000
FXPQ60 PGUM 230752
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
552 PM CHST MON NOV 23 2009

.SYNOPSIS...FRESH TO STRONG TRADE WINDS AND COMBINED SEAS 9 TO 10
FEET ARE THE RESULT OF A STRONG PRESSURE GRADIENT BETWEEN TROPICAL
DEPRESSION 26W EMBEDDED IN THE MONSOON TROUGH WEST OF CHUUK AND A
MODERATE RIDGE OF HIGH PRESSURE NORTH OF THE MARIANAS. SATELLITE
IMAGERY SHOWS CLOUD BANDS ASSOCIATED WITH 26W WITHIN 200 MILES OR
SO SOUTHWEST OF THE ISLANDS...WHICH RADAR IS PICKING UP AS WELL.
&&

.DISCUSSION...THE MOST SIGNIFICANT CHANGE TO THE FORECAST WAS TO
PLACE THE ENTIRE MARIANAS UNDER A SMALL CRAFT ADVISORY AND HIGH
SURF ADVISORY UNTIL THE TROPICAL CYCLONE IS FORECAST TO MOVE AWAY
FROM THE MARIANAS. WINDS AT GUAM AND SAIPAN ARE REGULARLY GUSTING
TO AROUND 25 KT...AND THE QUIKSCAT INDICATES MARINE WINDS ARE 20
TO 25 KT. WITH WINDS AND SEAS ONLY EXPECTED TO INCREASE AS TD 26W
APPROACHES THE SOUTHERN MARIANAS ITS A GOOD REASON TO HAVE A SMALL
CRAFT AND HIGH SURF ADVISORIES OUT DUE TO THE HAZARDOUS CONDITIONS.
THERE IS GOOD AGREEMENT BETWEEN THE VARIOUS MODEL FORECASTS FOR TD
26W. SO EXPECT THE CYCLONE TO MOVE NORTHWEST AND INTENSIFY AFTER AN
INITIAL PERIOD OF SLOW MOVEMENT WHILE EMBEDDED IN A MONSOON TROUGH.
&&

.MARINE...COMBINED EFFECT OF NE TRADE SWELL...WIND WAVES AND SWELL
GENERATED BY THE TROPICAL DEPRESSION WILL ALLOW SEAS TO BUILD TO
AROUND 11-12 FEET BY WEDNESDAY AND THURSDAY. WINDS AND SEAS WILL
BE HAZARDOUS FOR SMALL CRAFT AND BEACH-GOERS THE NEXT 3-4 DAYS.
&&

&&

.EASTERN MICRONESIA...
A TRADE DISTURBANCE OVER THE MARSHALLS WILL PROVIDE MAJURO WITH
SCATTERED SHOWERS THROUGH MID-WEEK. ALTHOUGH LITTLE SHOWER ACTIVITY
OCCURRED TODAY...MODELS REINVIGORATE CONVECTION TONIGHT ALONG A WEAK
TROUGH AXIS. A WEAK EMBEDDED CIRCULATION WITHIN THE MONSOON TROUGH
WILL PASS TO THE NORTH OF POHNPEI TONIGHT. CONVECTION ASSOCIATED
WITH THIS FEATURE HAS BEEN LIMITED AND MODELS SHOW EVEN LESS
ACTIVITY THROUGH TOMORROW AS RIDGING BUILDS OVER THE AREA AHEAD OF
THE NEXT DISTURBANCE CURRENTLY OVER THE MARSHALLS.

&&

.WESTERN MICRONESIA...
CONVECTION HAS CONTINUOUSLY REGENERATED OVER CHUUK TODAY WITH
CONSTANT RAINFALL THROUGH MUCH OF THE DAY. THE SLOW MOVEMENT AND
SIMULTANEOUS INTENSIFICATION OF 26W WILL PROMOTE MORE CONVECTION TO
FIRE OVER THE AREA THROUGH TOMORROW. SHOWERS SHOULD TAPER OFF
BEGINNING TUESDAY NIGHT AS 26W MOVES FURTHER NORTHWEST. MODELS ARE
IN FAIR AGREEMENT ON A DEVELOPING MONSOON TAIL ASSOCIATED WITH 26W
AS IT PASSES BETWEEN YAP AND GUAM. SCATTERED SHOWERS SHOULD DEVELOP
LATE TUESDAY INTO WEDNESDAY OVER KOROR BUT REMAIN SOUTH OF YAP UNTIL
THE WEEKEND.

FRESH TO STRONG SOUTHERLY WINDS ASSOCIATED WITH 26W CONTINUE TO
PRODUCE HAZARDOUS SEAS AND SURF ALONG SOUTH AND WEST FACING
EXPOSURES ON CHUUK. THEREFORE...CONTINUED HIGH SURF ADVISORY THROUGH
TUESDAY NIGHT...ESPECIALLY CONSIDERING THE SLOW MOVEMENT OF 26W.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...HIGH SURF ADVISORY UNTIL 10 AM CHST FRIDAY FOR GUZ001>004.

MARIANAS WATERS...SMALL CRAFT ADVISORY UNTIL 9 PM CHST THURSDAY
FOR PMZ151>154.

&&

$$

MUNDELL/WILLIAMS