231
FXPQ50 PGUM 170807
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
607 PM ChST Mon Jun 17 2024

.Marianas Synopsis...
Partly cloudy skies with isolated showers over the CNMI. Mostly
cloudy with scattered showers for Guam. Gentle to moderate trade
winds prevail across the Marianas. Ritidian buoy shows seas between 5
and 6 feet, while altimetry shows 3 to 6 feet.

&&

.Discussion...
A weak disturbance moving through to the south of Guam is producing
scattered showers and isolated thunderstorms over southern Guam and
coastal waters. This disturbance will move through overnight, with
drier conditions moving in around mid-morning Tuesday. Then, the dry
trade-wind pattern that is already in place over the CNMI is expected
to push into Guam, with a drier pattern continuing into next week.

&&

.Marine...
Gentle to moderate trade winds are expected to continue across the
coastal waters into the weekend. Winds could become mostly gentle
for a brief period on Thursday. Combined seas of 4 to 6 feet will
continue to slowly subside over the next couple of days, dropping to
between 2 and 4 feet by the end of the week. The trade-wind swell
will be sufficient to maintain a moderate risk of rip currents along
east facing reefs for the next several days.

&&

.Eastern Micronesia and Chuuk...
The ITCZ was fairly active across the region this morning, but
convection is starting to wane, especially around Kosrae where
satellite imagery shows skies have become partly cloudy with only
isolated showers. Otherwise scattered showers and isolated
thunderstorms are across the Marshall Islands, mainly near and south
of Kwajalein, and through Pohnpei and Chuuk. Models now show the ITCZ
fragmenting into a series a troughs Tuesday or Wednesday, which
would begin to concentrate showers around these troughs, still
supporting a wet pattern across the region, but allowing periods of
isolated showers across some of the islands like Kosrae this evening.
Kosrae is expected to have scattered showers and isolated
thunderstorms push back in Tuesday afternoon as the convergence near
the Marshall Islands pushes westward, which should allow showers to
briefly become isolated at Majuro Wednesday before the next trough
moves in from the central Pacific. For Chuuk and Pohnpei, periods of
isolated showers are possible but given the variation between
models, the exact timing of when this would occur is difficult to
pinpoint and will be evaluated in future forecasts.

Latest altimetry shows combined seas of 4 to 6 feet across the
region, with some locally higher seas possible near heavier showers
and thunderstorms. Seas are not expected to change much this week as
the trade swell is expected to change very little. Besides locally
stronger gusts near showers and thunderstorms, winds will remain
gentle to moderate this week, becoming moderate to fresh at Majuro
around Wednesday.

&&

.Western Micronesia for Palau and Yap...
Scattered to numerous showers and isolated thunderstorms are still
the predominate weather across western Micronesia as a broad
disturbance, made up of a surface trough that extends into the region
from the Philippines, and the ITCZ extending across Chuuk State.
Models suggest the surface trough will continue to linger in far
western Micronesia, though it may retreat slightly westward towards
130E as the trade winds push further into western Micronesia and the
surface trough struggles to extend westward to southeast Asia, as
Palau and Yap remain in this early transitional phase of the summer
monsoon pattern. This will continue to keep Palau and Yap in a fairly
active pattern through the rest of the week and into the weekend,
though a westward shift of the trough may allow some of the heavier
convection to move west of Palau and Yap, briefly decreasing the
potential for thunderstorms at Yap Wednesday and Thursday, and Friday
for Palau. Winds are expected to remain gentle to moderate overall,
with winds at Yap mainly from the southeast, while Palau will be more
variable overall likely switching between southeast and southwest at
times depending on how the troughs moves over the next few days.

Buoy and altimetry data show seas around 2 to 3 feet around Palau and
3 to 5 feet around Yap. Marine conditions are not expected to change
that much over the next several days.

&&

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

$$

Marianas: Kleeschulte
Micronesia: Schank