367
FXPQ50 PGUM 270850
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
650 PM ChST Mon May 27 2024

.Marianas Synopsis...
Satellite imagery is showing mostly clear skies for Tinian and
Saipan, with partly cloudy skies and isolated showers for Guam and
Rota. Latest altimetry data is indicating seas of 3 to 5 feet in the
coastal waters.

&&

.Discussion...
A surface trough is clipping the southern Marianas this evening.
Lingering showers this evening across Guam should diminish by late
evening. Spotty light showers possible for the CNMI. For the rest of
the week, expect partly cloudy skies and isolated showers to
continue, with the best coverage over Guam, being closest to the
deeper moisture and convergence down in Micronesia. May need to
increase showers and even thunderstorm potential Wednesday into
Thursday, as a weak Tropical Upper Tropospheric Trough (TUTT) is
predicted drift west across the Marianas.

Model guidance continues to suggest flow turning more southerly and
drawing deeper moisture from Micronesia across the region by late
weekend, with an increase in clouds and showers expected. For now,
confidence is too low this far out and capped Probability of
Precipitation (POP) at 20 percent, but skies becoming mostly cloudy.

&&

.Marine...
Fairly benign marine and surf conditions this week with a slightly
elevated trade swell impacting the waters. A background west to
northwest swell emanating from Typhoon Ewiniar, which is passing to
the northwest of the Marianas, looks to impact the waters by around
Thursday. Gentle to moderate trade winds expected through Thursday,
then becoming light to gentle late week. Sea heights 3 to 5 feet look
to rise about a foot tonight through Tuesday night, then drop back
down to 3 to 5 feet Wednesday.

Surf may increase along west and north facing reefs as a background
north swell looks to arrive Wednesday, followed by a west to
northwest swell emanating from distant Typhoon Ewiniar arriving by
around Thursday. Rip risk may become moderate along those reefs. A
moderate risk of rip currents along east facing reefs and a low risk
along south facing reefs should continue.

&&

.Eastern Micronesia...
A weak trough is moving into Majuro waters, producing cloud cover
with shower coverage expected to increase later tonight. Kosrae is
on the easternmost edge of the convergence zone, with some showers
and cloudiness expected tonight. Pohnpei is right in the middle of
the convergence zone, with thunderstorms being observed to form over
the coastal waters.

Once the aforementioned weak trough passes, Majuro can expect to see
fair weather for the next several days. The convergence zone is
expected to remain north of Majuro, but will remain close enough that
if it shifts southward, shower coverage may increase. The next real
chance of showers is this weekend as another convergence zone may
move into the region.

Kosrae can expect to see a couple of days of fair weather, however,
they can sees a trough moving through the region near mid week. Then,
the same convergence zone that is anticipated to bring showers to
Majuro may affect Kosrae, as it is projected to build westward and
strengthen.

Pohnpei is going to be wet for most of the week, with a little break
possibly around tomorrow night into Wednesday morning. A trough is
anticipated to move through before the next convergence zone arrives,
leaving Pohnpei in for a wet weekend.

Seas are expected to be fairly benign this week. Altimetry got a good
pass through RMI with 4 to 5 foot seas. Winds are expected be gentle
to moderate with the strongest of winds near Pohnpei.

&&

.Western Micronesia...
Currently, clouds are starting to form off Palau as a trough is
moving through the region and showers are expected to increase to
scattered before morning. Yap is inbetween spotty convective clouds,
and Yap can expected to see spotty but quick moving showers tonight.
Chuuk is right in the middle of the convergence zone, with scattered
to numerous showers.

Yap and Palau this week can expect to see fair weather for the
beginning half of the week and possibly see some showers for the
later half of the week. These showers are due to the convergence
zone that is over Chuuk, Pohnpei, and Kosrae at the moment. Yap will
likely see these showers first, then Palau.

Chuuk on the other hand, is going to be wet this week. Not only will
this convergence zone linger on for a few more days, a second one
may build in later this week. This would be the same system that is
anticipated for eastern Micronesia, just will be later in the week.

Seas are expected to be fairly benign this week. Altimetry got a good
pass through Yap State with 3 to 5 foot seas. Some WAVE guidance is
suggesting a minor north to northwest swell emanating from distant
Typhoon Ewiniar arriving in the Yap and Palau waters Wednesday, but
any impacts, if any, to seas and surf look minimal. Winds are
expected be gentle to moderate with the strongest of winds near
Chuuk.

&&

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

&&

$$

Marianas: Slagle
Micronesia: Bowsher