165
FXPQ50 PGUM 080723
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
523 PM CHST MON JUN 8 2026
MARIANAS SYNOPSIS
AN INCOMING TROUGH WILL MOVE THROUGH THE REGION, INCREASING SHOWER
COVERAGE FROM ISOLATED TO SCATTERED AFTER MIDNIGHT, WITH ISOLATED
THUNDERSTORMS POSSIBLE FOR GUAM. COMBINED SEAS ARE 3 TO 4 FEET AND
WILL PEAK BY A FOOT ON TUESDAY. A MODERATE RISK OF RIP CURRENTS
EXISTS ALONG NORTH- AND EAST-FACING REEFS.
DISCUSSION
LATEST MODEL GUIDANCE AND VISIBLE SATELLITE IMAGERY ARE TRENDING
TOWARDS A WETTER PATTERN THAN PREVIOUSLY ANTICIPATED. THERE IS
SUFFICIENT MOISTURE AND A WEAK CIRCULATION EMBEDDED WITHIN A TROUGH
CURRENTLY ESE OF GUAM TO PRODUCE LOW-END SCATTERED SHOWERS FOR THE
MARIANAS AFTER MIDNIGHT. GUAM WILL SEE THE POTENTIAL FOR ISOLATED
THUNDERSTORMS AFTER MIDNIGHT, REACHING ROTA THROUGH TUESDAY NIGHT.
THE SUBTROPICAL RIDGE CONTINUES TO BRING DRIER AIR NORTH OF 14N, SO
TINIAN AND SAIPAN WILL MOST LIKELY BE SPARED FROM ANY LIGHTNING
THREATS, AS EVIDENT BY AN OUTFLOW BOUNDARY THAT DECAYED RAPIDLY AS IT
WAS EJECTED NORTH FROM THE CONVECTIVE ACTIVITY FAR EAST OF GUAM.
EASTERLY TRADE WINDS OF 5 TO 10 MPH ARE EXPECTED WITH OCCASIONALLY
HIGHER GUSTS NEAR THUNDERSTORMS. ONCE THIS FEATURE PASSES THROUGH,
THE MARIANAS MAY RETURN TO THE DRY TRADE-WIND REGIME, WITH ISOLATED
SHOWERS IN THE FORECAST BEGINNING WEDNESDAY.
MARINE
BUOY DATA SHOWS BENIGN SEA CONDITIONS, WITH COMBINED SEAS AROUND 3 TO
4 FEET. A SLIGHT INCREASE IN THE NORTHEAST SWELL IS EXPECTED
ON TUESDAY, SO COMBINED SEAS MAY INCREASE BY A FOOT BEFORE TAPERING
BACK DOWN TO 3 TO 4 FEET TUESDAY NIGHT. THE MINOR NORTH SWELL WILL
BECOME NEGLIGENT TUESDAY NIGHT, SO NORTH- AND WEST-FACING SURF WILL
DECREASE A FOOT OR TWO. STILL, A MODERATE RISK OF RIP CURRENTS EXISTS
ALONG NORTH- AND EAST-FACING REEFS AT LEAST THROUGH WEDNESDAY. A
MODERATE RISK OF LIGHTNING IS IN STORE FOR GUAM AFTER MIDNIGHT,
SPREADING TO ROTA THROUGH TUESDAY NIGHT.
EASTERN MICRONESIA
AN OVERALL DRY PATTERN REMAINS OVER THE REGION. LATEST SATELLITE
IMAGERY SHOWS PARTLY CLOUDY SKIES WITH SPOTTY SHOWERS ACROSS MOST OF
THE REGION. A SURFACE TROUGH IS GENERATING SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS TO THE EAST OF MAJURO. ALTIMETRY SHOWS SEAS
BETWEEN 2 AND 4 FEET AT POHNPEI AND KOSRAE AND 3 TO 5 FEET FOR THE
MARSHALL ISLANDS.
THE DRY PATTERN CONTINUES ACROSS EASTERN MICRONESIA THIS AFTERNOON.
LATEST MODEL GUIDANCE SHOWS THIS PATTERN CONTINUING THROUGH THE WEEK.
A SURFACE TROUGH SEEN STRETCHING WESTWARD ACROSS THE MARSHALLS IS
GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO THE EAST
OF MAJURO AND THIS AREA OF CONVECTION IS MOVING SLOWLY TOWARD THE
MARSHALLS. MODELS KEEP MAJURO DRY, HOWEVER, BASED ON SATELLITE
TRENDS, DECIDED TO MOVE THE TROUGH EFFECTS OVER MAJURO TUESDAY, WITH
POPS (PROBABILITY OF PRECIPITATION) BOUNCING AROUND FROM 20 TO 40
PERCENT TUESDAY THROUGH WEDNESDAY NIGHT. THE REMAINDER OF THE REGION
LOOKS TO REMAIN FAIRLY DRY. THE MARINE FORECAST REMAINS BENIGN AS
WELL, WITH MOSTLY LIGHT WINDS AND SEAS OF 5 FEET OR LESS.
WESTERN MICRONESIA
SATELLITE IMAGERY SHOWS MOSTLY CLOUDY SKIES AND SCATTERED SHOWERS
ACROSS CHUUK STATE AND WENO. ISOLATED SHOWERS ARE SEEN ACROSS PALAU
AND YAP. ALTIMETRY SHOWS COMBINED SEAS BETWEEN 3 AND 5 FEET.
OVERALL, THERE IS VERY LITTLE CHANGE WITH THE FORECAST PACKAGE FOR
WESTERN MICRONESIA. SURFACE CONVERGENCE WILL CONTINUE TO BRING LOW-
END (30%) TO WENO TONIGHT. SHOWER COVERAGE LOOKS TO DROP TO ISOLATED
THROUGH THE PERIOD AS SURFACE DIVERGENCE MOVES IN FROM THE EAST.
PALAU AND YAP REMAIN IN A RELATIVELY DRY PATTERN. SCATTERED SHOWERS
ARE EXPECTED TOMORROW AS ENHANCED CONVERGENCE FROM THE DEPARTING
CIRCULATION WEST OF YAP WILL MOVE OVER THE REGION. THEN, ANOTHER
LULL IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY NIGHT AS A SURFACE
RIDGE MOVES INTO THE REGION. LATE THIS WEEK, GUIDANCE SHOWS ANOTHER
WEAK CIRCULATION MOVING SOUTH OF PALAU THAT LOOKS TO BRING SCATTERED
SHOWERS TO PALAU AND YAP AS WE HEAD INTO THE WEEKEND.
NO CHANGES WERE MADE TO THE MARINE FORECAST. COMBINED SEAS REMAIN
BENIGN BETWEEN 3 AND 5 FEET. THIS WILL PERSIST THROUGH THE NEXT
SEVERAL DAYS AS SUMMERTIME DOLDRUMS ARE IN FULL EFFECT.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS: MESA
EAST MICRONESIA: KLEESCHULTE
WEST MICRONESIA: WILLIAMS
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