Severe Thunderstorm Warning 89, NWS Detroit, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
315 PM EDT WED JUN 9 2004

.DISCUSSION...

MAX TEMPERATURES AROUND 90 DEGREES WITH DEW POINTS IN THE LOWER 70S
HAS LED TO A VERY UNSTABLE AIRMASS OVER SOUTHEAST MICHIGAN THIS
AFTERNOON...AS CAPES CLIMBED TO AROUND 4000 J/KG

COLD FRONT SLOWLY PUSHING SOUTH THROUGH THE CWA CONTINUES TO TRIGGER
NUMEROUS STRONG TO SEVERE THUNDERSTORMS. WILL HAVE TO CONTEND WITH
THUNDERSTORMS AT LEAST INTO THE EVENING HOURS BEFORE THE PEAK
DAYTIME HEATING/INSTABILITY SUBSIDES.

THE BIG QUESTION TONIGHT AND BEYOND...IS JUST HOW FAR SOUTH WILL THE
FRONTAL BOUNDARY SINK....AS A LARGE HIGH BUILDS INTO THE NORTHERN
LAKES FROM ONTARIO.

GFS/ETA IN DECENT AGREEMENT WITH THE FRONTAL POSITION THROUGH 60
HOURS...WITH THE ETA TRANSITIONING TO A FARTHER NORTH POSITION
BEYOND 60 HOURS. UNFORTUNATELY...LARGE RIDGE OVER THE SOUTHEAST
CONUS WILL CONTINUE TO PUMP ABUNDANT MOISTURE (PW VALUES 1.85 TO 2
INCHES) INTO THE NORTHERN OHIO VALLEY. WITH THE POTENTIAL OF A
COUPLE OF BOUTS OF SHOWERS AND THUNDERSTORMS...COULD SEE FLOODING
PROBLEMS RETURN TO THE SOUTHERN THIRD OF THE CWA (IN THE VICINITY OF
THE FRONT). RIGHT NOW...BANKING ON THE FRONT REMAINING JUST FAR
ENOUGH SOUTH NOT TO CAUSE TOO MANY PROBLEMS...AND WILL ONLY BE
CARRYING CHANCE POPS THURSDAY THROUGH SATURDAY. BOTH CANADIAN/UKMET
IMPLYING THE WARM FRONT BECOMING ACTIVE THURSDAY NIGHT AS SHORTWAVE
TRACKS THROUGH THE LOWER GREAT LAKES. WILL HAVE TO WATCH THIS
SITUATION CLOSELY.

.EXTENDED...

MODEL AGREEMENT IS QUITE GOOD ON THE LARGE SCALE PATTERN HEADING
INTO SUNDAY. THE UPPER AIR PATTERN WILL BE ANCHORED BY TROFS IN THE
GULF OF ALASKA AND OVER THE NORTH ATLANTIC. THE SHORT WAVE OVER THE
CENTRAL STATES WILL HELP THE NORTH ATLANTIC LONG WAVE TROF
RETROGRADE OVER THE GREAT LAKES HEADING INTO NEXT WEEK, AND WILL
KEEP THE PRECIPITATION PATTERN UNSETTLED BUT WITH TEMPERATURES RIGHT
AROUND NORMAL.

THE CENTRAL U.S. SHORT WAVE WILL BRING A FRONTAL SYSTEM INTO SE
MICHIGAN ON SUNDAY AND MONDAY WITH AT LEAST SCATTERED AREAL COVERAGE
OF SHOWERS AND STORMS. OUR TUESDAY FORECAST IS CURRENTLY DRY AND
THAT LOOKS GOOD. THE MODELS HAVE BEEN LOCKING ON TO THE SOLUTION FOR
MONDAY OVER THE LAST FEW RUNS, WHICH ADDS SOME CONFIDENCE ON THE
TIMING FOR TUESDAY. BY WEDNESDAY THE GFS SHOWS A SHORT WAVE MAKING
IT INTO THE GREAT LAKES FROM CENTRAL CANADA WITH OUR NEXT CHANCE OF
RAIN. THERE IS QUITE A BIT OF SPREAD IN THE GFS ENSEMBLE, AS WE
EXPECT FOR A SHORT WAVE FEATURE AT THAT TIME PERIOD, AND MOST OF THE
MEMBERS ARE WEAKER AND FARTHER NORTH THAN THE OPS GFS. WITH THIS IN
MIND, WELL START WITH A DRY FORECAST FOR WEDNESDAY.

BT

&&

.DTX WATCHES/WARNINGS/ADVISORIES...SEVERE THUNDERSTORM WATCH 414 IN
EFFECT UNTIL 6 PM FOR ALL OF SOUTHEAST MICHIGAN.

