Special Marine Warning 21, NWS Grand Rapids, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
344 PM EDT THU MAY 30 2002

NUMEROUS SHOWERS AND THUNDERSTORMS CONTINUE TO FORM ACROSS SOUTH
CENTRAL LOWER MICHIGAN THIS AFTERNOON.  THESE WERE PRIMARILY
DIURNALLY DRIVEN...AND SHOULD KEEP ON GOING A FEW  MORE HOURS
BEFORE GRADUALLY WEAKENING AROUND SUNSET.  NEXT THE CLUSTER OF STORMS
ACROSS EASTERN WI...MAY CLIP MY NORTHERN COUNTIES TONIGHT...AND WILL
CARRY LIKELY PROBABILITIES FOR THEM.  THE COLD FRONT WILL PUSH INTO
THE REGION TONIGHT...AND BY DAYBREAK...SHOULD BE SOUTH AND EAST OF
GRR.  WILL HOLD ONTO SOME SCATTERED PRECIPITATION UNTIL THIS FRONT
COMES THROUGH.

MUCH DRIER AIR FILTERS IN FOR FRIDAY AND WILL LAST INTO SATURDAY AM.
A WARM DAY IS EXPECTED FOR FRIDAY...BUT MUCH COOLER TEMPERATURES FOR
FRIDAY NIGHT.

SATURDAY NOW SHOWS A WARM FRONT LIFTING UP INTO SOUTHWEST LOWER
MICHIGAN WITH DECENT POOLING OF THE MOISTURE SOUTH OF THIS FEATURE.
WARM MOIST CONVERGENCE IS NOW EXPECTED TO LEAD TO AT LEAST A CHANCE
OF PRECIPITATION FOR SATURDAY AFTERNOON INTO EARLY SATURDAY NIGHT.

MJS

EXTENDED FORECAST
GENERALLY THE CANADIAN AND ECM KEEP THE 500MB LONG WAVE TROUGH IN
THE SOUTHWEST U.S. WHILE AVN MOVES IT EAST. EITHER WAY THE MODELS
ALL ARE SHOWING SEVERAL SHORT WAVES MOVING THROUGH THE GREAT LAKES
AND OHIO VALLEY THE NEXT SEVERAL DAYS. THE BEST CHC OF PCPN WILL BE
ON SUNDAY AND MONDAY WITH LOTS OF MOISTURE AVBL. A SHORT WAVE WILL
BE MOVING INTO THE AREA SUNDAY NIGHT WITH A SFC LOW PASSING THROUGH
ON MONDAY. COULD GET SOME LOCALLY HEAVY RAIN LATE SUNDAY AND MONDAY.
HIGH PRESSURE BEHIND IT SHOULD KEEP TUESDAY PCPN FREE. ON WEDNESDAY
A SHORT WAVE AND SFC LOW WILL MOVE TROUGH THE LOWER GREAT LAKES AND
OHIO VALLEY. WILL ADD PCPN TO THE WEDNESDAY FORECAST. THURSDAY THE
MODELS SHOW ANOTHER SHORT WAVE AND SFC LOW MOVING INTO THE GREAT
LAKES SO WILL ADD SOME PCPN TO THE THURSDAY FCST.

DGH

.GRR...NONE.