622
FZPQ50 PGUM 180656
SRFGUM

Surf Zone Forecast for the Mariana Islands
National Weather Service Tiyan GU
456 PM ChST Sat Oct 18 2025

.DISCUSSION...A moderate risk of rip currents is expected along north
and east facing reefs of the Marianas for much of the forecast period.
Surf is likely to taper down along all reefs once the swells weaken,
with the northerly swell to dissipate by the second half of next week.
High risk of lightning through midnight tonight, before becoming
moderate until early Sunday morning.

$$

GUZ001-MPZ001>003-182200-
Guam-Rota-Tinian-Saipan-
456 PM ChST Sat Oct 18 2025

36 hour Surf Zone Forecast for the Marianas from 600 PM Saturday
through 600 AM Monday

.TONIGHT...
Rip Current Risk.....Moderate *.
Surf Height
      North facing reefs............4 to 6 feet.
      East  facing reefs............5 to 7 feet.
      South facing reefs............1 to 2 feet.
      West  facing reefs............2 to 4 feet.
Swell/Period
      Primary swell................East at 3 to 5 feet.
      Primary period...............10 seconds.
      Secondary swell..............North at 2 to 3 feet.
      Secondary period.............11 seconds.
Water Temperature
      Ritidian buoy..........86 Degrees.
Winds...............East at 15 to 20 mph.

.SUNDAY...
Rip Current Risk.....Moderate *.
Surf Height
      North facing reefs............4 to 6 feet.
      East  facing reefs............5 to 7 feet.
      South facing reefs............1 to 2 feet.
      West  facing reefs............2 to 4 feet.
Swell/Period
      Primary swell................East at 3 to 5 feet.
      Primary period...............9 seconds.
      Secondary swell..............North at 2 to 3 feet.
      Secondary period.............10 seconds.
Max Heat Index.........Around 102.
Winds...............East at 15 to 20 mph.

.SUNDAY NIGHT...
Rip Current Risk.....Moderate *.
Surf Height
      North facing reefs............3 to 5 feet.
      East  facing reefs............5 to 7 feet.
      South facing reefs............1 to 2 feet.
      West  facing reefs............1 to 3 feet.
Swell/Period
      Primary swell................East at 3 to 5 feet.
      Primary period...............9 seconds.
      Secondary swell..............North at around 2 feet.
      Secondary period.............10 seconds.
Winds...............East at 10 to 20 mph.


Tide information for the next 36 hours...

At Apra Harbor, Guam...
High tide  2.3 feet at  6:08 PM Saturday
Low  tide  0.6 feet at 12:26 AM Sunday
High tide  2.0 feet at  6:14 AM Sunday
Low  tide  0.6 feet at 12:18 PM Sunday
High tide  2.3 feet at  6:30 PM Sunday
Low  tide  0.4 feet at 12:58 AM Monday

At Rota Island...
High tide  2.1 feet at  6:05 PM Saturday
Low  tide  0.6 feet at 12:20 AM Sunday
High tide  1.9 feet at  6:11 AM Sunday
Low  tide  0.5 feet at 12:12 PM Sunday
High tide  2.1 feet at  6:27 PM Sunday
Low  tide  0.4 feet at 12:52 AM Monday

At Tinian Island...
High tide  1.5 feet at  5:30 PM Saturday
Low  tide  0.5 feet at 11:47 PM Saturday
High tide  1.3 feet at  5:22 AM Sunday
Low  tide  0.4 feet at 11:32 AM Sunday
High tide  1.5 feet at  5:48 PM Sunday
Low  tide  0.3 feet at 12:26 AM Monday

At Tanapag Harbor, Saipan...
High tide  2.1 feet at  6:13 PM Saturday
Low  tide  0.7 feet at 12:22 AM Sunday
High tide  1.9 feet at  6:25 AM Sunday
Low  tide  0.6 feet at 12:17 PM Sunday
High tide  2.1 feet at  6:35 PM Sunday
Low  tide  0.5 feet at 12:57 AM Monday

* 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.

$$