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000
FXUS63 KARX 222243
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
545 PM CDT TUE APR 22 2014

.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 305 PM CDT TUE APR 22 2014

MAIN WEATHER IMPACTS THROUGH WEDNESDAY NIGHT LOOKS TO BE RAINFALL.

WATER VAPOR IMAGERY THIS AFTERNOON HAS A LARGE/HIGHLY AMPLIFIED
RIDGE OF HIGH PRESSURE EXTENDING FROM MEXICO THROUGH THE HIGH PLAINS
INTO THE CANADIAN ROCKIES. MEANWHILE...A VIGOROUS MID-LEVEL TROUGH
WAS MOVING INTO THE WEST COAST TOWARD THE INTERMOUNTAIN WEST
REGION. THIS WILL BE OUR WEATHER-MAKER FOR WEDNESDAY INTO THURSDAY.
AT THE SURFACE...A RIDGE OF HIGH PRESSURE WAS BUILDING EASTWARD INTO
THE AREA FROM MN/IA. PRESSURE GRADIENT AHEAD OF THIS RIDGE WAS
PRODUCING FAIRLY BRISK NORTHWEST WINDS GENERALLY IN THE 10-20 MPH
RANGE WITH A FEW GUSTS UP TO 25-30 MPH ACROSS PORTIONS OF NORTHEAST
IA/SOUTHEAST MN. TEMPERATURES ACROSS THE AREA THIS AFTERNOON RANGED
FROM THE UPPER 40S ACROSS NORTH CENTRAL WI...TO THE MID/UPPER 50S
ACROSS NORTHEAST IA/SOUTHWEST WI.

LOOK FOR THIS RIDGE OF HIGH PRESSURE TO PASS OVER THE AREA TONIGHT
FOR MOSTLY CLEAR SKIES AT THE ONSET...THEN THICKENING MID/HIGH
CLOUDS AFTER MIDNIGHT AHEAD OF THAT MID-LEVEL TROUGH MOVING INTO THE
CENTRAL/NORTHERN ROCKIES. THINKING THAT TOO MUCH DRY AIR WILL BE IN
PLACE FOR ANY PRECIPITATION CHANCES. OTHERWISE...PLAN ON LIGHT WINDS
PICKING UP FROM THE SOUTHEAST AFTER MIDNIGHT ON THE BACKSIDE OF THE
HIGH WITH TEMPERATURES BOTTOMING OUT IN THE LOWER 30S IN THE SAND
COUNTRY OF CENTRAL WI...AND IN THE UPPER 30S/LOWER 40S ELSEWHERE.

FOR WEDNESDAY...LOOK FOR THE MID-LEVEL TROUGH TO TRACK TOWARD THE
NORTHERN/CENTRAL PLAINS WITH ELONGATED AREA OF SURFACE LOW PRESSURE
ACROSS THE PLAINS. MODELS SHOWING INCREASING MOISTURE TRANSPORT AND
DECENT ARM OF ISENTROPIC LIFT AHEAD OF THE LOW PRESSURE PUSHING INTO
OUR REGION FOR THE LIKELIHOOD OF SHOWERS. INSTABILITY RATHER
LIMITED...SO WILL KEEP JUST A SLIGHT CHANCE MENTION OF THUNDER IN
FOR NOW. OTHERWISE...SOUTHEAST SURFACE WINDS/CLOUD COVER/RAIN ALL
EXPECTED TO KEEP TEMPERATURES IN CHECK WITH HIGHS ONLY EXPECTED TO
TOP OFF IN THE LOWER AND MIDDLE 50S.

HEAVIER SLUG OF RAINFALL LOOKS TO MOVE INTO THE AREA WEDNESDAY
NIGHT...MAINLY AFTER MIDNIGHT AHEAD OF SURFACE
CYCLOGENESIS/STRENGTHENING LOW LEVEL JET OVER THE CENTRAL PLAINS
INTO WESTERN IA. NAM/GFS SHOW PRECIPITABLE WATER VALUES INCREASING
INTO THE 1-1.25 INCH RANGE WITH INCREASING TAP FROM THE GULF OF
MEXICO. LOOKING AT BUFKIT AND MODEL CAPE VALUES SHOW INSTABILITY
RATHER LIMITED AGAIN...SO WILL GO WITH SLIGHT CHANCE THUNDER
VERBIAGE FOR NOW. WEDNESDAY NIGHT LOWS EXPECTED TO BE IN THE UPPER
30S TO MIDDLE 40S.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 305 PM CDT TUE APR 22 2014

SHOWER/ISOLATED THUNDER ACTIVITY EXPECTED TO CONTINUE THROUGH
THURSDAY AS THAT SURFACE LOW OVER IA LIFTS NORTHEAST ACROSS THE
AREA. PLAN ON HIGH TEMPERATURES IN THE UPPER 40S TO UPPER 50S.

