Severe Thunderstorm Warning 15, NWS Grand Rapids, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1203 PM EDT FRI MAY 13 2005

.UPDATED...

I UPDATED THE ZONES TO CONFINE THE POSSIBLE SEVERE WEATHER OUR
SOUTHEAST COUNTIES. THE AREA OF THUNDERSTORMS THAT MOVED ACROSS OUR
CENTRAL AND SOUTHERN COUNTIES THIS MORNING HAS WORKED OVER THE
ATMOSPHERE OVER MOST OF OUR COUNTY WARNING AREA IN SO DOING.  THUS
MOST OF THE CWA WILL SEE SHOWERS WITH A CHANCE OF A THUNDERSTORM
SINCE NORTH AND WEST OF A LINE FROM BTL TO LAN... WILL STAY IN THE
COLD AIR AND NORTH OF THE WARM FRONT. THE MVC WEST OVER NW ILLINOIS
WILL CONTINUE TO BRING ENOUGH LIFT TO KEEP THE SHOWERS WEST OF GOING
AS THEY MOVE THROUGH MOST OF OUR COUNTY WARNING AREA THIS AFTERNOON.

MEANWHILE...SOUTH AND EAST OF THAT LINE THE LOW LEVEL JET WHICH WAS
AIDED AT THE CONVECTION THIS MORNING WILL HELP FOCUS THE CONVECTION
IN THIS AREA. THIS SHOULD BE MOSTLY LATE THIS AFTERNOON AND EVENING.
MEANWHILE THAT MCV (MOVING INTO SOUTHERN WI) HAS ALREADY DEVELOPED A
WAVE ON THE FRONT WITH A NEW LOW OVER NORTHWEST ILLINOIS (15Z).
GIVEN THE AXIS OF THE LOW LEVEL JET BETWEEN 21Z AND 03Z AIMED TOWARD
DETROIT/TOLEDO...AND JUXTAPOSITION OF THE WARM FRONT NEAR INTERSTATE
94 AT THAT TIME... PLUS CONSIDERING THE AXIS OF THE MID LEVEL JET
WILL BE CROSSING LAKE MICHIGAN AT THAT TIME WITH 50 KNOTS ALMOST TO
MBS...SEEMS THE BEST AREA FOR STRONG TO SEVERE THUNDERSTORMS SHOULD
BE SOUTH AND EAST OF A LINE FROM LANSING TO BATTLE CREEK.   IT IS
THERE WERE THE BEST THREAT FOR SEVERE WEATHER IS. ISOLATED TORNADOES
NEAR THE WARM FRONT STILL WOULD BE POSSIBLE BASED ON THE 1 KM
HELICITY BEING MORE THAN HALF THE TOTAL HELICITY (OVER 150 NEAR JXN
AT 3 PM).  CAPES ARE FORECAST OVER 1500 J/KG IN THAT AREA BY LATE
AFTERNOON. WINDS WILL BE MOSTLY UNIDIRECTIONAL SOUTH OF THE WARM
FRONT (SOUTH OF LANSING AFTER 3 PM).

THIS ALL SHOULD BE EAST OF THE GRR CWA BY EARLY EVENING. THEN
LIGHTER WINDS AND ALL THAT RAIN THAT FELL TODAY SHOULD LEAD TO FOG
DEVELOPMENT OVERNIGHT.

&&

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

&&

WDM

HAZARDOUS WEATHER OUTLOOK...UPDATED FOR WEATHER WATCH
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
155 PM EDT FRI MAY 13 2005

LMZ843>849-MIZ037>040-043>046-050>052-056>059-064>067-071>074-141000-
ALLEGAN-BARRY-CALHOUN-CLARE-CLINTON-EATON-GRATIOT-INGHAM-IONIA-
ISABELLA-JACKSON-KALAMAZOO-KENT-LAKE-MASON-MECOSTA-MONTCALM-MUSKEGON-
NEWAYGO-OCEANA-OSCEOLA-OTTAWA-VAN BUREN-
GRAND HAVEN TO WHITEHALL-HOLLAND TO GRAND HAVEN-
NEW BUFFALO TO ST JOSEPH-PENTWATER TO MANISTEE-
SOUTH HAVEN TO HOLLAND-ST JOSEPH TO SOUTH HAVEN-
WHITEHALL TO PENTWATER-
155 PM EDT FRI MAY 13 2005

