000
FXUS63 KARX 081134
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
534 AM CST SUN DEC 8 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST SUN DEC 8 2013

FORECAST CONCERNS ARE ON SNOWFALL TODAY INTO THIS EVENING. FOCUS
THEN TURNS TO WIND CHILLS LATE MONDAY AFTERNOON THROUGH WEDNESDAY
NIGHT.

LATEST WATER VAPOR IMAGERY SHOWED A SHORTWAVE TROUGH LIFTING
NORTHEAST ACROSS NORTHERN IOWA/SOUTHERN MINNESOTA. A SECONDARY
STRONGER WAVE WAS LOCATED OVER THE FOUR CORNERS REGION. THE
SECONDARY WAVE WILL LIFT NORTHEAST ACROSS THE PLAINS AND INTO THE
UPPER MISSISSIPPI RIVER VALLEY THIS AFTERNOON INTO THIS EVENING.
WEAK ISENTROPIC UPGLIDE NOTED WITH THE FIRST WAVE WHICH WILL PRODUCE
SOME LIGHT SNOW THIS MORNING BUT THE STRONGER ISENTROPIC LIFT...ON
THE 275-290 K SURFACES...ARRIVES AFTER 12Z THIS MORNING THEN REMAINS
OVER THE AREA INTO THIS EVENING AS THE SECONDARY WAVE MOVES IN.
LIGHT SNOW WILL SPREAD FROM WEST TO EAST ACROSS THE FORECAST AREA
THIS MORNING AND WILL CONTINUE THROUGH THE AFTERNOON HOURS. WITH THE
COLD AIRMASS IN PLACE ACROSS THE REGION THE DENDRITIC GROWTH ZONE IS
DEEP...RIGHT AROUND 300 MB. THE LIFT WITHIN THE DENDRITIC GROWTH
ZONE IS A LITTLE STRONGER THIS SET OF MODEL RUNS AND LOCATED WITHIN
THIS ZONE. FLUFFY SNOW ACCUMULATIONS OF 3 TO 5 INCHES ARE EXPECTED
BY LATE THIS EVENING. SINCE SNOW IS ALREADY ACCUMULATING OVER
SOUTHEAST MINNESOTA...PORTIONS OF NORTHEAST IOWA AND WEST CENTRAL
WISCONSIN...THE WINTER WEATHER ADVISORIES ARE ALREADY IN EFFECT
FOR THESE AREAS. AT THE NWS OFFICE IN LA CROSSE WE HAVE ALREADY
RECEIVED AROUND 1/10 OF AN INCH OF SNOWFALL. THIS WILL CREATE SOME
SLICK TRAVEL ON AREA ROADS EARLY THIS MORNING. THE SNOW WILL
CREATE SLIPPERY DRIVING CONDITIONS THROUGH MUCH OF THE DAY TODAY
INTO THIS EVENING. THE WAVE WILL EXIT THE FORECAST AREA TONIGHT
WITH THE SNOW ENDING.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CST SUN DEC 8 2013

A TIGHT PRESSURE GRADIENT DEVELOPS OVER THE REGION IN THE WAKE OF
THE SYSTEM WITH WEST WINDS INCREASING TO 15 TO 20 MPH MONDAY MORNING
INTO MONDAY AFTERNOON WITH GUSTS TO AROUND 30 MPH POSSIBLE. THESE
WINDS WILL CREATE SOME PATCHY BLOWING AND DRIFTING
SNOW...ESPECIALLY ACROSS THE OPEN AREAS OF SOUTHEAST
MINNESOTA...NORTHEAST IOWA...AND ALONG RIDGETOPS. SOME SLICK SPOTS
ON AREA ROADS CAN BE EXPECTED. HAVE ADDED PATCHY BLOWING SNOW TO
THE FORECAST THROUGH THE DAY ON MONDAY. ANOTHER WAVE PUSHES ACROSS
THE REGION ON MONDAY WITH THE MAIN IMPACT BEING MUCH COOLER AIR
MOVING IN BEHIND IT. NAM FORECAST SOUNDINGS SUGGEST THE POTENTIAL
FOR STRATOCUMULUS AND POSSIBLY A FEW FLURRIES OR LIGHT SNOW
SHOWERS ON MONDAY. THE GFS IS MUCH DRIER AND WOULDN/T SUPPORT
THIS. WILL NOT ADD IT TO THE FORECAST YET BUT WILL HAVE TO KEEP A
CLOSE EYE ON THIS POTENTIAL. TEMPERATURES WILL FALL THROUGH THE
AFTERNOON ON MONDAY AND BY EARLY MONDAY EVENING WILL RANGE FROM
THE SINGLE DIGITS BELOW ZERO OVER NORTH CENTRAL WISCONSIN INTO
SOUTHEAST MINNESOTA TO THE SINGLE DIGITS ABOVE ZERO OVER FAR
SOUTHWEST WISCONSIN. A WIND CHILL ADVISORY MAY BE NEEDED OVER
SOUTHEAST MINNESOTA...NORTH CENTRAL WISCONSIN AND PORTIONS OF
NORTHEAST IOWA STARTING LATE MONDAY AFTERNOON AND PERSISTING
THROUGH MONDAY NIGHT. MONDAY NIGHT WILL BE BITTERLY COLD WITH LOW
TEMPERATURES RANGING FROM THE TEENS BELOW ZERO OVER NORTHERN
WISCONSIN TO THE SINGLE DIGITS BELOW ZERO ACROSS THE REST OF THE
FORECAST AREA. A FEW LOCATIONS OVER FAR NORTHEAST IOWA AND FAR
SOUTHWEST WISCONSIN MAY STAY IN THE 1 TO 3 DEGREES ABOVE ZERO
RANGE. WIND CHILL VALUES MONDAY NIGHT ARE EXPECTED TO RANGE FROM
20 TO 30 BELOW ZERO. A WEAK SHORTWAVE MOVING ACROSS NORTHERN
WISCONSIN MAY GENERATE SOME LIGHT SNOW FOR LOCATIONS NORTH OF
WISCONSIN HIGHWAY 10 LATE MONDAY NIGHT INTO EARLY TUESDAY MORNING.

