Severe Thunderstorm Warning 22, NWS Grand Rapids, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
345 AM EDT SAT MAY 10 2003

THE WEATHER WILL BE QUITE ACTIVE OVER THE NEXT COUPLE
OF DAYS.  SEVERE THUNDERSTORMS...HEAVY RAIN AND THEN
HIGH WINDS ALL APPEAR LIKELY ACROSS THE REGION.

WILL ISSUE A HIGH WIND WATCH FOR THE REGION FOR SUNDAY.
WILL MENTION HEAVY RAIN FOR TONIGHT.  THE AREA CONTINUES
IN THE SLIGHT RISK FOR SEVERE WEATHER THROUGH SATURDAY
NIGHT.

MODELS ARE NOT DOING A GOOD JOB OF HANDLING THE CURRENT
CONVECTION.  HAIL PRODUCING STORMS ARE OCCURRING IN AREAS
EXPECTED TO BE DRY. SO CONFIDENCE IS FAIRLY LOW IN THE MODEL
SOLUTIONS.

FOR THIS MORNING...AM EXPECTING LOTS OF SHOWERS AND
THUNDERSTORMS TO CONTINUE FOR PART OF THE MORNING
MAINLY ALONG AND SOUTH OF INTERSTATE 96.  NORTH OF INTERSTATE
94 THE STORMS HAVE BEEN GRADUALLY WEAKENING...STILL...CANNOT
RULE OUT SOME SMALL HAIL.  LOOKS LIKE  THE STRONGER CONVECTION
IS PULLING EAST AND SOUTH OF CHI.  SO IN A FEW HOURS...PERHAPS
BY 500 AM...WE MAY SEE A TAPERING OFF OF THE PRECIPITATION
BEGINNING ON THE LAKESHORE.  THEN FOR THE REMAINDER OF THE DAY
THERE WILL PROBABLY BE LOTS OF DEBRIS CLOUDS AROUND AND SOME
BOUNDARIES.  DEEP SURFACE BASED INSTABILITY REFORMS SO
CONVECTION IS EXPECTED TO REDEVELOP DURING THE AFTERNOON.
SOME OF THESE STORMS COULD FEATURE LARGE HAIL AND HIGH WINDS.

THEN TONIGHT...A STRONG LOW LEVEL JET REFORMS AHEAD OF THE
ADVANCING LOW PRESSURE SYSTEM.  WIDESPREAD THUNDERSTORMS ARE
EXPECTED. WHILE CAPE WILL BE FALLING OFF THROUGH THE
NIGHT...INCREASING TURNING AND STRENGTHENING OF THE LOW LEVEL WINDS
WILL MAINTAIN THE SEVERE WEATHER THREAT.  THE ARRIVAL OF HIGH
PRECIPITABLE WATER AIR WILL CREATE AN EFFICIENT HEAVY RAIN
ENVIRONMENT. WILL ADD HEAVY RAIN TO THE FORECAST.  THE CONVECTION IS
EXPECTED TO DROP OFF STEADILY AFTER MIDNIGHT...LEAVING ONLY
SOME SCATTERED SHOWERS BY DAYBREAK.

SUNDAY...AN UNSEASONABLY STRONG LOW PRESSURE SYSTEM LIFTS
NORTHEAST THROUGH WISCONSIN.  IMPRESSIVE WIND FIELDS TO
ACCOMPANY THIS SYSTEM.  MIXING LEVEL HEIGHTS SUGGEST WE
MAY TAP INTO THE 40 KT WINDS DURING THE DAY...AND THEREFORE
WILL ISSUE A HIGH WIND WATCH.  RAIN IS EXPECTED TO WRAP IN
BEHIND THE STORM FOR SUNDAY AFTERNOON AND LAST INTO SUNDAY NIGHT.

AS FOR THE EXTENDED PERIOD...WILL ADD A CHANCE OF SHOWERS
TO MONDAYS FORECAST.  LOOKS LIKE WE WILL STILL BE UNDER THE
INFLUENCE OF THIS STORM FOR  PART OF THE DAY.  THEN A DRY
PERIOD FOR TUE INTO TUE NIGHT...BUT THE POSSIBLE APPROACH OF
A WEAK STORM ON WEDNESDAY...COULD BRING SOME SHOWERS BACK
INTO THE AREA.

.GRR...HIGH WIND WATCH FOR SUNDAY...OVER THE ENTIRE CWA.

MJS

MIZ037>040-043>046-050>052-056>059-064>067-071>074-101000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1240 PM EDT FRI MAY 9 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE SOUTHWEST QUARTER OF LOWER
MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

A SLIGHT RISK OF SEVERE THUNDERSTORMS EXISTS ACROSS THE AREAS SOUTH
OF INTERSTATE 96 TODAY AND TONIGHT.  LARGE HAIL AND DAMAGING WINDS
ARE THE PRIMARY THREATS WITH THE STORMS.  THE MAIN TIME FRAME FOR
SEVERE THUNDERSTORMS TODAY IS LATE AFTERNOON AND EARLY EVENING. THE
ATMOSPHERE WILL BECOME UNSTABLE THIS AFTERNOON...AND THERE IS A
CHANCE THAT THUNDERSTORMS COULD FORM.  ANY STORMS THAT DO FORM THIS
AFTERNOON AND EVENING COULD BECOME SEVERE AND WILL TRACK NORTHEAST
AT 35 MPH.

A WARM FRONT WILL LIFT NORTH INTO THE REGION THIS AFTERNOON AND
BECOME STATIONARY.  THIS SYSTEM WILL BE THE MAIN FOCUSING MECHANISM
FOR THE STORMS TODAY AND TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

FOR SATURDAY AND SATURDAY NIGHT...A MODERATE RISK FOR SEVERE
THUNDERSTORMS EXISTS...ALONG AND SOUTH OF A LINE FROM MUSKEGON
TO GRAND RAPIDS TO LANSING.  THE REMAINDER OF THE REGION IS UNDER A
SLIGHT RISK.  A WIDESPREAD OUTBREAK OF SEVERE THUNDERSTORMS
FEATURING LARGE HAIL...DAMAGING WINDS IS EXPECTED. IN ADDITION...A
FEW TORNADOES ARE POSSIBLE...ESPECIALLY IN THE MODERATE RISK AREA.
THE MAIN TIMEFRAME FOR THE SEVERE WEATHER IS SATURDAY EVENING.
STORM MOVEMENT IS FORECASTED TO BE EAST AT 35 MPH.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON OR EVENING.
SPOTTER ACTIVATION WILL LIKELY BE NEEDED FOR LATER SATURDAY
AFTERNOON THROUGH SATURDAY EVENING.

OSTUNO