Marine Hail in Lake Huron, August 2, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1100 AM EDT MON AUG 2 2004

.SHORT TERM...MORNING SURFACE ANALYSIS SHOWED COLD FRONT EXTENDING
FROM CENTRAL UPPER...SW THROUGH NRN WI INTO MN. ATMOSPHERE WAS
DESTABILIZING RAPIDLY IN ADVANCE OF BOUNDARY...WITH PLENTY OF
SUNSHINE...AND DEW POINTS OF 65-70F OVERSPREADING REGION. MSAS SHOWS
LI/S OF -4 TO -6 AREAWIDE. OBVIOUS QUESTION FOR THE AFTERNOON
REMAINS SEVERE WEATHER THREAT.

MORNING KAPX SOUNDING SHOWED STEEP MID LEVEL LAPSE RATES...WITH
700-500 MB LAPSE RATE OF NEAR 7 C/KM. MOISTURE AT 850 MB WAS
LIMITED. HOWEVER...WITH KGRB SOUNDING SHOWING +15C 850 MB DEW POINTS
JUST UPSTREAM...LOW LEVEL MOISTURE WILL ONLY CONTINUE TO INCREASE.
ASSUMING AN AFTERNOON PARCEL OF 85/66 (QUITE LIKELY GIVEN FULL SUN
AND MOISTURE ADVECTION) MODIFIED KAPX SOUNDING PROVIDES AROUND 3100
J/KG CAPE...AND AN LI OF -9.

THOUGH MOISTURE/INSTABILITY LOOK IMPRESSIVE...WIND FIELDS ARE A BIT
MORE SUSPECT. 850 MB WINDS WILL HOVER IN THE 15-20 KT RANGE...WHILE
500 MB WINDS GENERALLY HOLD AROUND 30 KT (HIGHEST IN THE FAR N).
ASSOCIATED 0-6KM BULK SHEAR VALUES OF 15 KT (FAR S) TO NEAR 35 KT
(FAR N) SUGGEST BEST STORM ORGANIZATION THIS AFTERNOON MAY BE ACROSS
ERN UPPER (VICINITY OF ONGOING CONVECTION).

FOCUS ACROSS NRN LOWER MAY CONTINUE TO BE A PROBLEM THIS AFTERNOON.
SOME 850-500 MB QG SUPPORT IS EXPECTED (MAINLY WAA INDUCED).
HOWEVER...LOW LEVEL BOUNDARY (KICKER) ISN/T EXPECTED TO ARRIVE INTO
THE STRAITS AREA UNTIL EARLY EVENING. AND FURTHERMORE...950 MB WINDS
APPEAR A BIT TOO STRONG FOR LAKE BREEZES TO DEVELOP. AS A
RESULT...WILL LOWER RAIN CHANCES SLIGHTLY FOR SE PARTS OF FORECAST
AREA.

HIGH FREEZING LEVELS (NEAR 13K) AND WET BULB ZERO LEVELS (NEAR 12K)
WOULD TEND TO LIMIT LARGE HAIL THREAT...THOUGH A FEW OF THE STRONGER
STORMS (UPDRAFTS) MAY BE CAPABLE OF PRODUCING MARGINAL SEVERE HAIL.
BEST THREAT FOR STRONG WINDS BY LATE AFTERNOON APPEARS TO BE ACROSS
ERN UPPER AND FAR NRN LOWER.

SMITH

&&

.PREV DISCUSSION...ISSUED 445 AM MON AUG 2

LONG TERM...TONIGHT THROUGH WEDNESDAY...WEAK BOUNDARY CONTINUES
THROUGH NORTHERN LOWER MICHIGAN TONIGHT AND INTO SOUTHERN LOWER
MICHIGAN BY TUESDAY MORNING, WITH DRYER/COOLER AIR FILTERING INTO
THE REGION ON TUESDAY. WILL EXTEND LIKELY POPS FROM THIS AFTERNOON
INTO THE EARLY EVENING HOURS FOR NRN LOWER MI AS ANY CONVECTION WILL
STILL BE ONGOING...FOLLOWED BY A CHANCE OF RAIN SHOWERS OVERNIGHT IN
NRN LOWER MI BUT DRY UP NORTH. THEN...LOOKS LIKE WE GET A STRETCH OF
DRY WEATHER FOR MIDWEEK AS HIGH PRESSURE BECOMES ESTABLISHED OVER
THE REGION AND DAYTIME TEMPS COOL INTO THE 70S AND NIGHTTIME LOWS IN
THE UPPER 40S TO LOWER 50S. GFS/UKMET STILL DEPICTING A CONVECTIVE
BOMB ROLLING THROUGH SOUTHERN LOWER MI EARLY WED AND POSSIBLY
BRUSHING THE SOUTHERN REACHES OF THE CWA. WILL CONTINUE TO IGNORE
FOR NOW.

ADAM

&&

.APX...WATCHES/WARNINGS/ADVISORIES...NONE.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GAYLORD, MI
1215 PM EDT MON AUG 2 2004

MIZ008-015>036-041-042-LSZ321-322-LMZ323-341-342-344-345-
LHZ345>349-031100-
ALCONA-ALPENA-ANTRIM-ARENAC-BENZIE-CHARLEVOIX-CHEBOYGAN-CHIPPEWA-
CRAWFORD-EMMET-GLADWIN-GRAND TRAVERSE-IOSCO-KALKASKA-LEELANAU-
MACKINAC-MANISTEE-MISSAUKEE-MONTMORENCY-OGEMAW-OSCODA-OTSEGO-
PRESQUE ISLE-ROSCOMMON-WEXFORD...INCLUDING THE ADJACENT WATERS
WITHIN FIVE NAUTICAL MILES OF SHORE ON LAKE MICHIGAN...LAKE HURON
AND LAKE SUPERIOR
1215 PM EDT MON AUG 2 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN LOWER AND EASTERN
UPPER MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND TONIGHT ACROSS EASTERN
UPPER AND NORTHERN LOWER MICHIGAN. WIDESPREAD SEVERE WEATHER IS NOT
EXPECTED. HOWEVER...A FEW STORMS MAY APPROACH SEVERE LIMITS...AND
PRODUCE WIND GUSTS AROUND 50 MPH AND HAIL AROUND ONE HALF INCH IN
DIAMETER. THE GREATEST CHANCE FOR STRONG STORMS WILL BE THROUGH
10 PM THIS EVENING.

IN ADDITION...SLOW MOVING THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY
RAINFALL ACROSS NORTHERN LOWER AND EASTERN UPPER MICHIGAN THIS
AFTERNOON AND EVENING. SEE ONGOING WATCHES...WARNINGS...OR
ADVISORIES FOR ADDITIONAL INFORMATION.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION NOT ANTICIPATED.

&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING URL:
HTTP://WWW.CRH.NOAA.GOV/APX (ALL LOWER CASE)

SMITH