Area Forecast Discussion
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000
FXPQ60 PGUM 270743
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
543 PM CHST MON APR 27 2015

.SYNOPSIS...
SATELLITE IS SHOWING SCATTERED SHOWERS AROUND GUAM AND ROTA...AND
DEVELOPING EAST OF ALL FOUR ISLANDS AS A WEAK TROUGH IN THE TRADES
SLIPS THROUGH THE MARIANAS. OTHERWISE...MODERATE TRADES PERSIST
OVER THE REGION...WITH COMBINED SEAS OF 6-7 FEET AT THE IPAN BUOY.

&&

.DISCUSSION...
A VERY WEAK TROUGH...EVIDENT IN SATELLITE IMAGERY AND IN 850 MB
UKMET WINDS...WILL MOVE EAST OF THE ISLANDS THIS EVENING AND
SHOULD TAKE MOST OF THE SHOWERS WITH IT. GFS KEEPS SHOWERS ALMOST
STRICTLY OVER GUAM AND ROTA ALL NIGHT...BUT SATELLITE SHOWS PLENTY
OF SHOWERS DEVELOPING JUST EAST OF TINIAN AND SAIPAN. BEYOND
TONIGHT...HAVE MADE SOME SIGNIFICANT CHANGES IN TIMING FOR THE
NEXT WEEK. GFS AND ECMWF AGREE FAIRLY WELL ON MID-LEVEL DRYING
TUE NIGHT THROUGH FRIDAY...RESULTING IN PARTLY CLOUDY SKIES FOR
THAT PERIOD. DEEP MOISTURE AND MOSTLY CLOUDY SKIES RETURN FRIDAY
NIGHT AND PERSIST INTO THE FOLLOWING WEEK AS AN EQUATORIAL TROUGH
PUSHES NORTH INTO THE MARIANAS. THERE COULD BE SCATTERED SHOWERS
AT TIMES DURING THAT PERIOD BUT TOO EARLY TO SAY WHEN...ESPECIALLY
AS RECENT INCONSISTENT MODEL PERFORMANCE DOES NOT INSPIRE GREAT
CONFIDENCE.

&&

.MARINE...
BUMPED SEAS UP A FOOT TONIGHT AND TUESDAY...AS SEAS HAVE BEEN A
LITTLE HIGHER THAN WW3 GUIDANCE TODAY AT THE BUOY. OTHERWISE...IT`S
STEADY AS SHE GOES WITH MODERATE TRADES AND 4-6 FT SEAS ALL WEEK.

&&

.EASTERN MICRONESIA...
OTHER THAN ONGOING ACTIVE WEATHER ACROSS THE EASTERN REGION...
GENERAL FORECAST SCENARIO REMAINS UNCHANGED. SHOWERS PASSED OVER
KOSRAE TODAY FROM CONVECTION JUST NORTHWEST. ELSEWHERE...MAJURO
AND POHNPEI SAW FAIRLY DRY CONDITIONS TODAY. NUMEROUS SHOWERS AND
ISOLATED THUNDERSTORMS HAVE PERSISTED ACROSS KWAJALEIN ATOLL AND
AREAS EAST AND WEST OF THAT ATOLL BETWEEN 8N AND 11N. 00Z GFS
INITIALIZES FAIRLY WELL WITH SATELLITE AND 00Z ASCAT PASS SHOWING
VERY LIGHT SOUTHWEST TO SOUTHEAST FLOW SOUTH OF 6N...WITH MODERATE
TO FRESH NORTHEAST TRADES NORTH OF 8N. CONVERGENCE BETWEEN THESE
AREAS IS FUELING THE HEAVY WEATHER OVER KWAJALEIN. MODELS MAINTAIN
THIS GENERAL PATTERN THE NEXT COUPLE DAYS WITH UNSETTLED CONDITIONS
PERSISTING THROUGH THE END OF THE WEEK...BUT MAINLY NORTH OF
MAJURO...KOSRAE AND POHNPEI. SHORT-TERM UPDATES ARE POSSIBLE IF
CONVECTIVE CLUSTERS DEVELOP NEAR OR OVER ANY OF THE FORECAST ZONES
THE NEXT COUPLE DAYS AS IS SEEN AT KWAJALEIN TODAY. GFS SHOWS THE
GENTLE...AT TIMES VARIABLE...WIND FLOW REACHING KOSRAE AND MAJURO
ON TUESDAY AND WEDNESDAY.

&&

.WESTERN MICRONESIA...
A BROAD CIRCULATION CENTERED NEAR YAP AT 8N137E CONTINUES TO
GENERATE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS BETWEEN KOROR
AND YAP. FORECAST INDICATES ONLY ISOLATED SHOWERS AT BOTH LOCATIONS
TONIGHT...BUT EXPECT TO SEE MORE SHOWERS TOMORROW AT KOROR THEREFORE
ADDED SCATTERED SHOWERS TO THE TUESDAY FORECAST. ISOLATED
THUNDERSTORMS WILL DEVELOP AT KOROR BY MIDNIGHT. MODELS GRADUALLY
SHIFT THE ACTIVE WEATHER NEAR YAP TOWARDS THE WEST AS THE
CIRCULATION SLOWLY TRACKS WEST. DRIER WEATHER IS EXPECTED AT BOTH
LOCATIONS FOR THE END OF THE WEEK.

AT CHUUK...A SMALL CLUSTER OF SHOWERS WILL PASS OVER THE LAGOON THIS
EVENING...WITH OTHERWISE DRY CONDITIONS PREVAILING THROUGH THE NEXT
COUPLE DAYS. LONG RANGE FORECAST HERE IS A LOW-CONFIDENCE FORECAST
BASED ON MODEL DIFFERENCES. WEAK TROUGHING THE NEXT FEW DAYS COULD
PRODUCE SOME SHOWERS THE NEXT FEW DAYS...BUT TIMING IS UNCERTAIN.
WEATHER FARTHER EAST WILL GRADUALLY HEAD WEST BUT ANTICIPATE THE
BULK OF THIS WEATHER TO KEEP JUST NORTH OF CHUUK FOR NOW.

&&

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

$$

MIDDLEBROOKE/M. AYDLETT



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