Expires:No;;787730
FXUS63 KARX 181917
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
217 PM CDT TUE JUN 18 2013
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 217 PM CDT TUE JUN 18 2013
WATER VAPOR IMAGERY THIS AFTERNOON SHOWING A SHORTWAVE TROUGH 
ROTATING THROUGH SOUTHERN WI...WITH OUR AREA IN GENERAL 
SUBSIDENCE BEHIND THIS WAVE. OTHERWISE...A HIGHLY AMPLIFIED RIDGE WAS 
BUILDING ACROSS THE INTERMOUNTAIN WEST AND HIGH PLAINS AREA WHILE A 
DEEP TROUGH WAS DIGGING ALONG THE WEST COAST. RIDGE BUILDING AND 
ASSOCIATED INCREASING HEAT/HUMIDITY COMBINED WITH OCCASIONAL ENERGIES 
EJECTING OUT OF THE WESTERN TROUGH OVER THE RIDGE WILL SET THE STAGE 
FOR AN INCREASINGLY ACTIVE CONVECTIVE SCHEME THROUGH THE WEEKEND.
FOR TONIGHT...SURFACE HIGH PRESSURE CENTERS ITSELF OVER LOWER 
MICHIGAN WITH WEAK EAST-SOUTHEAST WINDS OVER THE FORECAST AREA. 
MOSTLY CLEAR SKIES AND LIGHT WINDS EXPECTED TO YIELD FAIRLY COOL 
TEMPERATURES...RANGING FROM THE MID 40S ALONG/NORTH OF I-94...TO THE 
LOWER/MIDDLE 50S ELSEWHERE. 
ON WEDNESDAY...SURFACE HIGH PRESSURE CONTINUES TO PUSH EAST INTO THE 
EASTERN CONUS WHILE THAT LOW OVER THE WEST COAST MOVES INTO THE 
INTERMOUNTAIN WEST. THIS SETS UP INCREASING 850MB MOISTURE TRANSPORT 
INTO THE PLAINS WITH THE EASTERN PERIPHERY OF THIS TRANSPORT NOSING 
INTO MN/IA. MEANWHILE...MODELS SHOWING A WEAK MID-LEVEL TROUGH 
MOVING ACROSS THE DAKOTAS WHILE ANOTHER WAVE SLIPS SOUTHEAST THROUGH 
WESTERN ONTARIO/NORTHERN MN. THIS IS EXPECTED TO SEND SOME 
MID-CLOUD/ACCAS INTO AREAS WEST OF THE MISSISSIPPI RIVER...BUT LOOKS 
TO REMAIN DRY WITH SHOWERS/THUNDERSTORMS HOLDING OFF TO OUR WEST. 
OTHERWISE...WARM AIR ADVECTION PUSHES TEMPERATURES INTO THE 
MID/UPPER 70S. 
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 217 PM CDT TUE JUN 18 2013
FOR WEDNESDAY NIGHT INTO THURSDAY...SHOWER AND THUNDERSTORM CHANCES 
INCREASE ACROSS THE FORECAST AREA AS A WARM FRONT PUSHES NORTH AND 
850MB MOISTURE TRANSPORT AXIS TAKES AIM ON THE UPPER MISSISSIPPI 
RIVER REGION. IN FACT...THE NAM IS DEPICTING 4500-4800J/KG OF 0-3KM 
MUCAPE AND AROUND 1500J/KG MLCAPE ALONG WITH 0-3KM BULK SHEAR IN THE 
25KT RANGE GOING INTO THURSDAY AFTERNOON. WILL HAVE TO WATCH THIS 
CLOSELY FOR SEVERE POTENTIAL AS THE WARM FRONT MAKES ITS WAY ACROSS 
THE AREA. ECMWF/GFS THEN SHOW A CONSISTENT SIGNAL SETTING UP FOR AN 
EXTENDED WARM/HUMID AND ACTIVE CONVECTIVE PATTERN THROUGH THE 
WEEKEND INTO EARLY NEXT WEEK. LOOKS LIKE SOUTHWEST FLOW ALOFT SET TO 
EJECT SYNOPTIC MID-LEVEL TROUGHS ALONG WITH MCV/S OUR WAY WHICH WILL 
INTERACT WITH WARM/HUMID AIRMASS IN PLACE FOR A CHANCE OF SHOWERS 
AND THUNDERSTORMS EVERY DAY. OTHERWISE...WITH HIGHS IN THE 80S AND 
DEW POINTS INCREASING INTO THE 70S FOR FRIDAY AND INTO THE 
WEEKEND...LOOK FOR AFTERNOON/EARLY EVENING HEAT INDICES IN THE 
MID/UPPER 90S.   
&&
.AVIATION...THROUGH 18Z WEDNESDAY
ISSUED AT 1251 PM CDT TUE JUN 18 2013
A FEW SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON
GENERALLY SOUTHEAST OF A DODGE CENTER MINNESOTA TO RICHLAND CENTER
LINE. OTHERWISE HIGH PRESSURE WILL PROVIDE VFR CONDITIONS AT THE
TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...BOYNE