449
FXPQ50 PGUM 220735
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
535 PM CHST WED JUL 22 2026
MARIANAS SYNOPSIS
VISIBLE SATELLITE IMAGERY DEPICTS PARTLY CLOUDY SKIES AND LOW-END
SCATTERED SHOWERS DIMINISHING TO ISOLATED. BUOY DATA INDICATES
COMBINED SEAS OF 3 TO 4 FT. THERE IS A MODERATE RISK OF RIP CURRENTS
ALONG EAST-FACING REEFS.
DISCUSSION
DAYTIME HEATING WARRANTED THUNDERSTORMS AND HEAVY DOWNPOURS OVER
NORTHERN GUAM EARLIER THIS AFTERNOON. AS A COL CONTINUES TO MOVE OVER
THE REGION FROM THE NORTHEAST, WINDS WILL REMAIN LIGHT AND VARIABLE
AT LEAST UNTIL THE WEEKEND. THEREFORE, ISLAND-EFFECT SHOWERS AND
THUNDERSTORMS ARE TO BE EXPECTED FOR THE NEXT COUPLE OF AFTERNOON
PERIODS FOLLOWED BY ISOLATED SHOWERS IN THE OVERNIGHT HOURS. A
FAIRLY DRY ENVIRONMENT WITH LIGHT TO GENTLE EASTERLY TRADE WINDS IS
POSSIBLE STARTING EARLY NEXT WEEK. DUE TO THE INCREASE IN WIND SPEED,
ISLAND-EFFECT SHOWERS, IF ANY, MAY BE CONCENTRATED OVER WESTERN
COASTAL WATERS AT LEAST UNTIL NEXT WEEKEND. THERE IS HIGH UNCERTAINTY
REGARDING A LATE-WEEK APPROACH OF INVEST 93W, SO ISOLATED
THUNDERSTORMS ARE INCLUDED IN THE LAST FEW PERIODS OF THE FORECAST.
MARINE
LIGHT AND VARIABLE WINDS WILL PREVAIL ACROSS THE REGION AT LEAST
UNTIL THE END OF THE WEEK. TANAPAG BUOY SUPPORTS COMBINED SEAS OF 3
TO 4 FT AS A RESULT OF THE PRIMARY, SECONDARY, AND TERTIARY SWELLS
OUT OF THE SOUTHWEST, EAST, AND SOUTHEAST, RESPECTIVELY. DUE TO THE 4
TO 5 FT SURF ALONG EAST-FACING REEFS, THERE IS A MODERATE RISK OF RIP
CURRENTS THAT WILL CONTINUE AT LEAST THROUGH TOMORROW NIGHT.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE A POSSIBILITY DURING
THE NEXT COUPLE OF AFTERNOON PERIODS DUE TO ISLAND-EFFECT HEATING.
TROPICAL SYSTEMS
THERE ARE 2 MONSOON DISTURBANCES ACROSS THE REGION. THE FIRST ONE IS
INVEST 92W, CENTERED NEAR 13.1N 136.0E, DRIFTING NORTH-NORTHWEST.
INVEST 92W HAS BEEN UPGRADED TO MEDIUM, MEANING THAT DEVELOPMENT IS
LIKELY, BUT EXPECTED BEYOND 24 HOURS. INVEST 92W IS SEEN AS A BROAD,
WEAK CIRCULATION WITH CONVECTION CURRENTLY NOT VERY IMPRESSIVE, BUT
APPEARS TO BE GETTING MORE ORGANIZED. 92W IS EXPECTED TO SLOWLY
STRENGTHEN OVER THE NEXT FEW DAYS AS IT MOVES NORTHWEST. LATEST
MODEL GUIDANCE SHOWS 92W POSSIBLY BECOMING A TROPICAL DEPRESSION TO
THE EAST OF LUZON, JUST BEFORE MOVING OUT OF THE GUAM AREA OF
RESPONSIBILITY (AOR). INVEST 92W IS NOT EXPECTED TO HAVE ANY DIRECT
IMPACT WITH POINTS IN MICRONESIA OR THE MARIANAS AS IT MOVES ACROSS
THE PHILIPPINE SEA. FOR MORE INFORMATION ON INVEST 92W, SEE BULLETINS
ISSUED BY THE JOINT TYPHOON WARNING CENTER UNDER WMO HEADER ABPW10
PGTW.
