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000
FXPQ60 PGUM 152149
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
749 AM CHST THU MAY 16 2013

.SYNOPSIS...
PGUA WSR-88D SHOWS ISOLATED SHOWERS MOVING THROUGH THE MARIANAS
WATERS...MAINLY GUAM AND SOUTHWARD. THE VAD WIND PROFILE REVEALS
GENTLE TO MODERATE TRADE WINDS WITH A FEW FRESH GUSTS THROUGH THE
LOWEST 12 THOUSAND FEET.

&&

.DISCUSSION...
SUBTROPICAL RIDGE REMAINS ANCHORED OVER THE NORTHERN MARIANAS
NORTH OF SAIPAN. THIS WILL MAINTAIN RATHER DRY WEATHER THROUGH THE
FORECAST PERIOD. WINDS AND SEAS WILL DIMINISH FOR THE WEEKEND. AN
UPPER-LEVEL LOW BETWEEN WAKE AND THE MARIANAS IS EXPECTED TO START
LIFTING NORTH AND EAST AND SHOULD NOT AFFECT THE ISLANDS. IF THE
WINDS GET LIGHT ENOUGH ISLAND THUNDER COULD BE A POSSIBILITY OVER
THE WEEKEND AND INTO NEXT WEEK.

&&

.EASTERN MICRONESIA...
A LARGE AREA OF TRADE-WIND CONVERGENCE PERSISTS OVER EASTERN
MICRONESIA. THE UPPER-LEVEL LOW THAT WAS HELPING TO ENHANCE THE
SHOWERS ALONG THE NORTHERN PORTION OF THE CONVERGENCE ZONE IS
DRIFTING NORTHWARD...AWAY FROM THE FORECAST AREA. THIS WILL HELP
DRAG THE CONVERGENCE FURTHER NORTH AS WELL. A BAND OF SHOWERS AND
THUNDERSTORMS THAT IS CURRENTLY NORTH OF POHNPEI WILL REMAIN TO THE
NORTH AND LIKELY BE PULLED FURTHER TO THE NORTH THROUGH THE DAY
TODAY. A SECOND BAND OF SHOWERS AND THUNDERSTORMS TO THE SOUTH WILL
ALSO DRIFT NORTHWARD BRINGING CONVECTION BACK TO ALL THREE FORECAST
POINTS BY THIS AFTERNOON. MODELS TEND TO AGREE THAT THIS CONVERGENCE
WILL REMAIN OVER THE REGION THROUGH THE WEEKEND. MODELS DO SHOW
PERIODS OF SCATTERED SHOWERS...BUT NONE OF THEM AGREE ON TIMING.
BASED ON THE UNCERTAINTY IN THE MODELS...CHOSE TO MAKE ONLY MINOR
SHORT TERM CHANGES TO THE PREVIOUS FORECAST.

LATEST ALTIMETRY DATA SHOWS SEAS OF SUFFICIENT HEIGHT TO CONTINUE TO
PRODUCE HAZARDOUS SURF ON EAST FACING REEFS OF KOSRAE THIS MORNING.
SURF OF AROUND 7 TO 8 FEET WILL GRADUALLY SUBSIDE THIS MORNING AND
IS EXPECTED TO FALL BELOW HAZARDOUS LEVELS BY THIS AFTERNOON.

&&

.WESTERN MICRONESIA...
TRADE-WIND CONVERGENCE IS PRODUCING SCATTERED SHOWERS OVER CHUUK
THIS MORNING. CONVERGENCE WILL REMAIN OVER THE AREA THROUGH EARLY
NEXT WEEK...KEEPING CHUUK IN A RELATIVELY MOIST PATTERN THROUGH THE
WEEKEND. A SURFACE TROUGH NEAR 147E WILL CONTINUE TO TRACK WESTWARD
TOWARD PALAU...BRINGING A HIGHER CHANCE OF CONVECTION TO KOROR
TONIGHT. THE TRADE-WIND CONVERGENCE THAT IS CURRENTLY OVER CHUUK
WILL MOVE IN BEHIND THE TROUGH AND PERSIST THROUGH THE
WEEKEND...KEEPING A HIGHER CHANCE OF SHOWERS OVER THE REGION THROUGH
THE MONDAY. YAP WILL SEE A SLIGHT INCREASE IN SHOWERS FRIDAY AND
SATURDAY...BUT THE MAJORITY OF THE PRECIPITATION WILL REMAIN TO THE
SOUTH OF THE STATE.

&&

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

$$

STANKO/KLEESCHULTE