383
FXPQ50 PGUM 080833
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
633 PM CHST WED APR 8 2026
MARIANAS SYNOPSIS
MODERATE TO FRESH NORTHEASTERLIES PREVAIL ACROSS THE MARIANAS.
SATELLITE IMAGERY AND DOPPLER RADAR INDICATE QUICKLY-PASSING LIGHT
SHOWERS ACROSS GUAM AND ROTA WATERS. BUOYS INDICATE SEAS ARE 6 TO 9
FEET.
DISCUSSION
A DRIER TRADE-WIND REGIME IS EXPECTED ACROSS THE MARIANAS THE NEXT
FEW DAYS, FOLLOWED BY A TRANSITION TO A WETTER AND GUSTIER PATTERN AS
TROPICAL DISTURBANCE INVEST 90W CONTINUES TO APPROACH THE MARIANAS AS
IT TREKS WEST ACROSS MICRONESIA. SHOWER INTENSITY IS EXPECTED TO
INCREASE SIGNIFICANTLY LATE THIS WEEKEND, WITH THE HEAVIEST SHOWERS
EXPECTED EARLY NEXT WEEK. RECENT MODEL TRENDS CONTINUE TO INDICATE A
WESTWARD PASSAGE AS 90W REMAINS SOUTH OF THE MARIANAS, BUT CONFIDENCE
REMAINS LOW IN DISTINGUISHING POTENTIAL WIND AND RAIN IMPACTS ACROSS
THE REGION AT THIS TIME. AS THIS SYSTEM CONTINUES TO MEANDER AND
DEVELOP IN CHUUK STATE, CERTAINTY WILL INCREASE IN ITS MOVEMENT AND
STRENGTH OVER THE COMING DAYS AS JTWC AND THE NATIONAL WEATHER
SERVICE CONTINUE TO MONITOR 90W CLOSELY THROUGH THE REST OF THE WEEK.
AS OF THIS FORECAST CYCLE, EXPECT WINDY CONDITIONS BROUGHT BY
HEAVIER CONVECTION AS EARLY AS SATURDAY, REMAINING AS SUCH COMING
INTO EARLY NEXT WEEK.
MARINE
COMBINED SEAS OF 7 TO 9 FEET WILL PERSIST FOR A DAY OR SO, TO THEN
BEGIN INCREASING BY THE WEEKEND AS TRADE SWELL AND LOCALIZED WIND
WAVES STRENGTHEN. A HIGH RISK OF RIP CURRENTS IS NOW EXPECTED THROUGH
FRIDAY AFTERNOON ALONG EAST FACING REEFS, WHILE REMAINING MODERATE
ALONG ALL OTHER REEFS THROUGH AT LEAST THURSDAY NIGHT. AFTER,
STRENGTHENING TRADE SWELL AND INCOMING TROPICAL DISTURBANCE 90W ARE
EXPECTED TO BRING INCREASING SURF, WITH A CHANCE FOR HAZARDOUS SURF
AND A HIGH RISK OF RIP CURRENTS TO DEVELOP ALONG SOUTH AND WEST FACING
REEFS BY EARLY NEXT WEEK.
TROPICAL SYSTEMS
A TROPICAL DISTURBANCE, KNOWN AS JOINT TYPHOON WARNING CENTER'S
(JTWC'S) INVEST 90W IS CENTERED NEAR 9N154E, THIS IS NORTHEAST OF
CHUUK LAGOON AND NORTHWEST OF POHNPEI. THIS SYSTEM IS RATED AT
MEDIUM, MEANING THAT TROPICAL CYCLONE DEVELOPMENT IS LIKELY, BUT
EXPECTED TO OCCUR BEYOND 24 HOURS. THIS SYSTEM IS PRODUCING SCATTERED
TO WIDESPREAD LOCALLY HEAVY SHOWERS AND ISOLATED THUNDERSTORMS FOR
FANANU, LOSAP, LUKUNOCH, ONOUN, CHUUK LAGOON AND POHNPEI. WINDS OF
10 TO 20 KNOTS WITH FREQUENT GUSTS TO 25 KNOTS ARE EXPECTED WITH THIS
FEATURE. AS 90W CONTINUES TO DEVELOP, IT IS EXPECTED TO MOVE FURTHER
TO THE NORTHWEST AND EVENTUALLY TURN TO THE WEST. CURRENT MODEL
TRENDS SHOW SHOW THAT 90W MAY PASS BETWEEN NORTHERN ISLAND/ATOLLS OF
YAP AND CHUUK STATES.
