Area Forecast Discussion
Issued by NWS La Crosse, WI

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000
FXUS63 KARX 130853
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
353 AM CDT SUN APR 13 2014

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 353 AM CDT SUN APR 13 2014

MAIN FORECAST CONCERN IS WITH THE PRECIPITATION CHANCES THROUGH
TONIGHT AND THE POSSIBILITY OF FLOODING.

LOCAL AND REGIONAL RADARS SHOW THE ONGOING CONVECTION IS MAKING
GOOD NORTHEASTWARD PROGRESS AND EXPECT THAT MOST OF IT WILL HAVE
CLEARED OUT OF THE AREA BY 12Z. ATTENTION THEN TURNS TO THE
SOUTHWEST AND THE SHORT WAVE TROUGHS MOVING ACROSS NEBRASKA AND
KANSAS. THE 13.00Z MODELS HAVE REMAINED CONSISTENT IN BRINGING
THESE WAVES ACROSS THE AREA TODAY AND TONIGHT. THE NEXT ROUND OF
CONVECTION APPEARS TO BE FIRING ACROSS SOUTHWEST IOWA AHEAD OF THE
LEAD SHORT WAVE TROUGH. GOOD FORCING WILL OCCUR ACROSS THE REGION
WITH THESE WAVES AS THEY PRODUCE WEAK TO MODERATE PV ADVECTION IN
THE 500-300 MB LAYER. THE POTENTIAL FOR A COUPLE JET STRUCTURE
STILL EXISTS BETWEEN THE NORTHERN STREAM JET OVER LAKE SUPERIOR
AND THE JET CORE COMING NORTHEAST WITH THE SHORT WAVE TROUGHS TO
PROVIDE SOME ADDITIONAL LIFT TO THE SYSTEM.

IN THE LOW LEVELS...THE SURFACE FRONT EXTENDS FROM SOUTHWEST IOWA
INTO SOUTHEAST WISCONSIN AND IS NOT EXPECTED TO MAKE ANY EASTWARD
PROGRESS UNTIL AN AREA OF LOW PRESSURE MOVES ALONG THE FRONT THIS
EVENING WITH THE SECOND SHORT WAVE TROUGH. MODERATE TO AT TIMES
STRONG FRONTOGENESIS WILL OCCUR ALONG THE FRONT TODAY IN THE
1000-500 MB LAYER. THE WARM AIR ADVECTION AHEAD OF THE SURFACE LOW
WILL RESULT IN 4 TO 6 UBAR/S OF UP GLIDE INTO AND OVER THE FRONT
ON THE 295K ISENTROPIC SURFACE. THE 13.00Z NAM INDICATES THE BEST
CAPE WILL REMAIN SOUTHEAST OF THE FRONT SO WILL CONTINUE TO ONLY
INCLUDE A SMALL CHANCE OF THUNDER ACROSS THE SOUTHEAST AREAS. WITH
ALL THE FORCING...EXPECT TO SEE WIDESPREAD RAINS MOVE BACK INTO
THE AREA DURING THE AFTERNOON. THE 13.00Z HI-RES ARW LOOKS TO HAVE
A GOOD HANDLE ON THE ONGOING CONVECTION AND STARTS TO BRING THE
ACTIVITY CURRENTLY OVER SOUTHWEST IOWA BACK INTO THE SOUTHERN
PARTS OF THE AREA AROUND 15Z AND THEN TO ABOUT THE IOWA/MINNESOTA
BORDER BY 18Z. THE BEST CHANCE FOR RAIN DURING THE AFTERNOON AND
EVENING WILL THEN BE ACROSS NORTHEAST IOWA INTO CENTRAL WISCONSIN.
BASED ON THIS...WILL START THE MORNING WITH JUST A VERY SMALL
CHANCE ACROSS THE FAR SOUTH AND THE SPREAD THE CHANCES NORTH TO
ABOUT INTERSTATE 90 BY 18Z WITH 80 PERCENT OR HIGHER ALONG AND
SOUTH OF THE IOWA/MINNESOTA BORDER. FOR THE AFTERNOON INTO THE
EVENING...WILL THEN CARRY 80 TO 100 PERCENT CHANCES ACROSS
NORTHEAST IOWA INTO CENTRAL WISCONSIN TAPERING OFF TO JUST A 20 TO
40 PERCENT CHANCE ACROSS THE THE NORTHERN SECTIONS.
OVERNIGHT...THE PRECIPITATION WILL END ACROSS THE WESTERN SECTIONS
AND TAPERING DOWN TO ABOUT A 60 PERCENT CHANCE OVER THE EAST WITH
ALL THE PRECIPITATION THEN ENDING MONDAY MORNING. STILL LOOKS TO
BE ENOUGH COLD AIR ON THE BACK SIDE OF THIS SYSTEM FOR A CHANGE
OVER TO SOME LIGHT SNOW WITH ANY ACCUMULATIONS ACROSS THE EAST
STAYING UNDER A HALF INCH.

