Severe Thunderstorm Warning 7, NWS Detroit, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
255 PM EDT WED APR 21 2004

.DISCUSSION...

CONVECTION HAS INCREASE IN FAR SOUTHEAST CWA...ON INTO NRN IN/OH
THE PAST FEW HOURS. WILL HAVE TO MONITOR TRENDS TO DECIDE JUST
NOW TO WORD THE LATE AFTN/EARLY EVENING. WILL LIKELY HAVE SCT SHRAS
AND STORMS IN ADVANCE OF COLD FRONT...AND PERHAPS A STORM OR TWO
WITH ACTUAL COLD FROPA AT AND BEYOND 00Z. CELLS HAVE BEHAVED WELL
SO FAR...WITH LITTLE MORE THAN GARDEN VARIETY GUSTY WINDS AND HEAVY
DOWNPOURS. WOULD NOT BE SURPRISED AT ALL TO SEE A FEW WARNINGS FLY
WITH STRONG WIND FIELD IN PLACE...AND AT LEAST MODEST INSTABILITY
DUE TO A FAIR AMOUNT OF SUNSHINE THIS AFTN. BIG MINUS HAS BEEN THE
MEAGER LLVL MOISTURE TO THIS POINT. THIS WILL IMPROVE JUST A BIT...
AS WEDGE OF 60F DWPTS SLIP INTO PARTS OF CWA FROM FAR SW LOWER MI
AND NRN IN.

NO MAIN BIG CHANGES TO THE FORECAST TODAY. BEYOND THIS EVENING...
REALLY ONLY FOCUSING ON A COUPLE OF PRECIP EVENTS...ONE THU NIGHT
INTO FRIDAY MORNING...AND THE OTHER IN THE SATURDAY NIGHT/SUNDAY
TIMEFRAME. ETA NOW SOMEWHAT ON BOARD WITH GFS WITH NORTHERN EXTENT
OF PRECIP FOR THE FIRST WX MAKER. GFS CONTINUES TO HAVE FEEDBACK
PROBLEMS...AND BLOWS UP QPF BOMB WELL NORTH...COVERING ALL OF CWA
BEFORE IT ENDS 18Z FRIDAY. AM MUCH MORE COMFORTABLE WITH THE ETA
DEPICTION...KEEPING FRONT/SFC WAVE BASICALLY SOUTH OF THE AREA...
WITH SRN 1/2 OF CWA ON TARGET FOR THE NRN EDGE OF PRECIP SHIELD
WITH THIS SYSTEM. WILL ADJUST GOING FCST AND EXTEND POPS INTO FRI
AM...AND BRING THEM FURTHER NORTH INTO CWA...SAY TO I-69 OR SO.

WEEKEND SYSTEM...THE REMNANTS OF STRONG UPPER STORM NOW DROPPING
SOUTHEAST OUT OF THE PAC NW...SEEMS LIKE A PRETTY GOOD BET AS WELL.
IN THIS CASE...HOWEVER...THE DETAILS ARE FAR MORE ELUSIVE...OR HAVE
BEEN OVER THE PAST SEVERAL DAYS ANYWAY. SEEMS MODELS HAVE NARROWED
THEIR SEARCH TO EITHER SAT NIGHT OR SUN (OR BOTH) FOR THE MOST PART.
WILL KEEP THE ONGOING CHC OF SHRAS/TSRAS IN PLACE. SUPPORT IS SEEN
PRETTY MUCH ACROSS THE BOARD FOR THIS SYS...WHICH LIFTS NORTHEAST
INTO THE WRN LAKES AS A FAIRLY POTENT SHORTWAVE.

SEASONABLY COOL TEMPERATURES APPEAR TO BE THE RULE FOR MUCH OF THE
NEXT WEEK...AS COLD FRONT THAT PASSES THRU THIS EVENING WILL HAVE
TROUBLE RETURNING NORTH THRU CWA AS IT MORE OR LESS STALLS IN THE
OH/TN VALLEY AREA. WITH A PREDOMINANT EAST FLOW...INFLUENCE OF THE
COLD LAKE WATERS WILL ALSO BE MAXIMIZED...ESP THU-SAT. PRETTY GOOD
COLD SHOT THEN TAKES OVER EARLY NEXT WEEK. BY IN LARGE...ONLY MADE
SMALL ADJUSTMENTS OF 1 OR 2 DEGREES.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

GURNEY

EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT
HTTP://WWW.CRH.NOAA.GOV/DTX  (ALL LOWER CASE)

HAZARDOUS WEATHER OUTLOOK FOR SOUTHEAST MICHIGAN
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
137 PM EDT WED APR 21 2004

MIZ047>049-053>055-060>063-068>070-075-076-082-083-221100-
BAY-GENESEE-HURON-LAPEER-LENAWEE-LIVINGSTON-MACOMB-MIDLAND-MONROE-
OAKLAND-SAGINAW-SANILAC-SHIAWASSEE-ST. CLAIR-TUSCOLA-WASHTENAW-WAYNE-
137 PM EDT WED APR 21 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST MICHIGAN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON. SOME OF THESE
STORMS MAY BE SEVERE...CAPABLE OF PRODUCING WIND GUSTS TO 70 MPH
AND HAIL TO ONE INCH IN DIAMETER. THUNDERSTORM MOVEMENT WILL BE TO
THE EAST AT 40 MPH.

A COLD FRONT OVER WISCONSIN AND ILLINOIS WILL MOVE INTO LOWER
MICHIGAN LATE THIS AFTERNOON. THIS FRONT WILL INTERACT WITH AN
UNSTABLE AIRMASS OVER SOUTHEAST MICHIGAN...LEADING TO SCATTERED
THUNDERSTORMS AND THE POTENTIAL FOR SEVERE WEATHER. THE BEST CHANCE
FOR THUNDERSTORMS IS BETWEEN 1 PM AND 5 PM FROM METRO DETROIT TO
THE SAGINAW VALLEY...AND BETWEEN 3 PM AND 7 PM ACROSS THE THUMB.

.DAY TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A CHANCE OF THUNDERSTORMS SATURDAY NIGHT THROUGH SUNDAY AS
AN UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO THE GREAT LAKES
REGION.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND INTO THE
EVENING.

BRAVENDER