RESIDENTS AND MARINERS SHOULD MONITOR THE LATEST FORECASTS FOR THE
REGION AT WEATHER.GOV/GUM/PUBLICFORECASTS AND ANY INFORMATION SHARED
BY WSO POHNPEI, WSO CHUUK, AND WSO YAP FOR THEIR LOCAL REGIONS.
EASTERN MICRONESIA
SATELLITE IMAGERY THIS AFTERNOON SHOWS INVEST 90W BECOMING MORE
CONSOLIDATED WITH THE CENTER LOCATED ROUGHLY AROUND 9N154E. INVEST
90W WILL CONTINUE TO TREK WEST-NORTHWEST DURING THE NEXT SEVERAL DAYS
AS IT MOVES AWAY FROM EASTERN MICRONESIA. HIGH-END SCATTERED TO
NUMEROUS HEAVY SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO BE
POSSIBLE AT POHNPEI AND KOSRAE THROUGH THURSDAY AS THE DISTURBANCES
MOVES AWAY FROM THE AREA. GUSTY AND ERRATIC WINDS CAN BE EXPECTED
WITH HEAVY SHOWERS AND THUNDERSTORMS. A SERIES OF WEAK TROUGHS WILL
KEEP ELEVATED SHOWER AND ISOLATED THUNDERSTORM CHANCES ACROSS THE
REGION FOR THE REMAINDER OF THE WEEK AT ALL FORECAST SITES. WINDS
WILL REMAIN MODERATE TO FRESH THROUGH THURSDAY AND WILL BECOME GENTLE
BY MIDDAY ON SATURDAY.
AN EASTERLY SWELL, A SMALL, LINGERING NORTH TO NORTHEAST SWELL, AND
LOCALLY GENERATED WIND WAVES WILL LIKELY CONTINUE TO GENERATE SEAS
HAZARDOUS TO SMALL CRAFT AT POHNPEI AND KOSRAE THROUGH TONIGHT.
ALTIMETRY PASSES FROM THIS MORNING SHOWED SEAS AROUND 10 FEET IN THE
VICINITY BOTH OF KOSRAE AND POHNPEI, SO HAVE EXTENDED THE SMALL
CRAFT ADVISORY FOR POHNPEI THROUGH TONIGHT AND ISSUED A SMALL CRAFT
ADVISORY FOR KOSRAE ALSO THROUGH TONIGHT. THE HIGH SURF ADVISORY FOR
NORTH-FACING REEFS AT POHNPEI WAS CANCELLED THIS AFTERNOON DUE TO
SURF LIKELY NO LONGER CONTINUALLY MEETING HAZARDOUS CRITERIA OF 9
FEET ALONG NORTH-FACING REEFS. THOUGH, SURF WILL REMAIN ELEVATED
ALONG EAST-FACING REEFS AND NORTH-FACING REEFS AT POHNPEI THROUGH
THURSDAY. HAZARDOUS SURF IS ALSO NO LONGER EXPECTED ALONG NORTH-
FACING REEFS OF KOSRAE, SO HAVE DROPPED THAT FROM THE ADVISORY, BUT
HAZARDOUS SURF ALONG EAST-FACING REEFS OF KOSRAE WILL CONTINUE
THROUGH AT LEAST THURSDAY AFTERNOON. COMBINED SEAS OF 8 TO 10 FEET AT
POHNPEI AND KOSRAE WILL SUBSIDE THROUGH THE REST OF THE WEEK AND
BECOME 6 TO 7 FEET BY THIS WEEKEND. SEAS OF 6 TO 8 FEET AT MAJURO
WILL FALL TO 4 TO 6 FEET BY THIS WEEKEND.
WESTERN MICRONESIA
THE MAIN TWO FEATURES THAT ARE EFFECTING THE REGION ARE THE NEAR
EQUATORIAL TROUGH (NET) AND THE INCOMING INVEST 90W (MORE ON THIS
FEATURE IN THE CHUUK SECTION). THE NET ENTERS THE REGION NEAR 4N130E
AND EXTENDS TO THE SOUTH EAST TO EQ159E (TO THE EAST OF
KAPINGAMARANGI). SOUTH OF THE NET AXIS, SCATTERED SHOWERS ARE SEEN
ON SATELLITE IMAGERY.
