Severe Thunderstorm Warning 47, NWS Grand Rapids, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
430 PM EDT SAT JUN 28 2003

...LOWS LIKE MORE SHOWERS POSSIBLE ON SUNDAY...

MAIN PROBLEMS WITH THIS FORECAST PACKAGE ARE TO FIGURE OUT JUST HOW
MUCH OF A RISK FOR SHOWERS REMAINS LATER TONIGHT AND THEN ON SUNDAY
AS
YET ANOTHER SHORTWAVE AND JET STREAK MOVE THROUGH THE WESTERN GREAT
LAKES. A SOUTHERN STREAM WAVE COULD BRING SHOWERS INTO OUR SOUTHERN
COUNTIES MONDAY IF THE GFS 12Z RUN IS CORRECT BUT THE OTHER MODELS
TO NOT SHOW THAT HAPPENING...SO THE QUESTION IS WILL IT? AFTER THAT
THE QUESTION IS JUST HOW BIG DOES THE SUBTROPICAL RIDGE GET LATER IN
THE WEEK AND WILL NRN STREAM WAVE (AS PER THE GFS) BRING YET ANOTHER
CLOSED UPPER LOW TO THE NORTHEAST U.S. BY THIS COMING WEEKEND?

AS FOR THE CONVECTION CURRENTLY GOING ON...THAT SHOULD CLEAR MOST OF
THE CWA BY MIDNIGHT. HOWEVER THAT IS NOT THE END OF THE SHOW. THERE
IS YET ANOTHER JET STREAK AND SHORTWAVE ON THE NORTHERN STREAM
HEADING WEST MICHIGAN.  CURRENTLY (20Z) THERE IS ANOTHER AREA OF
SHOWERS AND THUNDERSTORMS NEAR THE MISSISSIPPI RIVER ON THE NOSE OF
THAT JET STREAK.  IT WOULD APPEAR THE FRONT WILL HAVE A HARD TIME
CLEARING THE SOUTHERN CWA OVERNIGHT.  SO WHEN THAT JET STREAK COMES
THROUGH SUNDAY... THERE WILL BE A FAIR AMOUNT OF SUNSHINE EARLY IN
THE DAY SINCE THE MEAN 1000/500 RH IS AROUND 50 PCT... SO THAT WILL
ALLOW ENOUGH HEATING TO ALLOW SCATTERED SHOWERS AND THUNDERSTORMS TO
DEVELOPED DURING THE DAY.  THUS I HAVE CONTINUED THE CHANCE OF
SHOWERS AND THUNDERSTORMS FOR SUNDAY DURING THE DAY.

THE SOUTHERN STREAM SYSTEM SEEMS OVER DONE ON THE 12Z GFS (LIKELY
CONVECTIVE FEEDBACK).  SO... I WENT WITH THE ETA FOR SUNDAY NIGHT
AND MONDAY AND THAT KEEPS SOUTHWEST MICHIGAN DRY. THAT SHOULD KEEP
MOST OF THE CLOUDS SOUTH OF MICHIGAN LEAVING PARTLY SUNNY AS A GREAT
FORECAST.

TUESDAY UPPER RIDGE FROM THE WESTERN PLAINS STARTS TO BUILD EAST AS
THE NEXT PACIFIC SYSTEM  MOVES INTO SOUTHERN CANADA VIA BC.  THAT
SHOULD RESULT IN MOSTLY CLEAR TO PARTLY CLOUDY SKIES WITH A SLOW
WARMING TREND STARTING.

ZONES BY 500 PM.

