Area Forecast Discussion
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FXPQ60 PGUM 250735
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
535 PM CHST FRI JUL 25 2014

.MARIANAS SYNOPSIS...
ANIMATED VISIBLE SATELLITE IMAGERY SHOWS THE MONSOON TROUGH IS
APPROACHING FROM THE SOUTH. THE TROUGH IS CURRENTLY POSITIONED
SOUTH OF GUAM NEAR 10N. A TRADE-WIND DISTURBANCE IS PUSHING
THROUGH THE FORECAST ZONES AT PRESENT. ANOTHER UPSTREAM TRADE-
WIND DISTURBANCE IS POSITIONED ROUGHLY HALFWAY BETWEEN WAKE
ISLAND AND THE MARIANAS.

&&

.DISCUSSION...
FORECAST STILL ASSUMES PASSAGE OF THE MONSOON TROUGH THROUGH THE
FORECAST ZONES DURING THE NEXT DAY OR SO. ADDED SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS THIS EVENING TO FACTOR IN THE PASSAGE
OF THE FIRST TRADE-WIND DISTURBANCE. SECOND TRADE-WIND
DISTURBANCE SHOULD TRACK TOWARD THE NORTHWEST AND MISS THE
FORECAST DOMAIN. MODEL GUIDANCE SUGGESTS MONSOONAL CONVECTION
WILL DEVELOP DURING THE FAVORED OVERNIGHT HOURS ON SATURDAY NIGHT
AND SUNDAY NIGHT...THEN CONTINUE IN EARNEST ON MONDAY AND MONDAY
NIGHT AS LOW-LEVEL CONVERGENCE IMPROVES IN STRENGTHENING MONSOONAL
LOW-LEVEL FLOW. AS 96W LIFTS NORTHWESTWARD...PERIPHERAL RIDGE TO
THE SOUTHEAST SHOULD BUILD OVERHEAD AND PROMOTE IMPROVING WEATHER
DURING THE SECOND HALF OF NEXT WEEK. WILL IGNORE SYSTEM THE GFS
BRINGS OVER THE FORECAST ZONES DURING THE MIDDLE OF NEXT
WEEK...UNLESS THIS SYSTEM BEGINS TO DEVELOP NEAR POHNPEI EARLY
NEXT WEEK AS PROGGED.

&&

.MARINE...
FOR THE TIME BEING...EXPECT MODERATE RIP CURRENT RISK TO CONTINUE
THROUGH SATURDAY...THEN SWELL GENERATED BY THE SOUTHWEST MONSOON
ON THE SOUTHEAST SIDE OF 96W WILL CAUSE SURF AND SEAS TO BUILD.
TRIMMED BACK SOUTHWEST SWELL HEIGHTS TONIGHT THROUGH SATURDAY
BASED ON MARIANAS BUOY READINGS. ADDED SOUTHWEST SWELL FROM THE
WAVE WATCH MODEL SATURDAY NIGHT THROUGH TUESDAY NIGHT FROM
BUILDING SURGE ARRIVING FROM THE PHILIPPINE SEA. DID SHAVE A FEW
FEET FROM THE SOUTHWEST SWELL HEIGHTS DURING THIS TIME FRAME FOR
NOW...BUT IF 96W DOES INTENSIFY SIGNIFICANTLY...SOUTHWEST SWELL
COULD BECOME HIGH ENOUGH TO GENERATE HAZARDOUS SURF AS EARLY AS
SUNDAY NIGHT. WILL IGNORE SWELL GENERATED TO THE EAST OF GUAM
DURING THE SECOND HALF OF NEXT WEEK BY A SYSTEM THE GFS IS
DEVELOPING NEAR POHNPEI ON SUNDAY AND MONDAY.

&&

.EASTERN MICRONESIA...
A SPECIAL WEATHER STATEMENT WAS ISSUED FOR ALL OF MICRONESIA AND
HEAVY WEATHER CONTINUES TO DEVELOP ACROSS EASTERN MICRONESIA.
ASCAT ANALYSIS SHOWS THE MONSOON TROUGH RUNS EASTWARD ALONG 8N-9N
TO THE NORTH OF POHNPEI AND KOSRAE INTO THE NORTHWESTERN RMI.
ALSO...A WEAK CIRCULATION IS CENTERED NEAR 3N168E. SATELLITE
SHOWS HEAVY CONVECTION HAS BEEN DEVELOPING ALL AROUND BOTH THE
MONSOON TROUGH AND THE CIRCULATION...WITH NUMEROUS SHOWERS AND A
FEW THUNDERSTORMS DEVELOPING UPSTREAM FROM MAJURO. SHOWERY AND
INCLEMENT WEATHER WILL CONTINUE OVER EASTERN MICRONESIA FOR THE
NEXT COUPLE OF DAYS AT LEAST. MODELS INDICATE THE MONSOON TROUGH
WILL GRADUALLY LIFT FARTHER NORTH IN THE COMING DAYS AND WEATHER
SHOULD GRADUALLY IMPROVE FOR THESE FORECAST POINTS BY NEXT WEEK.

HAZARDOUS SURF ADVISORY REMAINS IN EFFECT FOR POHNPEI AND KOSRAE
AND THOSE CONDITIONS MAY BE SLOWER TO IMPROVE THAN PREVIOUSLY
THOUGHT. THE SITUATION WILL NEED TO BE WATCHED CLOSELY.

&&

.WESTERN MICRONESIA...
A SPECIAL WEATHER STATEMENT WAS ISSUED FOR ALL OF MICRONESIA AND
JTWC INVEST AREA 96W WILL NEED TO BE WATCHED CLOSELY. ASCAT
ANALYSIS INDICATES A WEAK LOW-LEVEL CIRCULATION ASSOCIATED WITH
96W IS VERY CLOSE TO KOROR. THE MONSOON TROUGH EXTENDS EASTWARD
FROM 96W ACROSS NORTHERN CHUUK STATE. THE DEVELOPMENT OF 96W IS
THE MAIN FORECAST PROBLEM FOR KOROR AND YAP. MODELS INDICATE IT
WILL INTENSIFY AS IT LIFTS NORTHWARD ALONG WITH THE MONSOON
TROUGH. MODELS INDICATE THAT MODERATE TO STRONG SOUTHWEST WINDS
AND SHOWERY WEATHER WILL CONTINUE ON KOROR AND YAP THROUGH THE
LONGER TERM. FOR CHUUK...MONSOON-TYPE WEATHER WILL CONTINUE AND
CONDITIONS WILL BE CHANGEABLE...DEPENDING ON HOW THE ACTIVE
WEATHER OVER EASTERN MICRONESIA DEVELOPS AND MOVES IN THE COMING
DAYS.

HAZARDOUS SURF ADVISORY WAS ISSUED FOR KOROR...YAP...AND CHUUK IN
ANTICIPATION OF MODERATE TO STRONG WEST TO SOUTHWEST MONSOONAL
FLOW PERSISTING ACROSS WESTERN MICRONESIA. CONDITIONS COULD
DETERIORATE EVEN MORE IF INVEST 96W QUICKLY BECOMES MORE INTENSE.

&&

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

$$

MCELROY/SIMPSON





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