS BACK TO OUR WEST. WITH NO
STRONG SIGNAL FOR PRECIPITATION, HAVE CONFINED SMALL POPS TO THE
FAR WEST FRIDAY MORNING, WITH THE AFTERNOON LOOKING DRIER. HIGHS
COULD BE A TOUCH WARMER THAN THURSDAY, WITH SOME LOCATIONS
APPROACHING THE UPPER 80S. ATTENTION THEN TURNS TO AN APPROACHING
COLD FRONT. DEEP SHEAR IS NOT VERY IMPRESSIVE WITH THIS FEATURE
(SUB-30 KT 0-6 KM BULK SHEAR IN THE GFS/ECMWF/CANADIAN, THOUGH THE
NAM IS A HIGHER OUTLIER), BUT INSTABILITY BUILDS IN SOUTHERLY,
MOIST FLOW AHEAD OF THE FRONT FRIDAY. LATEST GUIDANCE DOESN'T HAVE
THE FRONT ARRIVING IN OUR AREA UNTIL ABOUT 04Z SATURDAY, HOWEVER,
BY WHICH TIME INSTABILITY IS FORECAST TO HAVE REALLY WANED.
COULDN'T TOTALLY RULE OUT A STRONGER STORM OR TWO JUST AS THE
STORMS REACH THE AREA, BUT THE DIMINISHING INSTABILITY IS NOT SO
FAVORABLE FOR SEVERE WEATHER. LATEST SPC OUTLOOKS ARE
GEOGRAPHICALLY SIMILAR TO THIS THINKING, WITH THE 06Z DAY 2
OUTLOOK SLIGHT RISK MAINLY TO OUR NORTHWEST WHERE THE FRONT
ARRIVES EARLIER AND THE MARGINAL RISK ACROSS WESTERN/NORTHWESTERN
PORTIONS OF THE AREA.
THE FRONT PROGRESSES THROUGH THE AREA SATURDAY MORNING, EXITING TO
OUR SOUTHEAST BY EARLY AFTERNOON. IF THIS EXIT ENDS UP BEING A
LITTLE LATER INTO THE AFTERNOON, THERE COULD BE POTENTIAL FOR A FEW
STRONGER STORMS ACROSS FAR SOUTHWEST WI/FAR NORTHEAST IOWA, BUT
RIGHT NOW MOST GUIDANCE SEEMS TO FAVOR THE BEST INSTABILITY RECOVERY
OCCURRING TO THE SOUTHEAST OF OUR AREA.
COOLER, DRIER NORTHWEST FLOW THEN BUILDS IN SUNDAY THROUGH EARLY
NEXT WEEK. HIGHS ARE EXPECTED TO BE IN THE 70S, WITH LOWS IN THE
50S. RAIN CHANCES COULD RETURN MID-WEEK AS A STRONGER SHORTWAVE
MOVES THROUGH IN NORTHWEST FLOW, THOUGH PREDICTABILITY IS LOW THIS
FAR OUT.
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 637 AM CDT THU AUG 13 2020
SATELLITE IMAGERY AND RADAR SHOW WEATHER DISTURBANCES PASSING TO
THE NORTH AND SOUTH OF THE TAF SITES TODAY. THUS...WE ARE LOOKING
A VARIABLE CLOUD COVER, BUT GENERALLY DRY CONDITIONS. SOME PATCHY
MVFR CONDITIONS DID DEVELOP OVERNIGHT AND THERE IS A BROAD AREA OF
IFR CONDITIONS OVER WESTERN MN. THE MVFR CONDITIONS HAVE BROKEN
UP WITH SCATTERED CLOUDS FL040-050. SCT-BKN CLOUD FL050-150
THROUGH TODAY AND THIS EVENING. AS THE LOW LEVEL WINDS DECREASING
AGAIN TONIGHT, SHOULD SEE SOME PATCHES OF MVFR/IFR CONDITIONS RE-
DEVELOP AND FAVOR AFTER 08-10Z. SOUTH WINDS 6 TO 12KTS TODAY AND 4
TO 8 KTS TONIGHT.
ARX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
MN...NONE.
IA...NONE.
SHORT TERM...LEE
LONG TERM...LEE
AVIATION...ZAPOTOCNY
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