EXTENDED FORECAST

I BELIEVE THE GFS IS OVER DOING THE DEVELOPMENT OF THE NRN STREAM
SYSTEM THAT MOVES IN FROM BC ON TUESDAY TO THE NORTHERN GREAT LAKES
BY SATURDAY.  THE ECWMF HAS BEEN SHOWING A SIGNIFICANTLY STRONGER
UPPER HIGH TO OUR WEST BUILDING EAST AND SINCE THAT ALSO DOES NOT
MATCH THE ENSEMBLES OF THE GFS FROM THE 00Z RUN VERY WELL... I
BELIEVE THE NEXT SYSTEM WILL BE SLOWER THAN THE GFS IS FORECASTING.
THUS I KEEP TEMPERATURES ON THE WARM SIDE INTO SATURDAY.  I ALSO
KEPT OUR CHC OF SHOWERS FRIDAY (FORTH OF JULY). HOWEVER THE TREND IN
THE OTHER MODELS AND THE ENSEMBLES OF THE GFS SUGGEST IT MAY REALLY
TAKE UNTIL SATURDAY FOR THE THREAT OF SHOWERS TO RETURN. EVEN SO
SINCE I AM NOT SURE ON THIS ONE WAY OR THE OTHER... I KEEP THE CHC
IN FOR FRIDAY AND CONTINUED IT SATURDAY WHEN I THINK THE TREAT IS
HIGHER ACTUALLY.

.GRR...NONE.

WDM

MIZ037>040-043>046-050>052-056>059-064>067-071>074-291100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
950 AM EDT SAT JUN 28 2003

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

.DAY ONE...TODAY AND TONIGHT

SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING AS A
COLD FRONT APPROACHES. THE MAIN THREAT WITH THESE STORMS WILL BE
HAIL GREATER THAN THREE QUARTERS OF AN INCH IN DIAMETER. AN ISOLATED
TORNADO IS ALSO POSSIBLE AS WELL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

FAIR WEATHER SHOULD PREVAIL THROUGH MOST OF NEXT WEEK BUT THERE IS A
CHANCE FOR THUNDERSTORMS AGAIN ON INDEPENDENCE DAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING.

OSTUNO

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
0239 PM EDT SAT JUN 28 2003

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

0217 PM    5 E MOUNT PLEASANT        MI   WIND DAMAGE
06/28/03   ISABELLA                       TREE DOWN

0217 PM    MOUNT PLEASANT            MI   WIND DAMAGE
06/28/03   ISABELLA                       TREE DOWN

0211 PM    6 W MOUNT PLEASANT        MI   0.25 IN HAIL
06/28/03   ISABELLA

0150 PM    5 NW WALKER               MI   0.50 IN HAIL
06/28/03   OTTAWA

JK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
0256 PM EDT SAT JUN 28 2003

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

0100 PM    CEDAR SPRINGS             MI   WIND DAMAGE
06/28/03   KENT                           200 POUND JUNGLE GYM
                                          ROLLED OVER AND MOVED 50
                                          FEET

JK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
0343 PM EDT SAT JUN 28 2003

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

0326 PM    PAW PAW                   MI   0.88 IN HAIL
06/28/03   VAN BUREN

JK

MIZ037>039-043-044-050-282100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
355 PM EDT SAT JUN 28 2003

THE SEVERE THUNDERSTORM WATCH HAS BEEN CLEARED FOR PORTIONS OF THE
SOUTHWEST QUARTER OF LOWER MICHIGAN. THE WATCH IS NO LONGER IN
EFFECT FOR THE FOLLOWING COUNTIES

IN WEST CENTRAL MICHIGAN
     MASON...LAKE...OCEANA...NEWAYGO AND MUSKEGON

IN CENTRAL MICHIGAN
     OSCEOLA

JK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
0424 PM EDT SAT JUN 28 2003

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

0350 PM    WINN                      MI   1.75 IN HAIL
06/28/03   ISABELLA

0130 PM    1 NW EDMORE               MI   WIND DAMAGE
06/28/03   MONTCALM                       SEVERAL LARGE TREE LIMBS
                                          DOWN

JK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
0428 PM EDT SAT JUN 28 2003

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

0314 PM    SHEPHERD                  MI   1.75 IN HAIL
06/28/03   ISABELLA

JK