Severe Thunderstorm Warning 57, NWS Gaylord, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
347 PM EDT SUN OCT 3 2004

.DISCUSSION...FORECAST CONCERNS DEAL WITH PRECIPITATION CHANCES WITH
FRONTAL PASSAGE THIS EVENING...THEN LAKE EFFECT POTENTIAL AND PRECIP
TYPE ISSUES WITH THAT OVERNIGHT AND INTO MONDAY.  ATTENTION THEN
TURNS TO WATERSPOUT POTENTIAL FOR THE EARLY PART OF THE WEEK.

TONIGHT...SURFACE COLD FRONT MOVING THROUGH MN AT MID AFTERNOON WILL
SWEEP QUICKLY ACROSS THE STATE TONIGHT DRIVEN BY 3-4MB/3HR PRESSURE
RISES BEHIND THE BOUNDARY.  BAND OF QG FORCING/CONVERGENCE
ASSOCIATED WITH FRONT WILL MOVE ACROSS THE AREA THIS EVENING...
DEEPER MOISTURE WILL REMAIN GENERALLY NORTH OF M-32.  RADAR
COMPOSITES SHOWING JUST SOME WIDELY SCATTERED ACTIVITY ACROSS LAKE
SUPERIOR ATTM...SO WILL GO WITH CHANCE POPS THIS EVENING ALONG/NORTH
OF M-72.  COLD AIR COMES IN QUICKLY BEHIND FRONT WITH 850MB
TEMPERATURES FALLING TO AROUND -5/-6C OR SO BY DAYBREAK.  FLOW WILL
VEER AROUND FROM WNW TO NW DURING THE NIGHT.  ACROSS EASTERN UPPER...
INVERSION HEIGHTS AROUND 700MB WITH BEST 900-700MB RH (ABOVE 80
PERCENT BY MORNING)...THINK LIKELY POPS SHOULD WORK HERE.
CONDITIONS A LITTLE DRIER OVER NORTHERN LAKE MICHIGAN TO START
BEFORE COLDER 850MB AIR ARRIVES AND INVERSION HEIGHTS LIFT TO AROUND
750MB...SO WILL KEEP THINGS MORE SCATTERED ACROSS NORTHWEST LOWER.
AS FAR AS PRECIP TYPE GOES...WELL MIXED WARM LAYER TYPICAL OF EARLY
FALL COLD AIR MASSES COMING OVER THE LAKES KEEPING FREEZING LEVELS
ON AVERAGE ABOVE 2K FEET...THOUGH COULD DROP IN HEAVIER SHOWERS.  SO
WILL MAINTAIN THE POSSIBILITY OF SOME MIXED RAIN/SNOW ACROSS EASTERN
UPPER AND HIGHER TERRAIN AREAS OF NORTHERN LOWER.  MARINE...STRONG
MIXING IN CAA PATTERN BEHIND FRONT (30KT WINDS IN MIXED LAYER) AND
STRONG ISALLOBARIC GRADIENT MAY PUSH WINDS TO GALE FORCE FOR SEVERAL
HOURS AFTER FRONTAL PASSAGE THIS EVENING...AIDED IN THE STRAITS TO
PRESQUE ISLE ZONE BY NORTHWEST FLOW COASTAL CONVERGENCE.

MONDAY...RESIDUAL COLD AIR AND LOW LEVEL MOISTURE THE CONCERN FOR
MONDAY WITH DEEP LAYER SUBSIDENCE SETTLING IN BEHIND DEPARTING SHORT
WAVE TROUGH.  ANY ONGOING LAKE EFFECT RAIN/SNOW SHOWERS DURING THE
MORNING WILL BECOME MORE DISORGANIZED AS DIURNAL INFLUENCE KICKS IN.
WILL PRETTY MUCH DRAG TONIGHT POPS THROUGH THE DAY MONDAY...KEEPING
AREAS NEAR SAGINAW BAY DRY.  MARINE...WILL CONTINUE TO SEE HIGH END
SCA CONDITIONS IN ALL NEARSHORE ZONES AT LEAST THROUGH MONDAY
MORNING...BEFORE WINDS GRADUALLY START TO SUBSIDE THOUGH WAVES WILL
REMAIN CHOPPY THROUGH THE AFTERNOON.

MONDAY NIGHT...HIGH PRESSURE OVER EASTERN IOWA WILL TRACK EASTWARD
AND SPREAD WEAK COLD AIR ADVECTION ACROSS THE REGION THROUGH THE
EARLY MORNING HOURS. HAVE INCREASED CLOUDS SLIGHTLY ACROSS LAKE
EFFECT AREAS WITH NORTHWESTERLY FLOW...YET HAVE REMOVED ANY MENTION
OF PRECIPITATION. CONVECTIVE CLOUD DEPTH STRUGGLES TO REACH A COUPLE
THOUSAND FEET WITH LAKE TO 850 MB DELTA T ABOUT 18 C INDICATES NO
CHANCE OF WATERSPOUTS. PRECIPITATION WAS REMOVED DUE TO A LACK OF
LIFTING MECHANISM...THE SOLE SOURCE OF INSTABILITY BEING
DESTABILIZATION OVER LAKE WATERS AND LIMITED CONVECTIVE CLOUD DEPTH.

