000
FXUS63 KARX 061731
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1130 AM CST FRI DEC 6 2013

.SHORT TERM...(THIS AFTERNOON AND TONIGHT)
ISSUED AT 1130 AM CST FRI DEC 6 2013

MAIN FOCUS IN SHORT TERM CONTINUES TO BE COLD AND RELATED HEADLINES
FOR WIND CHILLS AGAIN TONIGHT.

SLIGHT MODIFICATIONS IN LOW TEMPERATURES TONIGHT...ESPECIALLY IN
NORTH CENTRAL WISCONSIN WHERE SNOW PACK EXISTS...HAS PRODUCED SLIGHT
CHANGES IN WIND CHILL VALUES OVERNIGHT AS NORTHWEST WINDS REMAIN
FAIRLY STEADY GIVEN SLOW CHANGING FLOW. KNOWING WIND CHILL
ADVISORIES WOULD BE NEEDED...MAINLY FOCUSED ON START TIME.
COORDINATION WITH SURROUNDING OFFICES PRODUCED A GOOD COMPROMISE OF
MID EVENING THROUGH DAY BREAK SATURDAY...WHICH HAS ALREADY BEEN
RELEASED.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 359 AM CST FRI DEC 6 2013

COLD HIGH PRESSURE WILL REMAIN IN CONTROL ON SATURDAY WITH MOSTLY
SUNNY SKIES AND COLD TEMPERATURES EXPECTED. PLAN ON HIGH
TEMPERATURES IN THE SINGLE DIGITS TO TEENS ABOVE ZERO. A SHORTWAVE
WILL MOVE OUT OF THE CENTRAL ROCKIES AND INTO THE UPPER MISSISSIPPI
RIVER VALLEY LATE SATURDAY NIGHT INTO SUNDAY MORNING. CLOUDS WILL
INCREASE FROM WEST TO EAST ACROSS THE AREA SATURDAY NIGHT AS THE
SHORTWAVE APPROACHES. ISENTROPIC LIFT INCREASES ACROSS THE FORECAST
AREA LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING ON THE 270-290K
SURFACES AND WILL LEAD TO THE DEVELOPMENT OF LIGHT SNOW. THE
DENDRITIC GROWTH ZONE WILL BE 200-300 MB DEEP AND WILL RESULT IN A
FLUFFY SNOW. LIFT...OMEGA...WITHIN THE DENDRITIC GROWTH ZONE
ISN/T OVERLY IMPRESSIVE AND IS MAINLY LOCATED JUST ABOVE THE
DENDRITIC GROWTH ZONE MAINLY IN THE 700-400 MB LAYER. THE SNOW
WILL BE FALLING ACROSS MUCH OF THE FORECAST AREA BY LATE SUNDAY
MORNING AND WILL PERSIST THROUGH SUNDAY AFTERNOON. THE WAVE WILL
THEN FINALLY EXIT THE REGION LATE SUNDAY NIGHT. PLAN ON SNOW
ACCUMULATIONS OF 2 TO 4 INCHES BEFORE THE SNOW TAPERS OFF SUNDAY
NIGHT. THE SNOW WILL LEAD TO SLICK TRAVEL CONDITIONS AND WINTER
WEATHER ADVISORIES WILL LIKELY BE NEEDED. SLIGHTLY WARMER AIR WILL
BE DRAWN INTO THE FORECAST AREA WITH THIS SYSTEM...WITH HIGHS ON
SUNDAY CLIMBING INTO THE TEENS TO LOWER 20S. THE PRESSURE GRADIENT
TIGHTENS OVER THE AREA MONDAY MORNING INTO MONDAY AFTERNOON AND
COULD LEAD TO SOME BLOWING AND DRIFTING OF THE FRESHLY FALLEN
SNOW. ANOTHER WAVE PUSHES INTO THE REGION MONDAY NIGHT INTO
TUESDAY MORNING AND WILL BRING A SLIGHT CHANCE OF SNOW WITH IT AS
IT MOVES THROUGH. ARCTIC HIGH PRESSURE THEN RETURNS WEDNESDAY INTO
WEDNESDAY NIGHT. WILL HAVE TO KEEP A VERY CLOSE EYE ON
TEMPERATURES WED/WED NIGHT AS FORECAST MODELS ARE TRENDING COLDER
DURING THIS TIMEFRAME. HIGHS ON WEDNESDAY WILL LIKELY STRUGGLE TO
GET OUT OF THE SINGLE DIGITS TO LOWER TEENS...WITH OVERNIGHT LOWS
FALLING INTO THE SINGLE DIGITS BELOW ZERO. FLOW ALOFT ATTEMPTS TO
GO ZONAL BRIEFLY LATE NEXT WEEK WITH HIGHS WARMING SLIGHTLY INTO
THE TEENS TO LOWER 20S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1130 AM CST FRI DEC 6 2013

VFR CONDITIONS WILL CONTINUE. LARGE AREA OF HIGH PRESSURE TO THE WEST
CONTINUED TO KEEP SKIES MAINLY CLEAR OUTSIDE OF A FEW STRATUS
POCKETS THAT BRING DOWN MVFR CEILINGS FOR A SHORT PERIOD. FAIRLY
UNCHANGING CONDITIONS EXPECTED INTO TOMORROW.

SOME HINTS OF MID LEVEL MOISTURE STREAMING IN FROM THE CENTRAL
PLAINS COULD BRING A FEW HOURS OF MID LEVEL CLOUDS TONIGHT.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...

WI...WIND CHILL ADVISORY FROM 9 PM CST TONIGHT UNTIL 9 AM SATURDAY
     FOR WIZ017-029-032-033-034.

MN...WIND CHILL ADVISORY FROM 9 PM CST TONIGHT UNTIL 9 AM SATURDAY
     FOR MNZ079-086-087-088-094-095.

IA...WIND CHILL ADVISORY FROM 9 PM CST TONIGHT UNTIL 9 AM SATURDAY
     FOR IAZ008-009-018-019.

&&

$$

SHORT TERM...SHEA
LONG TERM...WETENKAMP
AVIATION...SHEA