Hail and Damaging Winds in Wisconsin, July 10, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
ISSUED BY NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
301 PM CDT THU JUL 10 2008

.DISCUSSION...FORECAST FOCUS ON SERIES OF WEATHER SYSTEMS TO
AFFECT CWA TONIGHT THROUGH EARLY SATURDAY.

.SHORT TERM...TONIGHT AND FRIDAY...NGM/NAM/GFS/ECMWF HI RES PROGS
SHIFTING MIDDLE AND UPPER LEVEL FLOW TO A WESTERLY DIRECTION
TONIGHT. CURRENT CONVECTION OVER EASTERN MINNESOTA RIDING A VERY
IMPRESSIVE LOW LEVEL WARM AIR ADVECTION PATTERN. BUT ONGOING
CONVECTION OVER SOUTHERN WISCONSIN NOW IS RETARDING NORTHWARD
MOVEMENT OF SURFACE WARM FRONT. AS A RESULT CONVECTION WITH
STRONG SHORT WAVE OVER MINNESOTA WILL KEEP BULK OF CONVECTION JUST
TO THE SOUTH OF CWA DUE TO MORE SOUTHWARD POSITION OF SURFACE WARM
FRONT. MINNESOTA SHORTWAVE TIMED TO BE EAST OF CWA BY MIDNIGHT SO
HAVE REDUCED RAIN CHANCES AFTER MIDNIGHT AS WEAKER SHORT WAVE NEAR
LAKE WINNIPEG MAY BRUSH AREA LATER TONIGHT. ALTHOUGH GFS A BIT
SLOWER WITH STRONG SYSTEM FOR FRIDAY...MID LEVEL TEMPERATURE CAP
AT OR ABOVE +10C SHOULD PREVENT CONVECTION FROM FORMING DURING
MUCH OF THE DAY. HOWEVER RECENT PROGS HAVE BECOME MORE AGGRESSIVE
IN DEVELOPING MAINLY AFTERNOON CONVECTION AS MOIST UNSTABLE
AIRMASS DESTABILIZES. WILL ADD ISOLATED THUNDERSTORMS FOR FRIDAY
IN CASE MID LEVEL CAP DOES NOT DEVELOP AS ADVERTISED.

.LONG TERM...FRIDAY NIGHT THROUGH SATURDAY MORNING...PROGS
EVENTUALLY PULL WARM FRONT NORTHWARD ACROSS NORTHERN WISCONSIN
EARLY FRIDAY. NAM/GFS/ECMWF HI RES PROGS DEVELOP SOUTHWEST DECENT
SURFACE TO UPPER LEVEL FLOW WITH CWA IN THE WARM SECTOR. MID LEVEL
CAP TEMPERATURE AROUND +10C FORECAST TO RAPIDLY COLLAPSE LEADING
TO EXPECTED WIDESPREAD CONVECTION TO DEVELOP OVER CWA IN VERY
MOIST AND UNSTABLE AIRMASS. ADDED LOCALLY HEAVY RAIN FOR FRIDAY
NIGHT AS PRECIPITABLE WATER VALUES APPROACHING 2 INCHES AND
CORFIDI VECTORS REVEAL BACK BUILDING STORM SCENARIO. GFS/ECMWF
PROGS PULL THE COOL FRONT ACROSS CWA EARLY SATURDAY. ALTHOUGH GFS
SHOWING SLOWER TENDENCIES FOR ENDING PRECIPITATION WILL STILL KEEP
CHANCY PRECIPITATION IN FORECAST FOR SATURDAY MORNING FOR MAINLY
THE EASTERN PORTIONS OF CWA.

.LONG LONG TERM...SUNDAY THROUGH WEDNESDAY...GFS/NAM PROGS
INDICATE CYCLONIC CIRCULATION OVER SOUTHERN CANADA CLOSE ENOUGH TO
CWA TO SEND A LOBE OF ENERGY ACROSS CWA. WILL KEEP CHANCE MENTION
OF SHOWERS FOR SUNDAY AFTERNOON BUT OTHERWISE HIGH
PRESSURE...DRIER AND MORE STABLE AIR MOVING INTO REGION SHOULD
KEEP QUIET WEATHER GOING THROUGH WEDNESDAY.

