Hail in Wisconsin, September 1, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
321 AM CDT SUN SEP 1 2013

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 321 AM CDT SUN SEP 1 2013

MAIN FORECAST CONCERN THROUGH THE SHORT TERM IS ON SHRA/TSRA CHANCES
TODAY...THEN CLOUD OVER TONIGHT INTO MONDAY.

EARLY MORNING WATER VAPOR IMAGERY/RAP 500MB ANALYSIS SHOWS A
DISTINCT MID-LEVEL LOW/CIRCULATION NEAR INTERNATIONAL FALLS MN WITH
A TROUGH EXTENDING SOUTH THROUGH MN INTO EASTERN NEBRASKA. AT THE
SURFACE...LOW PRESSURE WAS CENTERED OVER THE ARROWHEAD OF MN WITH A
COLD FRONT TRAILING THROUGH NORTHWEST WI INTO NORTHERN IA. RADAR
MOSAIC SHOWING SCATTERED SHOWERS/THUNDERSTORMS ALONG AND AHEAD OF
THIS FRONT. CONVECTION HEADING INTO THE AREA HAS BEEN A GENERAL
DOWNWARD/WEAKENING TREND AS BETTER MOISTURE TRANSPORT/INSTABILITY
DIRECTED NORTHWARD INTO NORTHERN WI/MN. OTHERWISE...TEMPERATURES
ACROSS THE FORECAST AREA WERE IN THE MIDDLE 60S TO 70 DEGREES.

FOR TODAY...THE MID-LEVEL TROUGH AND SURFACE COLD FRONT WILL
CONTINUE TO SWING SOUTHEAST ACROSS THE AREA. WITH MOISTURE
TRANSPORT/INSTABILITY WANING...WILL CONTINUE TO CARRY SMALLER-END
SHOWER/THUNDERSTORM CHANCES...EXITING EAST BY THIS AFTERNOON. ONCE
THE SHOWER/THUNDERSTORM CHANCES EXIT THE AREA...LOOK FOR AN INCREASE
IN CUMULUS/STRATOCUMULUS LATER THIS MORNING INTO THIS AFTERNOON WITH
STEEPER LAPSE RATES UNDER THE MID-LEVEL TROUGH ROTATING THROUGH.
EXPECTING MOST OF THIS CLOUD COVER ALONG AND NORTH OF I-94.
OTHERWISE...SLIGHTLY COOLER/DRIER AIR OVERSPREADS THE AREA ON BREEZY
NORTHWEST WINDS IN THE 15-25 MPH RANGE. PLAN ON HIGHS TODAY IN THE
75-85 DEGREE RANGE WITH DEW POINTS IN THE LOWER 60S.

NAM/SREF/GFS SHOWING QUITE A BIT OF LOW-LEVEL MOISTURE SURGING
SOUTHWARD INTO THE AREA FROM LAKE SUPERIOR UNDER A SUBSIDENCE
INVERSION AS HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS.
INCREASED CLOUDS COVER  EAST OF THE MISSISSIPPI/AND MAINLY NORTHEAST
OF I-94 TO ACCOUNT FOR THIS. OTHERWISE...TEMPERATURES ARE EXPECTED TO
DIP INTO THE 50S.

.LONG TERM...(LABOR DAY THROUGH SATURDAY)
ISSUED AT 321 AM CDT SUN SEP 1 2013

CLOUD COVER COULD BE A BIT TRICKY FOR LABOR DAY AS MOISTURE WILL BE
TRAPPED UNDER THE SUBSIDENCE INVERSION WITH HIGH PRESSURE BUILDING
OVERHEAD. BELIEVE CLOUDIER CONDITIONS WILL BE SEEN NORTHEAST OF I-94
WITH CLOUD COVER THINNING OUT THROUGH THE DAY IN STRENGTHENING
SUBSIDENCE ALOFT. CLOUDS COULD WILL ALSO HAVE A POTENTIAL IMPACT ON
TEMPERATURES AS WELL. PLAN ON HIGHS IN THE MIDDLE AND UPPER 60S
ACROSS NORTH CENTRAL WI...AND THE LOWER AND MIDDLE 70S ELSEWHERE.

