Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Mon, 11 Oct 2010 01:10:05 -0500

152 
FXPQ60 PGUM 110609
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
409 PM CHST MON OCT 11 2010

.SYNOPSIS...A WEAK CIRCULATION IS LOCATED NEAR GUAM AND AN UPPER-
LEVEL LOW IS CENTERED NORTHWEST OF THE MARIANAS NEAR 19N143E.
SCATTERED SHOWERS ARE MOVING ACROSS THE LOCAL AREA MAINLY NEAR
GUAM AND ROTA.

&&

.DISCUSSION...RADAR AND SATELLITE LOOPS PLUS LOCAL OBSERVATIONS CLEARLY
SHOW A WEAK CIRCULATION JUST NORTHWEST OF GUAM THIS AFTERNOON. GFS
SEEMS TO HANDLE THIS BEST AND SHOW THAT IT WILL DRIFT SLOWLY WEST
DURING THE NEXT 24 HOURS. THE UPPER-LEVEL LOW TO THE NORTHWEST IS
PROBABLY ENHANCING THE SHOWER ACTIVITY ACROSS THE MARIANAS AS
WELL. KEPT FORECAST BASICALLY AS IS WITH JUST SMALL ADJUSTMENTS TO
THE WIND FORECAST TO REFLECT ACTUAL OBSERVATIONS. IT IS POSSIBLE
THAT THE SCATTERED SHOWERS WILL NOT LAST ALL THE WAY UNTIL TUESDAY
NIGHT...BUT THE SYSTEM OVER THE AREA IS SLOW TO MOVE AND POORLY
ORGANIZED SO THOUGHT BEST TO NOT TAMPER WITH THE FORECAST. DRIER
WEATHER IS EXPECTED THE SECOND HALF OF THE WEEK.

&&

.MARINE...
EAST TO NORTHEAST TRADE-WIND SWELL OF ABOUT FOUR FEET IS EXPECTED
THROUGH THE WEEK. WW3 HAD TWO SWELLS MOVING THROUGH THE AREA
WEDNESDAY AND THURSDAY...ONE FROM THE EAST AND ANOTHER FROM THE 
NORTH-NORTHEAST. BLENDED THE TWO TOGETHER TO ARRIVE AT A
NORTHEAST SWELL FOR THOSE DAYS. THIS DOES NOT REALLY CHANGE THE
SURF FORECAST AND EXPECT A LOW RISK OF RIP CURRENTS THROUGH THE WEEK.

&&

.EASTERN MICRONESIA...
SCATTERED SHOWERS QUICKLY PASSED BY KOSRAE TODAY AND REACHED
POHNPEI A LITTLE AHEAD OF SCHEDULE. HOWEVER...SATELLITE IMAGERY
SHOWS THAT SHOWERS WILL CARRY ON A FEW MORE HOURS BEFORE
DISSIPATING AND MOVING FARTHER WEST. MODELS STILL REMAIN
UNCERTAIN ABOUT JUST HOW MUCH OF AN EFFECT THE NEXT TROUGH...NOW
NORTHEAST OF MAJURO AND CROSSING THE DATE LINE...WILL HAVE ON
EASTERN MICRONESIA. MODELS DO INDICATE THAT THE MAJORITY OF
SHOWERS SHOULD REMAIN NORTH OF ALL LOCATIONS THROUGH THE WEEK.

&&

.WESTERN MICRONESIA...
CHUUK SITS IN A REGION OF FAIRLY LIGHT WINDS...BUT THE SYSTEM
THAT BROUGHT SCATTERED SHOWERS TO POHNPEI THIS MORNING SHOULD
ARRIVE LATER TONIGHT. GFS CONTINUES SHOWERS FOR CHUUK THROUGH
TUESDAY NIGHT WHILE ECMWF HOLDS ON SLIGHTLY LONGER INTO
WEDNESDAY. THE SHORTER PERIOD OF SCATTERED SHOWERS SEEMS MOST
LIKELY BASED ON SATELLITE OBSERVATIONS. A WEAK MONSOON TROUGH
NORTH OF YAP AND PALAU IS KEEPING MORE SHOWERS FOCUSED JUST NORTH
OF THE TWO LOCATIONS. RECENT SATELLITE IMAGERY SHOWS SHOWERS HAVE
DROPPED SOUTH A BIT SO HAVE ADJUSTED THE YAP FORECAST TO
FOLLOW...BUT PALAU SHOULD SUFFICE WITH ISOLATED SHOWERS...BUT A
FEW SHORT PERIODS OF SCATTERED SHOWERS IS NOT OUT OF THE QUESTION
OVERNIGHT. MODELS FORM A WEAK CIRCULATION NORTHWEST OF THE TWO
LOCATIONS OVER THE NEXT COUPLE OF DAYS...BUT THEY KEEP ASSOCIATED
CONVECTION WELL NORTH WITH SURFACE RIDGING KEEPING SHOWERS TO A
MINIMUM.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...NONE.
MARIANAS WATERS...NONE.
&&

$$

ZIOBRO/W. AYDLETT

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