870
FXPQ50 PGUM 022003
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
603 AM CHST FRI APR 3 2026
MARIANAS UPDATE
A BROAD, SUBTLE TROUGH IS CROSSING THE MARIANAS. CONDITIONS REMAIN
FAIRLY DRY FOR THE TROPICS, WITH PRECIPITABLE WATER TOTALS AROUND 1.5
INCHES. OVERNIGHT SCATTEROMETRY REVEALS MODERATE NORTHEAST TRADE
WINDS, WITH LITTLE IN THE WAY OF SURFACE CONVERGENCE. STILL,
SATELLITE AND RADAR IMAGERY SHOW AN AREA OF SHALLOW, ISOLATED TO
LOW-END SCATTERED SHOWERS CROSSING THE MARIANAS EARLY THIS MORNING.
THESE ARE EXPECTED TO DIMINISH TO ISOLATED BY LATE MORNING, WITH JUST
ISOLATED SHOWERS TO PERSIST THROUGH TONIGHT. A DRY PATTERN WILL
CONTINUE THROUGH MUCH OF NEXT WEEK.
OVERALL THERE WAS VERY LITTLE CHANGE IN THE FORECAST. LATEST BUOY AND
ALTIMETRY DATA DEPICT 4 TO 6 FT SEAS OVER MARIANAS COASTAL WATERS. A
TRADE WIND SURGE BEGINS TO DEVELOP EAST OF THE REGION TONIGHT AND
OVER THE WEEKEND AS HIGH PRESSURE BUILDS EASTWARD OFF THE COAST OF
JAPAN. THIS WILL RESULT IN WINDS INCREASING TO MODERATE TO FRESH
ACROSS THE MARIANAS, POTENTIALLY REACHING LEVELS HAZARDOUS TO SMALL
CRAFT, NEARING 22 KNOTS SUNDAY AND MONDAY. AN INCREASE IN TRADE-WIND
SWELL AND WIND WAVES WILL ALSO BUILD SEAS TO 6 TO 9 FEET OVER THE
WEEKEND. THEN, NORTHERLY SWELL LOOKS TO ARRIVE MONDAY, WHEN SEAS ARE
ANTICIPATED TO REACH 9 TO 11 FEET, BECOMING HAZARDOUS FOR SMALL
CRAFT. THE INCREASE IN SWELLS WILL ALSO BUILD SURF ALONG EAST AND
NORTH FACING REEFS, LIKELY INCREASING THE RIP CURRENT RISK FROM
MODERATE TO HIGH FOR EAST-FACING REEFS STARTING SUNDAY AND
POTENTIALLY PRODUCING ELEVATED SURF FOR NORTH-FACING REEFS.
EASTERN MICRONESIA UPDATE
THERE WAS LITTLE CHANGE IN THE FORECAST. SATELLITE THIS MORNING SHOWS
SCATTERED TO NUMEROUS SHOWERS BUILDING ACROSS THE EASTERN MARSHALL
ISLANDS INCLUDING OVER MAJURO. THESE ARE ASSOCIATED WITH A NEARBY
TROPICAL DISTURBANCE, CENTERED NEAR 5N170E, INTERACTING WITH A
TRADE-WIND TROUGH JUST EAST OF MAJURO ATOLL. TO THE WEST, SCATTERED
SHOWERS ARE FOCUSED ALONG AREAS OF CONVERGENCE WITHIN THE NEAR-
EQUATORIAL TROUGH (NET), NEAR AND SOUTH OF KOSRAE AND SOUTH OF
POHNPEI. GUIDANCE CONTINUES TO SHOW NUMEROUS TO WIDESPREAD SHOWERS
BUILDING ACROSS MAJURO TODAY AND TONIGHT AS THE DISTURBANCE
GRADUALLY MEANDERS WESTWARD. LOCALLY HEAVY SHOWERS ARE EXPECTED, WITH
GUSTS TO 25 KNOTS NEAR HEAVIER SHOWERS. THE DISTURBANCE AND ATTENDANT
TROUGHS WILL CONTINUE TO DEVELOP HEAVY SHOWERS AND THUNDERSTORMS
WESTWARD, INCREASING FOR KOSRAE AND POHNPEI THIS WEEKEND THROUGH
EARLY NEXT WEEK.
WESTERN MICRONESIA UPDATE
OVERALL CONDITIONS ARE FAIRLY QUIET ACROSS WESTERN MICRONESIA. A LINE
OF MODERATE TO DEEP CONVECTION IS SEEN TO THE SOUTH OF KOROR ALONG
THE NET AXIS, WITH SHALLOW LOW-END SCATTERED SHOWERS SEEN NEAR YAP
AND PALAU THIS MORNING. THESE ARE ASSOCIATED WITH WEAK TRADE-WIND
SPEED CONVERGENCE, AS AN AREA OF MODERATE TO FRESH WINDS PROPAGATE
SOUTHWEST ACROSS YAP TODAY. SATELLITE TRENDS INDICATE ISOLATED TO
SCATTERED SHOWERS NEAR CHUUK, WITH SWATHS OF UPPER-LEVEL CLOUDS
BLANKETING THE REGION FROM PRIOR DEEP CONVECTION FURTHER SOUTH. ALL
THREE LOCATIONS SIT NORTH OF THE NET AXIS, AND WEAK CONVERGENCE ALONG
IT IS EXPECTED TO SUPPORT ISOLATED TO LOW-END SCATTERED SHOWERS
THROUGH TONIGHT. A MORE ROBUST DISTURBANCE WILL BUILD SHOWERS
WESTWARD ACROSS CHUUK STARTING LATE THIS WEEKEND THROUGH EARLY NEXT
WEEK.
