Severe Thunderstorm Warning 64, NWS Detroit, MI

SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
345 PM EDT THU AUG 9 2001

COLD FRONT NOW WORKING ACROSS WI WILL BRING RELIEF FROM THE
HEAT...AND THREAT OF SEVERE WEATHER THIS EVENING.

ISOLATED/SCT CONVECTION ACROSS FAR SOUTHERN PORTION OF THE CWA THIS
MORNING AND EARLY AFTERNOON THE RESULT OF MOISTURE TRANSPORT
ASSOCIATED WITH THE REMNANTS OF BARRY. THIS MOISTURE IS NOW PULLING
OFF TO THE EAST.

MAIN CONCERN THIS FORECAST PACKAGE WILL BE SEVERE THREAT THIS
EVENING. MESOETA MODEL SHOWS IMPRESSIVE COUPLED LOW LEVEL/UPPER
LEVEL DIVERGENCE COINCIDENT WITH THE FRONT. /LOW LEVEL CONVERGENCE
FIELD MATCHING WELL WITH GRB/APX RADARS NOW./ THIS FORCING IS MOST
IMPRESSIVE ACROSS THE NORTHERN HALF OF THE CWA...AND WEAKENS SOME AS
THE FRONT MOVES SOUTH TONIGHT. /WILL PLAY ZONES FOR WIDESPREAD
COVERAGE FROM PTK NORTH AND NUMEROUS WORDING SOUTH OF THERE./
THERMODYNAMICALLY...NICE THETA-E RIDGE ASSOCIATED WITH THE FRONT AS
WELL. FRONT IS LAGGING 18Z MESOETA POSITION SLIGHTLY...PER LOW LEVEL
CONVERGENCE...SO EXPECT FRONT TO PROGRESS SLIGHTLY SLOWER THAN
MESOETA TIMING. LAPS DATA SHOWS 2500 TO 3000 J/KG NOW ACROSS CWA AND
MODEL SOUNDINGS INDICATE THESE VALUES NOT EXPECTED TO CHANGE MUCH.
MODEL SOUNDINGS ALSO SHOW AN AREA OF DRIER AIR CENTERED ABOUT
650MB...AND H20 VAPOR LOOP DOES INDICATE A RIBBON OF DRIER AIR
WORKING ACROSS LAKE MICHIGAN INTO CENTRAL LOWER MICHIGAN. WINDS
THROUGH THE COLUMN ARE UNI-DIRECTIONAL WITH MID LEVEL WINDS AROUND
30 KNOTS. ALL THESE FACTORS POINT TO THE POTENTIAL FOR SOME
THUNDERSTORMS TO BECOME SEVERE LATE THIS AFTERNOON AND EVENING. THE
MAIN THREAT WOULD BE WIND DAMAGE. WITH TEMPERATURE AND DEW POINT
READINGS PRODUCING HEAT INDICES BELOW ADVISORY CRITERIA THIS
AFTERNOON WILL CANCEL THE HEAT ADVISORY WITH ZONE ISSUANCE.

ONCE THE FRONT CROSSES TONIGHT...SIGNIFICANTLY DRIER AND COOLER AIR
MOVES INTO SOUTHEAST MICHIGAN FOR THE WEEKEND. MOST OF THE WEEKEND
WILL FEATURE MOSTLY CLEAR SKIES...ALTHOUGH MODELS BRING IN SOME MID
AND LOWER LEVEL MOISTURE ON SATURDAY...JUST ENOUGH TO FEATURE PARTLY
SUNNY SKIES.

EXTENDED...

MEAN RIDGE POSITION THROUGH THE PERIOD WILL BE BETWEEN THE ROCKIES
AND WEST COAST...WITH MEAN TROUGH ACROSS THE GREAT LAKES. THIS WILL
KEEP TEMPERATURES CLOSE TO SEASONAL NORMS...WITH OCCASIONAL FRONTAL
PASSAGES PROVIDING CHANCE POPS. WEAK COLD FRONT GRAZES NORTHERN
LOWER SUNDAY MORNING...BUT WITH LITTLE MOISTURE AND ALL DYNAMICS
REMAINING WELL NORTH...IMPACT IS MINIMAL. SURFACE HIGH PRESSURE
BUILDS IN ON MONDAY. WILL...HOWEVER...MAINTAIN MINIMAL CHANCE POPS
FOR MONDAY AS SHARP UPPER LEVEL TROUGH AND SLIGHT INCREASE IN MEAN
RH CROSSING CWA COULD STILL TRIGGER A SHOWER OR THUNDERSTORM.
STRONGER COLD FRONT PROGGED ACROSS CWA ON THURSDAY...BRINGING
ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS.

.DTX...NONE.

OKEEFE

MIZ047>049-053>055-060>063-068>070-075-076-082-083-100400-

SEVERE WEATHER OUTLOOK FOR SOUTHEAST LOWER MICHIGAN
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
325 PM EDT THU AUG 9 2001

...SEVERE WEATHER POTENTIAL STATEMENT FOR SOUTHEAST MICHIGAN...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY.

WHILE SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON... A LINE
OF STRONG TO SEVERE THUNDERSTORMS IS EXPECTED TO APPROACH THIS
EVENING. SOME OF THIS THUNDERSTORMS WITHIN THE LINE WILL BECOME
SEVERE WITH WIND GUSTS OVER 60 MPH. SPOTTER ACTIVATION WILL LIKELY BE
NEEDED LATE THIS AFTERNOON AND TONIGHT.