&&

SF

EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT
HTTP://WWW.CRH.NOAA.GOV/DTX  (ALL LOWER CASE)

HAZARDOUS WEATHER OUTLOOK FOR SOUTHEAST MICHIGAN
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1057 AM EDT WED JUN 9 2004

MIZ047>049-053>055-101200-
BAY-HURON-MIDLAND-SAGINAW-SANILAC-TUSCOLA-
1057 AM EDT WED JUN 9 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE TRI-CITIES AND THUMB
REGION.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL BECOME MORE NUMEROUS THIS AFTERNOON AND CONTINUE
THROUGH THE EVENING HOURS.  A FEW OF THESE THUNDERSTORMS MAY BECOME
SEVERE WITH PENNY SIZE HAIL AND WIND GUSTS TO 60 MPH.  IN
ADDITION...HEAVY RAINFALL IS EXPECTED WITH THESE THUNDERSTORMS AND
MAY BRING SOME LOCALIZED FLOODING.  THUNDERSTORM MOVEMENT WILL EAST
SOUTHEAST AT 20 MPH. THIS ACTIVITY WILL BE THE RESULT OF A COLD
FRONT THAT WILL SAG SOUTH THROUGH THE AREA THIS AFTERNOON.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE WILL BE A CHANCE OF THUNDERSTORMS FRIDAY NIGHT THROUGH MONDAY.
THIS ACTIVITY WILL BE THE RESULT OF A SLOW MOVING SURFACE FRONT AND
A SERIES OF UPPER LEVEL DISTURBANCES.

.SPOTTER INFORMATION STATEMENT...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGER IMMEDIATELY.
SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING.

MIZ060>063-068>070-075-076-082-083-101200-
GENESEE-LAPEER-LENAWEE-LIVINGSTON-MACOMB-MONROE-OAKLAND-SHIAWASSEE-
ST. CLAIR-WASHTENAW-WAYNE-
1057 AM EDT WED JUN 9 2004

THIS HAZARDOUS WEATHER OUTLOOK IS LOCATIONS ALONG AND SOUTH OF I-69.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL BECOME MORE LIKELY DURING THE AFTERNOON AND
CONTINUE INTO TONIGHT.  SOME OF THESE THUNDERSTORMS MAY BECOME
SEVERE WITH HAIL UP TO 1 INCH AND WIND GUSTS TO 65 MPH.  IN
ADDITION...HEAVY RAINFALL MAY ALSO PRODUCE SOME LOCALIZED FLOODING.
DEVELOPMENT OF THUNDERSTORMS WILL LIKELY OCCUR AFTER 2 PM.
THUNDERSTORMS WILL MOVE EAST AT 20 MPH. THIS ACTIVITY WILL BE THE
RESULT OF A COLD FRONT THAT WILL SAG SOUTH THROUGH THE AREA LATE
THIS AFTERNOON INTO TONIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE CHANCE OF SCATTERED THUNDERSTORMS WILL PERSIST ON THURSDAY AND
FRIDAY...WITH MOST OF THE ACTIVITY REMAINING CONFINED TO LOCATIONS
SOUTH OF THE M 59 CORRIDOR. THUNDERSTORMS WILL THEN BECOME MORE
WIDESPREAD ACROSS THE ENTIRE AREA THIS WEEKEND...AND PERSIST INTO
NEXT MONDAY.

THE AFOREMENTIONED COLD FRONT IS EXPECTED TO STALL OVER THE OHIO
VALLEY FOR SEVERAL DAYS...BEFORE RETURNING BACK THROUGH THE AREA
DURING THE WEEKEND...LEADING TO THIS CONTINUATION IN THUNDERSTORM
CHANCES.

.SPOTTER INFORMATION STATEMENT...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGER IMMEDIATELY.
SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON INTO TONIGHT.

BGM

HTTP://WWW.CRH.NOAA.GOV/DTX  (ALL LOWER CASE)

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
232 PM EDT WED JUN 09 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0113 PM     HAIL             HOLLY                   42.80N 83.62W
06/09/2004  1.00 INCH        OAKLAND            MI   TRAINED SPOTTER

0210 PM     TSTM WND DMG     ROMEO                   42.80N 83.01W
06/09/2004                   MACOMB             MI   TRAINED SPOTTER

            LARGE TREE FELL ON A HOUSE NEAR MAIN AND WASHINGTON
            STREET. SPOTTER ESTIMATED WIND GUST UP TO 60 MPH

0220 PM     HAIL             MELVIN                  43.18N 82.86W
06/09/2004  1.00 INCH        SANILAC            MI   TRAINED SPOTTER

&&

SF