FOR PALAU, A DRY TRADE-WIND PATTERN REMAINS OVER THE REGION. WINDS
ARE EXPECTED TO BE AROUND 5 TO 15 KNOTS AROUND PALAU, THEN THESE
WINDS ARE MAY BEGIN TO GRADUALLY BUILD NEAR THE BEGINNING OF NEXT
WEEK.
FOR YAP PROPER, A TRADE-WIND TROUGH IS MOVING THROUGH THE REGION,
THAT WILL PRODUCE SCATTERED SHOWERS FOR TONIGHT, THEN A RETURN TO A
DRIER PATTERN IS EXPECTED THROUGH THE REST OF THE WEEK. AROUND THE
BEGINNING OF NEXT WEEK, INVEST 90W MAY MOVE NEAR BY, AND MAY BRING
SHOWERS AND THUNDERSTORMS TO THE REGION.
FOR CHUUK, OUTER ISLANDS OF CHUUK AND YAP, AN UNSETTLED WEATHER
PATTERN IS IN STORE FOR THESE AREAS. INVEST 90W IS LOCATED NORTHEAST
OF WENO, AND IS PRODUCING SHOWERS AROUND CHUUK, THE OUTER ISLANDS OF
CHUUK AND EASTERN YAP ISLANDS. TONIGHT, SHOWERS ARE EXPECTED TO
BE SCATTERED TO WIDESPREAD WITH ISOLATED THUNDERSTORMS. SHOWERS MAY
BE HEAVY AT TIMES, WITH RAIN RATES IN THE 3 TO 5 INCHES FOR A 24 HOUR
PERIOD MODELS. MODEL GUIDANCE SUGGEST THAT INVEST 90W MAY START TO
LEAVE THE REGION AROUND THURSDAY. OVER THE LATTER HALF OF THE WEEK
THE OUTER BANDS OF INVEST 90W WILL TAKE OVER AS THE WEATHER MAKER FOR
THE REGION. THESE SHOWERS ARE ANTICIPATED TO BE AROUND 20 TO 30
PERCENT AS THEY ARE FORMED ALONG THE WESTERLY INFLOW OF INVEST 90W.
NEAR THE BEGINNING OF NEXT WEEK, CHUUK MAY RETURN TO A DRIER PATTERN.
COMBINED SEAS VARY OVER THE REGION WITH THE LOWEST IN THE WEST AND
THE HIGHEST IN THE EAST. SEAS OVER THE REGION ARE BETWEEN 3 TO 5
FEET TO THE WEST OF PALAU, SEAS NEAR YAP ARE 4 TO 7 FEET AND BUILD TO
7 TO 10 FEET NEAR CHUUK. AT CHUUK, A SMALL CRAFT ADVISORY (SCA) AND
A HIGH SURF ADVISORY (HSA) ALONG NORTH FACING REEFS REMAIN IN
EFFECT. SEAS AND WINDS, FOR CHUUK, ARE EXPECTED TO PEAK AROUND
TONIGHT INTO THURSDAY MORNING. FOR THIS REASON THE SCA WAS EXTEND BY
THROUGH 5 AM. THE SEAS AND SURF WILL TAKE SOME TIME TO FALL BELOW
THE 10 FOOT (FOR SEAS) AND 9 FOOT (FOR SURF) THRESHOLDS. CURRENT
ESTIMATIONS ARE FOR THURSDAY MORNING FOR SEAS AND LATER THAT EVENING
FOR SURF. SURF AND SEAS ARE ANTICIPATED TO RISE AGAIN ONCE INVEST
90W TAKES A MORE WESTERLY TREK.
GUM WATCHES/WARNINGS/ADVISORIES
GU...HIGH RIP CURRENT RISK THROUGH FRIDAY AFTERNOON FOR GUZ001.
MP...HIGH RIP CURRENT RISK THROUGH FRIDAY AFTERNOON FOR MPZ001>003.
MARIANAS WATERS...NONE.
MARIANAS: MONTVILA
EASTERN MICRONESIA: WHISNANT
WESTERN MICRONESIA: BOWSHER
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