253
FXPQ50 PGUM 110838
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
638 PM CHST SUN MAY 11 2025
MARIANAS SYNOPSIS
A RED FLAG WARNING REMAINS IN EFFECT THROUGH AT LEAST MONDAY
AFTERNOON. SATELLITE IMAGERY SHOWS ISOLATED SHOWERS. RITIDIAN BUOY
SHOWS COMBINED SEAS OF ABOUT 4 FEET.
DISCUSSION
THE DRY TRADE-WIND REGIME REMAINS INTACT AND IS EXPECTED TO CONTINUE
THROUGH MONDAY. THE TIME HEIGHTS STILL HAVE A FAIRLY DRY MID LEVEL
THROUGH THIS UPCOMING WEEK EXPECTED FOR TUESDAY. A TRADE-WIND TROUGH
IS ANTICIPATED TO INJECT SOME MOISTURE INTO THE REGION AND MAY BE
ENOUGH TO SPARK SOME SHOWERS. THE WINDS ARE EXPECTED TO INCREASE
WHILE THIS FEATURE PASSES THROUGH THE REGION. ONCE THIS TROUGH PASSES
THE DRY TRADE WINDS WILL RETURN.
MARINE
MAINLY MODERATE TRADE WINDS WILL BRIEFLY BUILD TO MODERATE TO FRESH
WINDS FOR MONDAY NIGHT AND TUESDAY, THEN WILL FALL BACK TO MODERATE
FOR THE REMAINDER OF THE WEEK. COMBINED SEAS OF 4 TO 6 FEET WILL
BUILD TO BETWEEN 5 AND 8 FEET AROUND MONDAY NIGHT AS A EAST-
NORTHEAST SWELL MOVES THROUGH THE REGION. THE SECONDARY SWELL IS
ANTICIPATED TO DIMINISH BY THE WEEKEND. SEA CONDITIONS WILL REMAIN
BENIGN THROUGH THE PERIOD.
FIRE WEATHER
0.06 INCHES OF RAIN HAS FALLEN SO FAR TODAY AT THE GUAM
INTERNATIONAL AIRPORT. THE KBDI REMAINS AT 730, WHICH IS IN THE
EXTREME CATEGORY DUE TO DAYTIME WINDS OF 15 TO 20 MPH. TERRAIN
FORCING OF WINDS AND OCCASIONAL GUSTS COULD MAKE FIRE FIGHTING
DRASTICALLY HARDER. THE FIRE DANGER IS EXPECTED TO BECOME CRITICAL
DURING THE DAYTIME HOURS, WITH AFTERNOON RELATIVE HUMIDITIES
EXPECTED TO DROP BELOW 60 PERCENT, AND ELEVATED WINDS, ESPECIALLY
IN HIGHER TERRAIN. A WETTING RAIN IS NOT EXPECTED FOR AT LEAST THE
NEXT SEVERAL DAYS, AND THE KBDI IS EXPECTED TO CONTINUE TO RISE.
EASTERN MICRONESIA
A SEASONAL TRADE-WIND REGIME IS EXPECTED TO CONTINUE AT ALL THREE
FORECAST LOCATIONS FOR THE NEXT DAY OR SO. OCCASIONAL UPTICKS IN
SHOWER COVERAGE ARE EXPECTED THROUGH WEDNESDAY, FOLLOWED BY A RETURN
OF CONSISTENTLY PATCHY SHOWERS AND ELEVATED WINDS ONCE A CONVERGENCE
ZONE REBUILDS IN THE SECOND HALF OF THE WEEK.
COMBINED SEAS OF 5 TO 7 FEET NEAR POHNPEI AND KOSRAE, AND 6 TO 8 FEET
NEAR MAJURO, ARE EXPECTED TO PERSIST AS SUCH FOR MUCH OF THE WEEK,
BEFORE TAPERING DOWN SLIGHTLY BY THE WEEKEND.
WESTERN MICRONESIA
A NEAR-EQUATORIAL TROUGH (NET) IS GENERATING SEVERAL POCKETS OF
MODERATE TO DEEP CONVECTION ACROSS THE REGION. SCATTEROMETRY DATA
SHOWS A VERY WEAK CIRCULATION EMBEDDED IN THE NET BETWEEN ANGUAR AND
SONSOROL IN PALAU. THIS AND A TRADE-WIND TROUGH EXTENDING TO THE
NORTHWEST ARE FOCUSING SOME CONVECTION NEAR THE MAIN ISLANDS OF PALAU
THIS AFTERNOON, WITH SCATTERED SHOWERS AND A FEW THUNDERSTORMS
MAINLY TO THE WEST AND SOUTH, BUT A BATCH OF SHOWERS IS ALSO
LINGERING TO THE EAST OF COASTAL WATERS. ACCORDING TO MODEL
GUIDANCE, THIS VORTICITY FEATURE IS EXPECTED TO ERODE FAIRLY QUICKLY
AS THE NET SHIFTS SLIGHTLY SOUTHWARD. KEPT SCATTERED SHOWERS IN FOR
PALAU TONIGHT BASED ON SATELLITE TRENDS, BUT EXPECTING TO SEE SHOWER
COVERAGE TREND DOWN TO ISOLATED FOR BRIEF PERIOD MONDAY. ONLY PARTLY
CLOUDY SKIES AND SPOTTY SHOWS CONTINUE NEAR YAP THROUGH MONDAY NIGHT.
THEN THE NET IS EXPECTED TO GRADUALLY DEVELOP, GENERATING UNSETTLED
WEATHER IN FAR WESTERN MICRONESIA STARTING TUESDAY.
MODERATE CONVECTION SPANS ACROSS MUCH OF CENTRAL MICRONESIA, WHERE
THE NET PATTERN AND TRADE-WIND PATTERN MEET. EXPECT SIMILAR PERIODS
OF SCATTERED SHOWERS NEAR CHUUK THROUGH MONDAY NIGHT, THEN THE MAIN
BAND OF CONVECTION SHIFTS TO THE SOUTHWEST, FOCUSING CLOSER TO THE
DEVELOPING NET. AROUND LATE WEEK, ENSEMBLE MODELS HINTS AT TRADE-
CONVERGENCE RE-DEVELOPING, BRINGING ANOTHER PERIOD OF SHOWERY
WEATHER ACROSS CHUUK STATE.
COMBINED SEAS OF 3 TO 5 FEET NEAR YAP AND PALAU, AND 4 TO 6 FEET
NEAR CHUUK ARE EXPECTED TO INCREASE ANOTHER FOOT TOWARDS THE MIDDLE
OF THE WEEK AS MINOR NORTHEAST SWELL CONTINUES TO MOVE THROUGH THE
REGION. OVERALL, WINDS WILL BE GENTLE TO MODERATE, INCREASING TO
MODERATE TO FRESH FOR CHUUK TUESDAY AND TO YAP WEDNESDAY AND
THURSDAY.
GUM WATCHES/WARNINGS/ADVISORIES
GU...RED FLAG WARNING UNTIL 4 PM CHST MONDAY FOR GUZ001.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS: BOWSHER
EAST MICRONESIA: MONTVILA
WEST MICRONESIA: CRUZ
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