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EARLY EVENING
SOUTH AND EAST 10 MILES NORTH OF HOLLAND TO NEAR ST JOHNS.  THE MOST
LIKELY TIME FOR THIS THREAT IS BETWEEN 3 PM AND 10 PM TONIGHT. WIND
GUSTS TO 70 MPH...HAIL TO 2 INCHES IN DIAMETER AND ISOLATED
TORNADOES ARE THE MOSTLY LIKELY THREATS.  THE ISOLATED
TORNADOES ARE POSSIBLE NEAR THE WARM FRONT DURING THE LATE AFTERNOON
INTO THE EARLY EVENING. THAT SHOULD MOSTLY BE SOUTH AND EAST OF
LANSING. HEAVY RAINFALL...WITH RAINFALL RATES OVER 1 INCH AN HOUR IS
ALSO POSSIBLE WITH THESE THUNDERSTORMS. FREQUENT CLOUD TO GROUND
LIGHTNING IS ALSO EXPECTED WITH THOSE THUNDERSTORMS. ISOLATED NONE
SEVERE THUNDERSTORMS... WITH THE THREAT OF HEAVY RAINFALL ARE
POSSIBLE ACROSS THE REST OF THE AREA.

A LOW PRESSURE SYSTEM SYSTEM NEAR CHICAGO AT 2 PM THIS AFTERNOON
WILL MOVE EAST NORTHEAST TOWARD THE DETROIT AREA BY EARLY THIS
EVENING. THAT WILL BRING THE WARM FRONT TO NEAR LANSING BY LATE THIS
AFTERNOON. IT IS NORTHWARD PUSH OF AIR WITH THE WARM FRONT THAT WILL
HELP TO FOCUS THE SEVERE WEATHER THREAT SOUTH AND EAST OF LANSING
LATE THIS AFTERNOON AND EVENING.

OVERNIGHT...ONCE THAT ALL MOVES OUT... WINDS WILL BECOME LIGHT. WITH
ALL THE RAIN THAT FELL DURING THE DAY TODAY... AREAS OF DENSE FOG
MAY DEVELOP AFTER MIDNIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THERE IS A CHANCE OF THUNDERSTORMS NEXT TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...ASSOCIATED WITH A FRONTAL SYSTEM MOVING THROUGH
THE AREA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE LIKELY THIS AFTERNOON AND EVENING. MORE
INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB PAGE:
WEATHER.GOV/GRANDRAPIDS (ALL LOWER CASE). REPORTS OF SEVERE WEATHER
WOULD BE MUCH APPRECIATED AND CAN BE SENT TO THE NATIONAL WEATHER
SERVICE VIA THE ONLINE SPOTTER REPORT FORM LINK ON THE MAIN PAGE.

&&

DUKE WDM

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1018 AM EDT FRI MAY 13 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0853 AM     HAIL             2 E KALAMAZOO           42.27N 85.55W
05/13/2005  0.75 INCH        KALAMAZOO          MI   TRAINED SPOTTER

            REPORTED NEAR THE INTERSECTION OF GULL ROAD AND SPRINKLE

0920 AM     HAIL             1 S BATTLE CREEK        42.28N 85.23W
05/13/2005  0.75 INCH        CALHOUN            MI   LAW ENFORCEMENT

            LOCATED AT CAPITOL AVENUE SOUTHWEST AND INTERSTATE 94

&&

GWETZEL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1139 AM EDT FRI MAY 13 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1100 AM     HAIL             SIDNEY                  43.25N 85.13W
05/13/2005  0.75 INCH        MONTCALM           MI   POST OFFICE

&&

GWETZEL