Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 181950
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
150 PM CST TUE NOV 18 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1203 PM CST TUE NOV 18 2014

CHALLENGES INCLUDE LIGHT SNOW TONIGHT..STRONG WINDS AND BLOWING
SNOW ON WEDNESDAY AND THEN THE POTENTIAL FOR A STRONGER WINTER
STORM FOR THE UPCOMING WEEKEND INTO EARLY NEXT WEEK.

FOR TONIGHT...SHORT-WAVE CURRENTLY OVER CENTRAL MANITOBA IN
NORTHWEST FLOW ALOFT WILL DIVE SOUTH ACROSS ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. EXPECT LIGHT SNOW TO DEVELOP ALONG MID-
LEVEL WARM FRONT. 850 TO 600 HPA FRONTOGENESIS AND LIFT ACROSS
DENDRITIC GROWTH ZONE NOT AS STRONG AS DEPICTED IN YESTERDAY/S
MODEL RUNS AND WITH THE QUICK FORWARD MOTION OF THIS SYSTEM...
EXPECT SNOWFALL AMOUNTS OF AN INCH OR LESS. CLOUD COVER AND WARM
AIR ADVECTION WILL KEEP TEMPERATURES NEARLY STEADY OVERNIGHT WITH
LOWS FROM THE SINGLE DIGITS ACROSS TAYLOR/CLARK COUNTIES TO THE
MID TEENS ALONG THE MISSISSIPPI RIVER VALLEY FLOOR.

LINGERING LIGHT SNOW POSSIBLE ON WEDNESDAY MAINLY ACROSS WISCONSIN
COUNTIES WITH PERHAPS ANOTHER HALF INCH ACCUMULATION. BIGGER
IMPACT WILL BE WINDS SHIFTING TO THE NORTHWEST FROM WEST TO EAST
BEHIND THE COLD FRONT...GUSTING AT TIMES TO 30 MPH. ADDED PATCHY
BLOWING SNOW TO THE ENTIRE FORECAST AREA TO COINCIDE WITH
INCREASING WIND...BUT IMPACT WILL LIKELY BE LIMITED TO THOSE
AREAS THAT RECEIVE NEW SNOWFALL. TEMPERATURES WILL TOP OUT IN THE
UPPER TEENS TO LOWER 20S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1203 PM CST TUE NOV 18 2014

WEDNESDAY NIGHT THROUGH FRIDAY WILL BE DRY AS A SURFACE RIDGE
DOMINATES THE REGIONAL WEATHER PATTERN. BRISK NORTHWEST WIND WILL
PERSIST THROUGH THE NOON HOUR ON THURSDAY...DIMINISHING THEREAFTER
AS HIGH PRESSURE CENTER DRIFTS ACROSS IOWA AND PRESSURE GRADIENT
SLACKENS. WINDS WILL THEN BE LIGHT AND VARIABLE THROUGH FRIDAY
MORNING WITH INCREASING SOUTHERLY FLOW BY FRIDAY AFTERNOON.
TEMPERATURES IN THE TEENS ON THURSDAY WILL RISE INTO THE 20S FOR
FRIDAY...WHICH SHOULD BE THE LAST SUB-FREEZING DAY OF THIS CURRENT
STRETCH OF UNSEASONABLE COLD.

FRIDAY NIGHT THROUGH MONDAY NIGHT...THERE IS STILL THE POTENTIAL
FOR A PROLONGED PRECIP EVENT AS A STRONG OPEN WAVE FROM THE
SOUTHERN PLAINS INTERACTS AND EVENTUALLY MERGES WITH A NORTHERN
STREAM TROUGH SOMEWHERE ACROSS THE UPPER MIDWEST. PRECIP TYPE WILL
BE AN ISSUE AS 18.12Z GFS/ECMWF ARE INITIALLY VERY WARM AND DRY
ALOFT...INCREASING THE THREAT FOR FREEZING RAIN/DRIZZLE AND
PERHAPS EVEN SOME SLEET GIVEN THE DEPTH OF THE NEAR SURFACE COLD
LAYER. FRIDAY/SATURDAY NIGHTS...MIXED PRECIP IS POSSIBLE...GIVING
WAY TO ALL RAIN DURING THE DAYLIGHT HOURS SATURDAY AND SUNDAY WITH
AFTERNOON HIGHS BOTH DAYS INTO THE MID 30S TO LOWER 40S. COLUMN
EVENTUALLY SATURATES AND DROPS BELOW FREEZING BY MONDAY MORNING
RESULTING IN A PERMANENT CHANGE OVER TO ALL SNOW. WAY TOO EARLY TO
DETERMINE AMOUNTS AS EVEN THE 24 CHANGE IN MODEL LOW TRACK HAS
SHIFTED SLIGHTLY TO THE EAST. WILL ADD GREATER DETAIL AS MODELS
CONVERGE ON A SOLUTION AND CERTAINTY INCREASES THROUGH THE WEEK.

IT DOES APPEAR THAT DRY AND SUB-FREEZING CONDITIONS WILL RETURN BY
NEXT TUESDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1200 PM CST TUE NOV 18 2014

SOME MVFR CEILINGS ARE STICKING AROUND SOUTHEAST MINNESOTA TO
WESTERN WISCONSIN BUT BASES ARE EXPECTED TO RISE OVER THE NEXT FEW
HOURS AS A RIDGE OF HIGH PRESSURE MOVES IN FROM THE WEST. ANY
LEFTOVER FLURRIES WILL COME TO AN END BY LATE AFTERNOON AS WINDS
COME AROUND TO THE SOUTH AHEAD OF THE NEXT SYSTEM. A BAND OF LIGHT
SNOW IS EXPECTED TO MOVE THROUGH THE REGION OVERNIGHT BUT NOT MUCH
IS FORECAST TO FALL FROM IT. IT LOOKS TO BE ABOUT A 3 HOUR PERIOD
OF LIGHT SNOW WITH CONFIDENCE A BIT HIGHER AT LSE THAN RST WITH
THE VISIBILITY DROPPING TO 2SM. WINDS WILL SWING AROUND TO THE
NORTHWEST AND BECOME GUSTY TOMORROW MORNING AFTER THE COLD FRONT
MOVES THROUGH AROUND DAYBREAK.

&&

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

$$

SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION...HALBACH



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