023
FNUS70 PGUM 152341
FWSGUM

Spot Forecast for SE-25-04...NMFS
National Weather Service Tiyan GU
941 AM ChST Wed Jul 16 2025

Forecast is based on forecast start time of 1000 ChST on July 16.
If conditions become unrepresentative...contact the National Weather
Service.

Please contact our office by email at nws.gum.operations@noaa.gov
if you have questions or concerns with this forecast.

.DISCUSSION...The TUTT cell is very close to the Marianas, currently
just east of the islands. There is currently a lull in showers this
morning, but expecting showers to increase along with the development
of thunderstorms this afternoon and tonight. Due to the lack of a
notable surface trough over the Marianas to interact with the TUTT,
expecting showers to remain scattered in coverage with a decrease to
isolated Thursday, but keeping the potential for isolated
thunderstorms elevated. Current model trends keep most of monsoonal
pattern west of the Marianas, but as the near-equatorial trough
in western Chuuk State lifts northward towards the Marianas as a
surface trough, still expect a wetter pattern for the end of the week
and weekend. However, showers are expected to be episodic in nature,
where there may be a periods of showery weather followed by more
sunshine. Winds west and southwest of the Marianas have remain fairly
moderate with some gusty winds near heavier showers. This will limit
much the west to southwest swell will build across the Marianas
over the next few days.

.TODAY (GUGUAN ISLAND)...

Sky/weather.........Partly sunny (55-65 percent). Scattered showers
                    and isolated thunderstorms by this afternoon.
Surface winds (kts).East winds 12 to 14 knots.
Wave heights........5 to 7 feet.

.TONIGHT (GUGUAN ISLAND)...

Sky/weather.........Mostly cloudy (55-65 percent). Scattered
                    showers and isolated thunderstorms.
Surface winds (kts).East winds 8 to 11 knots.
Wave heights........4 to 6 feet.

.THURSDAY (ZEALANDIA BANK)...

Sky/weather.........Partly sunny (45-55 percent). Isolated showers
                    and thunderstorms.
Surface winds (kts).East winds 10 to 13 knots.
Wave heights........4 to 6 feet.

$$
Forecaster...JS
Requested by...Benjamin Richards
Type of request...MARINE
.TAG 2518081.0/GUM
.DELDT 07/16/25
.FormatterVersion 2.0.0
.EMAIL co.sette@noaa.gov,ops.sette@noaa.gov,benjamin.richards@noaa.gov,nws.gum.operations@noaa.gov,eva.schemmel@noaa.gov