Severe Thunderstorm Warning 169, NWS Grand Rapids, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1123 PM EDT THU AUG 26 2004

.UPDATE...
LATEST KGRR RADAR IMAGERY CURRENTLY SHOWS QUIET CONDITIONS ACROSS
THE CWFA THIS EVENING. HOWEVER...REGIONAL RADAR IMAGERY SHOWS A
DIFFERENT PICTURE WITH PLENTY OF SHOWER AND THUNDERSTORM ACTIVITY
EXTENDING FROM THE U.P. OF MICHIGAN...DOWN THROUGH WI...AND THEN
INTO IA. EARLIER THIS EVENING...A FEW TORNADOES WERE REPORTED WITH
THE CELLS THAT BLEW UP IN IOWA. THE STORMS IN IOWA HAVE EVOLVED INTO
A LINEAR MCS WITH DAMAGING WINDS BEING MORE OF A THREAT OUT THERE
NOW. THE MAIN QUESTIONS FOR THE OVERNIGHT PERIOD IN SW LOWER ARE
PCPN CHCS WITH THE MCS OUT WEST AND WITH THETA-E ADV OCCURRING
OVERNIGHT.

WIND PROFILERS SW OF THE AREA ARE SHOWING THE LLJ INCREASING TO OUR
SW PRETTY MUCH AS EXPECTED...WITH MAYBE A LITTLE MORE SPEED THAN
EARLIER PROGGED. THE MCS CURRENTLY IN IOWA IS MOVING ALONG THE NRN
PERIPHERY OF THE STRONGEST PART OF THE LLJ. PART OF THE LLJ IS
EXPECTED TO BE AIMED AT SW LOWER DURING THE OVERNIGHT HOURS WITH
GOOD MID LEVEL THETA-E ADV OCCURRING AS A RESULT. ELEVATED
INSTABILITY WILL INCREASE WITH THE INFLUX OF WARM AND MOIST AIR
ALOFT. SHOWALTER INDICES ARE EXPECTED TO FALL TO AROUND -5 OR SO
OVERNIGHT. THE BEST WINDOW OF OPPORTUNITY WITH THE FORCING FROM THE
LLJ SEEMS TO BE AROUND 06Z GIVE OR TAKE A COUPLE OF HOURS BEFORE THE
JET WEAKENS. I WOULD EXPECT A FEW SCATTERED SHOWERS AND STORMS TO
OCCUR WITH THE INITIAL SHOT OF THETA-E ADV. PRETTY MUCH THE MAJORITY
OF THE CWFA HAS A CHC OF THE RESULTING SCT SHOWERS AND STORMS. THE
OTHER PLAYER TONIGHT THEN IS THE MCS ROLLING THROUGH ERN IA RIGHT
NOW. 850-300 MB THICKNESSES WOULD TAKE THE MAIN PART OF THIS MCS ON
A SLIGHTLY NORTH OF DUE EAST TRACK. THIS WOULD TAKE IT INTO THE NRN
SECTION OF THE CWFA DURING JUST BEFORE DAYBREAK. WITH ALL OF THIS
SAID...I KEPT THE LIKELY POPS UP NORTH...AND THE CHC OR SCT POPS
ELSEWHERE. AS FAR AS SEVERE THREAT GOES...SOME DAMAGING WINDS WOULD
BE POSSIBLE WITH THE REMNANTS OF THE MCS IF IT HOLDS TOGETHER. I
WOULD ANTICIPATE THE MCS WEAKENING AS IT APPROACHES THE CWFA AS IT
LOSES ITS SUPPORT. IN ADDITION...AN ISOLATED SEVERE HAIL REPORT
WOULD NOT BE OUT OF THE QUESTION. WITH FREEZING LEVELS UP AROUND 14K
FEET...THAT IS NOT LIKELY.

AS FAR AS TEMPS ARE CONCERNED...DEW POINTS ARE CURRENTLY AROUND 70
GIVE OR TAKE A DEGREE OR TWO. THE DEW POINTS SHOULD REMAIN STEADY
AND THUS TEMPS SHOULD FALL NO LOWER THAN AROUND 70.

