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000
FXUS63 KARX 282335
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
530 PM CST THU NOV 28 2013

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 325 PM CST THU NOV 28 2013

AT 3 PM...A LAKE INDUCED VORTICITY WAS LOCATED OVER THE APOSTLE
ISLANDS IN WESTERN LAKE SUPERIOR. MEANWHILE A SURFACE LOW WAS
LOCATED OVER EASTERN UPPER MICHIGAN. THIS LOW WAS PRODUCING WEAK
CYCLONIC FLOW ACROSS ACROSS WISCONSIN AND EAST CENTRAL MINNESOTA.
THIS CYCLONIC FLOW ALONG WITH STEEP 950-900 MB LAPSE RATES
/ASSOCIATED WITH A THERMAL TROUGH LOCATED FROM NORTHERN MINNESOTA
SOUTHEAST INTO EASTERN WISCONSIN/ IS HELPING MAINTAIN THESE
CLOUDS. THE 28.19Z RAP HAS A VERY GOOD HANDLE ON THESE CLOUDS AND
THEY SHOW THAT THEY WILL CONTINUE TO MOVE SOUTHEAST ACROSS MAINLY
OUR WISCONSIN COUNTIES AND THEN QUICKLY DISSIPATES THEM BETWEEN
28.01Z AND 28.03Z AS THE FLOW STARTS TO BECOME ANTICYCLONIC AND
THE 950-900 MB LAPSE RATES DECREASE.

FROM LATE TONIGHT INTO FRIDAY...THE 28.12Z MODELS CONTINUE TO
SHOW THAT WEAK WARM AIR ADVECTION WILL DEVELOP ABOVE 600 MB AS A
WEAK SHORT WAVE TROUGH APPROACHES THE REGION FROM THE CENTRAL
PLAINS. THIS WILL RESULT IN SOME MID TO HIGH CLOUDS ACROSS THE
AREA.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 PM CST THU NOV 28 2013

ON FRIDAY NIGHT...THE 28.12Z MODELS CONTINUE TO SHOW THAT A STRONG
SHORT WAVE TROUGH WILL MOVE SOUTHEAST ACROSS SOUTHWEST ONTARIO.
MUCH OF THE PV ADVECTION ASSOCIATED WITH THIS SYSTEM STAYS WILL
NORTH OF THE FORECAST AREA. THERE IS WEAK TO MODERATE 285 TO 300K
ISENTROPIC LIFT ACROSS NORTHERN AND EASTERN WISCONSIN. THIS LOWERS
THE CONDENSATION PRESSURE DEFICITS TO LESS 40 MB. MEANWHILE AT THE
285 AND 290K ISENTROPIC SURFACES YOU STILL NEED 100 TO 200 MB
OF LIFT FOR SATURATION. AS A RESULT...IT IS NOT LOOKING PROMISING
FOR ANY PRECIPITATION ACROSS TAYLOR AND NORTHERN CLARK COUNTY IN
NORTH CENTRAL WISCONSIN. HOWEVER WITH THE ECMWF...GEM...AND NAM
STILL INDICATING A POSSIBILITY. JUST KEPT A SLIGHT CHANCE /LESS
THAN 20 PERCENT/ ACROSS THIS AREA. BUFKIT SOUNDINGS CONTINUE TO
SHOW NO ICE...SO IF PRECIPITATION DOES INDEED OCCURS IT WOULD BE
IN THE FORM OF FREEZING DRIZZLE.

ON SATURDAY NIGHT...WEAK TO MODERATE WARM AIR ADVECTION AND STRONG
290 TO 300K ISENTROPIC LIFT DEVELOP ACROSS THE AREA AS A STRONG
SHORT WAVE TROUGH MOVES ACROSS THE REGION. THE 290-300K ISENTROPIC
CONDENSATION PRESSURE DEFICITS DROP TO LESS THAN 30 MB...SO WE
WILL LIKELY SEE CLOUDS WITH THIS WAVE. HOWEVER...THE 285K
CONDENSATION DEFICITS REMAIN IN THE 100 TO 200 MB RANGE...SO NOT
EXPECTING ANY PRECIPITATION WITH THIS WAVE.

FROM SUNDAY NIGHT INTO MONDAY...THE MODELS CONTINUE TO STRUGGLE
WITH THE TIMING OF A SHORT WAVE TROUGH COMING OUT AHEAD OF THE
DEVELOPING LONG WAVE TROUGH IN THE WESTERN UNITED STATE. BOTH THE
GEM AND ECMWF BRING A WAVE AHEAD OF THIS SYSTEM. MEANWHILE THE GFS
DOES NOT. AS AS RESULT...THE GEM AND ECMWF PRODUCES SOME LIGHT
PRECIPITATION ACROSS THE AREA. MEANWHILE THE GFS KEEPS THE AREA
DRY. SINCE THE MODELS HAVE BEEN CONSISTENT...JUST STAYED WITH THE
SLIGHT CHANCES THAT THE ALL BLEND PROVIDED.

FROM MONDAY NIGHT THROUGH THURSDAY...THE MODELS CONTINUE TO
STRUGGLE WITH THE EVOLUTION OF A LONG WAVE TROUGH OVER THE WESTERN
UNITED STATES. DUE TO THIS...THERE HAS BEEN A VARIETY OF DIFFERENT
LOW PRESSURE TRACKS FROM THE NORTHERN PLAINS EAST INTO THE GREAT
LAKES. THIS SYSTEM HAS THE POTENTIAL OF PRODUCING A WINTER STORM
SOMEWHERE ACROSS THE REGION...BUT WHERE IS VERY UNCERTAIN...SO
JUST STAYED WITH THE ALL BLEND FOR THIS TIME PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 530 PM CST THU NOV 28 2013

BANK OF VFR/MVFR STILL LINGERING ACROSS MUCH OF WI EARLY THIS
EVENING...BUT HAS BEEN SHOWING SOME DIMINISHING TREND/MOVEMENT EAST
PER LATEST FOG/STRATUS SATELLITE IMAGERY. EXPECT THIS TREND TO
CONTINUE...WITH SKC/SCT CONDITIONS AT KLSE BY 03Z.

LIGHT TO VRB WINDS DURING THE NIGHT TIME HOURS. WINDS WILL INCREASE
AND SHIFT TO THE SOUTH/SOUTHEAST A FEW HOURS AFTER DAYBREAK FRIDAY
AS HIGH PRESSURE EXITS OVER THE EASTERN GREAT LAKES. SHOULD SEE SOME
HIGH/MID LEVEL CLOUDS BY THIS TIME...MOSTLY IN THE 150-250 KFT
RANGE.

&&

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

$$

SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RIECK