Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Sun, 10 Oct 2010 02:58:02 -0500

229 
FXPQ60 PGUM 100757
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
557 PM CHST SUN OCT 10 2010

.SYNOPSIS...
PGUA WSR-88D SHOWS SCATTERED SHOWERS TO THE EAST OF THE MARIANAS
GRADUALLY MOVING CLOSER. THIS IS PART OF THE ACTIVITY ASSOCIATED
WITH AN UPPER-LEVEL TROUGH. THIS AREA INCLUDES PALAU AND YAP AS
WELL AS THE SOUTHERN MARSHALL ISLANDS AROUND MAJURO.

&&

.DISCUSSION...
AS HAS BEEN THE CASE THIS WET SEASON...THE MAJOR ACTION IS FROM
THE TROPICAL UPPER TROPOSPHERIC TROUGH /TUTT/. THERE IS A WEAK
MONSOON TROUGH SOUTH OF US...THE WEAKEST I HAVE SEEN IN ALL MY
TIME HERE. AT LEAST WE GOT SOMETHING THOUGH. MID LATITUDE EVENTS
ARE SNEAKING CLOSER ALL THE TIME...REACHING SOUTH OF TAIWAN NOW.
IT WILL NOT BE MUCH LONGER AND WE WILL BE MENTIONING SHEAR LINES
IN OUR PRODUCTS. TROPICAL SEASON IS WINDING DOWN. SINCE MOST OF
THE TUTT CONVECTION IS STILL EAST OF US...EXTENDED THE WEATHER A
BIT INTO MONDAY MORNING. OTHERWISE FORECAST LOOKED EXCELLENT SO
NO OTHER CHANGES WERE NECESSARY.

&&

.EASTERN MICRONESIA...
AN ITCZ IS PERSISTING ALONG 7N FROM CHUUK EASTWARD TO THE
MARSHALL ISLANDS...THEN EXTENDS NORTHEASTWARD THROUGH THE DATE
LINE TO SOUTH OF HAWAII. IMPULSES TRACKING WESTWARD ALONG THE
CONVERGENCE ZONE WILL TRIGGER PERIODS OF SHOWERS FROM CHUUK
EASTWARD TO KOSRAE INTO MIDWEEK. MAJURO HAS BEEN AT THE STRONGER
CONVERGENCE ZONE BETWEEN TRADE SURGES BOTH FROM THE NORTH AND
SOUTH. NEARLY ONE AND A HALF INCHES OF RAIN HAVE FALLEN UPON
MAJURO SINCE THIS MORNING. AN ADDITIONAL HALF TO AN INCH IS
POSSIBLE BY MONDAY MORNING. THEN THE SW TO NE ORIENTATION OF THE
ITCZ EAST OF THE DATE LINE WILL CAUSE THE CONVERGENCE ZONE TO
SHIFT NORTH OF MAJURO AND BRING IN IMPROVING CONDITIONS BY MONDAY
NIGHT. THIS SAME DRYING TREND IS EXPECTED TO SLIDE WESTWARD FROM
KOSRAE TO CHUUK AFTER MIDWEEK. FINALLY... INCREASING DIVERGENT
WINDS ALOFT MIGHT INTRODUCE SHOWERS BACK TO THE MARSHALLS TOWARD
THE WEEKEND.

&&

.WESTERN MICRONESIA...
A MARGINAL MONSOON TROUGH IS STRETCHING EASTWARD FROM THE
SOUTHERN PHILIPPINES ACROSS JUST NORTH OF PALAU AND YAP...THEN
TURNS NORTHEASTWARD TO THE MARIANAS. WEAK CONVERGING SOUTH WINDS
BETWEEN THE TROUGH AXIS AND A SURFACE RIDGE FARTHER SOUTH WILL
CONTINUE TO COUPLE WITH MODERATE UPPER-LEVEL DIVERGENCE TO FIRE
UP ISOLATED TO WIDELY SCATTERED CONVECTION FOR BOTH LOCATIONS
THRU TUESDAY NIGHT. SOME OF THIS CONVECTION CAN BECOME SCATTERED
DURING THIS DURATION... FUTURE SHIFTS WILL NEED TO MONITOR THIS
SITUATION. MODERATE TO FRESH TRADES CURRENTLY NEAR THE DATE LINE
SHOULD GRADUALLY PUSH THE MONSOON TROUGH NORTHWESTWARD DURING
MIDWEEK. THIS WILL ALLOW THE SURFACE RIDGE SOUTH OF PALAU AND YAP
TO TAKE CONTROL OF THE AREA AND PROMOTE PARTLY CLOUDY SKIES
TOWARD THE WEEKEND.

&&

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

$$

STANKO/CHAN

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
To unsubscribe from WX-TROPL send e-mail to [email-masked] with
"unsub wx-tropl" in the body of your message. For help with WX-TROPL
write to [email-masked]. For more information on tropical weather products, see the NHC Homepage at http://www.nhc.noaa.gov.