&&

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

NJJ

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1230 PM EDT THU AUG 26 2004

LMZ843>849-MIZ037>040-043>046-050>052-056>059-064>067-071>074-271000-
ALLEGAN MI-BARRY MI-CALHOUN MI-CLARE MI-CLINTON MI-EATON MI-
GRATIOT MI-INGHAM MI-IONIA MI-ISABELLA MI-JACKSON MI-KALAMAZOO MI-
KENT MI-LAKE MI-MASON MI-MECOSTA MI-MONTCALM MI-MUSKEGON MI-
NEWAYGO MI-OCEANA MI-OSCEOLA MI-OTTAWA MI-VAN BUREN MI-
INCLUDING THE CITIES OF...ALBION...ALLEGAN...ALMA...BALDWIN...
BATTLE CREEK...BELDING...BIG RAPIDS...CHARLOTTE...CLARE...EASTWOOD...
EATON RAPIDS...EVART...GRAND HAVEN...GRAND RAPIDS...GREENVILLE...
HART...HASLETT...HASTINGS...HOLLAND...IONIA...ITHACA...JACKSON...
KALAMAZOO...LANSING...LOWELL...LUDINGTON...MARSHALL...MASON...
MOUNT PLEASANT...MUSKEGON...NEWAYGO...PAW PAW...PLAINWELL...
PORTAGE...PORTLAND...SOUTH HAVEN...ST. JOHNS...STANTON...
VANDERCOOK LAKE...WESTWOOD AND WHITE CLOUD
1230 PM EDT THU AUG 26 2004

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON AND TONIGHT.
THE STORM PREDICTION CENTER HAS PLACED ALL OF SOUTHWEST LOWER
MICHIGAN IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS. WIND GUSTS
TO 70 MPH WILL BE THE MAIN THREAT. HEAVY RAIN WILL BE POSSIBLE WITH
EACH OF THESE STORMS. THE BEST CHANCE FOR SEVERE STORMS IS AFTER 7
PM TONIGHT. STORM MOVEMENT WILL BE NORTHEAST AT 35 MPH.

WAVES ON LAKE MICHIGAN WILL BUILD TO 3 TO 6 FEET TONIGHT RESULTING
IN HAZARDOUS CONDITIONS FOR SMALL CRAFT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THUNDERSTORMS ARE POSSIBLE FRIDAY THROUGH SUNDAY. A FEW OF THE
THUNDERSTORMS COULD BE STRONG FRIDAY AFTERNOON AND EVENING AS A COLD
FRONT APPROACHES. ONCE AGAIN HEAVY RAIN AND WIND GUSTS TO 60 MPH WILL
BE THE MAIN THREATS.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING.

93 MEADE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
234 AM EDT FRI AUG 27 2004

MIZ037>040-043>046-050>052-056>059-064>066-071-072-271200-
ALLEGAN-BARRY-CLARE-CLINTON-EATON-GRATIOT-IONIA-ISABELLA-KALAMAZOO-
KENT-LAKE-MASON-MECOSTA-MONTCALM-MUSKEGON-NEWAYGO-OCEANA-OSCEOLA-
OTTAWA-VAN BUREN-
234 AM EDT FRI AUG 27 2004

THE STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR PORTIONS OF THE SOUTHWEST QUARTER OF LOWER MICHIGAN EFFECTIVE
UNTIL 800 AM EDT FRIDAY MORNING. THIS WATCH INCLUDES THE FOLLOWING
COUNTIES

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

IN CENTRAL MICHIGAN
     OSCEOLA...CLARE...ISABELLA...MECOSTA...MONTCALM AND GRATIOT

IN SOUTHWEST MICHIGAN
     KENT...ALLEGAN...BARRY...KALAMAZOO...VAN BUREN AND OTTAWA

IN SOUTH CENTRAL MICHIGAN
     IONIA...CLINTON AND EATON

THIS WATCH INCLUDES THE ADJOINING COASTAL WATERS OF AFFECTED
LAKESHORE COUNTIES.

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.

MJS