370
FZPQ50 PGUM 220611
SRFGUM

Surf Zone Forecast for the Mariana Islands
National Weather Service Tiyan GU
411 PM ChST Tue Jul 22 2025

.DISCUSSION...A moderate risk of rip currents is expected along north
and east facing reefs through at least Wednesday night. A significant
monsoon gyre developing far west-northwest of the Marianas, as well
as tropical disturbance Invest 98W potentially consolidating just east
of the region, are expected to introduce significantly higher east
and west swells in the second half of the week. This will elevate the
risk of rip currents and the potential for hazardous surf conditions
by the weekend, but there remains high uncertainty as to timing and
location.

$$

GUZ001-MPZ001>003-222115-
Guam-Rota-Tinian-Saipan-
411 PM ChST Tue Jul 22 2025

36 hour Surf Zone Forecast for the Marianas from 600 PM Tuesday
through 600 AM Thursday

.TONIGHT...
Rip Current Risk.....Moderate *.
Surf Height
      North facing reefs............3 to 5 feet.
      East  facing reefs............3 to 5 feet.
      South facing reefs............1 to 2 feet.
      West  facing reefs............2 to 3 feet.
Swell/Period
      Primary swell................East at 3 to 4 feet.
      Primary period...............8 seconds.
      Secondary swell..............West at around 2 feet.
      Secondary period.............8 seconds.
Water Temperature
      Ritidian buoy..........86 Degrees.
Winds...............East at 10 to 15 mph.

.WEDNESDAY...
Rip Current Risk.....Moderate *.
Surf Height
      North facing reefs............3 to 5 feet.
      East  facing reefs............4 to 6 feet.
      South facing reefs............1 to 3 feet.
      West  facing reefs............1 to 3 feet.
Swell/Period
      Primary swell................East at 3 to 5 feet.
      Primary period...............8 seconds.
      Secondary swell..............West at around 2 feet.
      Secondary period.............8 seconds.
Max Heat Index.........Around 101.
Winds...............Southeast at 10 to 15 mph shifting to the east
                    in the afternoon.

.WEDNESDAY NIGHT...
Rip Current Risk.....Moderate *.
Surf Height
      North facing reefs............4 to 6 feet.
      East  facing reefs............4 to 6 feet.
      South facing reefs............2 to 3 feet.
      West  facing reefs............1 to 2 feet.
Swell/Period
      Primary swell................East at 3 to 5 feet.
      Primary period...............8 seconds.
      Secondary swell..............West at around 1 foot.
      Secondary period.............8 seconds.
Winds...............Northeast at around 10 mph.


Tide information for the next 36 hours...

At Apra Harbor, Guam...
High tide  2.5 feet at  7:20 PM Tuesday
Low  tide  2.0 feet at 11:59 PM Tuesday
High tide  2.7 feet at  4:50 AM Wednesday
Low  tide -0.4 feet at 12:33 PM Wednesday
High tide  2.6 feet at  8:06 PM Wednesday
Low  tide  1.9 feet at  1:01 AM Thursday

At Rota Island...
High tide  2.4 feet at  7:17 PM Tuesday
Low  tide  1.8 feet at 11:53 PM Tuesday
High tide  2.5 feet at  4:47 AM Wednesday
Low  tide -0.4 feet at 12:27 PM Wednesday
High tide  2.4 feet at  8:03 PM Wednesday
Low  tide  1.8 feet at 12:55 AM Thursday

At Tinian Island...
High tide  1.7 feet at  7:19 PM Tuesday
Low  tide  1.5 feet at 10:44 PM Tuesday
High tide  2.0 feet at  3:48 AM Wednesday
Low  tide -0.6 feet at 12:07 PM Wednesday
High tide  1.7 feet at  8:03 PM Wednesday
Low  tide  1.5 feet at 11:50 PM Wednesday

At Tanapag Harbor, Saipan...
High tide  2.2 feet at  7:43 PM Tuesday
Low  tide  1.8 feet at 11:37 PM Tuesday
High tide  2.3 feet at  4:33 AM Wednesday
Low  tide -0.7 feet at 12:34 PM Wednesday
High tide  2.3 feet at  8:29 PM Wednesday
Low  tide  1.8 feet at 12:54 AM Thursday

* Low Risk of rip currents - Strong currents can still occur near
jetties and reef channels. Always have a flotation device with you
in the water.

Moderate Risk of rip currents - Wave conditions support stronger or
more frequent rip currents. Always have a flotation device with you
in the water.

High Risk of rip currents - Large waves will produce strong rip
currents, especially along narrow reefs and beaches. Rip currents
will be life threatening. If caught in a rip current, swim parallel
to the beach rather than against the current.

$$