Severe Thunderstorm Warning 138, NWS Grand Rapids, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
325 AM EDT THU AUG 03 2006

.SHORT TERM...
SFC ANALYSIS SHOWS A FRONTAL BOUNDARY STRETCHING FROM NEAR MKG
SOUTHWEST TO NORTHEAST MISSOURI. IR IMAGERY SHOWED CONVECTION LINED
UP ALONG THE FRONT AND MOVING NORTHEAST FROM THE MISSOURI VALLEY TO
THE SOUTHERN CWA. OF PARTICULAR NOTE WAS FORWARD PROPAGATING MCS
OVER SOUTHEAST IOWA AND NORTHEAST MISSOURI. FORECAST CONCERNS IN THE
SHORT TERM DEAL WITH CONVECTIVE POTENTIAL TODAY.

THE FRONTAL BOUNDARY IS GOING TO SINK SOUTH THROUGH THE CWA TODAY.
THE CURRENT CONVECTIVE ACTIVITY WILL ALSO SLOWLY MOVE SOUTH. BUT
EARLY THIS MORNING EXPECT QUITE A BIT OF CONVECTION OVER THE
SOUTHERN 2 ROWS OF COUNTIES. THE MCS OVER NW MISSOURI IS A BIT
ELEVATED NORTH OF THE FRONTAL BOUNDARY AND WILL CONTINUE TO RACE
NORTHEAST TOWARD LOWER MICHIGAN ALONG THE THICKNESS CONTOURS.
TIMING TOOL PUTS THE MCS NEAR THE LAKESHORE BY 12Z. WILL KEEP
THE MENTION OF NUMEROUS TSRA OVER THE SOUTH THIS MORNING WITH CHC
POPS ELSEWHERE. BULK SHEAR INCREASES TO 40-45 KTS BY 12Z ACROSS THE
CWA. THIS IMPLIES A SEVERE THREAT THIS MORNING. WE CAN/T RULE OUT
THE DAMAGING WIND THREAT JUST YET. THE HAIL THREAT LOOKS RATHER
LIMITED GIVEN TAMDAR SOUNDINGS SHOWING FREEZING LEVELS AOA 15K FT.

SCATTERED SHOWERS AND STORMS WILL DIMINISH FROM NORTH TO SOUTH THIS
AFTERNOON AS THE BOUNDARY CONTINUES TO MOVE SOUTH. HIGH PRESSURE
WILL BUILD SOUTHEAST FROM CANADA TONIGHT AND PROVIDE COOLER AND
SOMEWHAT DRIER AIR TONIGHT INTO FRIDAY. THAT SAID...SFC DEWPOINTS
ARE STILL PROGD IN THE 60S...SO IT WILL STILL FEEL HUMID.

THE HIGH WILL DRIFT EAST OF THE CWA BY SATURDAY AND ANOTHER WARMUP
WILL COMMENCE.

.LONG TERM
THE NEXT MAJOR NORTHERN STREAM WAVE PHASES WITH A LARGE SYSTEM OVER
THE NORTH ATLANTIC TO CURVE OUT ANOTHER EASTERN TROUGH BY EARLY NEXT
WEEK. AS THE COLD FRONT WITH THAT SYSTEM MOVES THE GREAT LAKES
SUNDAY NIGHT OR EARLY MONDAY...THERE COULD BE THUNDERSTORMS WITH
IT.  AFTER THE COLD FRONT COMES THROUGH MONDAY MORNING QUIET WEATHER
SHOULD PREVAIL MOST OF THE COMING WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...NONE.

&&

93 WDM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
617 AM EDT THU AUG 3 2006

LMZ844>849-MIZ037>040-043>046-050>052-056>059-064>067-071>074-041030-
ST JOSEPH TO SOUTH HAVEN-SOUTH HAVEN TO HOLLAND-
HOLLAND TO GRAND HAVEN-GRAND HAVEN TO WHITEHALL-
WHITEHALL TO PENTWATER-PENTWATER TO MANISTEE-MASON-LAKE-OSCEOLA-
CLARE-OCEANA-NEWAYGO-MECOSTA-ISABELLA-MUSKEGON-MONTCALM-GRATIOT-
OTTAWA-KENT-IONIA-CLINTON-ALLEGAN-BARRY-EATON-INGHAM-VAN BUREN-
KALAMAZOO-CALHOUN-JACKSON-
617 AM EDT THU AUG 3 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST LOWER
MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SIGNIFICANT RISK OF SEVERE THUNDERSTORMS WITH DAMAGING
STRAIGHT LINE WINDS THIS MORNING FROM INTERSTATE 96 SOUTH AS A
DERECHO FROM NORTHERN ILLINOIS RACES EAST NORTHEAST AT 55 MPH
TOWARD LOWER MICHIGAN. ONCE THIS SYSTEM MOVES THROUGH BEFORE NOON
QUIET WEATHER WILL RETURN TO SOUTHERN MICHIGAN.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THERE IS A CHANCE OF THUNDERSTORMS LATER SUNDAY INTO MONDAY AHEAD
OF A COLD FRONT WHICH WILL MOVE THROUGH LOWER MICHIGAN DURING
MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS MORNING.

WDM