Area Forecast Discussion
Issued by NWS La Crosse, WI

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000
FXUS63 KARX 270205
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
905 PM CDT SAT JUL 26 2014

.UPDATE...
ISSUED AT 904 PM CDT SAT JUL 26 2014

THUNDERSTORMS CONTINUE IN NORTHWEST WISCONSIN WITH AN INCREASE
SEEN OVER THE PAST HOUR SOUTH OF HAYWARD. THE SOUTHERNMOST STORM
IS MOVING A BIT TO THE RIGHT OF THE MEAN FLOW AND IS TAKING AIM ON
TAYLOR COUNTY NOW AROUND 11 PM. HAIL OF 2.75 INCHES WAS RECEIVED
FROM THIS STORM AT 847PM.

STORMS CONTINUE TO MAINTAIN INTENSITY IN THE MOISTURE AND
INSTABILITY AXIS CURRENTLY RUNNING FROM SOUTHCENTRAL MN THROUGH
KMSP TO HAYWARD. THIS IS THE LOW-LEVEL MOISTURE PLUME AXIS WHERE
2000 J/KG MUCAPE AND LITTLE CAP CONTINUES. WHILE SOME CONVERGENCE
AND TROUGHING IS ALONG THE STORM AXIS IN THE LOW-LEVELS...THE
INITIAL QG FORCING FROM THE DEEPER LOW NW OF KINL IS PROVIDING A
MORE FAVORABLE LIFT ENVIRONMENT FROM I-94 AND NORTH. THIS WOULD
TEND TO FAVOR AN ISOLATED LARGE HAIL STORM TONIGHT NEAR AND NORTH
OF I-94.

FURTHER SOUTH /KMSP AND SOUTH/ MORE ISOLATED STORMS COULD POP UP
WITH INSTABILITY AND WEAK CONVERGENCE IN THE LOW- LEVELS SOUTH TO
ST JAMES. HRRR IS CONSISTENT IN ITS SIGNALS OF SCT SHOWERS AND
ISOLATED TSRA DEVELOPING EAST THROUGH THE OVERNIGHT ALONG THE NEAR
SURFACE CONVERGENCE LINE AND CAPE AXIS. HAVE SOME DOUBTS ABOUT
STORMS MAINTAINING IN SUCH WEAK SURFACE CONVERGENCE SOUTH OF I-94.

OVERNIGHT...THIS WEAK CONVERGENCE/FRONT SLIDES EAST AND EXITS
CENTRAL AND SWRN WI AROUND 10Z. WITH DEEPER SHEAR IN SUPERCELL
RANGE...AND INSTABILITY REMAINING UP OVERNIGHT IN LOW-LEVEL
MOISTURE AXIS...CANNOT RULE OUT A SEVERE STORM SOUTHWEST OF I-94.
LARGE HAIL IS THE MAIN THREAT OVERNIGHT.

&&

.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 200 PM CDT SAT JUL 26 2014

WATER VAPOR IMAGERY SHOWING A CLOSED LOW OVER SOUTHERN MANITOBA
CANADA WITH A FAIRLY HIGH ZONAL FLOW ACROSS THE NORTHERN TIER OF THE
CONUS. FAIRLY STRONG 850-500MB FRONTOGENESIS WAS PRODUCING A
SCATTERED BAND OF SHOWERS/ISOLATED THUNDERSTORMS ALONG AND SOUTH OF
THE I-90 CORRIDOR FROM THE MISSISSIPPI RIVER...BACK TO NEAR SIOUX
FALLS SD. DESPITE THICK CLOUD COVER ACROSS THE ARX FORECAST AREA...
TEMPERATURES WERE IN THE UPPER 70S/LOWER 80S. WITH DEW POINTS IN THE
60S/LOWER 70S...RATHER MUGGY CONDITIONS WERE ALSO IN PLACE.