PREV DISCUSSION
/ISSUED 515 PM CHST THU APR 2 2026/
MARIANAS SYNOPSIS...
A QUIET WEATHER WEATHER PATTERN IS SEEN ACROSS THE REGION THIS
AFTERNOON. SATELLITE IMAGERY SHOWS PARTLY CLOUDY SKIES AND A THIN
LINE OF SPOTTY SHOWERS THAT FORMED ON THE LEEWARD SIDE OF THE
ISLANDS, OFF TO THE SOUTHWEST. BUOYS SHOW SEAS HAVE DECREASED TO 4
TO 6 FEET.
DISCUSSION...
SATELLITE AND MODEL TRENDS STILL POINT TO A SMALL UPTICK IN SHOWERS
LATE TONIGHT AND EARLY TOMORROW MORNING DUE TO A BROAD, BUT SHALLOW
TROUGH PASSING THROUGH. OTHERWISE, A RELATIVELY DRY PATTERN IS
EXPECTED THROUGH THE MIDDLE OF NEXT WEEK, WITH BRIEF UPTICKS IN
SHOWERS POSSIBLE WITH WEAK, PASSING TROUGHS. THE LEADING EDGE OF
TRADE-WIND SURGE IS EXPECTED TO INCREASE WINDS TO MODERATE TO FRESH
STARTING FRIDAY NIGHT OR SATURDAY, WITH BREEZY CONDITIONS SUNDAY
THROUGH MONDAY.
MARINE/SURF...
GENTLE TO MODERATE NORTHEAST WINDS AND COMBINED SEAS OF 4 TO 6
FEET PREVAIL ACROSS THE REGION THROUGH FRIDAY. A TRADE WIND SURGE
BEGINS TO DEVELOP EAST OF THE REGION FRIDAY NIGHT AND OVER THE
WEEKEND, RESULTING IN WINDS INCREASING TO MODERATE TO FRESH ACROSS
THE MARIANAS, POTENTIALLY REACHING HAZARDOUS LEVELS OF 22 KT
SUNDAY AND MONDAY. AN INCREASE IN TRADE-WIND SWELL AND WIND WAVES
WILL ALSO BUILD SEAS TO 6 TO 9 FEET OVER THE WEEKEND. THEN,
NORTHERLY SWELL LOOKS TO ARRIVE MONDAY, WHEN SEAS ARE ANTICIPATED
TO REACH HAZARDOUS LEVELS OF 10 FEET. A MODERATE RISK OF RIP
CURRENTS ALONG NORTH AND EAST FACING REEFS AND LOW RISK ALONG SOUTH
AND WEST FACING REEFS CONTINUES OVER THE NEXT COUPLE DAYS, WITH
PRIMARY SWELL FROM THE NORTHEAST. THE INCREASE IN EAST-NORTHEAST
TRADE WINDS AND SWELL ARE EXPECTED TO BUILD SURF ALONG EAST AND
NORTH FACING REEFS, LIKELY INCREASING THE RIP RISK TO HIGH FOR EAST-
FACING REEFS STARTING SUNDAY AND POTENTIALLY PRODUCING ELEVATED SURF
FOR NORTH-FACING REEFS.
EASTERN MICRONESIA...
SATELLITE IMAGERY SHOWS PARTLY TO MOSTLY CLOUDY SKIES AND ISOLATED
TO SCATTERED SHOWERS ACROSS EASTERN MICRONESIA. ALTIMETRY DATA SHOWS
COMBINED SEAS BETWEEN 5 AND 7 FEET ARE SEEN ACROSS THE REGION.
CONDITIONS HAVE GENERALLY BEEN QUIET ACROSS EASTERN MICRONESIA. THE
TROPICAL DISTURBANCE LOCATED NEAR 2N175E. NUMEROUS TO WIDESPREAD
SHOWERS ARE SEEN ACROSS THE DISTURBANCE AND ALONG THE NET AXIS THAT
IS INTERACTING WITH THE TROPICAL DISTURBANCE. GUIDANCE SHOWS THE
NET AND THE TROPICAL DISTURBANCE MOVING WEST-NORTHWEST AT A NEAR
CRAWL. THIS WILL KEEP EASTERN MICRONESIA IN A WET PATTERN LATE THIS
WEEKEND AND INTO NEXT WEEK. LOCALLY HEAVY RAINFALL AND BREEZY
CONDITIONS WILL BE POSSIBLE. AS THE NET AND DISTURBANCE CONTINUE TO
LIFT TO THE WEST-NORTHWEST, GUIDANCE SHOWS THE DISTURBANCE BEGINNING
TO ORGANIZE. THIS COULD LEAD SHOWERS AND THUNDERSTORMS CONCENTRATING
OVER A SMALLER AREA THAN OVER A LARGER AREA. NONETHELESS, DROUGHT
RELIEF OVER THE NEXT WEEK APPEARS POSSIBLE FOR UTIRIK AND WOTJE.
