FXUS63 KARX 050849
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
249 AM CST SUN FEB 5 2012

.SHORT TERM...TODAY THROUGH WEDNESDAY
249 AM CST SUN FEB 5 2012

ANOTHER DAY OF TRYING TO FORECAST STRATUS AND TEMPERATURES IS ON
DECK FOR TODAY FOLLOWED BY A COLD FRONT THAT WILL COME THROUGH
MONDAY NIGHT.

ODDLY SITUATED MID LEVEL PATTERN IN PLACE WITH A TROUGH AND TWO
EMBEDDED VORT MAXES EXTENDING WEST FROM THE EASTERN GREAT LAKES
TOWARD NEVADA WITH A CUT OFF RIDGE SET UP ALONG THE US/CANADA
BORDER FROM THE PACIFIC NORTHWEST GOING EAST TOWARD THE DAKOTAS.
AT THE SURFACE...A BROAD RIDGE OF HIGH PRESSURE IS IN PLACE ALONG
THE EASTERN ROCKIES/WESTERN PLAINS WITH A RIDGE AXIS EXTENDING EAST
THROUGH THE UPPER MISSISSIPPI RIVER VALLEY AND GREAT LAKES REGION.
TWO MAIN POCKETS OF STRATUS REMAIN TRAPPED UNDER THE 950-900MB
INVERSION WITH ONE ADVANCING SOUTH-SOUTHEAST ACROSS MINNESOTA AND
ANOTHER OVER THE UPPER PENINSULA OF MICHIGAN AND NORTHEAST
WISCONSIN ADVANCING SOUTH-SOUTHWEST ACROSS EASTERN WISCONSIN.

WHAT HAPPENS WITH THIS CLOUD DECK TODAY IS THE MAIN QUESTION SINCE
IT WILL HAVE A DIRECT IMPACT ON HOW HIGH TEMPERATURES GET ONCE
AGAIN. BASED ON THE 05.06Z HRRR AND RECENT IR SATELLITE
TRENDS...IT LOOKS LIKE THE MINNESOTA STRATUS WILL HOLD ON THROUGH
THE MORNING ACROSS MN/IA WITH THE WISCONSIN STRATUS REACHING THE
MISSISSIPPI RIVER BY LATE MORNING. WHILE SOME HOLES WILL LIKELY
FORM THROUGH THE DAY...WENT A BIT ON THE PESSIMISTIC SIDE FOR
CLOUD COVER TODAY WHICH IN TURN WILL KEEP TEMPERATURES DOWN.
WHERE THE HOLES DO OPEN UP TODAY...HIGHS WILL LIKELY END UP IN THE
LOW TO MID 40S WITH TEMPERATURES IN THE 30S UNDER THE CLOUD DECK.
SOME INCREASING WESTERLY WINDS WILL PUSH DOWN ACROSS NORTHERN
WISCONSIN TODAY AND TONIGHT AND MAY HELP TO MIX OUT SOME OF THIS
LOW STRATUS AND CLEAR SKIES FROM THE NORTH.

THE FOCUS THEN GOES TO A COLD FRONT THAT WILL DROP THROUGH THE
REGION ON MONDAY NIGHT. AHEAD OF IT...WARM AIR ADVECTION AND
INCREASED LOW LEVEL MIXING WILL LEAD TO SUNNY SKIES AND A MILD DAY
WITH HIGHS LIKELY TO REACH THE MID TO UPPER 40S. THE TIMING OF THE
COLD FRONT PASSAGE MONDAY AFTERNOON AND NIGHT IS PRETTY CONSISTENT
BETWEEN THE 05.00Z MODEL SOLUTIONS WITH THE FRONT GETTING SOUTH
OF LA CROSSE AND ROCHESTER BEFORE 00Z TUESDAY AND SOUTH OF THE
WISCONSIN STATE LINE BY 06Z. LOW LEVEL CLOUD COVER WILL BE ON THE
INCREASE AS THE FRONT PASSES WITH THE QUESTION NOW BEING WHETHER
ANY FLURRIES WILL BE POSSIBLE AS THIS FEATURE PASSES. 05.00Z
NAM/GFS SOUNDINGS ARE TRENDING TOWARD HAVING A DEEPER LOW LEVEL
MIXED TEMPERATURE PROFILE WITH A DECENT AMOUNT OF MOISTURE AND
LIFT IN THIS LAYER AVAILABLE TO POSSIBLY PRODUCE SOME SNOWFLAKES
AS THE LAYER COOLS TOWARD -10/-12C. CONFIDENCE IS NOT THAT HIGH AT
THIS POINT TO PUT THESE POSSIBLE FLURRIES IN THE FORECAST...BUT IT
IS AT LEAST SOMETHING TO KEEP TABS ON OVER THE NEXT FEW DAYS.

