Severe Thunderstorm Warning 149, NWS Detroit, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
300 PM EDT MON AUG 2 2004

.DISCUSSION...

IMMEDIATE CONCERN IS THE THREAT OF SEVERE WEATHER THIS EVENING. 18Z
DTX SOUNDING SHOWS A GOOD LAPSE RATE FROM 800 TO 550 MBS WITH
IMPRESSIVE CAPE OVER 3000 J/KG. 18Z DTX SOUNDING ALSO SHOWED VERY
LITTLE WIND. BEST CHANCE OF SEVERE WEATHER WILL BE IN CURRENT WATCH
AREA WHERE THAT INSTABILITY HAS A CHANCE TO BE REALIZED WITH THE
POTENTIAL OF SOME STRONG WINDS. STILL MAY HAVE ISOLATED SEVERE
STORMS SOUTH AND EAST OF THE WATCH JUST DUE TO THE INSTABILITY. THAT
WILL LESSEN WITH SUNSET.

MODELS IN OVERALL AND GENERAL SYNOPTIC AGREEMENT. GFS AND EVEN THE
ETA SHOW SOME CONVECTIVE FEEDBACK. GFS MUCH MORE PRONOUNCED WITH THE
DEVELOPMENT OF A 1001 MB SURFACE LOW BY WEDNESDAY MORNING. GIVEN THE
FEEDBACK PROBLEMS OF THE GFS WILL LEAN TOWARD THE ETA.
OVERALL...WILL KEEP POPS AT 50 PERCENT OR LESS UNTIL THE COLD FRONT
MOVES THROUGH THE REGION...WHICH WILL BE ON TUESDAY FOR MOST OF THE
CWA...AND TUESDAY EVENING FOR THE FAR SOUTHEAST.

AFTER THE CURRENT ROUND OF CONVECTION ENDS LATE THIS EVENING...OR
OVERNIGHT...EXPECT A LULL IN ACTIVITY LATE TONIGHT AND EARLY
TUESDAY. EXPECT SOME SUNSHINE ON TUESDAY. WITH TEMPS WARMING INTO
THE 80S AND DEW POINTS STILL NEAR 70 EXPECT CAPES OF 1500 TO AROUND
2000 J/KG TO BE AVAILABLE. 500 MB SHORTWAVE OVER MT/WY THIS
AFTERNOON WILL MOVE EAST AND INTO THE GREAT LAKES REGION BY TUESDAY
AFTERNOON. WHILE THIS SHORTWAVE MAY NOT AMPLIFY LIKE THE ETA OR
GFS...IT IS STILL A REAL FEATURE THAT SHOULD INITIATE STORMS WITH
THE CONVERGENCE ALONG THE COLD FRONT. IN ADDITION...500 MB WINDS DO
INCREASE TO 30 TO 40 KTS. THIS ALL SHOULD LEAD TO A THREAT OF SEVERE
STORMS...ESPECIALLY FOR THE SOUTH HALF OF THE CWA WHERE TEMPS AND
DEW POINTS SHOULD BE HIGHER.

ONCE THE FRONT PASSES THE REGION...DRIER AND COOLER CONDITIONS MOVE
INTO SOUTHEAST MI. WILL CARRY PARTLY SUNNY ON WEDNESDAY GIVEN SOME
CONVECTIVE DEBRIS AND SCT TO BKN CU.

MOS TEMPS IN GENERAL WERE CLOSE AND FOLLOWED THROUGH WEDNESDAY.

IN THE EXTENDED...TREND IS STILL FOR THE COOL NW FLOW WITH SURFACE
HIGH TO COME DOWN OVER THE GREAT LAKES. GFS CONTINUES TO BE THE MOST
AGGRESSIVE WITH THE UPPER LOW OVER THE EASTERN GREAT LAKES. GFS IS
THE FARTHEST SOUTHWEST AND DEEPEST WITH THE UPPER LOW. WILL LEAN
TOWARD THE OTHER EXTENDED RUNS...AND THEREFORE GO A COUPLE OF
DEGREES WARMER THAN MOS ON THURSDAY THRU SUNDAY. MOISTURE WILL BE
OVER SOUTHEAST MI ON THE BACK SIDE OF THE UPPER LOW. EXPECT DIURNAL
BKN CU TO FORM THURSDAY THROUGH SATURDAY...JUST NOT THE SHOWERS THAT
THE 12Z GFS WANTS TO GIVE SOUTHEAST MI.
&&

.DTX WATCHES/WARNINGS/ADVISORIES...SEVERE THUNDERSTORM WATCH FOR
MIDLAND...BAY..SAGINAW...AND SHIAWASSEE COUNTIES UNTIL 7 PM.

