Area Forecast Discussion
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000
FXPQ60 PGUM 190715
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
515 PM CHST FRI DEC 19 2014

.MARIANAS SYNOPSIS...
A ROBUST SHEAR LINE STRETCHES SOUTHWESTWARD OVER THE FAR NORTHERN
MARIANAS. A CLUSTER OF SHOWERS IS PASSING THROUGH GUAM WATERS BUT
THE HEAVIEST CONVECTION REMAINS SOUTH OF GUAM WATERS. RADAR WIND
PROFILE SHOWS 30 TO 35 KT NORTHEAST WINDS FROM 2000 TO 5000 FEET
WHILE SURFACE OBSERVATIONS SHOW 20 KT WITH GUSTS TO 30 KT ACROSS
THE REGION.

&&

.DISCUSSION...
FRESH TO STRONG NORTHEAST WINDS WILL PREVAIL THROUGH SATURDAY
BEFORE DIMINISHING SOMEWHAT LATE SATURDAY. MAINLY DRY CONDITIONS
ARE EXPECTED FOR THE NEXT SEVERAL DAYS AS THE SHEAR LINE STALLS
ACROSS THE FAR NORTHERN MARIANAS OVER THE WEEKEND. WINDS WILL
DECREASE A BIT SATURDAY NIGHT BUT WILL REMAIN FRESH THROUGH THE
NEXT FEW DAYS. A SECONDARY TRADE-WIND SURGE WILL INCREASE WINDS
ONCE AGAIN BY THE MIDDLE OF NEXT WEEK BUT NO MAJOR WEATHER
SYSTEMS ARE EXPECTED TO AFFECT THE MARIANAS.

&&

.MARINE...
RITIDIAN BUOY SHOWS SEAS HAVE RISEN STEADILY TODAY TO AROUND 11
FEET. A SMALL CRAFT ADVISORY REMAINS IN EFFECT AT LEAST THROUGH
WED MORNING. MOST OF THE WAVE ENERGY IS WIND WAVES BUT PERSISTENT
FRESH TO STRONG TRADE WINDS WILL CONTINUE TO BUILD A SIGNIFICANT
ENE SWELL OVER THE NEXT 36 HOURS. THIS WILL BRING SURF ON EAST
FACING SHORES VERY CLOSE TO HAZARDOUS LEVELS BY SATURDAY MORNING.
A HIGH SURF ADVISORY ISSUANCE WILL LIKELY BE NEEDED OVERNIGHT FOR
EAST FACING REEFS.

&&

.AVIATION...
WIND SHEAR COULD BE AN ISSUE OVERNIGHT ON GUAM IF SIGNIFICANT
DECOUPLING OF THE PBL OCCURS. WINDS AT THE SURFACE WOULD HAVE TO
DECREASE TO BETWEEN 10 AND 15 KNOTS FOR WIND SHEAR TO BECOME AN
ISSUE.

&&

.EASTERN MICRONESIA...
SATELLITE SHOWS SHOWERS ASSOCIATED WITH A TRADE-WIND DISTURBANCE
MOVING WESTWARD ACROSS THE DATE LINE TOWARD MAJURO AND THE TARAWA
AND BUTARITARI AREAS. A WEAK CIRCULATION NEAR 2N169E IS CAUSING
SHOWERS IN A SMALL AREA SOUTHEAST OF KOSRAE. MODELS INDICATE THE
CIRCULATION AND THE DISTURBANCE WILL MOVE WESTWARD IN THE COMING
DAYS WITH SHOWERS FOCUSED MAINLY BETWEEN 3N TO 7N. MODERATE TO
FRESH TRADE WINDS ARE DEVELOPING FOR EASTERN MICRONESIA AND
RELATIVELY WET WEATHER IS EXPECTED TO SPREAD WESTWARD...
ESPECIALLY TOWARD KOSRAE. THE HEAVIER SHOWER ACTIVITY COULD
REMAIN SOUTH OF MAJURO AND POHNPEI IF MODEL SOLUTIONS ARE
CORRECT.

RELATIVELY DRY WEATHER IS EXPECTED AT CHUUK NEXT COUPLE DAYS...
THEN SOME CLOUDINESS AND SHOWERS COULD SPREAD TOWARD CHUUK FROM
EASTERN MICRONESIA EARLY NEXT WEEK.

NORTHWEST SWELL PRODUCED BY STRONG WINDS OVER THE NORTHWEST
PACIFIC ALONG WITH LARGE TRADE-WIND SWELL AND WIND WAVES WILL
CAUSE SEA CONDITIONS TO RISE FROM CHUUK STATE EASTWARD TO THE
MARSHALL ISLANDS OVER THE NEXT FEW DAYS. CONDITIONS COULD
POSSIBLY BECOME HAZARDOUS FOR SMALL CRAFT BY SUNDAY OR MONDAY.
TRADE-WIND WAVES MAY ALSO CAUSE HAZARDOUS SURF FOR KOSRAE AND THE
MARSHALLS AS WELL. AND...WITH SPRING HIGH TIDE CYCLE STARTING
MONDAY...COASTAL INUNDATIONS ARE LIKELY ON MAJURO AND NEARBY
ATOLLS.

&&

.WESTERN MICRONESIA...
REASONING FOR THE CHUUK FORECAST IS INCLUDED UNDER THE EASTERN
MICRONESIA SECTION ABOVE DUE TO A SIMILAR TRADE-WIND PATTERN.

MODELS INDICATE A PERIOD OF MODERATE TO FRESH TRADE WINDS CAN BE
EXPECTED ACROSS WESTERN MICRONESIA. WEATHER THERE WILL BE
RELATIVELY UNSETTLED EVEN THROUGH THE LONGER TERM. SATELLITE
SHOWS SCATTERED SHOWERS AND A FEW THUNDERSTORMS SOUTH OF GUAM
BETWEEN 10N AND 12N THAT ARE MOVING WESTWARD. THE SHOWERS COULD
AFFECT YAP THE NEXT DAY OR TWO. SATELLITE ALSO SHOWS PATCHY
CLOUDS AND A FEW SHOWERS JUST WEST AND SOUTHEAST OF KOROR. MODELS
INDICATE THAT A LITTLE DRIER WEATHER WILL DEVELOP FOR KOROR THIS
WEEKEND...BUT SURGING TRADES FROM EASTERN MICRONESIA COULD
INCREASE THE CHANCE OF SHOWERS FOR BOTH YAP AND KOROR NEXT WEEK.

HAZARDOUS SURF WILL PERSIST ACROSS THE REPUBLIC OF PALAU AND YAP
STATE THRU SATURDAY EVENING AS NORTH SWELLS PRODUCED BY GALE
FORCE WINDS OVER THE NW PACIFIC CONTINUE TO AFFECT THE REGION. AS
NW SWELL COMBINE WITH TRADE-WIND SWELLS AND WIND WAVES...SEAS
WILL ALSO REMAIN HAZARDOUS FOR SMALL CRAFT UNTIL SUNDAY.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...NONE.
MARIANAS WATERS...SMALL CRAFT ADVISORY UNTIL 6 AM CHST WEDNESDAY
                  FOR PMZ151>154.

&&

$$

WILLIAMS/SIMPSON





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