305
FXPQ50 PGUM 161950
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
550 AM CHST SUN MAY 17 2026
MARIANAS UPDATE
ISOLATED SHOWERS AND BREEZY WINDS WILL CONTINUE TODAY BEFORE A
PASSING TRADE-WIND TROUGH TO THE SOUTH INCREASES SHOWER AND
THUNDERSTORM POTENTIAL FOR GUAM AND ROTA STARTING LATE TONIGHT.
COMBINED SEAS OF 4 TO 7 FEET WILL CONTINUE TO BUILD TODAY, LIKELY
BECOMING 6 TO 8 FEET BY LATE MONDAY. EAST WINDS WILL BE MOSTLY
MODERATE TO FRESH THROUGH EARLY THIS WEEK. A MODERATE RISK OF RIP
CURRENTS ALONG BOTH NORTH AND EAST-FACING REEFS WILL PERSIST THROUGH
EARLY THIS WEEK, POSSIBLY BECOMING HIGH RISK ALONG EAST-FACING REEFS
STARTING MONDAY.
EASTERN MICRONESIA UPDATE
WET AND UNSETTLED WEATHER WILL CONTINUE TODAY AND INTO EARLY NEXT
WEEK AS THE ITCZ BECOMES REESTABLISHED AND SEVERAL TRADE-WIND TROUGHS
MOVE THROUGH THE EASTERLY FLOW AND INTERACT WITH THE ITCZ. COMBINED
SEAS OF 5 TO 8 FEET WILL PERSIST OVER THE NEXT SEVERAL DAYS. EAST
WINDS WILL HOVER MOSTLY IN THE GENTLE TO MODERATE RANGE THROUGH EARLY
THIS WEEK. OTHERWISE, MINOR COASTAL INUNDATION WILL CONTINUE TO BE
POSSIBLE AT MAJURO THROUGH MONDAY.
WESTERN MICRONESIA UPDATE
SEVERAL TRADE-WIND TROUGHS MOVING THROUGH THE EASTERLY FLOW AND WEAK
CONVERGENCE WILL KEEP WET AND UNSETTLED WEATHER THROUGH EARLY THIS
WEEK AT CHUUK. ISOLATED TO LOW-END SCATTERED SHOWERS WILL BE POSSIBLE
AT YAP AND PALAU THROUGH EARLY THIS WEEK. A TRADE SWELL WILL CONTINUE
TO BUILD INTO WESTERN MICRONESIA AND SEAS WILL BUILD A FOOT OR TWO
THROUGH MONDAY. MOSTLY GENTLE TO MODERATE EAST WINDS ARE EXPECTED TO
PREVAIL THROUGH AT LEAST EARLY THIS WEEK.
PREV DISCUSSION
/ISSUED 546 PM CHST SAT MAY 16 2026/
MARIANAS SYNOPSIS...
MODERATE TO FRESH EASTERLIES PREVAIL ACROSS THE MARIANAS. SATELLITE
IMAGERY AND DOPPLER RADAR INDICATE MOSTLY CLEAR TO PARTLY CLOUDY
LOW-LEVEL CLOUDS ACROSS THE REGION. THE BUOYS INDICATE SEAS ARE 3 TO
5 FEET.
DISCUSSION...
A DRY TRADE-WIND PATTERN IS LIKELY TO BE INTERRUPTED BY AN ASCENDING
TRADE-WIND TROUGH IN THE FIRST HALF OF THE WEEK, BRINGING HIGHER
SHOWER AND THUNDER COVERAGE TO GUAM AND ROTA BEGINNING MONDAY. TINIAN
AND SAIPAN WILL CONTINUE TO DODGE MOST OF THE SHOWERS AND
THUNDERSTORMS OVER THE COMING DAYS; HOWEVER, WINDS WILL CONTINUE TO
INCREASE ACROSS THE MARIANAS, BEFORE DIMINISHING ONCE AGAIN IN THE
SECOND HALF OF THE WEEK.
MARINE...