THE NEXT DISTURBANCE IS INVEST 93W, CENTERED ALONG THE MONSOON
TROUGH NNE OF MAJURO NEAR 12.2N 174.7E. 93W REMAINS SUB-LOW, MEANING
DEVELOPMENT INTO A SIGNIFICANT TROPICAL CYCLONE IS NOT EXPECTED OVER
THE NEXT FEW DAYS. IT HAS DRIFTED SLOWLY WEST OVER THE LAST 24
HOURS. 93W IS EXPECTED TO MOVE SLOWLY TOWARD THE WEST TO WEST-
NORTHWEST OVER THE NEXT SEVERAL DAYS WITH LITTLE TO NO CHANGE IN
INTENSITY. IT COULD APPROACH THE MARIANAS LATE IN THE WEEKEND OR
EARLY NEXT WEEK, THOUGH IT IS EXPECTED TO REMAIN FAIRLY WEAK, AS THE
LATEST MODEL GUIDANCE SHOWS INVEST 93W DISSIPATING BEFORE REACHING
THE MARIANAS. INVEST 93W WILL BE MONITORED CLOSELY OVER THE COMING
DAYS FOR ANY INDICATION OF STRENGTHENING.
EASTERN MICRONESIA
A FAIRLY DRY PATTERN REMAINS IN PLACE ACROSS THE FORECAST POINTS IN
EASTERN MICRONESIA THIS AFTERNOON. THIS DRY PATTERN LOOKS TO SLOWLY
ERODE AS THE MONSOON TROUGH MEANDERS ACROSS THE REGION. A WEAK
CIRCULATION, INVEST 93W, REMAINS NORTH OF MAJURO WITH A SECOND
WEAKER CIRCULATION SEEN TO THE WEST OF KOSRAE. THESE TWO FEATURES
WILL HELP INCREASE CONVECTION ACROSS MAINLY POHNPEI AND KOSRAE OVER
THE NEXT SEVERAL DAYS AS THEY ENHANCE THE MONSOON TROUGH. THIS WAS
ALREADY WELL REFLECTED IN THE PREVIOUS FORECAST, SO ONLY MINOR TWEAKS
WERE NEEDED IN THE GRIDS.
FOR THE MARINE ENVIRONMENT, SEAS OF 3 TO 5 FEET WITH LIGHT TO GENTLE
WINDS WILL PREVAIL THROUGH THE BEGINNING OF NEXT WEEK.
WESTERN MICRONESIA
THE SPECIAL WEATHER STATEMENT FOR PALAU AND YAP HAS BEEN ALLOWED TO
EXPIRE. CONDITIONS OVER THE DAY HAVE VASTLY IMPROVED SINCE LAST
NIGHT. THIS IS MAINLY DUE TO INVEST 92W PULLING THE MONSOON TROUGH
AWAY FROM THESE ISLANDS. YAP FOR THE MOST PART IS OUT OF THE EASTERN
PERIPHERIES, WHILE PALAU IS JUST INSIDE THE EASTERN EXTENT. SATELLITE
IMAGERY SHOWS MOSTLY A CIRRUS COVER OF PALAU WITH A FEW OUTFLOW
BOUNDARIES PASSING THROUGH. THESE BOUNDARIES WILL BRING PERIODS OF
THICKER CLOUD COVER AND SOME SHOWERS OVERNIGHT. AS 92W MOVES FURTHER
AWAY, A RIDGE WILL BUILD IN, AND WILL BRING FAIRER WEATHER TO THE
AREA FOR THE WEEKEND. SHOWERS MAY BUILD BACK IN AROUND THE BEGINNING
OF NEXT WEEK AS THE CONVERGENCE ZONE OVER CHUUK MOVES FURTHER WEST.
ALTIMETRY SHOWS COMBINED SEAS NEAR PALAU AND YAP ARE AROUND 5 TO 7
FEET, WITH GENTLE TO FRESH SOUTHWESTERLY WINDS. THESE WINDS ARE
EXPECTED TO DIMINISH TO LIGHT TO GENTLE AS EARLY AS FRIDAY NIGHT.
FOR CHUUK, A BAND OF CONVERGENCE WILL PRODUCE SCATTERED SHOWERS FOR
THE LAGOON FOR THE NEXT SEVERAL DAYS. THIS BAND OF CONVERGENCE IS
PRODUCED BY THE INTERACTION BETWEEN THE WESTERLY FLOW AND THE TRADE
WINDS. THIS INTERACTION IS ANTICIPATED TO REMAIN QUASI-STATIONARY
THROUGH THE WEEKEND. ALTIMETRY SHOWS COMBINED SEAS OF 3 TO 5 FEET AND
THESE SEAS HEIGHTS WILL PREVAIL THROUGH THE BEGINNING OF NEXT WEEK.
WINDS ARE EXPECTED TO REMAIN LIGHT TO GENTLE THROUGH THE WEEKEND.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS: MESA
EAST MICRONESIA: KLEESCHULTE
WEST MICRONESIA: BOWSHER
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page