RAP SHOWS BAND OF 850-500MB FRONTOGENESIS WEAKENING/SAGGING SOUTH
OUT OF THE AREA INTO IL BY EARLY THIS EVENING...TAKING
SHOWERS/ISOLATED THUNDERSTORMS WITH IT. FOCUS THEN TURNS TO THAT
CLOSED LOW DROPPING SOUTHEAST OUT OF SOUTHERN MANITOBA INTO NORTHERN
MN/WI TONIGHT. STRONG 700-300MB PV-ADVECTION/QG-RESPONSE ASSOCIATED
WITH THIS WAVE ALONG WITH STEEPENING MID-LEVEL LAPSE RATES. THIS
WILL PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS NORTH OF I-94 THIS
EVENING INTO EARLY SUNDAY MORNING. IN FACT...NAM INDICATES ELEVATED
MUCAPE IN THE 850-300MB LAYER OF 1500-1800J/KG ALONG WITH BULK SHEAR
IN THE 25-45KT RANGE. WILL THEREFORE HAVE TO KEEP AN EYE ON THE
POSSIBILITY OF A FEW STRONGER STORMS WITH LARGER HAIL/WIND
POTENTIAL. OTHERWISE...LOOK FOR LOWS TONIGHT IN THE UPPER 50S TO THE
MIDDLE 60S.

THE LIKELIHOOD OF SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE
THROUGH SUNDAY AS THE CLOSED LOW DRIFTS SOUTHEAST ACROSS THE REGION.
COOLER BREEZY CONDITIONS WILL ALSO BE SEEN WITH HIGHS ONLY TOPPING
OFF IN THE 70-80 DEGREE RANGE AS NORTHWEST WINDS BLOW AT 10 TO 20
MPH.

FOR SUNDAY NIGHT...PLAN ON SHOWERS TAPERING OFF RAPIDLY FROM WEST TO
EAST WITH A FEW EVENING SHOWERS LINGERING ACROSS CENTRAL WI THROUGH
9 PM. OTHERWISE...SURFACE HIGH PRESSURE BUILDING IN FROM THE
NORTHERN PLAINS WILL PRODUCE A DIMINISHING TREND TO THE CLOUDS WITH
OVERNIGHT TEMPERATURES DROPPING INTO THE UPPER 40S/LOWER 50S ACROSS
CENTRAL WI...TO THE MIDDLE 50S ELSEWHERE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 200 PM CDT SAT JUL 26 2014

COOLER AND DRIER CONDITIONS WILL FILTER INTO THE AREA MONDAY/MONDAY
NIGHT AS HIGH PRESSURE ESTABLISHES ITSELF ACROSS THE UPPER
MISSISSIPPI RIVER REGION. LOOK FOR HIGHS MONDAY IN THE LOWER/MIDDLE
70S AND LOWS MONDAY NIGHT IN THE UPPER 40S ACROSS THE
SANDY/CRANBERRY BOG AREAS OF CENTRAL WI...TO THE LOWER/MIDDLE 50S
ELSEWHERE.

A FEW SHOWERS MAY SNEAK INTO PORTIONS OF EASTERN/CENTRAL WI ON
TUESDAY AS THE MODELS BRING ANOTHER WEAK MID-LEVEL TROUGH SOUTHWARD
THROUGH THE REGION. HIGHS TUESDAY LOOK TO BE IN THE MID/UPPER 70S.

COOLER CYCLONIC FLOW ALOFT CONTINUES THROUGH THE REMAINDER OF THE
PERIOD WITH CHANCES OF MAINLY DAYTIME HEATING SHOWERS/ISOLATED
THUNDERSTORMS. OTHERWISE...LOOK FOR HIGHS IN THE 75-80 DEGREE RANGE
WITH LOWS IN THE MIDDLE 50S TO LOWER 60S. THESE TEMPERATURE ARE MORE
TYPICAL OF EARLY SEPTEMBER.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 700 PM CDT SAT JUL 26 2014

AN UNUSUALLY DEEP AND COOL WEATHER SYSTEM WILL SHIFT INTO THE
MIDWEST OVERNIGHT AND PROVIDE MVFR CIGS SUNDAY. SHOWERS WILL BE
MORE WIDESPREAD FURTHER EAST /WI/ AND THUS SHRA WAS INCLUDED IN
THE KLSE TAF. THE WINDS WILL ALSO BE GUSTY FROM THE NORTHWEST
SUNDAY...UP TO 30KTS. THERE ARE SOME SMALL TSRA CHANCES TO THE
NORTH OF THE AIRFIELDS THIS EVENING...BUT VFR CONDITIONS ARE
EXPECTED.


&&

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

$$

UPDATE...BAUMGARDT
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...BAUMGARDT



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