&&

.AVIATION...FAST MOVING SHORT WAVE TO PRODUCE WIDESPREAD AREA OF
SHOWERS AND THUNDERSTORMS EARLY TONIGHT WITH A SECOND WEAKER SHORT
WAVE ARRIVING LATER TONIGHT. EXPECT VFR CEILINGS AND UNRESTRICTED
THROUGH 18Z FRIDAY WITH LOCAL MVFR VISIBILITIES IN THUNDERSTORMS
THROUGH MIDNIGHT. LOCAL MVFR VISIBILITIES IN FOG ALSO POSSIBLE
FROM 10Z TO 15Z. SOUTHERLY SURFACE WINDS AROUND 10 KNOTS TO
DECREASE TO AROUND 5 KNOTS BY MIDNIGHT AND INCREASE TO 10 TO 20
KNOTS AFTER 15Z FRIDAY.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

TZ

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE GREEN BAY WI
ISSUED BY NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1053 AM CDT THU JUL 10 2008

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-111600-
VILAS-ONEIDA-FOREST-FLORENCE-NORTHERN MARINETTE-LINCOLN-LANGLADE-
MENOMINEE-NORTHERN OCONTO-DOOR-MARATHON-SHAWANO-WOOD-PORTAGE-
WAUPACA-OUTAGAMIE-BROWN-KEWAUNEE-WAUSHARA-WINNEBAGO-CALUMET-
MANITOWOC-SOUTHERN MARINETTE-SOUTHERN OCONTO-
1053 AM CDT THU JUL 10 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
WISCONSIN...EAST CENTRAL WISCONSIN...NORTH CENTRAL WISCONSIN AND
NORTHEAST WISCONSIN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL BE LIKELY OVER CENTRAL WISCONSIN BY MID
AFTERNOON. THERE IS A CHANCE OF THUNDERSTORMS OVER EAST
CENTRAL...NORTH CENTRAL AND NORTHEAST WISCONSIN THIS AFTERNOON.
THE CHANCE OF STORMS WILL CONTINUE INTO TONIGHT OVER THE ENTIRE
FORECAST AREA. A WARM FRONT WORKING INTO SOUTHERN WISCONSIN WILL BE
THE PRIMARY FOCUS FOR THE DEVELOPMENT OF STORMS. THERE IS A SLIGHT
RISK OF SEVERE STORMS LATER THIS AFTERNOON AND INTO TONIGHT AS
SOUTHWEST WINDS BEGIN TO BRING IN A MORE MOIST UNSTABLE AIR MASS.
DAMAGING WINDS...LARGE HAIL AND LOCALLY HEAVY RAINFALL ARE THE
PRIMARY THREATS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

VERY WARM AND HUMID CONDITIONS ARE FORECAST FOR FRIDAY ACROSS
NORTHEAST WISCONSIN. THE COMBINATION OF TEMPERATURES WELL INTO THE
80S...WITH DEW POINTS IN THE UPPER 60S...WILL CREATE HEAT INDICES
IN THE UPPER 80S TO LOWER 90S.

FOR FRIDAY NIGHT...A COLD FRONT WILL TRIGGER ANOTHER ROUND OF
STORMS. THERE IS A SLIGHT RISK OF SEVERE STORMS DURING THIS
PERIOD...WITH DAMAGING WINDS AND LARGE HAIL THE PRIMARY THREATS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND TONIGHT.

LMZ521-522-541>543-111600-
THE BAY OF GREEN BAY SOUTH OF LINE FROM CEDAR RIVER MI TO ROCK
ISLAND PASSAGE AND NORTH OF A LINE FROM OCONTO WI TO LITTLE
STURGEON BAY WI-
THE BAY OF GREEN BAY SOUTH OF LINE FROM OCONTO WI TO LITTLE
STURGEON BAY WI-
LAKE MICHIGAN FROM ROCK ISLAND PASSAGE TO STURGEON BAY WI-
LAKE MICHIGAN FROM STURGEON BAY WI TO TWO RIVERS WI-
LAKE MICHIGAN FROM TWO RIVERS WI TO SHEBOYGAN WI-
1053 AM CDT THU JUL 10 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE IS A CHANCE OF THUNDERSTORMS THIS AFTERNOON AND INTO TONIGHT.
A DEVELOPING WARM FRONT WORKING INTO SOUTHERN WISCONSIN WILL BE THE
PRIMARY FOCUS FOR THE DEVELOPMENT OF STORMS. THERE IS A SLIGHT
RISK OF SEVERE STORMS LATER THIS AFTERNOON AND INTO TONIGHT AS
SOUTHWEST WINDS BEGIN TO BRING IN A MOIST AND UNSTABLE AIR MASS.
DAMAGING WINDS AND LARGE HAIL ARE THE PRIMARY THREATS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

FOR FRIDAY NIGHT...A COLD FRONT WILL TRIGGER ANOTHER ROUND OF
STORMS. THERE IS A SLIGHT RISK OF SEVERE STORMS DURING THIS
PERIOD...WITH DAMAGING WINDS AND LARGE HAIL THE PRIMARY THREATS.

TZ