A BROAD RIDGE OF HIGH PRESSURE WILL MOVE INTO THE UPPER
MISSISSIPPI RIVER VALLEY TUESDAY INTO WEDNESDAY AND WILL KEEP
TEMPERATURES DOWN TOWARD NORMAL INTO MID WEEK.

.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY
249 AM CST SUN FEB 5 2012

FOCUS IN THE EXTENDED CONTINUES TO BE WITH A COLD FRONT THAT IS
PROGGED TO COME THROUGH LATER IN THE WEEK. THE 05.00Z GFS
CONTINUES ITS TREND OF BEING THE FASTEST WITH THIS FEATURE AND
BRINGS IT THROUGH EARLY ON THURSDAY WHILE THE 05.00Z ECMWF IS
STILL SLOWER AND DOES NOT DROP THE FRONT THROUGH UNTIL FRIDAY.
INTRODUCED SOME LIGHT SNOW CHANCES ACROSS NORTH CENTRAL WISCONSIN
WITH THIS FEATURE AS THE GFS HAS BEEN SHOWING SOME POSSIBLE QPF UP
THERE THE PAST FEW RUNS.

OTHERWISE DIFFERENCES CROP UP GOING INTO THE WEEKEND WITH HOW LONG
THE COLD LOW LEVEL AIR REMAINS IN PLACE WITH THE 05.00Z GFS NOW
HOLDING ONTO 850MB TEMPERATURES BELOW -20C INTO THE WEEKEND WHILE
THE 05.00Z ECMWF PUSHING THE COLD AIR RAPIDLY OFF TO THE EAST LOW
LEVEL WARM AIR ADVECTION KICKING IN BY SATURDAY. GIVEN THESE
DISCREPANCIES...CONFIDENCE IS NOT ALL THAT HIGH IN HOW
TEMPERATURES WILL END UP TOWARD THE LATER PORTION OF THE FORECAST
PACKAGE.

&&

.AVIATION...THROUGH 06Z MONDAY
1133 PM CST SAT FEB 4 2012

A LARGE AREA OF STRATUS OVER MINNESOTA WAS PUSHING
SOUTHEAST...WITH THE LEADING EDGE EXTENDING FROM NEAR KONA...TO
KCCY. QUITE A BIT OF REPORTS OF CEILINGS IN THE LIFR CATEGORY
UNDER THE STRATUS AT 05Z. VISIBILITIES ON THE OTHER HAND WERE
RANGING FROM 1/2SM TO 5SM. 05.04Z RUC 975MB RELATIVE HUMIDITY PROG
SHOWS THIS STRATUS TO CONTINUE TO ADVECT EASTWARD BLANKETING BOTH
TAF SITES THROUGHOUT THE NIGHT. KLSE WILL LIKELY SEE THE STRATUS
BETWEEN 06Z-07Z. EXPECT LIFR CONDITIONS AT KRST AND IFR CONDITIONS AT
KLSE THROUGH AROUND 16Z. BY THAT TIME BOTH THE 05.04Z RUC AND
05.00Z NAM BUFKIT SOUNDINGS SHOW ENOUGH MIXING TO SCATTER OUT THE
CLOUDS. VFR CONDITIONS WILL THEN PREVAIL INTO THE EVENING HOURS.
COULD SEE SOME MVFR VISIBILITIES DEVELOP BETWEEN 04Z-06Z SUNDAY AS
COLUMN COOLS.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
249 AM CST SUN FEB 5 2012

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING



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