Area Forecast Discussion
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FXPQ60 PGUM 302047
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
647 AM CHST MON AUG 31 2015

.SYNOPSIS...LIGHT EAST WINDS AND A FEW SHOWERS PREVAIL ACROSS THE
MARIANAS THIS MORNING. LIGHT WINDS AND ISOLATED SHOWERS AND
THUNDERSTORMS IS EXPECTED THROUGH TUESDAY NIGHT.

&&

.DISCUSSION...
LITTLE CHANGE MADE TO THE FORECAST. SCATTEROMETER DATA FROM LAST
NIGHT DEPICTED A MONSOON TROUGH STRETCHING ACROSS MUCH OF THE
WESTERN PACIFIC. THIS MORNING THE TROUGH IS LOCATED SOUTH OF GUAM.
THE TROUGH IS PREDICTED TO REMAIN JUST SOUTH OF GUAM THROUGH AT
LEAST MID-WEEK.

LIGHT EAST WINDS PREVAIL ACROSS THE MARIANAS NORTH OF THE TROUGH.
DEEP LAYER MOISTURE HAS INCREASED ACROSS THE AREA OVER THE LAST
24 HOURS. THIS MOISTURE COMBINED WITH LOW-LEVEL CONVERGENCE NORTH
OF THE TROUGH WILL GENERATE MOSTLY CLOUDY SKIES...ON AND OFF
SHOWERS AND ISOLATED THUNDERSTORMS THROUGH AT LEAST TUESDAY NIGHT.

&&

.MARINE...
RITIDIAN AND SAIPAN BUOY DATA SHOWS SEAS ARE AROUND 5 FEET. THE
NORTH SWELL STILL PERSIST BUT HAS DECREASED SINCE YESTERDAY. THE
BUOYS SHOW A NORTH SWELL OF 3 TO 5 FEET WITH A PERIOD OF AROUND 13
SECONDS. EXPECT A SURF HEIGHT OF 5 TO 7 FEET ON NORTH AND EAST
FACING REEFS. THIS SURF HEIGHT IS BELOW HAZARDOUS LEVELS AND HAVE
CANCELED THE HIGH SURF ADVISORY.

&&

.EASTERN MICRONESIA...
A MONSOON TROUGH STRETCHES EAST-SOUTHEASTWARD FROM NEAR 15N130E
THROUGH A WEAK CIRCULATION CENTERED WEST OF THE MARIANAS NEAR
13N141E TO BEYOND THE DATE LINE AT 8N. A BAND OF CONVERGENCE TO THE
SOUTH OF THE TROUGH IS PRODUCING SCATTERED TO NUMEROUS SHOWERS TO
THE SOUTH OF MAJURO AND EAST OF KOSRAE THIS MORNING. MODEL GUIDANCE
PUSHES THE TROUGH FURTHER NORTHWARD OVER THE COMING DAYS...DRAGGING
THE SHOWERS ALONG WITH IT. DUE TO POOR INITIALIZATION WITH THE
SHOWERS...CHOSE TO MAINTAIN PREVIOUS FORECAST FOR ISOLATED SHOWERS
AND A SLIGHT CHANCE OF THUNDER. THE GFS40 SHOWS A WEAK CIRCULATION
DEVELOPING NEAR MAJURO BY MONDAY EVENING...THEN MOVING OUT TO THE
NORTHWEST. IF THIS OCCURS...THE FOCUS OF SCATTERED SHOWERS WILL
SHIFT NORTHWARD...AFFECTING MAJURO. IF THE CIRCULATION DRIFTS
NORTHWESTWARD AS THE MODELS PREDICT...THE BAND OF SHOWERS WILL ALSO
DRIFT NORTHWESTWARD AND COULD BRING SCATTERED SHOWERS TO MAJURO
WITHIN THE NEXT 24 HOURS. AS THE SYSTEM PROGRESSES...CONDITIONS WILL
BEGIN TO DETERIORATE AT KOSRAE AND POHNPEI AS WELL...THOUGH NOT TO
THE DEGREE AS WHAT WILL OCCUR AT MAJURO. THIS SITUATION WILL NEED TO
BE MONITORED CLOSELY FOR THE NEXT COUPLE OF DAYS TO DETERMINE IF
SHOWERS WILL INCREASE TO SCATTERED ANY TIME THROUGH THE WEEK. EITHER
WAY...DRIER CONDITIONS ARE EXPECTED TO RETURN TO MAJURO
WEDNESDAY...KOSRAE THURSDAY AND FINALLY POHNPEI FRIDAY.

&&

.WESTERN MICRONESIA...
MODEL GUIDANCE SHOWS THE LOW-LEVEL CONVERGENCE SOUTH OF THE MONSOON
TROUGH IS STILL LIKELY TO PRODUCE SHOWERS AND THUNDERSTORMS OVER YAP
STATE AND PALAU BEGINNING THIS AFTERNOON. LATEST SATELLITE IMAGERY
SHOWS THE SHOWERS HAVE DECREASED BOTH IN INTENSITY AND AERIAL
COVERAGE. BASED ON CURRENT INFORMATION...CHOSE TO DELAY THE ONSET OF
SCATTERED SHOWERS UNTIL NOON AT KOROR. OTHERWISE...NO CHANGES TO
INHERITED FORECAST AS MODELS ARE STILL LEANING TOWARD SHIFTING THE
ACTIVE WEATHER SOUTHWARD TOWARDS KOROR WITH SCATTERED SHOWERS
EXPECTED LATER TODAY THROUGH TUESDAY NIGHT.

A WEAK WEST TO SOUTHWEST FLOW REMAINS IN PLACE OVER CHUUK THIS
MORNING. RIDGING WILL AID IN KEEPING A MOSTLY DRY WEATHER PATTERN
THERE FOR THE NEXT SEVERAL DAYS BEFORE SHOWER ACTIVITY INCREASES
LATER IN THE WEEK.

&&

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

$$

ZIOBRO/KLEESCHULTE



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