Marine Thunderstorm Wind in Lake St. Clair, July 21, 2003

SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
300 PM EDT MON JUL 21 2003

FOCUS IS ON THE SHORT TERM AS CONVECTION CONTINUES TO BREAK OUT
AHEAD OF ADVANCING SHORT WAVE AND SURFACE FRONT THIS AFTERNOON. EAST
WEST SURFACE BOUNDARY ACROSS SOUTHERN LOWER WITH BETTER THAN 2K J/KG
POOLING ALONG THE BOUNDARY AS DEW POINTS START TO CLIMB TOWARD 70.
MID LEVEL WIND FIELDS ARE ALSO GRADUALLY INCREASING AS SHORT WAVE
AXIS APPROACHES... INCREASING CHANCES THAT CONVECTION WILL BECOME
MORE ORGANIZED WITH TIME. CONVECTION HAS BEEN RELATIVELY SLOW MOVING
THIS AFTERNOON.. AND SOME ALIGNMENT ALONG THE BOUNDARY HINTING
TOWARD THE POSSIBILITY OF SOME TRAIN ECHOING. THUS HAVE OPTED TO
BUMP UP QPF... AND MENTION POSSIBILITY OF HEAVY RAIN IN THE
FORECAST.

LOOKS LIKE CONVECTION WILL CONTINUE ACROSS MOST OF THE CWA...
PARTICULARLY IN THE SOUTH HALF... WELL INTO THE EVENING HOURS. AFTER
THAT WILL CUT BACK DRAMATICALLY ON POPS... AND THINGS SHOULD PRETTY
MUCH BE OVER BY 06 UTC. MAIN QUESTION AFTER THAT FOR TUESDAY AND
WEDNESDAY WILL BE ABILITY TO KICK OFF SCATTERED SHOWERS UNDER THE
UPPER COLD POOL. BOTH DAYS... AFTERNOON STABILITY INDICES POINT
TOWARD UNSTABLE ENOUGH PROFILES TO JUSTIFY SMALL POPS... ALTHOUGH A
FOCUSING MECHANISM WILL BE SOMEWHAT LACKING. HAVE OPTED TO
CONTINUE/INCLUDE SMALL POPS EACH AFTERNOON... AND REMOVE POPS FOR
THE MORE STABLE OVERNIGHT/MORNING PERIODS.

LITTLE CHANGE TO LATER PERIODS OF THE FORECAST... WITH A GENERALLY
COOLER THAN NORMAL TREND THROUGH THE WEEKEND.

.DTX...NONE.

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

MIZ047>049-053>055-060>063-068>070-075-076-082-083-221000-

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1210 PM EDT MON JUL 21 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST LOWER MICHIGAN

.DAY ONE...THIS AFTERNOON AND TONIGHT

NUMEROUS THUNDERSTORMS ARE EXPECTED ACROSS ALL OF SOUTHEAST MICHIGAN
THIS AFTERNOON. LOCATIONS NEAR FLINT...OWOSSO AND THE TRI CITIES
WILL SEE THESE THUNDERSTORMS MOVE IN FROM THE WEST SHORTLY AFTER 1
PM. MEANWHILE...LOCATIONS ACROSS THE THUMB AND AROUND THE METRO
DETROIT AREA WILL SEE MORE NUMEROUS THUNDERSTORMS AFTER 3 PM.
THUNDERSTORMS WILL DIMINISH ACROSS THE AREA BY 8 PM THIS EVENING.
SOME OF THE STRONGER STORMS THIS AFTERNOON AND EARLY THIS EVENING
MAY PRODUCE WIND GUSTS TO 60 MPH AND HAIL TO 1 INCH IN DIAMETER.
FREQUENT LIGHTNING AND TORRENTIAL RAINFALL CAN BE EXPECTED WITH ANY
THUNDERSTORM THAT DEVELOPS THIS AFTERNOON. THIS MAY LEAD TO SOME
LOCALIZED FLOODING IN LOCATIONS ALONG AND SOUTH OF AN ANN ARBOR TO
DETROIT LINE DUE TO THE RAINFALL RECEIVED LAST NIGHT. THE
THUNDERSTORMS WILL MOVE EAST AT 20 MPH.

THESE THUNDERSTORMS ARE ASSOCIATED WITH A COLD FRONT AND WEAK LOW
PRESSURE SYSTEM THAT WILL SLOWLY BE MOVING EAST ACROSS THE STATE
THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

ISOLATED THUNDERSTORMS ARE POSSIBLE TUESDAY AFTERNOON AND WEDNESDAY
AFTERNOON...BUT SEVERE WEATHER IS NOT EXPECTED.

THERE IS A CHANCE OF THUNDERSTORMS AGAIN ON SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EARLY THIS
EVENING.

&&

STAY TUNED TO NOAA WEATHER RADIO...OR LOCAL MEDIA OUTLETS...FOR THE
LATEST FORECAST INFORMATION FROM THE NATIONAL WEATHER SERVICE. YOU
CAN ALSO OBTAIN THE LATEST FORECAST ON THE NATIONAL WEATHER SERVICE
WEB SITE HTTP://WWW.CRH.NOAA.GOV/DTX/ (ALL LOWER CASE)

CONSIDINE

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
447 PM EDT MON JUL 21 2003

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0335 PM    HADLEY                    MI   .75 INCH HAIL
07/21/03   LAPEER                         REPORTED BY GOLF COURSE
                                          EMPLOYEE.

0355 PM    ALMONT                    MI   WIND DAMAGE
07/21/03   LAPEER                         SEVERAL LARGE TREE
                                          BRANCHES WERE BLOWN DOWN.
                                          REPORTED BY SPOTTERS.

0355 PM    ALMONT                    MI   1.00 INCH HAIL
07/21/03   LAPEER                         REPORTED BY SPOTTERS

0315 PM    3 S DAVISON               MI   .75 INCH HAIL
07/21/03   GENESEE                        REPORTED BY SPOTTERS

SC