COMBINED SEAS OF 4 TO 6 FEET WILL QUICKLY RISE THE NEXT COUPLE OF
DAYS AS A SIGNIFICANT EASTERLY SWELL MAKES IT TO THE MARIANAS,
POSSIBLY BECOMING 6 TO 8 FEET BY MONDAY NIGHT. EVEN SO, SEAS ARE
EXPECTED TO BECOME CHOPPY BUT REMAIN BELOW LEVELS HAZARDOUS TO SMALL
CRAFT. A MODERATE RISK OF RIP CURRENTS IS EXPECTED ALONG EAST
FACING REEFS TONIGHT, TO THEN BECOME MODERATE ALONG NORTH FACING REEFS
AS WELL BEGINNING SUNDAY. SURF WILL CONTINUE TO INCREASE OVER THE
COMING DAYS AS THE EASTERLY SWELL STRENGTHENS, POTENTIALLY INTRODUCING
A HIGH RIP CURRENT RISK ALONG EAST FACING REEFS BEFORE THE MIDWEEK.
EASTERN MICRONESIA...
SIMILAR TO YESTERDAY, THE MODELS SHOW A PERSISTENT UNSETTLED PATTERN
AS AN ITCZ (INTER-TROPICAL CONVERGENCE ZONE) RE-ESTABLISHES ITSELF
OVER THE NEXT WEEK OR SO, BUILDING WEST AS IT DOES SO, ACCOMPANIED BY
EMBEDDED TROUGHS IN THE TRADE FLOW. THIS WILL KEEP SCATTERED SHOWERS
IN THE FORECAST FOR THE NEXT 7 DAYS AND BEYOND. MAINLY GENTLE TO
MODERATE TRADES WILL PERSIST. THERE MAY BE SLIGHTLY HIGHER-THAN-
AVERAGE TIDAL CYCLES AND WE THOUGHT ABOUT INCLUDING A HEADLINE FOR
SUCH AT MAJURO, BUT GIVEN HOW FREQUENTLY THIS OCCURS AND THAT IT
LOOKS TO BE A NOMINAL EVENT, WE OPTED NOT TO INCLUDE SO WE DON'T
"OVER-WARN/CAUSE WARNING FATIGUE". OTHERWISE, SEAS OF 5 TO 7 FEET
LOOK TO CONTINUE THROUGH THE MIDDLE OF NEXT WEEK, DROPPING A FOOT
TOWARDS NEXT WEEKEND.
WESTERN MICRONESIA...
OVERALL CONVECTION ACROSS CHUUK HAS WEAKENED, BUT A SERIES OF
TROUGHS AND WEAK TRADE-WIND CONVERGENCE WILL CONTINUE TO GENERATE
SCATTERED SHOWERS ACROSS THE REGION OVER THE NEXT FEW DAYS. LATEST
MODEL GUIDANCE CONTINUES TO SHOW AN UNSETTLED PATTERN SLOWLY TAKING
SHAPE THIS UPCOMING WEEK, HINTING AT ONE OR TWO WEAK DISTURBANCES IN
THE SECOND HALF OF THE WEEK. SIGNIFICANT DEVELOPMENT IS NOT EXPECTED,
BUT MAY STILL YIELD BROAD AREAS OF CONVECTION, ESPECIALLY ACROSS
PARTS OF CHUUK AND YAP STATE. PALAU LOOKS TO BE ON THE SOUTHWEST SIDE
OF THIS PATTERN, WITH RELATIVELY LESS SHOWER COVERAGE, HOWEVER,
MODEL GUIDANCE STILL SHOWS A LARGELY DISORGANIZED PATTERN, SO THE
TIMING AND INTENSITY OF SHOWERS WILL CONTINUE TO BE RE-ASSESSED.
BENIGN MARINE CONDITIONS CONTINUE THROUGH MUCH OF THE UPCOMING WEEK.
ALTIMETRY SHOWS 2 TO 4 SEAS AT PALAU AND YAP, INCREASING TO 4 TO 6
FEET AT CHUUK. TRADE-WIND SWELL CONTINUES TO BUILD INTO THE REGION,
AND IS EXPECTED TO INCREASE SEAS TO 4 TO 6 FEET AT YAP AND SLIGHTLY
INCREASE SEAS AT PALAU TO 3 TO 4 FEET MONDAY AND MONDAY NIGHT.
AFTERWARDS, TRADE WINDS AND SWELL SUBSIDE, ALLOWING SEAS TO DECREASE
BACK DOWN TO 3 TO 5 FEET TOWARDS THE SECOND HALF OF THE WEEK.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS/EAST AND WEST MICRONESIA UPDATE: WHISNANT
MARIANAS: MONTVILA
EAST MICRONESIA: DOLL
WEST MICRONESIA: CRUZ
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