Severe Thunderstorm Warning 63, NWS Gaylord, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
335 PM EDT MON SEP 3 2001

SYNOPSIS...COLD FRONT MOVING THROUGH THE REGION RUNS FROM JUST EAST
OF ANJ TO GRB (18Z) WITH SHOWERS AND THUNDERSTORMS ASSOCIATED WITH
IT. MOISTURE BEHIND THE FRONT IS MAKING ITS WAY INTO NORTHERN LAKE
SUPERIOR. TO THE WEST THE 500 MB RIDGE IS BEGINNING TO BUILD. THE
MAIN CONCERN FOR THIS PACKAGE WILL BE THE ENDING OF THE
THUNDERSTORMS IN THE SOUTHERN PART OF THE CWFA AND WHETHER THERE ARE
SHOWERS TONIGHT AND TOMORROW WITH THE AREA OF MOISTURE MOVING SOUTH
OUT OF CANADA. THE MODELS ARE IN GOOD AGREEMENT EXCEPT IN THE
HANDLING OF THE 850 MOISTURE THAT WILL MOVE INTO THE REGION
OVERNIGHT. THE ETA IS MORE CONSISTENT AND COMPARED TO THE SAT.
PICTURES LOOKS LIKE IT HAS A BETTER HANDLE ON THE SYSTEM. THE AVN IS
MUCH DRY AND TAKES MOST OF THE MOISTURE EAST.

TONIGHT...THE COLD FRONT WILL MOVE OUT OF THE REGION BY 03Z TAKING
THE THUNDERSTORMS WITH IT. THERE WILL BE SHORT TIME OF MOSTLY CLEAR
SKIES IN N LOWER BEFORE THE LOW CLOUDS IN CANADA MOVES INTO THE
REGION. BASED ON THE UPSTREAM OBSERVATIONS AND THE CANADIAN RADARS,
WILL PUT IN A FEW SHOWERS FOR THE E UPPER AND THE STRAITS COUNTIES
FOR N LOWER. THINK THAT MOST OF THIS WILL BE DIURNALLY DRIVEN SO
THINK THAT THE COUNTIES SOUTH OF THERE WILL ESCAPE WITHOUT ANY
SHOWERS TONIGHT.

TUESDAY/TUESDAY NIGHT...THE COUNTIES THAT ESCAPED THE SHOWERS WILL
PROBABLY HAVE SPRINKLES AS THE HEATING FROM THE DAY AND THE CAA
ALOFT WILL CREATE INSTABILITY (1000-850 LAPSE RATE IS 7.5C/KM) IN
THE LOW LEVELS TO GET SPRINKLES GOING. IN E UPPER DRY, AIR BEGINS TO
MIX DOWN AND THE CLOUDS WILL BEGIN TO BREAK UP. THIS TREND WILL
CONTINUE INTO THE NIGHT AS THE DRY AIR TO THE NORTH ERODES THE CLOUD
COVER DURING THE EVENING IN N LOWER.

WEDNESDAY/WEDNESDAY NIGHT...CLEAR SKIES AS THE 500 RIDGE AXIS IS
JUST TO THE WEST IN WISCONSIN AS WELL AS THE SFC AND 850 HIGHS
SITTING OVER THE GREAT LAKES.

EXTENDED...THE ENSEMBLES AND THE OPERATIONAL MODELS SEEM TO BE IN
GOOD AGREEMENT FOR THE EXTENDED PERIOD AND ARE CONSISTENT WITH
YESTERDAYS FORECAST. THE MRF SEEMS A BIT MORE PROGRESSIVE ON DAY 6
AND 7, BUT IS CLOSE ENOUGH TO THE ENSEMBLE MEANS. SO THE FORECAST
WILL LOOK LIKE THIS...MOST OF THURSDAY WILL BE PARTLY CLOUDY WITH
THE SFC HIGH MOVING OFF TO THE EAST. IN E UPPER, THE COLD FRONT
MAKES A MOVE AND LOOKS LIKE IT WOULD BE THERE LATE. N LOWER LOOKS
LIKE IT WILL STAY DRY UNTIL FRIDAY WHEN THE FRONT MOVES THROUGH THE
REST OF THE REGION. SATURDAY, THE 500 MB TROUGH AXIS MOVES THROUGH
PROVIDING SHOWERS IN THE REGION. THE 850 THERMAL TROUGH PASSES
THROUGH ON SATURDAY AS WELL SO CLOUDY SKIES AND SCATTERED SHOWERS
WOULD BE EXPECTED. SUNDAY, WILL LEAVE MOSTLY CLOUDY WITH 850
TEMPERATURES STILL AT 6C OR COLDER. MONDAY, 500 MB HEIGHTS BEGIN TO
BUILD WITH THE SFC HIGH MOVING INTO THE GREAT LAKES TO WILL GO
PARTLY CLOUDY THEN.

COORDINATED WITH MQT.

.APX...NONE.

LUTZ