MARINE CONDITIONS CONTINUE TO BE BENIGN AT AROUND 5 TO 7 FEET ACROSS
EASTERN MICRONESIA. COMBINED SEAS WILL RISE LATE THIS WEEK AND INTO
THE WEEKEND ACROSS POHNPEI AND MAJURO. SEAS LOOK TO REMAIN BELOW
HAZARDOUS TO SMALL CRAFT CRITERIA, BUT SURF LOOKS TO BECOME
HAZARDOUS ALONG NORTH FACING REEFS.
WESTERN MICRONESIA...
THE MAIN FEATURE IN THE REGION CONTINUES TO BE THE NEAR EQUATORIAL
TROUGH (NET) WITH AN EMBEDDED CIRCULATION. THE NET ENTERS THE REGION
NEAR 3N130E AND EXTENDS EASTWARD ACROSS THE SOUTHERN PORTION OF PALAU
AND THROUGH THE EMBEDDED CIRCULATION NEAR 3N138E (TO THE SOUTH-
SOUTHWEST OF YAP PROPER AND SOUTHEAST OF PALAU). THEN, THE NET
CONTINUES TO EXTEND EASTWARD THROUGH SOUTHERN YAP AND CHUUK STATES
WHERE IT CONTINUES INTO EASTERN MICRONESIA. ALONG THE NET AXIS
SCATTERED TO WIDESPREAD SHOWERS ARE SEEN ON SATELLITE IMAGERY, WITH
THE MOST VIGOROUS SHOWERS NEAR THE EASTERN BORDER OF THE REGION.
THE WEATHER IS FAIRLY BENIGN OVER THE THREE MAIN ISLANDS. A WEAK
TROUGH IS EXPECTED TO PASS OVER YAP PROPER TONIGHT AND PALAU
FRIDAY. THIS TROUGH WILL BRING WITH IT SOME SCATTERED SHOWERS TO
BOTH ISLANDS. ONCE THIS TROUGH PASSES BOTH YAP AND PALAU IS EXPECTED
TO RETURN TO DRIER CONDITIONS. CHUUK ON THE OTHER HAND, IS WHERE ALL
THE FORECASTING CHALLENGES ARE. THROUGH THE END OF THE WEEKEND, CHUUK
IS EXPECTED TO REMAIN FAIRLY BENIGN, WEATHER-WISE. MODEL GUIDANCE
SUGGESTS THE TROPICAL DISTURBANCE THAT IS CURRENTLY FORMING IN
EASTERN MICRONESIA WILL MEANDER ITS WAY TOWARDS CHUUK. TO REFLECT
THIS PROBABILITY OF PRECIPITATION (POPS) WERE ELEVATED TO 50 PERCENT
FOR THE BEGINNING OF NEXT WEEK. DURING THIS TIMEFRAME THERE IS ALSO A
SLIGHT CHANCE FOR THUNDERSTORMS.
ALTIMETRY SHOWS 3 TO 4 FEET ACROSS THE REGION. THESE SEAS ARE
EXPECTED TO REMAIN FAIRLY STABLE PALAU, HOWEVER, YAP AND CHUUK'S SEAS
ARE EXPECTED TO RISE STARTING TONIGHT FOR CHUUK AND FRIDAY FOR YAP.
YAP'S COMBINED SEAS ARE ANTICIPATED TO BUILD TO AROUND 7 TO 8 FEET
BY AROUND TUESDAY AND CHUUK IS ANTICIPATED TO BUILD TO 8 TO 10 FEET.
THIS IS DUE TO AN INCREASE IN THE TRADE-WIND SWELL AND A NORTH SWELL
MOVING INTO THE REGION. CHUUK MAY SEE SURF AND SEAS HIGH ENOUGH TO
WARRANT HIGH SURF ADVISORY AND A SMALL CRAFT ADVISORY.
WINDS NEAR PALAU ARE EXPECTED TO REMAIN LIGHT TO GENTLE THROUGH THE
FIRST HALF OF NEXT WEEK, WHILE WINDS NEAR YAP ARE EXPECTED TO BE
GENTLE TO MODERATE. LIGHT TO MODERATE WINDS NEAR CHUUK ARE EXPECTED
TO BUILD TO GENTLE TO FRESH BY AROUND SUNDAY AND REMAIN FOR THE
FOLLOWING DAY OR TWO.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS/EAST AND WEST MICRONESIA UPDATE: DECOU
MARIANAS: CRUZ
EAST MICRONESIA: WILLIAMS
WEST MICRONESIA: BOWSHER
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