Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 270522
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1122 PM CST MON JAN 26 2015

.UPDATE...
ISSUED AT 856 PM CST MON JAN 26 2015

CONDITIONS HAVE GREATLY IMPROVED OVER THE PAST HOUR. THIS IS DUE
TO A COMBINATION OF DIFFERENT REASONS:

1. PRECIPITATION HAS BEEN ON THE WANE. THERE WAS A NICELY EVIDENT
VORT MAX ON RADAR THAT CAME THROUGH THE FORECAST AREA BETWEEN
23-01Z. SUBSIDENCE IN THE WAKE OF THIS VORT HAS HELPED TO SQUASH A
LOT OF THE DEVELOPMENT PREVIOUS MODEL RUNS WERE SUGGESTING ALONG
THE INVERTED SURFACE TROUGH. ADDITIONALLY...SURFACE CONVERGENCE
ALONG THE TROUGH IS NOT THAT STRONG AS WINDS HAVE DIMINISHED SOME
WEST OF THE MISSISSIPPI RIVER. LASTLY...ALL THE PREVIOUS SNOW
THAT WAS UP IN NORTHWEST WISCONSIN HAS NOW PROGRESSED TO THE
SOUTHEAST INTO EASTERN WI AND OUT OF THE FORECAST AREA.

2. ROADS HAVE BEEN IMPROVING RESULTING FROM TREATMENTS WORKING ON
THEM. THE DIMINISHING OF PRECIPITATION HAS ONLY AIDED THIS MORE.

DUE TO THE IMPROVING CONDITIONS...HAVE CANCELLED THE WINTER
WEATHER ADVISORY EARLY. STILL CANNOT RULE OUT SOME PATCHY LIGHT
FREEZING DRIZZLE OR LIGHT SNOW WITH THAT INVERTED TROUGH
AROUND...BUT NOT ENOUGH COVERAGE EXISTS TO WARRANT THE ADVISORY
OUT ANYMORE.

UPDATE ISSUED AT 459 PM CST MON JAN 26 2015

HAVE EXPANDED THE ADVISORY INTO FAR SOUTHWEST WISCONSIN WHERE
NUMEROUS REPORTS OF BAD ROADS HAVE BEEN RECEIVED...ESPECIALLY
SECONDARY ROADS.

ALSO HAVE EXTENDED THE ADVISORY UNTIL MIDNIGHT. A WARM FRONT SITS
ALONG THE MISSISSIPPI RIVER...WHICH APPEARS TO BE STUCK NOW THAT
ITS PARALLEL WITH THE UPPER LEVEL FLOW. ADDITIONALLY...A SURFACE
LOW OVER NORTHWEST WI WILL RIDE DOWN ALONG THIS FRONT...SETTING UP
AN INVERTED TROUGH IN ITS WAKE. LOW LEVEL VERTICAL MOTION SHOULD
PERSIST ALONG AND EAST OF THIS BOUNDARY...AND WITH TEMPERATURES IN
THIS ZONE BELOW FREEZING...WE SHOULD SEE A CONTINUATION OF
FREEZING DRIZZLE THROUGH THE EVENING. THIS IS SHOWN NICELY IN THE
LATEST HRRR RUNS...RAP...26.12Z REGIONAL CANADIAN AND 26.18Z NAM.
ANOTHER CONCERN IS THE MASS OF SNOW MARCHING SOUTH OUT OF
NORTHWEST WISCONSIN...WHICH SHOULD MARCH DOWN THROUGH CENTRAL WI
OVER THE NEXT FEW HOURS. THE COMBINATION OF THIS SNOW AND
FREEZING DRIZZLE WARRANTS A CONTINUATION OF THE ADVISORY. LUCKILY
IMPACTS SHOULD CONTINUE TO DECREASE AS ROADS CONTINUE TO BE
TREATED...THOUGH THE LOSS OF DAYTIME HEATING WILL ALLOW UNTREATED ROADS
TO COOL AND MAKE THINGS WORSE.

&&

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 331 PM CST MON JAN 26 2015

MAIN FORECAST PROBLEM WILL BE LINGERING FREEZING DRIZZLE
CHANCES THROUGH THIS EVENING.

SURFACE MAP THIS AFTERNOON HAS SURFACE LOW OVER THE ARROWHEAD WITH A
WARM FRONT EXTENDING ACROSS EASTERN MN/IA. TEMPERATURES RANGED FROM
THE MIDDLE 30S TO MIDDLE 40S BEHIND THE FRONT ACROSS SOUTHEAST
MN/NORTHEAST IA...TO THE LOWER TO MIDDLE 20S EAST OF THE MISSISSIPPI
RIVER/AHEAD OF THE FRONT. LOWER LEVEL ISENTROPIC LIFT ACROSS THIS
FRONT WAS PRODUCING AREAS OF FREEZING DRIZZLE EAST OF THE
MISSISSIPPI WITH REPORTS OF SOME SLIPPERY STRETCHES ON ROADWAYS VIA
WI 511 AND FROM LOCAL ROAD CREW.

