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000
FXUS63 KARX 150842
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
341 AM CDT WED MAY 15 2013

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 341 AM CDT WED MAY 15 2013

WATER VAPOR IMAGERY EARLY THIS MORNING SHOWS A FAIRLY HIGH ZONAL
FLOW ACROSS THE NORTHERN CONUS WITH A WEAK EMBEDDED MID-LEVEL
SHORTWAVE TROUGH MOVING OUT OF THE MT/WY ROCKIES. THIS WAVE AND WEAK
850-700MB UPSLOPE FLOW WAS KICKING OFF A SMALL COMPLEX OF SHRA/TS
ACROSS SD. MEANWHILE...AT THE SURFACE AND CLOSER TO HOME...THE COLD
FRONT THAT SPARKED SCATTERED HIGH-BASED THUNDERSTORMS TUESDAY
EVENING STRETCHED FROM CENTRAL UPPER MICHIGAN...SOUTHWARD ACROSS THE
WEST SHORE OF LAKE MICHIGAN...AND THEN WESTWARD THROUGH CENTRAL
IA. TEMPERATURES EARLY THIS MORNING BEHIND THE FRONT ACROSS THE AREA
AND  UNDER MOSTLY CLEAR SKIES WERE STILL FAIRLY WARM IN THE MIDDLE
TO  UPPER 60S.

FOR TODAY...LOOK FOR THAT ROCKIES WAVE TO MOVE EAST TOWARD THE AREA
THIS MORNING WHILE DAMPENING OUT. THIS SHOULD WEAKEN THE CONVECTION
THAT IS CURRENTLY OUT IN TH SD AS IT MOVES EAST. RESULT WILL BE AN
INCREASE IN MID-LEVEL CLOUDS WITH BASES AT OR ABOVE 12KFT//PER
BUFKIT SOUNDINGS// AND SOME ISOLATED -SHRA ACTIVITY INTO EARLY THIS
AFTERNOON. LOOK FOR BEST CHANCE FOR ANY SHOWERS TO BE ALONG AND
SOUTH OF I-94. OTHERWISE...CLOUDS EXPECTED TO BE ON THE DECREASE
FROM NORTH TO SOUTH LATER IN THE AFTERNOON AS THE MID-LEVEL WAVE
EXITS AND HIGH PRESSURE BUILD OVERHEAD. PLAN ON HIGHS TODAY IN THE
70S.

TONIGHT...WEATHER APPEARS QUIET AS HIGH PRESSURE TAKES CONTROL OVER
THE AREA. UNDER PARTLY CLOUDY/MOSTLY CLEAR SKIES AND LIGHT
WINDS...LOOK FOR TEMPERATURES TO DROP OFF INTO THE MID 40S TO MID
50S.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 341 AM CDT WED MAY 15 2013

MODELS CONTINUE TO SHOW THE COLD FRONT THAT SLIPPED SOUTH OF THE
AREA...RETURNING NORTHWARD AS A WARM FRONT STARTING LATE THURSDAY
AFTERNOON INTO THURSDAY NIGHT. MODEL CONSENSUS SHOWS EASTERN
PERIPHERY OF INCREASING 850MB MOISTURE TRANSPORT OVER THIS FRONTAL
BOUNDARY NOSING INTO THE AREA THURSDAY NIGHT. KEPT THURSDAY DRY FOR
NOW AND WENT WITH INCREASING SHRA/THUNDER CHANCES MOVING IN THURSDAY
NIGHT. NOT MUCH IN THE WAY OF CAPE...SO KEPT THUNDER AT ISOLATED FOR
NOW. PLAN ON HIGHS THURSDAY IN THE 70S ONCE AGAIN WITH LOWS THURSDAY
NIGHT IN THE 50S.

MODELS DIFFERENCE START CROPPING UP FRIDAY AS TO MOVEMENT OF THE
WARM FRONT AND RESULTING PRECIPITATION CHANCES. THE NAM WANTS TO
LIFT THE FRONT INTO SOUTHERN PORTIONS OF THE AREA WITH HINTS AT AN
MCS ROLLING ACROSS AREAS NORTH OF I-94. THE GFS ON THE OTHERHAND
KEEPS THE FRONT JUST SOUTH OF THE AREA WITH DRIER EAST SURFACE FLOW.
THIS WOULD LIMIT ANY PRECIPITATION. THE ECMWF FAVORS THE GFS MORE
AND THE GEM IS MORE IN THE NAM CAMP. WILL GO WITH A CONSENSUS FOR
NOW WHICH WOULD INCLUDE AROUND A 40 PERCENT CHANCE OF SHRA/TS.
TEMPERATURES WILL BE A BIT OF A CONSENSUS BLEND AS WELL WITH HIGHS
ENDING UP IN THE MID 60S ACROSS NORTH CENTRAL WI...TO THE MIDDLE
70S ACROSS NORTHEAST IA INTO FAR SOUTHWEST WI.

FOR FRIDAY NIGHT THROUGH THE WEEKEND...MODELS HINTING AT RIDGE
BUILDING OVER THE AREA/ATMOSPHERE CAPPING OFF THROUGH AT LEAST
SATURDAY NIGHT AS THE LOW HANGS UP OVER THE PLAINS. THIS WOULD
DIMINISH SHRA/TS CHANCES ACROSS OUR AREA AS BETTER MOISTURE
TRANSPORT/INSTABILITY REMAINS WEST OF THE REGION. WILL LEAVE
MID-RANGE POPS IN FOR NOW...BUT WILL HAVE THE DAYSHIFT ASSESS THE
POSSIBILITY OF DRYING THIS OUT MORE IN THE SATURDAY/SATURDAY NIGHT
TIME FRAME. FOR SUNDAY THROUGH TUESDAY TIME FRAME...APPEARS ACTIVE
WEATHER SETS UP WITH THE LOW MAKING ITS WAY ACROSS THE AREA. CANNOT
HANG A HAT ON MOST FAVORABLE TIME FOR ANY SEVERE THREAT...BUT
APPEARS ARE TRENDING MORE TOWARD A SUNDAY NIGHT MONDAY TIME FRAME.
WILL HAVE TO WATCH THE MODEL TRENDS AND CONTINUE TO KEEP A CLOSE EYE
ON THINGS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1212 AM CDT WED MAY 15 2013

SKIES WILL BE CLEAR TONIGHT...AND THEN A 12-15K BROKEN DECK OF
CLOUDS WILL MOVE INTO THE AREA AS A WEAK SYSTEM SLIDES SOUTHEAST
ACROSS NORTHERN MINNESOTA AND NORTHERN WISCONSIN ON WEDNESDAY. IN
THE WAKE OF THIS SYSTEM...THE 12-15K DECK OF CLOUDS WILL BECOME
SCATTERED DURING THE LATE AFTERNOON AND THEN CONTINUE THROUGH THE
EVENING. WINDS WILL REMAIN OUT OF THE NORTHWEST AT 10 TO 15 KNOTS
OVERNIGHT...AND THEN GRADUALLY SHIFT TO WEST AND SOUTHWEST ON
WEDNESDAY WITH WIND SPEEDS FALLING TO AROUND 5 KNOTS.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...DAS
LONG TERM...DAS
AVIATION...BOYNE