TEMPERATURES WILL BE WELL BELOW NORMAL BEHIND THIS SYSTEM AND
LOWERED THE HIGHS FOR MONDAY INTO THE 30S FOR MOST AREAS AND THEN
SLIGHTLY WARMER FOR TUESDAY WITH HIGHS RANGING FROM THE MIDDLE 30S
TO THE MIDDLE 40S.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 353 AM CDT SUN APR 13 2014

WITH ALL THE ONGOING WEATHER CONCERNS IN THE SHORT TERM...DID NOT
DEVIATE FROM THE MODEL CONSENSUS GRIDS. APPEARS THE MODELS
CONTINUE TO SHOW A SYSTEM COMING FOR THE MIDDLE OF THE WEEK WITH
THE FRONT REMAINING NEARLY STATIONARY OVER THE REGION TO KEEP THE
PRECIPITATION CHANCES GOING THROUGH THE REMAINDER OF THE PERIOD.
TEMPERATURES WILL REMAIN BELOW NORMAL RESULTING IN THE CHANCE FOR
RAIN DURING THE DAY AND SNOW AT NIGHT.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1140 PM CDT SAT APR 12 2014

BULK OF AREA ON COLD SIDE OF THIS SYSTEM WITH REINFORCING NORTHEAST
WINDS THAT CONTINUE TO SATURATE AREAS UNDER LOW LEVEL INVERSION. NOT
MUCH IMPROVEMENT EXPECTED WITH BULK OF AREA SOCKED UNDER LIFR
CONDITIONS OVERNIGHT. SOME IMPROVEMENT EXPECTED AFTER DAYBREAK BUT
BIG CHANGES COME LATER SUNDAY AS MAIN SHORT WAVE KICKS OUT SURFACE
SYSTEM.

AS SURFACE LOW SLIPS BY TO THE SOUTH...EXPECT PRECIPITATION TO
REFORM IN THE AREA BY EARLY SUNDAY AFTERNOON. MVFR CONDITIONS
EXPECTED AT BEST AS NORTH WINDS INCREASE AS SURFACE LOW TRACKS BY TO
THE SOUTHEAST OF AREA. COLDER AIR BEGINS TO WRAP IN SUNDAY EVENING
SO EXPECT SOME TRANSITION OVER TO MIX BEFORE ENDING SUNDAY NIGHT.


&&

.HYDROLOGY...
ISSUED AT 353 AM CDT SUN APR 13 2014

WILL ISSUE A FLOOD WATCH FOR A SMALL PORTION OF NORTHEAST IOWA
INTO CENTRAL WISCONSIN. BEST ESTIMATES ARE THAT THIS AREA RECEIVED
ANY WHERE FROM 1 TO 3 INCHES OF RAIN SATURDAY AND SATURDAY NIGHT.
CURRENT EXPECTATIONS ARE THAT ANOTHER 1 TO 2 INCHES OF RAIN ARE
POSSIBLE THROUGH THIS EVENING AND CONCERNED THAT THIS COULD PUSH
SOME OF THE SMALLER STREAMS OUT OF THEIR BANKS. MODELS INDICATE
PRECIPITABLE WATERS WILL BE ON THE ORDER OF 1 TO 1.25 INCHES NEAR
THE STALLED FRONT TODAY AND THE 13.03Z SREF HAS VERY HIGH
PROBABILITIES OF RAINFALL AMOUNTS EXCEEDED A HALF INCH IN 6 HOURS
ACROSS NORTHEAST IOWA INTO CENTRAL WISCONSIN STARTING LATE THIS
AFTERNOON AND CONTINUING THROUGH THE EVENING.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH FROM 1 PM CDT THIS AFTERNOON THROUGH LATE TONIGHT
     FOR WIZ043-044-053>055-061.

MN...NONE.
IA...FLOOD WATCH FROM 1 PM CDT THIS AFTERNOON THROUGH LATE TONIGHT
     FOR IAZ030.

&&

$$

SHORT TERM...04
LONG TERM...04
AVIATION...SHEA
HYDROLOGY...04



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