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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
539 PM CHST WED MAY 6 2015

.SYNOPSIS...
RADAR AND SATELLITE IMAGERY SHOW GENERALLY PARTLY CLOUDY SKIES
AND ONLY VERY-ISOLATED SHOWERS WITHIN AND AROUND THE MARIANAS
MARINE ZONES. SATELLITE AND STREAM LINE ANALYSIS SHOW A
CIRCULATION SOUTH OF POHNPEI 4N158E WITH EXTENSIVE CLOUD COVER.

&&

.DISCUSSION...
TRADE-WIND REGIME REMAINS IN PLACE THROUGH THE WEEKEND FOR THE
MARIANAS. THE GFS SHOWS THE AFOREMENTIONED CIRCULATION THAT IS
NOW SOUTH OF POHNPEI MOVING NORTHWEST BEGINNING ABOUT SATURDAY 
AND LOCATED SOUTHEAST OF GUAM AS A TROPICAL STORM AT ABOUT
10N148E ON MONDAY MORNING. THE ECMWF SHOWS THE SAME SYSTEM AS 
A TROPICAL DEPRESSION AT ABOUT 9N154E ON MONDAY MORNING. UNTIL
MODEL GUIDANCE SHOWS BETTER CONSENSUS IN TIMING...HAVE MAINTAINED
JUST SCATTERED SHOWERS IN THE FORECAST MONDAY NIGHT THROUGH
WEDNESDAY.

&&

.TROPICAL SYSTEMS...
TYPHOON NOUL CONTINUES TO MOVE WEST AND AWAY FROM YAP. THE TYPHOON
WARNING IS NO LONGER IN EFFECT. WINDS AND SEAS WILL GRADUALLY
SUBSIDE TONIGHT AND THURSDAY AS THE TYPHOON MOVES FARTHER AWAY
FROM THE AREA AND INTO THE PHILIPPINE SEA.

FARTHER TO THE EAST IS JTWC INVEST AREA 93W. THIS BROAD
CIRCULATION IS CENTERED NEAR 4N158E. EXTENSIVE CLOUD COVER AND
HEAVY SHOWERS ENCOMPASS MUCH OF POHNPEI AND CHUUK STATES. STRONG
WEST WINDS OF 20 TO 30 KT ARE SEEN ALONG THE EQUATOR...UP TO
AROUND 4N FROM SOUTH OF KOROR TO NEAR KAPINGAMARANGI. MODELS KEEP
THE CIRCULATION IN THE GENERAL AREA SOUTH OF POHNPEI FOR ANOTHER
DAY OR TWO BEFORE PUSHING IT UP TO THE NORTHWEST. GFS...ECMWF AND
NAVGEM MODELS SHOW SLIGHT VARIATIONS IN TIMING WHEN THE NORTHWEST
MOVEMENT BEGINS...SOMEWHERE BETWEEN FRIDAY AND SATURDAY. MODELS
HAVE BEEN QUITE CONSISTENT IN BRINGING 93W TO THE MARIANAS...
NEAR GUAM OR JUST SOUTH OF GUAM...FOR SEVERAL DAYS. ARRIVAL TIMES
RANGE FROM MONDAY TO WEDNESDAY...ALL DEPENDING ON WHEN IT BEGINS
TO MOVE OUT OF POHNPEI STATE. THE RATE OF DEVELOPMENT IS STILL
UNCERTAIN...BUT TROPICAL STORM CONDITIONS MAY BE POSSIBLE FOR SOME
OF THE MARIANAS EITHER EARLY OR MIDWEEK.

&&

.EASTERN MICRONESIA...
SPECIAL WEATHER STATEMENT WAS ISSUED FOR INVEST AREA 93W WHICH IS A 
CIRCULATION AT ABOUT 4N158E. THIS DEVELOPING CIRCULATION WILL AFFECT 
CHUUK...POHNPEI AND KOSRAE STATE TO SOME EXTENT. AREAS OF SCATTERED 
SHOWERS AND A FEW THUNDERSTORMS ARE OVER MUCH OF CHUUK...POHNPEI AND 
KOSRAE STATES THIS AFTERNOON. POHNPEI COULD RECEIVE HEAVY RAIN AT 
TIMES AND WILL BE AT RISK FOR MUDSLIDES. COMPUTER MODELS DIFFER IN 
THE DETAILS BUT INDICATE THE CIRCULATION WILL FURTHER DEVELOP AND 
START MOVING TOWARD NORTHWEST WITHIN THE NEXT FEW DAYS. THE FUTURE 
DEVELOPMENT AND TRACK OF THIS DISTURBANCE WILL NEED TO BE MONITORED 
CLOSELY.

FOR MAJURO...A DISTURBANCE IS ALSO SOUTHEAST OF MAJURO AND CAUSING 
UNSTABLE WEATHER FROM NEAR MAJURO ACROSS BUTARITARI AND TARAWA. THIS 
DISTURBANCE IS ALSO EXPECTED TO MOVE WESTWARD WITH SCATTERED SHOWERS 
MOVING ACROSS THE SOUTHERN RMI THROUGH ABOUT FRIDAY NIGHT.

&&

.WESTERN MICRONESIA...
CHUUK DISCUSSION IS INCLUDED WITH EASTERN MICRONESIA BECAUSE OF 
SIMILAR SYNOPTIC CONDITIONS.

YAP AND KOROR...TYPHOON NOUL IS MOVING WESTWARD AWAY FROM YAP
THIS AFTERNOON. IT IS EXPECTED TO TURN TOWARD THE NORTHWEST AND
MOVE AWAY FROM WESTERN MICRONESIA OVERNIGHT. THE TYPHOON WARNING
HAS BEEN CANCELLED NOW THAT NOUL HAS MOVED WELL WEST OF YAP WATERS
AND WINDS HAVE SUBSIDED SUFFICIENTLY ACROSS THE AREA. A HIGH SURF
ADVISORY IS NOW IN EFFECT DUE TO HAZARDOUS SURF. HAZARDOUS SURF
CONDITIONS AND SEAS HAZARDOUS TO SMALL CRAFT WILL PERSIST AT KOROR
OVERNIGHT...AND GRADUALLY SUBSIDE LATE THURSDAY. IMPROVING WEATHER
IS EXPECTED FOR BOTH YAP AND KOROR BY THE WEEKEND.

&&

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

$$

DEVITA/SIMPSON

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