968
FPMY50 PGUM 202355
ZFPGUM

Zone Forecast for Guam and the Northern Marianas
National Weather Service Tiyan GU
955 AM ChST Fri Aug 21 2026

GUZ001-MPZ001-210900-
Guam-Rota-
955 AM ChST Fri Aug 21 2026

...HIGH RIP CURRENT RISK IN EFFECT FROM 3 PM CHST THIS AFTERNOON
THROUGH SUNDAY AFTERNOON ALONG EAST FACING REEFS...

.REST OF TODAY...Partly cloudy. Isolated showers in the morning,
then scattered, locally heavy island enhanced showers and isolated
thunderstorms beginning near noon for Guam. Light and variable winds.
Highs around 86. Chance of showers 50 percent.
.TONIGHT...Partly cloudy with isolated showers and thunderstorms.
Light and variable winds becoming southwest 10 to 15 mph after
midnight. Lows around 77. Chance of showers 20 percent.
.SATURDAY...Breezy. Partly sunny with isolated showers. Southwest
winds 15 to 25 mph. Highs around 87. Chance of showers 20 percent.
.SATURDAY NIGHT AND SUNDAY...Breezy. Mostly cloudy. Scattered
showers and isolated thunderstorms. Locally heavy showers possible.
Southwest winds 20 to 25 mph. Lows around 77. Highs around 86. Chance
of showers 50 percent.
.SUNDAY NIGHT AND MONDAY... Mostly cloudy. Scattered showers and
isolated thunderstorms. Locally heavy showers possible. Lows in the
upper 70s. Highs in the mid 80s. Chance of showers 30 percent.
.MONDAY NIGHT THROUGH WEDNESDAY...Mostly cloudy with a 40 percent
chance of showers and a slight chance of thunderstorms. Lows in the
upper 70s. Highs in the mid 80s.
.WEDNESDAY NIGHT AND THURSDAY...Breezy. Mostly cloudy with showers
likely and a slight chance of thunderstorms. Lows in the upper 70s.
Highs in the mid 80s. Chance of showers 60 percent.

$$

MPZ002-003-210900-
Tinian-Saipan-
955 AM ChST Fri Aug 21 2026

...TROPICAL STORM WATCH IN EFFECT...
...HIGH RIP CURRENT RISK IN EFFECT FROM 3 PM CHST THIS AFTERNOON
THROUGH SUNDAY AFTERNOON ALONG EAST FACING REEFS...

.REST OF TODAY...Mostly cloudy Scattered showers and isolated
thunderstorms. Light and variable winds becoming northwest around 10
mph in the afternoon. Highs around 86. Chance of showers 50 percent.
.TONIGHT...Tropical storm conditions possible. Mostly cloudy with
scattered showers, becoming numerous and heavy after midnight.
Isolated thunderstorms. Locally heavy showers possible. West winds 10
to 15 mph, increasing to 25 to 40 mph after midnight. Lows around
75. Chance of showers 60 percent.
.SATURDAY THROUGH SUNDAY...Tropical storm conditions possible.
Cloudy. Periods of rain, widespread heavy showers and scattered
thunderstorms. Southwest winds 30 to 40 mph with gusts to 45 mph near
heavier showers. Highs near 84. Lows around 76. Chance of showers 90
percent.
.SUNDAY NIGHT THROUGH WEDNESDAY...Cloudy with a 50 percent chance of
showers and a slight chance of thunderstorms. Lows in the mid 70s.
Highs in the mid 80s.
.WEDNESDAY NIGHT THROUGH THURSDAY...Mostly cloudy with a 40 percent
chance of showers. Lows in the upper 70s. Highs in the upper 80s.

$$