000
FXUS63 KGRR 052005
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
400 PM EDT FRI SEP 5 2008

LATEST UPDATE...ALL SECTIONS BUT AVIATION...

.SYNOPSIS...(400 PM EDT FRI SEP 5 2008)
AN UPPER LEVEL TROUGH OF LOW PRESSURE COVERING THE MID SECTION OF
THE NATION WILL RESULT IN A SOMEWHAT UNSETTLED WEATHER PATTERN
THROUGH EARLY NEXT WEEK. DISTURBANCES PASSING THROUGH THIS UPPER
TROUGH WILL LEAD TO PERIODIC EPISODES OF SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS. HOWEVER PRECIPITATION AMOUNTS WILL BE MOSTLY
UNDER ONE HALF INCH AND SCATTERED IN NATURE.

&&

.SHORT TERM...(400 PM EDT FRI SEP 5 2008)
(TONIGHT THROUGH SUNDAY NIGHT)
MUCH OF THE CLOUDINESS LINGERING AROUND THE AREA THIS AFTERNOON
APPEARS DIURNALLY DRIVEN AND SHOULD TEND TO DECREASE AFTER SUNSET.
WINDS WILL ALSO BE DIMINISHING WITH WEAK HIGH PRESSURE BUILDING
IN... WHICH COULD SET THE STAGE FOR SOME FOG FORMATION ESPECIALLY
CONSIDERING ALL THE RAIN WHICH HAS RECENTLY FALLEN. NOT SURE JUST
HOW WIDESPREAD OR DENSE THE FOG MAY GET... BUT WILL INCLUDE PATCHY
FOG IN THE GRIDS AFTER 06Z.

SHORTWAVE DISTURBANCE CURRENTLY SEEN OVER THE CENTRAL AND SRN PLAINS
IN BASE OF BROAD LONGWAVE TROUGH WILL HEAD TO THE NORTHEAST TONIGHT
AND SATURDAY. HAVE MAINTAINED POPS FOR SHOWERS ON SATURDAY IN NRN
PORTIONS OF THE CWFA TO ACCOUNT FOR THE TRACK/EXTRAPOLATION OF THIS
FEATURE.

THE H5 VORT PATTERN SHOWN BY THE MODELS WITHIN THE LONGWAVE TROUGH
IS VERY NOISY AND THE TIMING/LOCATION OF SUBSEQUENT SHORTWAVES TO
IMPACT THE REGION AFTER SATURDAY IS VERY DIFFICULT. FOR THAT REASON
WILL CARRY POPS IN EACH PERIOD. POPS SHOULD INCREASE WITH TIME
HOWEVER AS THE ENTIRE LONGWAVE TROUGH MIGRATES SLOWLY EAST AND A
FRONTAL BOUNDARY APPROACHES FROM THE WEST. THIS FRONT LOOKS TO
SLOW/STALL SUNDAY NIGHT FROM SRN LWR MI TO THE SRN PLAINS.

&&

.LONG TERM...(400 PM EDT FRI SEP 5 2008)
(MONDAY THROUGH FRIDAY)
THE ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE EXTENDED
PERIOD. WE/LL SEE THE POSSIBILITY OF RAIN MONDAY AND ESPECIALLY
MONDAY NIGHT WHEN A LOW IS PROGD TO RIDE ALONG A FRONTAL BOUNDARY TO
THE SOUTH AND MOVE ACROSS NRN INDIANA. ALONG WITH THE SFC WAVE THERE
IS ALSO A SHARP UPPER TROUGH TO HELP IN PCPN PRODUCTION. DUE TO WEAK
INSTABILITY...MORE SHRA THAN TSRA ARE EXPECTED. DRY WX RETURNS TUE
AND WED NIGHT BEFORE A WARM FRONT TRIES TO COME BACK NORTH THURSDAY
AHEAD OF ANOTHER APPROACHING COLD FRONT THAT IS CURRENTLY PROGD TO
MOVE THROUGH FRIDAY. WE/LL HAVE TSRA IN THE GRIDS TO ACCOUNT FOR
BOTH OF THE FRONTS. TEMPS WILL REMAIN NEAR NORMAL WITH HIGHS AROUND
70 AND LOWS IN THE 40S AND 50S.

&&

.MARINE...(400 PM EDT FRI SEP 5 2008)
THE LAKE GOT STIRRED UP PRETTY WELL TODAY IN CYCLONIC FLOW/COLD
ADVECTION PATTERN BEHIND THE DEPARTING SYSTEM. WILL LET THE SMALL
CRAFT ADVISORY RUN THROUGH 6 PM BUT SFC RIDGING BUILDING IN SHOULD
LEAD TO RELATIVELY TRANQUIL CONDITIONS FOR THE OVERNIGHT PERIOD AND
FOR MOST OF THE WEEKEND FOR THAT MATTER.

&&

.AVIATION...(131 PM EDT FRI SEP 5 2008)
LOOK FOR IMPROVING CIGS ACROSS THE TAF SITES THROUGH THE AFTERNOON.
VFR CONDITIONS WILL SPREAD FROM NW TO SE. VISIBLE SATELLITE IMAGERY
SHOWS A CLEARING LINE CURRENTLY EXTENDING FROM NEAR CADILLAC SW TO
GRAND HAVEN MOVING STEADILY SE. SKIES WILL SCATTER OUT AROUND
SUNSET. VFR CONDITIONS THEN EXPECTED THROUGH 18Z SAT.

&&

.HYDROLOGY...(400 PM EDT FRI SEP 5 2008)
MAX RAINFALL FROM GUSTAV WAS 3-5 INCHES ALONG THE LAKESHORE BETWEEN
SOUTH HAVEN AND WHITEHALL... EAST NORTHEAST FROM THERE ACROSS GRAND
RAPIDS AND NEWAYGO AND INTO BIG RAPIDS AND GREENVILLE. AMOUNTS
TAPERED OFF RAPIDLY SOUTHEAST OF A LINE FROM BATTLE CREEK TO ALMA
WHERE LESS THAN ONE INCH WAS REPORTED.

THERE HAVE BEEN A FEW REPORTS OF STANDING WATER IN YARDS AND A FEW
SMALLER CREEKS AND STREAMS OUT OF THEIR BANKS... BUT IN GENERAL NO
SERIOUS FLOODING HAS BEEN REPORTED DUE TO THE EXTREMELY DRY
CONDITIONS PRECEDING THIS EVENT. NONE OF THE RIVER FCST POINTS ARE
FCST TO REACH FLOOD STAGE OVER THE NEXT FEW DAYS.

RAINFALL AMOUNTS OVER THE WEEKEND ARE EXPECTED TO BE MOSTLY BELOW
ONE HALF INCH AND SCATTERED IN NATURE. THIS SHOULD HAVE LITTLE OR NO
IMPACT ON THE CURRENT HYDRO SITUATION. ANY HIGHER AMOUNTS WOULD
LIKELY BE VERY ISOLATED.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SCA ST. JOSEPH TO MANISTEE THROUGH 22Z TODAY.

&&

$$

SYNOPSIS:     MEADE
SHORT TERM:   MEADE
LONG TERM:    93
MARINE:       MEADE
AVIATION:     93
HYDROLOGY:    MEADE

NWS GRR Office Area Forecast Discussion