FXUS63 KGRR 131932
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
232 PM EST SAT NOV 13 2004

.SHORT TERM...
TEMPS ARE THE ONLY CONCERN IN THE NEAR TERM AS DRY WEATHER UNDER SFC 
AND UPPER RIDGING IS EXPECTED. FOR TONIGHT...CLEAR SKIES AND LIGHT 
WINDS WILL LEAD TO ANOTHER COLD NIGHT. MINS ALONG THE LAKE SHORE 
WERE A FEW DEGREES BELOW GUIDANCE ONCE AGAIN...AND WITH WINDS 
EXPECTED TO BE CALM OR WEAK OFFSHORE TEMPS SHOULD ONCE AGAIN BE AS 
COLD AS INLAND TEMPS...GENERALLY IN THE LOWER 20S.

AIRMASS SLOWLY MODIFIES AND WEAK WESTERLY FLOW SHOULD RESULT IN 
MILDER OVERNIGHT LOWS ALONG THE COAST SUNDAY AND MONDAY NIGHTS. 
INLAND TEMPS SHOULD CONTINUE TO RUN AT OR SLIGHTLY BELOW GUIDANCE.

CLOUDS ON THE INCREASE TUESDAY AS RETURN FLOW BRINGS IN SOME MID 
LEVEL MOISTURE BUT PRECIP IS NOT EXPECTED UNTIL AFTER 00Z WEDNESDAY.

.LONG TERM...
12Z GFS AND ETA GUIDANCE INDICATES A SHORTWAVE WILL MOVE INTO OUR 
REGION LATE TUESDAY. WE STILL BELIEVE THE GUIDANCE IS PROBABLY 
OVERDONE WITH MOISTURE AND QPF. HOWEVER...GIVEN PRETTY STRONG PVA 
DOWNSTREAM OF THE FAIRLY VIGOROUS VORT MAX...AND AFTER COORD WITH 
SURROUNDING OFFICES...WE HAVE DECIDED TO GO WITH LOW CHC POPS FOR 
SHOWERS TUESDAY NIGHT. TIMING A SHORTWAVE THAT FAR OUT IS PRETTY 
TRICKY...BUT GFS GUIDANCE SHOWS THE SHORTWAVE AND PVA ASSOCIATED 
WITH IT WILL BE EAST OF OUR AREA BY 12Z WEDNESDAY. THEREFORE WE WILL 
GO WITH A DRY FORECAST WEDNESDAY AS H5 RIDGING GRADUALLY BEGINS TO 
NUDGE IN FROM THE WEST. 

CONSIDERABLE MEDIUM RANGE GUIDANCE DISCREPANCIES ARISE FOR LATE NEXT 
WEEK. LATEST GFS GUIDANCE IMPLIES THE UPPER LEVEL PATTERN WILL 
GRADUALLY BECOME A LITTLE MORE ZONAL WHILE ECMWF GUIDANCE SHOWS A 
SPLIT FLOW PATTERN WITH VERY STRONG SHORTWAVE COMING ONSHORE IN THE 
PAC NW LATE IN THE WEEK. REGARDLESS OF WHICH MODEL IS CHOSEN...WE DO 
NOT SEE ANY SIGNIFICANT SFC OR UPPER LEVEL WX SYSTEM ON THE HORIZON 
WHICH WOULD AFFECT OUR AREA. THEREFORE...WE WILL GO WITH A DRY 
FORECAST FOR THURSDAY AND FRIDAY AND A CHANCE OF SHOWERS SATURDAY. 
THIS IS VERY CONSISTENT WITH THE EXTENDED FORECAST OF SURROUNDING 
OFFICES TOO. 

&&

.GRR WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

OSTUNO LAURENS