Hail in Michigan, March 20, 2003

SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
301 PM EST THU MAR 20 2003

MODELS OVERALL SIMILAR IN THE SHORT TERM. AT THE SURFACE...PRIMARY
MO LOW KICKS OUT TONIGHT INTO LOWER MICHIGAN FRIDAY MORNING AND
ACROSS LOWER MI DURING FRIDAY...THEN GRADUALLY PULLS
NORTHEAST...PULLING COLDER AIR IN FROM THE WEST AND SOUTHWEST. SOME
VARIATION SEEN IN PLACEMENT OF WEAK LOW...WITH MODELS TRENDING MORE
TOWARD THE SOUTHEAST WITH THE LOW. WILL THUS FAVOR ETA...SUPPORTED
BY WEAK 300 MB JET JUST SOUTH OF FORECAST AREA FRIDAY. AT 500
MB...MODELS INDICATE WEAKENING/FILLING SYSTEM COMING IN FROM THE
SOUTHWEST TONIGHT...THEN MOVING ACROSS OH/PA FRIDAY...AS ROBUST
NORTHERN STREAM LOW AS SEEN IN WATER VAPOR IMAGERY NEAR THE
ND/CANADIAN BORDER DIVES SOUTHEAST AND HANGS AROUND INTO THE
WEEKEND.

FORECAST WILL STRONGLY REFLECT PREVIOUS ISSUANCE INTO THE WEEKEND.
OMEGA LIFT 850 TO 700 MB QUITE GOOD THIS EVENING...AGAIN LATE
TONIGHT ESPECIALLY SOUTH...MORE LIFT MOST OF FRIDAY LINGERING INTO
FRIDAY NIGHT...THEN LITTLE OR NONE THROUGH SUNDAY. 850 TO 500 MB
QVECTOR CONVERGENCE ALSO MODEST OVERNIGHT...AND SUCH MAINLY NORTH OF
FORECAST AREA FRIDAY...WITH MODEST FRONTOGENETICAL FORCING FRIDAY
AFTERNOON/EVENING ALONG WITH 250 MB/850 MB DIVERGENCE/CONVERGENCE
COUPLING.

AS FOR MOISTURE...850 TO 500 MB MOISTURE QUITE GOOD THROUGH
FRIDAY...THEN DRY SLOTTING SETTING IN FRIDAY NIGHT...FOLLOWED BY
WRAPAROUND MOISTURE SATURDAY INTO SATURDAY NIGHT...THEN DRIER SUNDAY.
MODEL SOUNDINGS ALSO SHOW STRONG DRYING ALOFT FRIDAY NIGHT...THEN
BETTER MOISTURE ALOFT DRYING AGAIN BY SATURDAY NIGHT. SOUNDINGS
SUPPORTIVE OF RAIN OR SNOW TYPE SATURDAY...AS PER GOING FORECAST.
WILL LEAVE OUT PRECIPITATION MENTION SATURDAY NIGHT AS DEEPER
MOISTURE WANES.

THERMODYNAMICS...SHOWING AXIS OF RESPECTABLE CAPES/UNSTABLE LIFTED
INDICES WEST AND SOUTHWEST OF FORECAST AREA WEAKENING THIS
EVENING...WITH ONLY WEAK INSTABILITY FRIDAY. 850 MB LIFTED INDICES
THROUGH FRIDAY ZERO TO PLUS 2...BUT WILL RETAIN SOME MENTION OF
THUNDER INTO FRIDAY EVENING WITH LAPSE RATES ALOFT STILL
RESPECTABLE.

LATER PERIODS...
MODELS SHOW REASONABLE CONSENSUS FOR THE MOST PART...ESPECIALLY
EARLY ON. AT 500 MB...CONSENSUS SHOWS GREAT LAKES LOW MOVING OUT BY
SUNDAY...THEN RATHER ZONAL FLOW WITH ANOTHER SHORTWAVE TROUGH
ZIPPING EAST TO NORTHERN LAKES REGION BY MONDAY NIGHT...THENCE ON TO
THE EAST...THOUGH CANADIAN GLOBAL AND NOGAPS SLOWER/MORE AMPLIFIED.
AT THE SURFACE...LOW/TROUGH PERSISTING INTO THE WEEKEND...WITH WEAK
RIDGE IN PLACE BY SUNDAY...THEN AWAIT NEXT COLD FRONT...WHERE
CANADIAN GLOBAL/NOGAPS SLOWER. GFS BRINGS MORE MID LEVEL SHORTWAVE
ENERGY INTO LAKES AREA BY WEDNESDAY...WHILE SURFACE WAVE PASSES TO
THE SOUTH TUESDAY NIGHT AND WEDNESDAY...BEFORE RIDGING BY THURSDAY.
WILL CONTINUE GOING CLOSEST TO GFS IDEA...BEING SUPPORTED BY 12Z
RUNS OF ETA/GFS...THOUGH MAY BUFFER SLIGHTLY TO ALLOW FOR POSSIBLE
TREND TOWARD SLOWER CANADIAN/NOGAPS PROGRESSION. WILL ALSO MENTION
POSSIBLE MIX IN NORTHERN COUNTIES WEDNESDAY BASED ON GFS SYNOPTIC
PATTERN AND 1000 TO 850 MB THICKNESSES.

.DTX...NONE.

DWD

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

...MICHIGAN SEVERE WEATHER AWARENESS WEEK IS MARCH 16TH THROUGH
MARCH 22ND...

MIZ047>049-053>055-060>063-068>070-075-076-082-083-211200-

HAZARDOUS WEATHER OUTLOOK...CORRECTED TYPO
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
235 PM EST THU MAR 20 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST MICHIGAN

.DAY ONE...TODAY AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE INTO SOUTHEAST
MICHIGAN DURING THE REMAINDER OF THE AFTERNOON HOURS. AN ISOLATED
THUNDERSTORM COULD PRODUCE HAIL UP TO AN INCH IN DIAMETER...ALONG
AND WEST OF US 23. OTHERWISE...EXPECT JUST SMALL HAIL WITH ANY
THUNDERSTORMS THAT DEVELOP.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THERE IS A CHANCE OF THUNDERSTORMS FRIDAY AND FRIDAY EVENING ACROSS
ALL OF SOUTHEAST LOWER MICHIGAN. THESE STORMS ARE NOT EXPECTED TO BE
SEVERE.

WITH THE PERIODIC SHOWERS AND EVEN A FEW THUNDERSTORMS...THE
POTENTIAL FOR MINOR FLOODING EXISTS THROUGH SATURDAY.  THIS
POTENTIAL WOULD BE DUE TO THE COMBINATION OF PRECIPITATION...RECENT
SNOW MELT...AND FROZEN GROUND.

SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

&&

SF

YOU CAN OBTAIN THE LATEST FORECAST ON THE NATIONAL WEATHER SERVICE
WEB SITE HTTP://WWW.CRH.NOAA.GOV/DTX/ (ALL LOWER CASE)