TUESDAY AND TUESDAY NIGHT...MERIDIONAL UPPER LEVEL FLOW WILL PERSIST
AS THE UPPER LEVEL RIDGE PROGRESSES EASTWARD TO THE LEE EDGE OF THE
ROCKIES TUESDAY AFTERNOON. SURFACE HIGH PRESSURE SLIDES INTO THE
OHIO VALLEY AND WEAK WARM AIR ADVECTION WILL BEGIN WITH THE WIND
SHIFT TO SOUTHWESTERLY. LAKE TO 850 MB DELTA T WILL REMAIN NEAR
18 C...HOWEVER THE CONVECTIVE CLOUD DEPTH OF A COUPLE THOUSAND FEET
WILL AGAIN PREVENT WATERSPOUTS. TUESDAY EVENING AN UPPER LEVEL
DISTURBANCE WILL PASS THROUGH SOUTHERN QUEBEC...BUT WILL REMAIN FAR
ENOUGH NORTH THAT CLOUDS WILL INCREASE OVER EASTERN UPPER WITH NO
PRECIPITATION ANTICIPATED ACROSS THE CWA.

WEDNESDAY AND WEDNESDAY NIGHT...MERIDIONAL UPPER LEVEL PATTERN
BEGINS TO FLATTEN SLIGHTLY AS THE RIDGE WEAKENS AS IT MOVES THROUGH
THE UPPER PLAINS/CENTRAL CANADA. THE UPPER LEVEL LOW WILL TRACK INTO
ONTARIO AND SURFACE HIGH PRESSURE WILL ONCE AGAIN RIDGE INTO THE
REGION. WITH SURFACE WINDS RETAINING A SOUTHERLY COMPONENT
TEMPERATURES WILL RISE ANOTHER COUPLE OF DEGREES. WITH THE LAKE TO
850 MB DELTA T DECREASING TO 10 C OR LESS AND SURFACE WINDS AROUND
10 KTS...WILL EXPECT SOME LAKE ENHANCED CLOUDINESS ACROSS THE AREAS
OF NORTHWEST LOWER AND EASTERN UPPER WHICH ARE PRONE TO LAKE
ENHANCEMENT FROM SOUTHWESTERLY FLOW.

THURSDAY AND BEYOND...NO DRASTIC CHANGES TO THE FORECAST DURING
THESE PERIODS DUE TO MODEL CONFLICTS. MODELS BRING LARGE AMOUNTS OF
MOISTURE INTO THE CENTRAL US ON THE WESTERN SIDE OF THE HIGH
PRESSURE WHICH IS NOT ACCOUNTED FOR. AS A RESULT HAVE INCREASED THE
CLOUDINESS FOR LATE THURSDAY INTO FRIDAY...BUT HAVE NOT INCLUDED ANY
PRECIPITATION IN THE FORECAST AT THIS TIME. ANALYSIS OF THE LONG
WAVE PATTERN WOULD ALSO SUGGEST THAT THE MOISTURE WOULD REMAIN TO
THE SOUTH AS THE MAIN BRANCH OF THE JET WILL REMAIN THROUGH THE
CENTRAL CANADIAN PROVINCES.

&&

.APX...WATCHES/WARNINGS/ADVISORIES...GALE WARNING...LSZ321-
        LMZ342-344-345-LHZ345-347-348.

&&

FORECASTERS...
00Z 4 OCT-00Z 5 OCT GRIDS...JPB
00Z 5 OCT-00Z 11 OCT GRIDS...MJP
FIRE WEATHER GRIDS...KAB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GAYLORD MI
935 PM EDT SUN OCT 3 2004

MIZ008-015>036-041-042-LSZ321-322-LMZ323-341-342-344-345-
LHZ345>349-041100-
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
935 PM EDT SUN OCT 3 2004

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

.DAY ONE...TONIGHT

THUNDERSTORMS NORTH OF M-68 WILL END BY MIDNIGHT. ISOLATED
THUNDERSTORMS MAY PRODUCE HAIL TO THREE QUARTERS OF AN INCH IN
DIAMETER...ESPECIALLY ACROSS EASTERN UPPER MICHIGAN ALONG AND EAST
OF I-75...BY THAT TIME.

GALES ARE EXPECTED TONIGHT ON THE SOME NEARSHORE WATERS OF NORTHERN
LOWER MICHIGAN. SEE ONGOING WATCHES..WARNINGS OR ADVISORIES FOR
DETAILS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SUNDAY

GALES MAY CONTINUE INTO THE MORNING HOURS OF MONDAY ON LAKE HURON
FROM THE STRAITS EAST TO PRESQUE ISLE LIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

&&

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

JPB/SPR