Strong Wind in Wisconsin, July 10, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
412 AM CDT FRI JUL 10 2009

.SHORT TERM...

LEADING EDGE OF CONVECTIVE COMPLEX CURRENTLY ENTERING
CWA EARLY THIS MORNING. PRECIP IS MAINLY STRATIFORM...WITH A FEW
EMBEDDED LIGHTING STRIKES. MESOSCALE MODELS SUGGEST THIS PRECIP WILL
CONTINUE EASTWARD INTO THE CWA...EVENTUALLY FALLING APART FURTHER
EASTWARD. GIVEN CURRENT RADAR TRENDS...FELT CATEGORICAL POPS IN WEST
LOOK GOOD...WITH LIKELY POPS ELSEWHERE.

THE PICTURE IS STILL NOT CLEAR FOR TODAY...AS STORMS LATER ON DEPEND
ON WHAT WILL HAPPEN WITH CURRENT PRECIP AND CLOUDS. THE MAIN
ISSUES ARE HOW LONG THE CLOUD COVER FROM THE CURRENT CONVECTION
LINGERS...AND THE TIMING OF THE FRONT. IF CLOUDS CAN BREAK UP
TODAY AND THE SUN CAN HEAT THINGS UP...MODELS ARE INDICATING THE
POTENTIAL FOR SOME DECENT CAPE BY LATE AFTERNOON/EARLY EVENING.
THINK THE GFS IS A BIT OVERDONE WITH SFC CAPES APPROACHING 4000
J/KG...AS IT BRINGS IN DEWPOINTS OVER 75F. THE NAM DEWPOINTS SEEM
MORE REASONABLE...AROUND 70F ACROSS THE SRN CWA...BUT NOT QUITE
BUYING THE SLOWER NAM SOLUTION. WITH THE NAM RUNNING ABOUT 6 HOURS
SLOWER THAN THE GFS AND ECMWF...THE TIMING WOULD BE A BIT OFF WITH
THE FRONTAL PASSAGE AND BEST HEATING. DECIDED TO GO FOR EARLIER
SOLUTION...WHICH WOULD BRING THE BEST FORCING INTO THE AREA BEFORE
THE BULK OF DAYTIME HEATING IS LOST. WITH 0-6 KM SHEAR OF 40-50
KTS...THE POTENTIAL DEFINITELY EXISTS FOR STRONG TO SEVERE
THUNDERSTORMS. SPC HAS ALL OF SOUTHEAST WISCONSIN IN A SLIGHT RISK
FOR SEVERE STORMS TODAY...WITH STRONG DAMAGING WINDS BEING THE
STRONGEST THREAT...THOUGH HAIL AND TORNADOES WILL ALSO BE A
POSSIBILITY. CURRENT THINKING WOULD BRING STRONGEST STORMS ACROSS
THE AREA LATE AFTERNOON AND INTO THE EVENING.

EVEN WITH THE SLOWER NAM SOLUTION...SHOWERS AND STORMS SHOULD COME
TO AN END BY MIDNIGHT OR SO...WITH A DRIER NORTHWEST FLOW MOVING
IN BEHIND THE FRONT. WITH NO BIG PUNCH OF COLDER AIR BEHIND THIS
FRONT...AND DECENT HEIGHTS STICKING AROUND...EXPECT HIGHS TO
REMAIN AROUND NORMAL ON SATURDAY.

.LONG TERM...

MODELS IN FAIRLY GOOD AGREEMENT IN KEEPING NORTHWEST FLOW ACROSS
THE CWA SUNDAY AND MONDAY...WITH WEAK RIDING OR ZONAL FLOW ON
TUESDAY. THE GFS...NAM...AND UKMET ALL PRODUCING QPF WITH AN
EMBEDDED WAVE ON SUNDAY...SO THREW IN A SLIGHT CHANCE ACROSS THE
NRN CWA. OTHERWISE...NEXT GOOD CHANCE FOR PRECIP LOOKS TO BE
LATER TUESDAY AND INTO WEDNESDAY AS LOW PRESSURE SWINGS INTO THE
AREA. WITH RESPECTABLE MODEL AGREEMENT THIS FAR OUT...WENT WITH
HIGH CHANCE POPS FOR TUESDAY NIGHT.