HIGH PRESSURE SETTLES OVERHEAD MONDAY NIGHT. CLEARING SKIES/CALM
WINDS/COOLING LOWER BOUNDARY LAYER WILL LEAD TO FOG FORMATION...
ESPECIALLY RIVER VALLEY AREAS. OTHERWISE...LOOK FOR RATHER CHILLY
CONDITIONS WITH OVERNIGHT LOWS EXPECTED TO DIP INTO THE 40S.

GFS AND ECMWF IN GOOD AGREEMENT IN SWINGING A COLD FRONT THROUGH THE
AREA WEDNESDAY/WEDNESDAY NIGHT. WITH SUCH A DRY ATMOSPHERE...
EXPECTING NOTHING MORE THAN A FEW ALTOCUMULUS. LOOK FOR HIGHS ON
WEDNESDAY IN THE UPPER 70S TO THE LOWER 80S AND LOWS WEDNESDAY NIGHT
IN THE 50S.

NORTHWEST FLOW ALOFT DOMINATES THE REGION THURSDAY THROUGH SATURDAY
AS A RIDGE OF HIGH PRESSURE ANCHORS ITSELF OVER THE INTERMOUNTAIN
WEST. GFS/ECMWF HINT AT ANOTHER MID-LEVEL TROUGH/SURFACE COLD FRONT
BRUSHING OUR AREA FRIDAY NIGHT/SATURDAY. APPEARS ANY PRECIPITATION
ASSOCIATED WITH THIS TROUGH/COLD FRONT SHOULD STAY NORTHEAST OF THE
AREA. OTHERWISE...A SLOW WARMING TREND EXPECTED IN THE THURSDAY
THROUGH SATURDAY. PLAN ON HIGHS IN THE 75-80 DEGREE RANGE
THURSDAY...WARMING INTO THE LOWER/MIDDLE 80S BY SATURDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1143 PM CDT SAT AUG 31 2013

LINE OF CONVECTION ALONG THE FRONT HAS PRETTY MUCH DISSIPATED
EXCEPT FOR A FEW SHOWERS OVER CENTRAL AND EASTERN MINNESOTA.
CEILINGS WITH THIS ACTIVITY REMAINS VFR AND WITH THE SCATTERED
NATURE...PLAN TO HOLD ONTO JUST A VCSH FOR BOTH TAF SITES UNTIL
THE FRONT MOVES THROUGH. THE FRONT EXTENDS FROM THE MAIN SURFACE
LOW OVER SOUTHWEST ONTARIO THROUGH CENTRAL MINNESOTA INTO THE
NORTHWEST CORNER OF IOWA. THE WINDS INITIALLY GO AROUND TO THE
WEST/NORTHWEST BEFORE GOING TO THE NORTHWEST BEHIND A SECONDARY
TROUGH. HELD ON TO THE CURRENT TIMING OF BRINGING THE FRONT THROUGH
LATE TONIGHT AND THEN SHOW THE NORTHWEST WINDS SPREADING IN AROUND
12Z. MIXING DURING THE AFTERNOON WILL GET DEEP ENOUGH TO PRODUCE
SOME GUSTS AT KRST. THE CLOUDS OVER MANITOBA AND SASKATCHEWAN HAVE
MADE LITTLE OR NO SOUTHWARD PROGRESS THROUGH THE EVENING. THE
01.00Z NAM CONTINUES TO SHOW THIS MOISTURE FIELD COMING IN LATE
SUNDAY AFTERNOON WITH THE POSSIBILITY OF A VFR CEILING. WITH THE
LACK OF MOVEMENT OF THESE CLOUDS THIS EVENING...CONFIDENCE THAT
THEY WILL GET HERE IS NOT VERY HIGH AND WILL STAY WITH JUST SOME
SCATTERED CLOUDS FOR NOW.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...

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

&&

SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04