176
FXPQ50 PGUM 230805
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
605 PM CHST THU APR 23 2026
MARIANAS SYNOPSIS
GENTLE TO MODERATE TRADES PREVAIL ACROSS THE MARIANAS, WITH SATELLITE
IMAGERY AND DOPPLER RADAR INDICATING QUICK-PASSING LIGHT SHOWERS
SOUTHEAST OF GUAM. BUOYS INDICATE SEAS ARE AROUND 6 FEET.
DISCUSSION
A MODERATELY DRIER TRADE-WIND PATTERN WILL CONTINUE ACROSS THE
MARIANAS THE NEXT SEVERAL DAYS, WITH A CHANCE FOR A SHOWER OR TWO TO
MAKE ITS WAY ACROSS GUAM AND ROTA OVERNIGHT. WINDS WILL BEGIN TO
PICKUP BEGINNING SATURDAY, FOLLOWED BY AN ARRIVAL OF A BROAD TRADE-
WIND TROUGH THAT IS EXPECTED TO BRING LOW-END SCATTERED SHOWERS EARLY
NEXT WEEK. WINDS WILL REMAIN ELEVATED FOR THE REST OF THE FORECAST
PERIOD AS THE HIGH OFF THE COAST OF JAPAN CONTINUES ITS TREK EAST AND
INCREASING PRESSURE GRADIENTS WITH THE TROPICS.
MARINE
COMBINED SEAS OF 5 TO 7 FEET WILL BRIEFLY TAPER DOWN SATURDAY, TO
THEN INCREASE ONCE AGAIN THEREAFTER AS TRADE SWELL AND WIND WAVES
INCREASE. A MODERATE RISK OF RIP CURRENTS IS EXPECTED ALONG NORTH
AND EAST FACING REEFS OF THE MARIANAS FOR AT LEAST THE NEXT SEVERAL
DAYS. SURF IS EXPECTED TO PERSIST AT CURRENT LEVELS UNTIL SATURDAY,
WHEN IT MAY DECREASE A FOOT OR TWO ALONG NORTH AND EAST FACING REEFS
AS TRADE SWELL BRIEFLY WEAKENS, TO THEN INCREASE ONCE AGAIN WHEN
TRADE SWELL AND LOCALIZED WIND WAVES STRENGTHEN NEXT WEEK.
EASTERN MICRONESIA
AFTERNOON SATELLITE IMAGERY SHOWS THE ITCZ ENTERING THE REGION AT
5N180 AND EXTENDING TO THE WEST-SOUTHWEST TO AROUND 3N163E. NUMEROUS
TO WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ARE OBSERVED IN THE
VICINITY OF THE ITCZ WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ON THE NORTHERN AND SOUTHERN PERIPHERY. SCATTERED
SHOWERS WILL BE POSSIBLE AT KOSRAE AND MAJURO TONIGHT WITH ISOLATED
THUNDERSTORMS ALSO POSSIBLE. ISOLATED SHOWERS AND A STRAY
THUNDERSTORM OR TWO WILL BE POSSIBLE AT POHNPEI TONIGHT. THE ITCZ
WILL SHIFT WEST AND NORTHWARD THROUGH THIS WEEKEND AND WILL BRING
INCREASED SHOWER AND THUNDERSTORM CHANCES AT ALL FORECAST POINTS AS
SEVERAL TRADE-WIND TROUGHS MOVE THROUGH THE TRADE WINDS. MODERATE TO
FRESH EAST TO NORTHEAST WINDS WILL CONTINUE THROUGH SATURDAY WITH
GUSTY AND ERRATIC WINDS POSSIBLE IN HEAVIER SHOWERS AND
THUNDERSTORMS.
COMBINED SEAS WILL BEGIN TO INCREASE ON FRIDAY AS WINDS RAMP UP AND
A TRADE SWELL BUILDS INTO MICRONESIA STARTING WITH THE MARSHALL
ISLANDS LATE ON FRIDAY. A MID-PERIOD NORTH SWELL WILL ALSO LINGER
THROUGHOUT THE REGION. ELEVATED TO POSSIBLY HAZARDOUS SURF WILL BE
POSSIBLE ALONG NORTH-FACING REEFS OF POHNPEI AND NORTH AND EAST-
FACING REEFS OF KOSRAE STARTING LATE ON FRIDAY AND CONTINUING
THROUGH THE WEEKEND. COMBINED SEAS OF 4 TO 6 FEET WILL INCREASE BY A
FOOT OR TWO THIS WEEKEND AS THE TRADE SWELL BUILDS WITH SEAS UP TO 8
FEET POSSIBLE AT MAJURO.
WESTERN MICRONESIA
A SOMEWHAT UNSETTLED PATTERN IS BUILDING ACROSS WESTERN MICRONESIA
WITH A SERIES OF TRADE-WIND TROUGHS PROPAGATING WEST THROUGH THE
REGION. HIMAWARI VISIBLE SATELLITE IMAGERY SHOWS LINES OF SCATTERED
SHOWERS OVER THE REPUBLIC OF PALAU AND YAP PROPER, WITH TROUGHS SEEN
OVER PALAU AND JUST EAST OF YAP. AN AREA OF SCATTERED TO NUMEROUS
SHOWERS IS CENTERED ROUGHLY HALFWAY BETWEEN THE MARIANAS AND YAP
PROPER, NORTH OF A BROADER TROUGH SEEN FURTHER SOUTH OVER WESTERN
YAP STATE. EAST OF CHUUK, A LINE OF HEAVIER SHOWERS IS BUILDING
WESTWARD ALONG AN AREA OF WEAK TRADE-WIND CONVERGENCE AND TROUGHING,
AND MODEL GUIDANCE INDICATES THIS FEATURE WILL CONTINUE WESTWARD AND
INCREASE SHOWERS NEAR CHUUK OVERNIGHT. FRIDAY THROUGH THE WEEKEND,
SHOWERS AND THUNDERSTORMS WILL INCREASE ACROSS THE REGION AS
TROUGHING BUILDS OVER FAR WESTERN MICRONESIA, AND AS A BROAD, ROBUST
DISTURBANCE BEGINS TO FORM ALONG THE WESTERN EXTENT OF THE ITCZ,
SOUTH OF POHNPEI AND CHUUK. SHOWERS WILL BE LOCALLY HEAVY AT TIMES,
ESPECIALLY FRIDAY THROUGH SATURDAY FOR YAP AND PALAU, AND FRIDAY
NIGHT THROUGH SUNDAY OVER CHUUK STATE. A FAIRLY WET PATTERN IS THEN
EXPECTED FOR MUCH OF THE COMING WEEK AS THE BROAD DISTURBANCE FORMING
SOUTH OF CHUUK PROPAGATES SLOWLY WEST ACROSS YAP STATE.
RECENT ALTIMETRY INDICATES COMBINED SEAS AROUND 4 TO 5 FEET ACROSS
THE REGION. SEAS WILL INCREASE BY A FOOT OR SO AROUND YAP AND CHUUK
INTO THE WEEKEND AS A PULSE OF NORTH-NORTHEAST TO NORTHEAST SWELL
MOVES THROUGH THE REGION.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS: MONTVILA
EAST MICRONESIA: WHISNANT
WEST MICRONESIA: DECOU
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