Area Forecast Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
000
FXPQ60 PGUM 020811
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
611 PM CHST THU APR 2 2015

.SYNOPSIS...
FORECAST ZONES LIE IN THE RIDGE BETWEEN TYPHOON MAYSAK OVER THE
PHILIPPINE SEA AND A DEVELOPING SYSTEM OVER POHNPEI AND KOSRAE
WHICH IS NOW THE SUBJECT OF A TROPICAL CYCLONE FORMATION ALERT.
VISIBLE AND IR SATELLITE IMAGERY INDICATE PARTLY CLOUDY SKIES
OVER THE MARIANAS.

&&

.DISCUSSION...
NO SIGNIFICANT CHANGES TO FORECAST PHILOSOPHY OR GRIDS. MODELS
INDICATE DIVERGENT SOLUTIONS WITH RESPECT TO THE DEVELOPING
SYSTEMS IN EASTERN MICRONESIA. THE GFS MODEL MOVES THE SYSTEM
GENERALLY NORTHWARD THROUGH TUESDAY. THE ECMWF MOVES THIS TROPICAL
CYCLONE GENERALLY WESTWARD THROUGH TUESDAY. UNTIL MORE IS KNOWN WE
WILL MAINTAIN A DRY BIAS IN THE FORECAST FOR THE MARIANAS THROUGH
TUESDAY.

&&

.MARINE...
THE IPAN BUOY EAST OF GUAM INDICATES COMBINED SEAS AROUND 5 FEET.
THIS BUOY IS BLOCKED FROM THE WEST SWELL WHICH WOULD MAKE THE
OVERALL COMBINED SEAS HIGHER. WATCH MODELS INDICATE COMBINED SEAS
OF 6 TO 9 FEET THROUGH MONDAY. MODERATE RIP CURRENT RISK IS
EXPECTED TO PREVAIL THROUGH MONDAY.

&&

.EASTERN MICRONESIA...
A NEAR-EQUATORIAL TROUGH EXTENDS NORTHEASTWARD FROM NEAR EQ150E
THROUGH A TROPICAL DISTURBANCE CENTERED WEST OF KOSRAE NEAR
5N160E...THEN CONTINUES EASTWARD TO END AT A WEAK DISTURBANCE NEAR
3N180. THIS SYSTEM WILL BE THE MAIN FOCUS FOR WEATHER OVER EASTERN
MICRONESIA FOR THE NEXT FEW DAYS...MAINTAINING UNSETTLED
CONDITIONS ACROSS THE REGION. MOST RECENT MODEL RUNS SHOW PLENTY
OF UNCERTAINTY IN BOTH TRACK AND INTENSITY OF THIS DISTURBANCE.
IT SHOULD BE NOTED HOWEVER THAT THE JOINT TYPHOON WARNING CENTER
HAS NOW ISSUED A TROPICAL CYCLONE FORMATION ALERT ON IT. THE GFS40
TAKES IT A BIT NORTHWESTWARD THEN RECURVES IT AS A WEAK TROPICAL
STORM. AFTER MOVING IT TO THE NORTHEAST A WAYS...THE MODEL OPENS
IT UP INTO A TROUGH AND STARTS ADVECTING IT WESTWARD TOWARD THE
MARIANAS. THE NAVGEM STARTS SIMILARLY BUT REALLY WINDS THIS ONE
UP INTO A TYPHOON. THEN...INSTEAD OF OPENING INTO A TROUGH AND
HEADING FOR THE MARIANAS...IT JUST STALLS OFF TO THE EAST AND
GRADUALLY WINDS DOWN. THE MOST SIMILAR ARE THE UKMET AND THE ECMWF-
HIRES. THESE KEEP IT SOUTH OF 10N AS A TD OR MINIMAL TS. THE LAST
BIT OF WEIRDNESS IS THAT THE ECMWF-HIRES OPENS IT UP INTO A TROUGH
THEN MORPHS THIS INTO A NEAR EQUATORIAL TROUGH ACROSS MOST OF THE
MICRONESIAN AREA. IT SEEMS THE ONLY CONSISTENT THING IS THAT IT IS
EITHER WEEK OR HEADING INTO THE MIDDLE OF NOWHERE...A BIT OF GOOD
NEWS FOLLOWING THE DAMAGE CAUSED BY MAYSAK. THIS SYSTEM HAS BROUGHT
AND WILL CONTINUE TO BRING BENEFICIAL RAINFALL TO POHNPEI...KOSRAE
AND MAJURO OVER THE NEXT COUPLE OF DAYS. THE ONLY WORRY HERE IS IF
TOO MUCH COMES TOO QUICKLY...THERE WILL BE A CHANCE OF LAND SLIDES.
AFTER A BRIEF RESPITE...TRADE-WIND CONVERGENCE ALONG THE NEAR
EQUATORIAL TROUGH WILL BRING IN MORE SHOWERS FOR KOSRAE AND MAJURO.

SEAS HAVE FALLEN BELOW 10 FEET...AND NO MAJOR WAVE EVENTS ARE
FORESEEN IN THE NUMERICAL MODELS FOR EASTERN MICRONESIA.

&&

.WESTERN MICRONESIA...
THE APPROACH OF THE TROPICAL DISTURBANCE NEAR KOSRAE IS BRINGING
MORE CLOUDS INTO CHUUK. THIS WILL LIKELY BE FOLLOWED BY AN INCREASE
IN SHOWERS LATER. IF THE CIRCULATION TENDS CLOSER TO CHUUK...SOME
PERIODS OF HEAVY RAIN COULD BE IN THE OFFING. AT ANY RATE...THERE
SHOULD BE AN INCREASE IN SHOWER COVERAGE. FOR NOW WENT WITH A
BARELY NOTICEABLE INCREASE SO JUST KEPT ALL THE PERIODS ISOLATED.
A SIGNIFICANTLY CLOSER TREND COULD REQUIRE SOME SCATTERED SHOWERS.

TYPHOON MAYSAK CONTINUES TO MOVE WEST-NORTHWESTWARD...PULLING AWAY
FARTHER FROM YAP AND PALAU. THE PERIPHERAL RIDGE HAS BUILT IN
BEHIND MAYSAK...BRINGING PARTLY CLOUDY AND DRY CONDITIONS BACK TO
BOTH YAP AND KOROR. A TRADE-WIND SURGE OVER THE WEEKEND WILL BRING
INCREASING CLOUDS AND A SLIGHT INCREASE IN SHOWERS TO YAP ON
SATURDAY AND KOROR ON SUNDAY. HOWEVER...SLIGHT WILL BE THE KEY
WORD.

SWELL GENERATED BY TYPHOON MAYSAK WILL MAINTAIN HAZARDOUS SURF
ACROSS THE REPUBLIC OF PALAU AND YAP STATE THROUGH TONIGHT. ONCE
THESE SWELLS FINISH SUBSIDING...NO MAJOR WAVE EVENTS ARE FORESEEN
IN THE NUMERICAL MODELS FOR WESTERN MICRONESIA.

&&

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

$$

DEVITA/STANKO



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.