188
FXPQ50 PGUM 271852
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
452 AM ChST Fri Jun 28 2024

.Marianas Synopsis...
Satellite shows mainly fair skies across the local region, with just
scattered low clouds and a few mid to higher level clouds also
streaming across the region. Surface winds are gentle and Ritidian
Buoy shows combined seas 4 to 5 feet with occasional bigger sets.

&&

.Discussion...
Dry trade winds will persist for the near term. Later over the
weekend, a trade-wind trough is expected to move through the
Marianas, with a second trough seen a little farther south not far
behind the first trough. Also, an upper-level low expected to be to
the northwest of the Marianas will help develop locally heavy showers
and isolated thunderstorms for the Marianas over the weekend.

&&

.Marine/Surf...
Combined seas of 4 to 6 feet are expected into the weekend, then
slowly subside to 3 to 5 feet on Sunday. There will be a moderate
risk of rip currents along east facing reefs through at least the
middle of next week. There will also be a moderate risk of lightning
Saturday and Saturday night.

&&

.Eastern Micronesia...
Convergence trailing behind a departing trade-wind trough is
maintaining scattered showers and isolated thunderstorms around
Pohnpei, and to a lesser extent Kosrae this morning. Over towards
Majuro, isolated showers are expected today, then trade convergence
ahead of a trough that is moving across the Date Line is expected to
increase showers tonight and Saturday. Overall, the region remains in
a wetter pattern, especially with a more active ITCZ pattern taking
shape over the weekend and into next week.

Fairly benign marine conditions expected over the next several days.
No hazards anticipated other than localized effects from areas of
heavier showers or thunderstorms. Winds will be mostly moderate,
occasionally fresh with seas between 3 and 5 feet, maybe up to 6 or
7 feet just east of the Marshalls. Wave model data shows a dominant
east swell, though Pohnpei and Kosrae will see some southeasterly
swell from southeast trades across the South Pacific.

&&

.Western Micronesia...
Satellite imagery shows moderate to strong convection along a trough
east of Chuuk this morning. A cluster of thunderstorms are over far
southern Chuuk waters this morning, however the bulk of convection
remains alongside the trough axis and is expected to move through
Chuuk tonight.

Farther west, showers and thunderstorms are spread out across Palau
and Yap State due to weak trade-wind convergence. Well to the south,
near the equator, scatterometry shows some weak turning of the winds.
From this, models indicate a weak disturbance developing as it
drifts northwestward and anchors a trough that will stretch across
Yap and Palau by tonight. Scattered to numerous showers and isolated
thunderstorms are expected through tonight as trade-convergence
strengthens north of this feature. Latest WRF model winds suggests
convectively-driven gusts are possible for Palau so decided to add
gust potentials into the forecast, despite the lukewarm support seen
in the deterministic models. The trough pushes off to the northwest
after tonight, however convergent southerly winds behind the trough
are expected to maintain scattered showers and isolated thunderstorms
through at least Saturday night. By next week, the regional weather
transitions into a weak surface wind pattern and may at times allow
some weak circulations to briefly appear but models show nothing of
significance taking root beyond a weak flow pattern.

Scatterometry data reveals mainly moderate trades around Chuuk and
gentle to moderate winds around Palau and Yap. Strong to fresh gusts
are possible for Palau with heavier showers, then winds for the
region are anticipated to weaken to light to gentle by next week.
Buoy data indicates seas between 4 and 6 feet, and seas are expected
to decrease to 3 to 5 feet over the weekend.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...None.
MP...None.
Marianas Waters...None.
&&

$$

Marianas: Simpson
Micronesia: Cruz