&&

.AVIATION...
EXPECT AN AREA OF THUNDERSTORMS TO MOVE SLOWLY EAST INTO SOUTHWEST
WISCONSIN.  LOW LEVEL MOISTURE AND INSTABILITY ARE INCREASING...BUT
LOW LEVEL JET SPLITS INTO A NORTHERN AND SOUTHERN AREA...WITH
SOUTHERN WISCONSIN BETWEEN THE TWO.  AS A RESULT THE RESULTANT MCS
SHOULD WEAKEN SOMEWHAT THIS MORNING. SOME MVFR VSBYS IN FOG EARLY
THIS MORNING.

THIS AFTERNOON THE SOUTHERN LOW LEVEL JET ADVANCES NORTH AND 850 MB
WINDS INCREASE.  THIS SHOULD RESULT IN ANOTHER AREA OF THUNDERSTORMS
DEVELOPING THIS AFTERNOON AND EVENING AS A COLD FRONT APPROACHES
FROM THE NORTHWEST.  THE ACTUAL FRONT IS SLOW TO PUSH THROUGH
SOUTHEAST WISCONSIN...OCCURRING LATER TONIGHT. AS A RESULT LOOK FOR
MAINLY MID LEVEL CLOUDS FROM THE UPSTREAM CONVECTION...WITH SOME
MVFR CIGS POSSIBLE THIS MORNING MAINLY WEST OF MADISON.  THEN WITH
DAYTIME HEATING CUMULUS SHOULD INCREASE.  MAINLY MVFR CIGS IN
THUNDERSTORMS WITH SOME IFR CONDITIONS.

&&

.MARINE...MAINLY LIGHT SOUTHEAST TO SOUTH WINDS AHEAD OF AN
APPROACHING COLD FRONT TONIGHT. AN AREA OF THUNDERSTORMS EARLY THIS
MORNING WILL BE PUSHING EAST...BUT IS EXPECTED TO WEAKEN BEFORE
REACHING LAKE MICHIGAN. MAIN THUNDERSTORM CHANCES EXPECTED TO BE
THIS AFTERNOON AND TONIGHT.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

SHORT/LONG TERM...07/DDV
AVIATION/MARINE...06/HENTZ

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
459 AM CDT FRI JUL 10 2009

WIZ046-047-051-052-056>060-062>072-111000-
MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE-
WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE-
LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA-
459 AM CDT FRI JUL 10 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
WISCONSIN...SOUTH CENTRAL WISCONSIN AND SOUTHEAST WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

AN AREA OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO PUSH INTO
SOUTH CENTRAL AND SOUTHEAST WISCONSIN THIS MORNING. THESE STORMS
ARE EXPECTED TO WEAKEN AS THEY PUSH EAST. HOWEVER SOUTH WINDS WILL
BRING AN INCREASE IN MOISTURE AND INSTABILITY TODAY AND MORE
THUNDERSTORMS ARE LIKELY THIS AFTERNOON AND TONIGHT. SOME OF THESE
THUNDERSTORMS MAY BE SEVERE...AND COULD PRODUCE SOME HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS SUNDAY AFTERNOON...
MAINLY OVER PORTIONS OF SOUTH CENTRAL WISCONSIN. THERE IS A CHANCE
OF THUNDERSTORMS AGAIN TUESDAY AND WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EARLY TONIGHT.

LMZ643>646-111000-
SHEBOYGAN TO PORT WASHINGTON WI-
PORT WASHINGTON TO NORTH POINT LIGHT WI-
NORTH POINT LIGHT TO WIND POINT WI-
WIND POINT WI TO WINTHROP HARBOR IL-
459 AM CDT FRI JUL 10 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

ISOLATED THUNDERSTORMS ARE POSSIBLE THIS MORNING. SOUTH WINDS
WILL BRING AN INCREASE IN MOISTURE AND INSTABILITY TODAY AND THUNDERSTORMS
ARE LIKELY THIS AFTERNOON AND TONIGHT. SOME OF THESE THUNDERSTORMS
MAY BE SEVERE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

HERE IS A SLIGHT CHANCE OF THUNDERSTORMS SUNDAY AFTERNOON...
MAINLY NORTH TOWARD SHEBOYGAN.

THERE IS A CHANCE OF THUNDERSTORMS AGAIN TUESDAY AND WEDNESDAY.

HENTZ

WWW.WEATHER.GOV/MKX