Area Forecast Discussion
Issued by NWS La Crosse, WI

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000
FXUS63 KARX 280446
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1146 PM CDT SUN JUL 27 2014

.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 157 PM CDT SUN JUL 27 2014

WATER VAPOR SATELLITE AND RAP 500MB ANALYSIS THIS AFTERNOON SHOWING
MID LEVEL LOW OVER EAST CENTRAL WI. RADAR/VIS SATELLITE SHOWING
QUITE AN EXTENSIVE FIELD OF CUMULUS/CUMULONIMBUS AND SCATTERED
SHOWER/ISOLATED THUNDERSTORM ACTIVITY ACROSS THE ARX FORECAST AREA
IN THE CYCLONIC/STEEP LAPSE RATE ENVIRONMENT. TEMPERATURES THIS
AFTERNOON RANGED FROM THE UPPER 60S ACROSS NORTH CENTRAL WI...TO THE
MIDDLE AND UPPER 70S ALONG AND SOUTH OF I-90.

LOOK FOR A RAPID DISSIPATION THIS EVENING IN SHOWER ACTIVITY WITH
LOSS OF SURFACE HEATING AND THEN A FAIRLY RAPID CLEARING CLOUD TREND
AS THE MID LEVEL LOW MOVES OFF INTO THE GREAT LAKE REGION.

COOLER/DRIER AIRMASS ASSOCIATED WITH HIGH PRESSURE OVER THE NORTHERN
PLAINS WILL BE WORKING INTO THE AREA TONIGHT. THIS WILL ALLOW
TEMPERATURES TO FALL INTO THE UPPER 40S IN THE SANDY/CRANBERRY BOG
COUNTRY OF CENTRAL/NORTH CENTRAL WI...AND IN THE LOWER/MIDDLE 50S
ELSEWHERE.

SURFACE HIGH PRESSURE WILL CONTINUE BUILDING INTO THE AREA ON MONDAY
FOR DRY AND COOLER THEN NORMAL CONDITIONS. LINGERING CYCLONIC FLOW
ALOFT WILL ALLOW FOR A BUILD-UP IN DAYTIME FAIR WEATHER
CUMULUS...BUT MOSTLY SUNNY CONDITIONS OVERALL SHOULD RESULT. PLAN ON
HIGHS IN THE LOW-MID 70S...OR SOME 6-8 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR. MOSTLY CLEAR AND COOL CONDITIONS WILL BE SEEN MONDAY
NIGHT AS WELL WITH LOWS BOTTOMING OUT IN THE UPPER 40S TO MIDDLE 50S
ONCE AGAIN.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 157 PM CDT SUN JUL 27 2014

MODELS IN GOOD AGREEMENT IN BRINGING A MID-LEVEL/SURFACE TROUGH
THROUGH THE REGION ON TUESDAY IN BROAD CYCLONIC FLOW ALOFT. THIS
WILL PRODUCE THE LIKELIHOOD OF SCATTERED SHOWER AND ISOLATED
THUNDERSTORMS GIVEN THE FORCING FROM THE TROUGH AND COMBINATION OF
COOL CYCLONIC FLOW ALOFT/DAYTIME HEATING AND STEEPENING LOW-MID LEVEL
LAPSE RATES. OTHERWISE ANOTHER COOLER THAN NORMAL DAY ON TAP WITH
HIGHS TOPPING OFF IN THE 70S.

DEEP LONG WAVE TROUGH WILL SET UP CAMP OVER THE UPPER MISSISSIPPI
RIVER VALLEY REGION/EASTERN CONUS THROUGH THE REST OF THE PERIOD. AS
A RESULT...LOOKS TO REMAIN COOLER THAN NORMAL...WITH TEMPERATURES
CLOSER TO EARLY SEPTEMBER NORMALS. SEVERAL WEAK EMBEDDED TROUGHS
WITHIN THE LONG WAVE TROUGH WILL ROTATE THROUGH THE REGION FOR
PERIODIC/MAINLY DAYTIME SHOWER AND ISOLATED THUNDERSTORM CHANCES.
PLAN ON HIGHS IN THE 70S WITH LOWS IN THE 50S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1146 PM CDT SUN JUL 27 2014

WHILE THE CLOUD FORECAST IS CHALLENGING FOR THIS TAF CYCLE...IT
APPEARS THE CLOUDS WILL BE VFR FOR THE PERIOD. CYCLONIC FLOW
AROUND A LARGE SCALE LOW WILL KEEP CLOUDS POSSIBLE ACROSS THE TAF
SITES THROUGH THE PERIOD IN NORTHERLY FLOW OUT OF CANADA.
SOUNDINGS AT 00Z ACROSS THE REGION SHOW MOIST CONDITIONS WITH
DEWPOINT DEPRESSIONS AT 4C OR LESS. SATELLITE SHOWING MN MUCH MORE
CLOUDY THAN WI AND THE MODEL GUIDANCE SEEMS TO HOLD ONTO THAT
TREND THROUGH THE FORECAST. THUS...HAVE KEPT KRST MORE CLOUDY THAN
KLSE THIS CYCLE. DETAILS ON THE CLOUDS ARE TOUGH AND CONFIDENCE IS
LOW. HOWEVER...CONFIDENCE IS HIGHER THAT THE CLOUDS WILL REMAIN
VFR FOR THE MOST PART.

&&

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

$$

SHORT TERM...DAS
LONG TERM...DAS
AVIATION...BAUMGARDT


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