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000
FXUS63 KARX 192007
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
307 PM CDT SAT JUL 19 2014

.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 307 PM CDT SAT JUL 19 2014

CURRENTLY WATCHING A MID-LEVEL SHORTWAVE TROUGH MOVING ACROSS NW WI
THROUGH SCNTL MN. THERE WAS A SCATTERED LINE OF SHOWER/THUNDERSTORMS
AHEAD OF THE WAVE THROUGH THE MORNING BUT THESE HAVE BEEN DIMINISHING
THROUGH EARLY THIS AFTERNOON AS 850MB MOISTURE TRANSPORT WANES...
PER THE RAP ANALYSIS. OTHERWISE...SCATTERED TO BROKEN CUMULUS AND
ALTOCUMULUS CLOUD WAS PRESENT ACROSS THE AREA WITH TEMPERATURES
GENERALLY IN THE 75 TO 80 DEGREE RANGE.

FOR TONIGHT...A SHORTWAVE RIDGE MOVES ACROSS THE REGION BEHIND THE
DEPARTING TROUGH FOR PARTLY CLOUDY SKIES AND OVERNIGHT LOW READINGS
IN THE LOWER/MIDDLE 60S.

FOR SUNDAY...WILL SEE SURFACE CYCLOGENESIS OVER THE HIGH PLAINS WITH
A WARM FRONT LIFTING NORTHWARD TOWARD THE AREA FROM THE PLAINS.
STRENGTHENING SOUTHERLY FLOW TAKES BETTER AXIS OF 850MB MOISTURE
TRANSPORT ACROSS/OVER THE WARM FRONT INTO WESTERN/NORTHERN MN...SO
THINKING ANY SHOWER THUNDERSTORM CHANCES SHOULD BE CONFINED ACROSS
THAT AREA LEAVING US PRECIPITATION FREE WITH TEMPERATURES AGAIN
TOPPING OFF IN THE 80-85 DEGREE RANGE. WILL FEEL A TAD MORE HUMID
THOUGH AS DEW POINTS CREEP UPWARD THROUGH THE 60S.

THUNDERSTORM CHANCES LOOK TO BE ON THE INCREASE ACROSS OUR AREA
SUNDAY NIGHT AS THE SURFACE WARM FRONT LIFTS INTO SOUTHERN
MN/CENTRAL WI. ECMWF HAS SHOWN BEST RUN-TO-RUN CONSISTENT MCS SIGNAL
AS 850MB MOISTURE TRANSPORT TAKES AIM INTO OUR AREA. QUESTION
REMAINS ON WHERE EXACTLY THIS MCS WILL TRACK. LATEST 19.12Z RUN
TAKES THE MCS FROM NORTHERN MN INTO NORTHERN WISCONSIN IN THE 06-12Z
TIME FRAME. NAM/GFS SHOWING SOME RESPONSE/QPF-WISE...BUT NOT AS
INTENSE. ECMWF SHOWS 0-3KM MUCAPE 1000-2000J/KG...MAINLY ABOVE 850MB
WITH WEAK EFFECTIVE BULK SHEAR. AT THE SAME TIME... PRECIPITABLE
WATER VALUES INCREASE TO NEAR 1.8 INCHES. SO...COULD SEE THE
POTENTIAL FOR SOME HEAVY RAINFALL OUT OF THIS SYSTEM. WILL HAVE TO
WATCH HOW THIS EVOLVES GIVEN FORWARD MOVING CORFIDI VECTORS WOULD
TAKE THE MCS MORE INTO OUR AREA.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 307 PM CDT SAT JUL 19 2014

A FEW LINGER SHOWERS AND THUNDERSTORMS MAY BE SEEN MONDAY
MORNING...BUT THE ATTENTION TURNS TO INCREASING HEAT AS THE WARM
FRONT LIFTS NORTH OF THE AREA AND UPPER RIDGE BUILDS. LOOKING FOR
HIGH TEMPERATURE READINGS IN THE 85-90 DEGREE RANGE WITH DEW POINTS
RISING INTO THE 70S. THIS WILL PRODUCE HEAT INDICES IN THE 95-100
DEGREE RANGE...ESPECIALLY ACROSS PORTIONS OF SOUTHEAST MN/WEST
CENTRAL WI. WILL HAVE TO KEEP AN EYE ON THIS FOR POSSIBLE HEAT
HEADLINES.

LATE MONDAY NIGHT INTO TUESDAY SHOWING THE POTENTIAL FOR SOME SEVERE
WEATHER AS AN AREA OF LOW PRESSURE AND A COLD FRONT TRACK ACROSS THE
AREA. ECMWF SHOWS 0-3KM MUCAPE INCREASING INTO THE 1500-3000J/KG
RANGE WITH 0-3KM BULK SHEAR IN THE 25-35KT RANGE. WILL HAVE TO KEEP
A CLOSE WATCH ON THIS SCENARIO FOR SEVERE POTENTIAL.

SHOWER AND THUNDERSTORM CHANCES WILL LINGER INTO TUESDAY
NIGHT/MAINLY EVENING AS THE COLD FRONT PUSHES OUT OF THE AREA.

CANADIAN HIGH PRESSURE BUILDS INTO THE AREA ON WEDNESDAY THROUGH
THURSDAY FOR COOLER/DRIER CONDITIONS. LOOK FOR HIGHS LOWERING INTO
THE MID/UPPER 70S.

SHOWER AND THUNDERSTORM CHANCES SPREAD BACK INTO THE REGION FRIDAY
INTO THE WEEKEND AS BOTH THE ECMWF/GFS SHOW A CLOSED LOW MOVING INTO
THE UPPER MISSISSIPPI REGION. LOOKS LIKE COOLER THAN NORMAL
TEMPERATURE WILL ALSO RESULT WITH HIGHS IN THE 70S TO NEAR 80.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 102 PM CDT SAT JUL 19 2014

VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH THE FORECAST
PERIOD. A WEAK SHORTWAVE WILL PUSH THROUGH THE UPPER MISSISSIPPI
RIVER VALLEY THIS AFTERNOON GENERATING SCATTERED CUMULUS WITH CLOUD
BASES AROUND 5 KFT. A MORE EXPANSIVE AREA OF CIRRUS AND SCATTERED
CUMULUS WAS LOCATED NEAR THE INTERSTATE 35 CORRIDOR OVER SOUTHERN
MINNESOTA EARLY THIS AFTERNOON AHEAD OF THE APPROACHING TROUGH. THIS
AREA OF CUMULUS AND CIRRUS SHOULD GRADUALLY DIMINISH AS IT SLIDES
EAST BUT MAY PRODUCE BROKEN CEILINGS AT KRST AND KLSE AT TIMES LATE
THIS AFTERNOON INTO THIS EVENING BUT CLOUD BASES WILL REMAIN VFR.
SOUTH/SOUTHWEST WINDS AT 12 TO 15 KTS WILL SUBSIDE LATE THIS
AFTERNOON INTO EARLY THIS EVENING WITH THE LOSS OF DAYTIME HEATING.

&&

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

$$

SHORT TERM...DAS
LONG TERM....DAS
AVIATION...WETENKAMP