FXPQ50 PGUM 240734

AFDGUM



Area Forecast Discussion

National Weather Service Tiyan GU

534 PM ChST Fri Oct 24 2025



.Marianas Synopsis...

Satellite shows mostly cloudy skies and isolated showers moving

through the Marianas Waters. The buoys reveal combined seas of 4 to 5

feet, composed of a moderate trade-wind swell, a small north swell,

and wind waves. This general setup will continue most of next week.



&&



.Discussion...

A few showers will move through tonight with a weak trade-wind

trough. The TUTT, or Tropical Upper Tropospheric Trough, may

contribute some thunderstorms to the mix Saturday. Overall though,

what you see is what you're going to continue to get, through next

Wednesday at least. A tropical disturbance could approach during the

second half of next week, which would increase the showers at that 

time.



&&



.Marine...

Little change is expected in marine conditions. Look for an east

swell that's the largest, a north swell that just detectable, and

wind waves that you can just feel. This will continue through most

of next week.



&&



.Eastern Micronesia...

The interaction of the ITCZ, TUTT, and enhanced convergence east of 

Pohnpei has lead to widespread showers (some with briefly heavy

rainfall) and another prolonged period of thunderstorms continued

from the overnight hours through this afternoon. This looks to

continue tonight as well, so categorical wording with a heavy

rainfall wording was used tonight there. Outflow moving south is also

attempting to backbuild into northern portions of Kosrae, where

lower-end rainfall probabilities/scattered coverage is in the

forecast. 



Additionally, the models show the ITCZ strengthening this

weekend and into next week across the region. Thus, at least chance

probabilities were retained area-wide for the forecast period.

Mariners can expect mainly light to gentle winds, with higher gusts

probable near heavier showers or thunderstorms. Seas will hold in the

4 to 6 foot range.



&&



.Western Micronesia...

A surge in the westernmost extent of the ITCZ is expected to bring

periods of heavier showers, thunderstorms, and stronger winds to

Palau and Yap tonight. After, more pulses in the ITCZ are then going

to bring on-and-off showers with some thunderstorms for the next few

days, with a peak in shower and thunder coverage expected early next

week. Weather conditions will improve slightly thereafter, while a

wet trade-wind pattern continues through at least the middle of next

week. At Chuuk, peak ITCZ action is expected tonight, with scattered

heavy showers and some thunderstorms bringing occasionally near-gale

force gusts, followed by less activity after once the bulk of the

convection continues west toward Palau and Yap.



Combined seas of 4 to 6 feet are expected to taper down by a foot or

two in Palau, Yap and Chuuk waters by the middle of next week, once

the dominant trade swell continues to diminish.



&&



.GUM WATCHES/WARNINGS/ADVISORIES...

GU...None.

MP...None.

Marianas Waters...None.



&&



$$



Marianas: Stanko

East Micronesia: Doll

West Micronesia: Montvila