LINGERING SHOWERS MAINLY EAST OF THE MISSISSIPPI RIVER THURSDAY
EVENING AND NORTHEAST OF I-94 AFTER MIDNIGHT AS THE MAIN MID-LEVEL
TROUGH OF LOW PRESSURE ROTATES THROUGH THE AREA. OVERNIGHT LOWS
THURSDAY NIGHT EXPECTED TO BOTTOM OUT IN THE UPPER 30S TO LOWER 40S
IN COLD AIR ADVECTION.

PLAN ON GENERAL COOLER CYCLONIC FLOW OVERHEAD ON FRIDAY WITH
STEEPENING AFTERNOON LAPSE RATES FOR SOME GOOD CUMULUS DEVELOPMENT/
ISOLATED SHOWER ACTIVITY. OTHERWISE...IT LOOKS BRISK WITH DEEPER
MIXING WITH HIGHS IN THE LOWER 50S ACROSS NORTH CENTRAL WI...TOT HE
LOWER 60S ACROSS PORTIONS OF NORTHEAST IA INTO SOUTHWEST WI.

DRY WEATHER IS EXPECTED FOR FRIDAY NIGHT INTO SATURDAY AS CANADIAN
HIGH PRESSURE NOSES SOUTHWARD INTO THE AREA. THIS PERIOD OF DRY
WEATHER LOOKS SHORT-LIVED THROUGH AS BOTH THE LATEST EC AND GFS
BRING ANOTHER AREA OF LOW PRESSURE AND RAIN OUT OF THE
NORTHERN/CENTRAL PLAINS INTO THE AREA SUNDAY INTO EARLY NEXT WEEK.
THERE COULD EVEN BE SOME LIGHT SNOW MIXING IN AT TIMES LATE SATURDAY
NIGHT  INTO SUNDAY MORNING AND AGAIN LATE SUNDAY NIGHT INTO MONDAY
MORNING.

BOTH GFS/EC HINTING AT KEEPING A LARGE UPPER CLOSED LOW OVER THE
OHIO RIVER VALLEY AND MID-UPPER MISSISSIPPI RIVER VALLEY REGION
THROUGH THE END OF NEXT WEEK FOR A COOLER BOUT OF TEMPERATURES ALONG
WITH ON/OFF SHOWER ACTIVITY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 545 PM CDT TUE APR 22 2014

HIGH/MID LEVEL CLOUDS WILL FILTER IN THE FROM THE WEST...GRADUALLY
THICKENING AND BECOMING A CIG TOWARD 12Z WED. THE CLOUDS WILL
CONTINUE TO LOWER AS A WARM FRONT APPROACHES FROM THE WEST. A FEW
-SHRA WILL BE SCATTERED AHEAD OF THE FRONT...BUT EXPECTING A BAND TO
DEVELOP IN THE LOW LEVEL THERMODYNAMICS...IMPACTING KRST/KLSE FOR
THE AFTERNOON/EARLY EVENING HOURS. BUFKIT SOUNDINGS SUGGEST THAT VFR
CIGS WILL HOLD...ALTHOUGH A PERIOD OF MVFR VSBYS WITH THE RAIN WOULD
BE POSSIBLE BY MID AFTERNOON. WILL LEAVE FORECAST VFR FOR NOW.

THERE LOOKS TO BE A BREAK IN THE PCPN FOR THE EVENING HOURS...POST
THE WARM AIR ADVECTION RAIN AND PCPN ASSOCIATED WITH THE SYSTEM/S
SFC LOW AND UPPER LEVEL SHORTWAVE INTERACTION. EXPECTING MVFR CIGS
WHEN THIS RAIN TO MOVE IN OVERNIGHT WED...PERSISTING THROUGH THU
MORNING. LOOK FOR A PROLONGED PERIOD OF RAIN WITH LOW CIGS AND VSBY
REDUCTIONS IN THE RAIN. MVFR/IFR CONDITIONS ARE PROBABLE.

WINDS WILL GO LIGHT TONIGHT...MOSTLY FROM THE NORTHEAST. LOOK FOR AN
INCREASE BY MID MORNING...WITH SOME AFTERNOON GUSTINESS LIKELY. A
TIGHT PRESSURE GRADIENT WILL KEEP THE WINDS UP THROUGH WED NIGHT.

&&

.HYDROLOGY...
ISSUED AT 305 PM CDT TUE APR 22 2014

PLAN ON THE MISSISSIPPI RIVER AT MCGREGOR IA TO SLOWLY FALL BELOW
FLOOD STAGE THIS EVENING. CONTINUED SNOWMELT FROM NORTHWEST
WISCONSIN AND CENTRAL INTO PORTIONS OF NORTHERN MINNESOTA MAKES WILL
EVENTUALLY MAKE ITS WAY INTO THE LOCAL AREA OVER THE NEXT SEVERAL
DAYS. IN ADDITION...SOME MINOR RUNOFF FROM RAINFALL WEDNESDAY INTO
THURSDAY WILL ALSO OCCUR. THIS COMBINATION IS EXPECTED TO KEEP AREA
RIVER LEVELS ELEVATED INTO NEXT WEEK...BUT NO FLOODING IS EXPECTED.

&&

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

&&

$$

SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
HYDROLOGY....DAS