&&

RBP

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
339 PM EDT MON AUG 2 2004

MIZ063-068>070-075-076-082-083-030900-
LENAWEE-LIVINGSTON-MACOMB-MONROE-OAKLAND-ST. CLAIR-WASHTENAW-WAYNE-
339 PM EDT MON AUG 2 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR FAR SOUTHEAST LOWER MICHIGAN

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE WILL BE A CHANCE OF THUNDERSTORMS THIS EVENING. AN ISOLATED
STORM MAY BECOME SEVERE.  THE BEST CHANCE OF THUNDERSTORM ACTIVITY
WILL BE FROM 6 PM TO ABOUT 2 AM. HAIL UP TO THE SIZE OF PENNIES AND
WIND GUSTS TO 60 MPH ARE POSSIBLE IN ANY ISOLATED SEVERE STORM
THAT FORMS. BRIEF HEAVY RAINFALL WILL ALSO BE POSSIBLE. AVERAGE STORM
MOVEMENT WILL BE TO THE SOUTHEAST BETWEEN 10 AND 20 MPH.

THE AIRMASS ACROSS SOUTHEAST MICHIGAN CONTINUES TO QUITE
UNSTABLE. A WEAK FRONT OVER THE UPPER PENINSULA AND WISCONSIN WILL
SLOWLY MOVE ACROSS NORTHERN LOWER MICHIGAN TONIGHT. SCATTERED
THUNDERSTORMS WILL CONTINUE TO DEVELOP AHEAD OF THIS FRONT THIS
EVENING AND TONIGHT.

.DAY TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THUNDERSTORMS WILL AGAIN DEVELOP ON TUESDAY AND CONTINUE INTO
TUESDAY EVENING ALONG AND AHEAD OF THE COLD FRONT. THERE IS A SLIGHT
CHANCE THAT A FEW OF THE STORMS COULD BECOME SEVERE. THE THREAT OF
THUNDERSTORMS AND SEVERE WEATHER WILL END WITH THE PASSAGE OF THAT
COLD FRONT...WHICH WILL BE DURING THE EVENING HOURS ON TUESDAY.

.SPOTTER INFORMATION STATEMENT...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY.
SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING.

MIZ047>049-053>055-060>062-030900-
BAY-GENESEE-HURON-LAPEER-MIDLAND-SAGINAW-SANILAC-SHIAWASSEE-TUSCOLA-
339 PM EDT MON AUG 2 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL LOWER MICHIGAN

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED TONIGHT. SOME OF THE STORMS
MAY BECOME SEVERE THIS EVENING.  HAIL UP TO THE SIZE OF PENNIES AND
WIND GUSTS TO 60 MPH ARE POSSIBLE ALONG WITH BRIEF HEAVY RAINFALL.
AVERAGE STORM MOVEMENT WILL BE TO THE EAST BETWEEN AROUND 20 MPH. THE
THREAT OF SEVERE WEATHER WILL END BY MIDNIGHT WITH THE LOSS OF
DAYTIME HEATING.

THE AIRMASS ACROSS SOUTHEAST MICHIGAN CONTINUES TO QUITE
UNSTABLE. A WEAK FRONT OVER THE UPPER PENINSULA AND WISCONSIN WILL
SLOWLY MOVE ACROSS NORTHERN LOWER MICHIGAN TONIGHT. SCATTERED
THUNDERSTORMS WILL CONTINUE TO DEVELOP AHEAD OF THIS FRONT THIS
EVENING AND TONIGHT.

.DAY TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THERE WILL BE A CHANCE OF THUNDERSTORMS ON TUESDAY...HOWEVER SEVERE
WEATHER IS NOT EXPECTED. THE COLD FRONT WILL CONTINUE TO MOVE
THROUGH EAST CENTRAL LOWER MICHIGAN ON TUESDAY. SCATTERED
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF THE COLD
FRONT. THE THREAT OF THUNDERSTORMS WILL END LATE TUESDAY
AFTERNOON WITH THE PASSAGE OF THAT COLD FRONT.

.SPOTTER INFORMATION STATEMENT...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY.
SPOTTER ACTIVATION HAS OCCURRED.

RBP