Severe Thunderstorm Warning 75, NWS Grand Rapids, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1100 AM EDT FRI JUL 14 2000

CHALLENGE THIS AFTERNOON IS EXTENT OF CONVECTIVE DEVELOPMENT IN SW
MI. MAIN SFC TROUGH IS EAST OF HERE... FROM THE THUMB AREA SW INTO
INDIANA. HOWEVER... ANOTHER LOBE OF VORTICITY PIVOTING AROUND THE
UPPER LOW WILL SWING THROUGH THIS AFTERNOON. 12Z DTX/APX SOUNDINGS
ARE RATHER UNSTABLE WITH LI/S OF -3 TO -8... AND A MODIFIED DTX
SOUNDING FOR T/TD OF 85/68 YIELDS CAPES OF 3400 AND LI/S OF -10.
CONVECTIVE TEMP IS IN THE LOWER 80S.

WHILE BEST CHANCE OF TSTMS WILL BE WITH THE BETTER SFC CONVERGENCE
ALONG/NEAR THE SFC TROUGH TO OUR EAST... CANT RULE OUT OTHER
SCATTERED ACTIVITY BEHIND THE MAIN TROUGH WITH COLD/DRY POOL ALOFT
AND LINGERING UPPER 60 DEW POINTS. NEXT VORT SEEN IN WATER VAPOR
DROPPING S/SE FROM UPPER MI MAY INDUCE ANOTHER SFC TROUGH AND
PROVIDE BETTER SFC CONVERGENCE. OBVIOUSLY BEST CHC FOR SVR WILL BE
IN THE MORE UNSTABLE AIR MASS OVER SE LWR AND WILL ACKNOWLEDGE
LATEST SPC OUTLOOK IN AN UPDATED SPS HAZARDOUS WX OUTLOOK STATEMENT
AROUND 1130 AM.

.GRR...NONE.
MEADE

MIZ037>040-043>046-050>052-056>059-064>067-071>074-151000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1130 AM EDT FRI JUL 14 2000

...HAZARDOUS WEATHER POTENTIAL STATEMENT FOR THE SOUTHWEST QUARTER
OF LOWER MICHIGAN FOR THIS AFTERNOON AND TONIGHT...

DISPATCHERS PLEASE PASS THIS INFORMATION ALONG TO YOUR EMERGENCY
MANAGERS.

HAZARDS...WIDELY SCATTERED THUNDERSTORMS ARE LIKELY THIS AFTERNOON
AND EARLY EVENING. A FEW STORMS COULD BECOME SEVERE SOUTH AND EAST
OF A LINE FROM ROUGHLY ST JOHNS TO KALAMAZOO. THE MAIN THREAT WILL
BE HAIL GREATER THAN ONE INCH IN DIAMETER... BUT A FEW WIND GUSTS
OVER 60 MPH ARE ALSO POSSIBLE. STORM CELL MOVEMENT WILL BE SOUTHEAST
AT 25 MPH.

DISCUSSION...COLD AIR ALOFT AND WARM MOIST CONDITIONS AT THE SURFACE
WILL CREATE AN UNSTABLE AIR MASS ACROSS THE SOUTHWEST QUARTER OF
LOWER MICHIGAN TODAY. AN UPPER LEVEL DISTURBANCE PASSING ACROSS THE
AREA THIS AFTERNOON AND EARLY THIS EVENING WILL LEAD TO THE
SCATTERED THUNDERSTORM DEVELOPMENT.

SPOTTER ACTIVATION...SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON.

...HAZARDOUS WEATHER POTENTIAL OUTLOOK FOR SATURDAY THROUGH
TUESDAY...

AFTE~R TONIGHT... FAIR WEATHER WILL PREVAIL UNTIL TUESDAY WHEN
THUNDERSTORMS ARE POSSIBLE.

BDM

MIZ067-074-142200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
128 PM EDT FRI JUL 14 2000

THE STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR PORTIONS OF SOUTH CENTRAL LOWER MICHIGAN EFFECTIVE UNTIL 600 PM
EDT FRIDAY EVENING. THIS WATCH INCLUDES THE FOLLOWING COUNTIES

IN SOUTH CENTRAL MICHIGAN
     INGHAM AND JACKSON

A SEVERE THUNDERSTORM WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR
THE DEVELOPMENT OF SEVERE THUNDERSTORMS IN AND NEAR THE WATCH AREA.
REMEMBER...SEVERE THUNDERSTORMS PRODUCE WIND GUSTS IN EXCESS OF 58
MPH AND/OR HAIL THREE-QUARTERS OF AN INCH IN DIAMETER OR GREATER. IF
YOU LIVE IN OR NEAR THE WATCH AREA YOU SHOULD REMAIN ALERT TO RAPIDLY
CHANGING WEATHER CONDITIONS. STAY TUNED TO NOAA WEATHER RADIO OR THE
LOCAL NEWS OUTLETS FOR THE LATEST UPDATES AND POSSIBLE WARNINGS.

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