A STRONG COLD FRONT ACROSS CENTRAL WISCONSIN WILL PUSH SOUTHEAST
TOWARD SOUTHEAST LOWER MICHIGAN TONIGHT.  IN ADVANCE OF THIS
COLD FRONT IS A VERY WARM AND HUMID AIR MASS THAT WILL BECOME
INCREASINGLY UNSTABLE.  WINDS IN THE MIDDLE AND UPPER LEVELS OF THE
ATMOSPHERE WILL CONTINUE TO STRENGTHEN ALLOWING THUNDERSTORMS TO TAP
INTO THIS ENERGY AND TRANSPORT IT TO THE SURFACE.  WHILE THE
POTENTIAL EXISTS FOR HAIL AND LOCALLY HEAVY RAINFALL...THE MAIN
THREAT WILL BE DAMAGING WIND GUSTS.

THE SEVERE WEATHER THREAT ACROSS ALL OF SOUTHEAST LOWER MICHIGAN WILL
BE PRIMARILY BETWEEN 5 PM TONIGHT AND 3 AM FRIDAY.  AT THIS TIME...
THE LINE OF THUNDERSTORMS ARE EXPECTED TO APPROACH THE TRI-CITIES
REGION BETWEEN 5 PM AND 7 PM...AFTER 7 PM BETWEEN INTERSTATE 69
AND 94...AFTER 9 PM ALONG AND SOUTH OF INTERSTATE 94.

SCATTERED THUNDERSTORMS THIS EVENING WILL INITIALLY MOVE EAST BETWEEN
10 AND 15 MPH. LATER TONIGHT THUNDERSTORM MOVEMENT WITH THE LINE WILL
BE TOWARD THE SOUTHEAST AND INCREASE IN FORWARD SPEED BETWEEN 15 AND
25 MPH. THUNDERSTORMS ARE EXPECTED TO CLEAR SOUTHEAST LOWER MICHIGAN
AFTER MIDNIGHT.

STAY TUNED TO NOAA WEATHER RADIO...OR TO YOUR FAVORITE MEDIA
OUTLET...FOR LATER WEATHER UPDATES. YOU CAN ALSO REACH YOUR NATIONAL
WEATHER SERVICE ONLINE AT
HTTP://WWW.CRH.NOAA.GOV/DTX/START.HTM (ALL LOWER CASE)

BGM

MIZ047>049-053>055-060>062-100300-

SEVERE WEATHER OUTLOOK FOR SOUTHEAST LOWER MICHIGAN
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
432 PM EDT THU AUG 9 2001

...SEVERE THUNDERSTORM WATCH 668 IN EFFECT UNTIL 11 PM FOR PORTIONS
OF SOUTHEAST LOWER MICHIGAN...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY.

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR PORTIONS OF SOUTHEAST MICHIGAN EFFECTIVE UNTIL 11 PM.  A SEVERE
THUNDERSTORM WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR SEVERE
THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA...WITH HAIL DIME SIZED
OR LARGER AND WINDS OF 58 MPH OR GREATER.  THE WATCH COVERS THE
FOLLOWING COUNTIES IN SOUTHEAST LOWER MICHIGAN.

MIDLAND...BAY...HURON...SAGINAW...TUSCOLA...SANILAC...SHIAWASSEE...
GENESEE...AND LAPEER.

THIS WATCH INCLUDES THE COMMUNITIES AND SURROUNDING AREAS OF
MIDLAND...BAY CITY...SAGINAW...FLINT...BAD AXE...AND CARO.

ONCE AGAIN A SEVERE THUNDERSTORM WATCH MEANS THAT CONDTIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.

STAY TUNED TO NOAA WEATHER RADIO...OR TO YOUR FAVORITE MEDIA
OUTLET...FOR LATER WEATHER UPDATES. YOU CAN ALSO REACH YOUR NATIONAL
WEATHER SERVICE ONLINE AT
HTTP://WWW.CRH.NOAA.GOV/DTX/START.HTM (ALL LOWER CASE)

MANN

MIZ047>049-053>055-060>062-100300-

SEVERE WEATHER OUTLOOK FOR SOUTHEAST LOWER MICHIGAN
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
648 PM EDT THU AUG 9 2001

...SEVERE THUNDERSTORM WATCH 668 REMAINS IN EFFECT UNTIL 11 PM FOR
PORTIONS OF SOUTHEAST LOWER MICHIGAN...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY.

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR PORTIONS OF SOUTHEAST MICHIGAN EFFECTIVE UNTIL 11 PM. THE
FOLLOWING COUNTIES ARE INCLUDED IN THE WATCH...

MIDLAND...BAY...HURON...SAGINAW...TUSCOLA...SANILAC...SHIAWASSEE...
GENESEE...AND LAPEER.

THIS INCLUDES THE CITIES OF SAGINAW...OWOSSO...FLINT...LAPEER...AND
SANDUSKY.

A LINE OF THUNDERSTORMS WAS MOVING INTO CENTRAL LOWER MICHIGAN EARLY
THIS EVENING. THESE THUNDERSTORMS WILL MOVE INTO MIDLAND AND BAY
COUNTIES BY 740 PM...AND WILL GRADUALLY CONTINUE SOUTH AND EAST
ACROSS THE REST OF THE WATCH AREA THIS EVENING. THESE STORMS COULD
PRODUCE WIND GUSTS AROUND 60 MPH AND HAIL TO ONE INCH IN DIAMETER.

A SEVERE THUNDERSTORM WATCH MEANS THAT CONDTIONS ARE FAVORABLE FOR
SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. STAY TUNED TO
NOAA WEATHER RADIO...OR TO YOUR FAVORITE MEDIA OUTLET...FOR LATER
WEATHER UPDATES. YOU CAN ALSO REACH YOUR NATIONAL WEATHER SERVICE
ONLINE AT
HTTP://WWW.CRH.NOAA.GOV/DTX/START.HTM (ALL LOWER CASE)

ZOLTOWSKI