Area Forecast Discussion
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000
FXPQ60 PGUM 281940
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
540 AM CHST TUE JUL 29 2014

.MARIANAS SYNOPSIS...
JTWC WARNED ON TROPICAL DEPRESSION 11W WHICH IS NEAR 12N149E AND
MOVING SLOWLY TOWARD WEST-NORTHWEST. WE ISSUED THE FIRST PUBLIC
ADVISORY AT 100 AM. RADAR SHOWS AREAS OF RAIN OVER SOUTHERN AND
FAR EASTERN PARTS OF THE COVERAGE AREA AND SATELLITE SHOWS HEAVY
CONVECTION ASSOCIATED WITH TD 11W IS ABOUT 150 MILES SE OF GUAM
AND EDGING OUR WAY. RITIDIAN AND SAIPAN BUOYS SHOW COMBINED SEAS
NEAR 8 FT MAINLY FROM SOUTHWEST.

&&

.DISCUSSION...
TRACKING TD 11W WILL DOMINATE OUR WEATHER IN THE COMING DAYS AND
WATCHES AND/OR WARNINGS MAY BE NEEDED FOR THE MARIANAS BY LATER
TODAY. THIS MORNINGS FORECAST WAS BASED ON GRIDS THAT WERE ADAPTED
FROM THE JTWC FORECAST OF TRACK AND INTENSITY WHILE RESTRICTING THE
ACTUAL CONDITIONS TO JUST BELOW TROPICAL STORM FORCE. MOST MODELS
HAVE SIMILAR IDEAS ABOUT 90W MOVING ROUGHLY TOWARD NORTHWEST BUT
DIFFER SIGNIFICANTLY IN ITS EXACT TRACK AND INTENSITY. THE GENERAL
TREAD IS FOR TD 11W TO GRADUALLY INTENSIFY...AND THE CENTRAL TRACK
SHOULD MOVE SOMEWHERE CLOSE TO/OR THROUGH THE LOCAL FORECAST ZONES
BY ABOUT WEDNESDAY EVENING.

&&

.MARINE/TROPICAL SYSTEMS...
HAZARDOUS SURF ADVISORY REMAINS IN EFFECT. SMALL CRAFT ADVISORY WILL
LIKELY BE NEEDED LATER TODAY. SOME MODELS DIFFER BUT THE MOST LIKELY
SCENARIO THAT WE NEED TO ACCOUNT FOR IS THAT 11W WILL MOVE INTO OUR
MARINE ZONES WEDNESDAY AS A TROPICAL DEPRESSION THAT IS GRADUALLY
INTENSIFYING INTO A TROPICAL STORM. MANY ADJUSTMENTS AND EDITS WERE
NEEDED TO MAKE THE MARINE GRIDS COHERENT WITH THAT SCENARIO. THE DAY
SHIFT SHOULD BE BETTER ABLE TO MAKE DECISIONS ABOUT THE NEED FOR
WATCHES AND WARNINGS IN OUR FORECAST AREA BASED ON HOW TD 11W HAS
DEVELOPED AND MOVED DURING THE OVERNIGHT HOURS.

&&

.EASTERN MICRONESIA...
TROPICAL DEPRESSION 11W CENTERED NORTH-NORTHWEST OF CHUUK AT 12N149E
CONTINUES TO MOVE SLOWLY TOWARD THE WEST-NORTHWEST. DRIER WEATHER
CONTINUES TO BUILD IN ACROSS KOSRAE...POHNPEI AND CHUUK AS 11W
MOVES AWAY. FARTHER EAST...IR SATELLITE SHOWS SCATTERED SHOWERS
AND A FEW THUNDERSTORMS ACROSS THE MARSHALL ISLANDS JUST WEST OF
MAJURO. MODELS TAKE THIS WEAK DISTURBANCE WESTWARD...PASSING JUST
NORTH OF KOSRAE AND POHNPEI NEXT COUPLE DAYS. LIGHT WINDS...PARTLY
CLOUDY SKIES AND ISOLATED SHOWERS ARE EXPECTED AT KOSRAE...POHNPEI
AND CHUUK THE NEXT FEW DAYS. MODELS SHOW NO MAJOR WEATHER FEATURES
ACROSS THE REGION WITH THE EXCEPTION OF PERSISTENT LOW-LEVEL
CONVERGENCE NEAR MAJURO. SOME CLOUDS AND SHOWERS MAY SPREAD ACROSS
KOSRAE AND POHNPEI TOWARDS THE END OF THE WEEK AS THE AREA OF WEAK
CONVERGENCE SHIFTS WEST.

&&

.WESTERN MICRONESIA...
CHUUK WEATHER DISCUSSION IS INCLUDED IN THE EASTERN MICRONESIA
DISCUSSION DUE TO SIMILAR REASONING.

THE MONSOONAL DISTURBANCE WELL NORTH-NORTHWEST OF KOROR CONTINUES TO
PULL AWAY FROM YAP AND KOROR. IR SATELLITE SHOWS IMPROVING WEATHER
CONDITIONS AT BOTH LOCATIONS. FRESH SOUTHWEST WINDS WILL PERSIST
TODAY. WINDS WILL BEGIN TO WEAKEN TONIGHT AT BOTH LOCALES WHILE
PLEASANT WEATHER PERSISTS. RIDGING WILL KEEP FAIR WEATHER IN PLACE
AT LEAST THROUGH THURSDAY. MODELS STILL SHOW ENHANCED SOUTHWEST
WINDS LATER IN THE WEEK AT YAP IN RESPONSE TO DEVELOPING TROPICAL
DEPRESSION 11W NEAR THE MARIANAS. INCREASED WINDS...CLOUDS AND
SHOWERS ARE POSSIBLE FRIDAY AND SATURDAY AT YAP DEPENDING ON THE
EXACT TRACK OF TD 11W.

LINGERING MONSOONAL SWELL WILL MAINTAIN HAZARDOUS SEAS FOR SMALL
CRAFT UNTIL TUESDAY NIGHT...AND HIGH SURF THRU WEDNESDAY FOR THE
REPUBLIC OF PALAU AND YAP STATE. SURF HAS FALLEN BELOW HAZARDOUS
LEVELS AT CHUUK.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...HIGH SURF ADVISORY UNTIL 6 PM CHST THURSDAY FOR GUZ001>004.

MARIANAS WATERS...NONE.
&&

$$

SIMPSON/M. AYDLETT





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