LOOK FOR THE SURFACE LOW TO MOVE SOUTHEAST FROM THE ARROWHEAD OF MN
THIS AFTERNOON INTO NORTHWEST IL BY EARLY THIS EVENING. MAIN LIFT
AHEAD OF THIS LOW ...WHICH IS PRESENTLY CAUSING THE FREEZING DRIZZLE
WILL THEREFORE BE IN A WANING PHASE WITH ITS PASSAGE. HOWEVER...RAP
BUFKIT SOUNDING SHOWS SOME LINGERING LIFT ACROSS CENTRAL WI THROUGH
LATER THIS EVENING AS THE MID-LEVEL/SURFACE INVERTED TROUGH HANGS
UP. WILL THEREFORE CONTINUE TO CARRY FREEZING DRIZZLE MENTION INTO
THIS EVENING. THERE MAY BE SOME LIGHT SNOW AS WELL WITH POCKETS OF
FEEDER/SEEDER ICE. MAY HAVE TO EXTEND CURRENT ADVISORY A LITTLE
LONGER INTO THIS EVENING TO COVER FOR THIS. WILL KEEP A CLOSE EYE ON
IT.

HIGH PRESSURE BUILDS OVER THE AREA LATER TONIGHT THROUGH TUESDAY FOR
QUIET WEATHER. LOOKS LIKE IT WILL REMAIN MOSTLY CLOUDY THOUGH DESPITE
HIGH BUILDING IN DUE TO MOISTURE BEING TRAPPED UNDER THE SUBSIDENCE
INVERSION. WITH PARTIAL SUNSHINE LATE IN THE MORNING THROUGH THE
AFTERNOON...PLAN ON HIGHS REBOUNDING INTO THE 30S.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 331 PM CST MON JAN 26 2015

UNSEASONABLY MILD CONDITIONS EXPECTED FOR WEDNESDAY AHEAD OF
APPROACHING LOW PRESSURE ACROSS THE PLAINS. DESPITE AN INCREASE IN
STRATUS CLOUD...LOOK FOR HIGHS WELL INTO THE 30S WITH POSSIBLY A FEW
LOWER 40 READINGS ACROSS PARTS OF NORTHEAST IA INTO FAR SOUTHWEST WI.

A WINTRY MIX LOOKS TO IMPACT THE AREA WEDNESDAY NIGHT INTO THURSDAY
MORNING AS THE LOW OVER THE PLAINS MOVES TOWARD THE GREAT LAKES
REGION. MODEL SOUNDINGS NOT SHOWING A LOT OF ICE IN CLOUD FOR SNOW
PRODUCTION...SO LOOKS LIKE MORE OF A FREEZING RAIN/DRIZZLE POTENTIAL
AS A RESULT. WILL CONTINUE TO MONITOR THIS.

LATEST GFS/ECMWF SHOW ANOTHER STORM SYSTEM MOVING OUT OF THE PLAINS
TOWARD THE UPPER MISSISSIPPI RIVER REGION SATURDAY AFTERNOON INTO
SUNDAY FOR SNOW CHANCES.

OTHERWISE...LOOKS LIKE A SIGNIFICANT COOL DOWN THROUGH THE
WEEKEND/EARLY NEXT WEEK AS PATTERN SHIFTS TO NORTHWEST FLOW ALOFT.

HIGHS ON SATURDAY EXPECTED TO BE IN THE 20S...COOLING INTO THE
SINGLE DIGITS/TEENS BY MONDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1122 PM CST MON JAN 26 2015

STRATUS CONTINUES TO PLAGUE THE TAF SITES THIS EVENING...MOSTLY
OF THE MVFR VARIETY BUT OCCASIONALLY VFR. WITH THE FLOW TURNING
NORTHERLY AND PLENTY OF STRATUS THAT EXTENDS INTO NORTHERN
ONTARIO...BELIEVE THE STRATUS WILL STICK AROUND THROUGH MUCH OF
TUESDAY. ADDITIONALLY...WITH TEMPERATURES ABOVE THE CLOUD
WARMING...ITS POSSIBLE THAT THE CLOUD WILL GET PUSHED LOWER
CAUSING CEILINGS TO LOWER. FOR NOW STILL KEPT THE CEILINGS IN THE
MVFR RANGE...BUT BEARS WATCHING. AS WINDS SWING AROUND TO THE
SOUTH TO SOUTHWEST TUESDAY EVENING...FOLLOWING THE PASSAGE OF A
SURFACE RIDGE OF HIGH PRESSURE...ANTICIPATING CLEARING OF THE LOW
CLOUDS CURRENTLY IN WESTERN IOWA TO SURGE THROUGH THE TAF SITES.

ONLY LAST ITEM OF NOTE ARE SOME SNOW SHOWERS MOVING THROUGH LSE.
THESE SHOULD BE DONE BY 07Z AS THE TROUGH FORCING THEM WEAKENS.
ANY VISIBILITY REDUCTION SHOULD BE LIMITED TO MVFR.

&&

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

$$

UPDATE...AJ
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...AJ


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