ANOTHER SHORTWAVE DROPS SOUTH INTO THE REGION FROM SOUTHERN CANADA
TUESDAY NIGHT AND MAY GENERATE SOME LIGHT SNOW OR FLURRIES ACROSS
MUCH OF THE FORECAST AREA AS IT MOVES THROUGH. SNOW ACCUMULATIONS OF
1 TO 2 INCHES ARE POSSIBLE SOUTH OF INTERSTATE 94. ANOTHER ARCTIC
HIGH THEN QUICKLY BUILDS IN ON WEDNESDAY WITH HIGHS ONLY IN THE
SINGLE DIGITS. NORTH CENTRAL WISCONSIN MAY NOT REACH THE ZERO
MARK...WITH HIGHS OF -1 TO -2. A BITTERLY COLD NIGHT IN STORE FOR
THE AREA AGAIN WEDNESDAY NIGHT WITH LOWS FALLING INTO THE TEENS TO
SINGLE DIGITS BELOW ZERO. A WIND CHILL ADVISORY MAY BE NEEDED
AGAIN WEDNESDAY NIGHT. ANOTHER WEAK WAVE MOVES ACROSS NORTHERN
WISCONSIN THURSDAY NIGHT INTO FRIDAY MORNING...POSSIBLY PRODUCING
A FEW FLURRIES OR LIGHT SNOW OVER NORTH CENTRAL WISCONSIN.
TEMPERATURES MAY WARM A BIT THURSDAY INTO FRIDAY AS FLOW ALOFT
TURNS MORE ZONAL. HIGH ON THURSDAY LOOK TO RANGE FROM THE TEENS TO
LOWER 20S...THEN WARM INTO THE LOWER 20S TO UPPER 20S ON FRIDAY.
COOLER AIR RETURNS ON SATURDAY AS ANOTHER SYSTEM MOVES THROUGH AND
BRINGS SOME LIGHT SNOW CHANCES TO THE REGION. PLAN ON HIGHS ON
SATURDAY RANGING FROM THE TEENS TO LOWER 20S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 534 AM CST SUN DEC 8 2013

LIGHT SNOW HAS DEVELOPED AT THE TAF SITES WITH VISIBILITIES OF IFR
AT RST AND MVFR AT LSE. ANTICIPATING VISIBILITIES TO DROP TO IFR
AT LSE SHORTLY...THOUGH IT IS POSSIBLE VISIBILITIES BOUNCE AROUND
BETWEEN MVFR AND IFR THROUGH THE MORNING AT LSE. SNOW IS EXPECTED
TO PERSIST AT THE TAF SITES THROUGH THE EVENING WITH THE HEAVIEST
OCCURRING LATE THIS AFTERNOON AND EVENING. UNCERTAIN IF THE
HEAVIEST WILL OCCUR AT RST...THUS HAVE HELD THE VISIBILITIES
THERE AT IFR WHILE CEILINGS FALL EVENTUALLY TO LIFR. LSE SEEMS TO
HAVE A BETTER CHANCE OF HEAVIER SNOW PER GFS/NAM/RAP MODELS...
THUS INCLUDED LIFR VISIBILITIES WITH OCCASIONAL DROPS TO IFR IN
CEILINGS. VISIBILITIES AND CEILINGS WILL GRADUALLY IMPROVE QUICKLY
DURING THE OVERNIGHT HOURS...RESULTING FROM THE SNOW TAPERING OFF
AND WINDS TURNING WEST WHICH BRING IN DRIER AIR.

FLUFFY SNOW ACCUMULATIONS OF NEAR 3 INCHES ARE EXPECTED TODAY WITH
ANOTHER 1 TO 2 INCHES DURING THE EVENING. LITTLE ADDITIONAL
ACCUMULATION IS FORECAST AFTER MIDNIGHT.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ032-033-041.

     WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ017-029-034-
     042-053-054.

     WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 6 AM CST
     MONDAY FOR WIZ043-044-055-061.

MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ079-086>088-
     094>096.

IA...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR IAZ008>010-018-
     019.

     WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR IAZ011-029-030.

&&

$$

SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...AJ