Severe Thunderstorm Warning 20, NWS Detroit, MI

SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1115 AM EDT MON JUN 17 2002

UPDATE FOCUS IS ON THUNDERSTORM POTENTIAL. WATER VAPOR LOOP SHOWS
TWO WEAK VORT CENTERS SWINGING AROUND THE UPPER LOW CURRENTLY
MOVING INTO QUEBEC. ONE OVER SOUTHEAST LOWER LEADING TO AN AREA OF
SHOWERS/ISOLATED THUNDERSTORMS JUST CLEARING OUT OF THE METRO
DETROIT AREA. NEXT VORT UPSTREAM MOVING INTO NORTHERN LOWER AND WILL
BE OF INTEREST FOR THE AFTERNOON/EVENING...WITH A FEW SHOWERS
ALREADY APPARENT NORTHWEST OF THE CWA. SURFACE ANALYSIS SHOWS A WEAK
TROUGH CROSSING LOWER MICHIGAN FROM CENTRAL LAKE MICHIGAN TO CENTRAL
LAKE HURON. OTHER THAN THE MORNING CONVECTION...EARLY VISIBLE
SATELLITE SHOWS MOSTLY SUNNY SKIES ACROSS THE REMAINDER OF THE CWA.

12Z RUC/ETA DROP THE NORTHERN VORT INTO THE CWA THIS EVENING...WITH
A WEAK FRONT/WAVE AT THE SURFACE. GENERALLY A WEAK GRADIENT BUT WITH
BOTH RUC/ETA DEPICTING SOME 925MB CONVERGENCE INTO THE EVENING.
INSTABILITY WILL BE A QUESTION FOR THE AFTERNOON WITH -23C COLD POOL
AT 500MB SHIFTING EAST WITH WARM ADVECTION BEGINNING. HOWEVER
850-500MB LAPSE RATES STILL NEAR 7C/KM. DEWPOINTS IN THE LOWER 50S
POOLING ALONG THE TROUGH AFTER MORNING RAIN SHOWERS...WITH
TEMPERATURES CLIMBING INTO THE LOWER 70S. MODIFIED 12Z DTX SOUNDING
FOR T/TD OF 72/52 WOULD YIELD 2500J/KG OF CAPE. HOWEVER WITH WARM
ADVECTION THE GRB SOUNDING WOULD BE MORE REPRESENTATIVE OF THE
AFTERNOON AIRMASS...AND YIELDS 1300J/KG CAPE WITH SAME INITIAL T/TD.
UPPER DIVERGENCE NOT THAT IMPRESSIVE...ALTHOUGH CWA LOCATED NEAR
GENERAL LEFT-EXIT OF 60KT 300MB JET. WILL KEEP A CHANCE OF
THUNDERSTORMS FOR THE AFTERNOON CARRIED INTO THE EVENING. CLIMBING
FREEZING LEVELS WITH THE WARMING COLUMN IN ADDITION TO MARGINAL WIND
FIELDS AND INSTABILITY SHOULD PRECLUDE SEVERE WEATHER.

WITH LINGERING LOW-LEVEL MOISTURE AND GENERALLY STEEP LAPSE RATES
WITH THERMAL THROUGH STILL JUST SHIFTING EAST...EXPECT DECENT CU TO
DEVELOP BY AFTERNOON LEADING TO PARTY SUNNY SKIES.

.DTX...NONE.

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MIZ047>049-053>055-060>063-068>070-075-076-082-083-180000-

HAZARDOUS WEATHER OUTLOOK FOR SOUTHEAST MICHIGAN
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1044 AM EDT MON JUN 17 2002

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

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY.

HAZARD...
SCATTERED THUNDERSTORMS ARE POSSIBLE THROUGH 8 PM. SEVERE WEATHER IS
NOT EXPECTED.

DISCUSSION...
AN UPPER LEVEL DISTURBANCE WILL INTERACT WITH A WEAK SURFACE TROUGH
OVER LOWER MICHIGAN...LEADING TO A CHANCE OF THUNDERSTORMS FOR THIS
AFTERNOON AND EVENING. STORMS THAT DEVELOP WILL MOVE SOUTHEAST AT
30 MPH...AND WILL BE CAPABLE OF PRODUCING HAIL UP TO HALF AN INCH
IN DIAMETER AND WIND GUSTS TO 35 MPH.

SPOTTER ACTIVATION...
SPOTTER ACTIVATION IS NOT ANTICIPATED.

OUTLOOK FOR TUESDAY AND WEDNESDAY...
NO HAZARDOUS WEATHER EXPECTED.

STAY TUNED TO NOAA WEATHER RADIO...OR LOCAL MEDIA OUTLETS...FOR
THE LATEST FORECAST INFORMATION. YOU CAN ALSO OBTAIN THE LATEST
FORECAST ON THE NATIONAL WEATHER SERVICE WEB SITE.

HTTP://WWW.CRH.NOAA.GOV/DTX/ (ALL LOWER CASE)

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