Area Forecast Discussion
Issued by NWS La Crosse, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KARX 271857
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
157 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 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1244 PM CDT SUN JUL 27 2014

UPPER SYSTEM DROPPING SOUTHEAST ACROSS WI AT MID-DAY WITH EXTENSIVE
WRAP AROUND CLOUD AND SHOWER ACTIVITY. AS THE LOW PULLS OFF TO THE
EAST AND BEST LIFT EXITS ALONG WITH IT...ANTICIPATE SOME DOWNWARD
MOTIONS TO HELP FLATTEN AND EVENTUALLY THIN/DISSIPATE THE CLOUD
COVER. MODEL MOS GUIDANCE VERY AGGRESSIVE WITH THIS TREND...BUT AM
LEARY OF THIS GIVEN THE AMOUNT OF MOISTURE REMAINING IN THE BOUNDARY
LAYER. PLAYED IT A BIT MORE PESSIMISTIC FOR THE 18Z TAF ISSUANCE.
DID GO WITH A PERIOD OF SCT CLOUD COVER...BUT ONCE DIURNAL HEATING
BEGINS AGAIN TOMORROW...WENT BACK TO BKN.

&&

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

$$

SHORT TERM...DAS
LONG TERM...DAS
AVIATION...WELVAERT


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.