293
FXPQ50 PGUM 031924
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
524 AM ChST Tue Jun 4 2024

.Marianas Synopsis...
Gentle to moderate trades prevail in the region, with satellite
imagery indicating a minor disturbance just south of Guam`s coastal
waters. Latest altimetry passes indicate seas are 3 to 4 feet.

&&

.Discussion...
Little change has been made to the forecast. A combination of
elevated winds and sub 2-inch PWAT values indicate a low chance
for island convection this afternoon, with mostly pleasant weather
expected through tonight. A minor disturbance is expected to move
through the region Wednesday, bringing low-end scattered showers
through Wednesday night with a chance for thunderstorms due to the
Tropical Upper-Tropospheric Trough (TUTT) overhead, before drier
conditions return thereafter.

&&

.Marine...
Combined seas of 3 to 4 feet will start to increase in the second
half of the week, as wind waves and trade swell strengthen over the
next several days. A low rip current risk is expected along all reefs
through tonight, before becoming moderate along east reefs starting
Wednesday. Surf will continue to increase along north and east facing
reefs in the second half of the week, introducing a moderate risk of
rip currents along north facing reefs as early as Thursday.

&&

.Eastern Micronesia...
The bulk of the convection along the Inter-Tropical Convergence Zone
(ITCZ) has lifted slightly northward overnight, likely due to the
upper-level influence of the TUTT cell east of the Marianas.
Scattered showers are still occurring at Pohnpei this morning, but
showers have lifted to just north of Kosrae and west of Majuro and
Kwajalein. Expecting convection to rebuild along the ITCZ later today
bringing scattered showers back into Kosrae and Majuro this
afternoon. The ITCZ will continue to support an overall wet pattern
across the region this week, but models show convection weakening
again this weekend along the ITCZ, potentially allowing for more
periods of isolated showers across the islands.

Persistent southeast winds associated with the ITCZ and south of the
Equator have generated a 3 to 5 foot southeast swell that is
affecting mainly Kosrae and Pohnpei, while the primary swell at
Majuro is still easterly. This will produce elevated surf along
south facing reefs, but surf is expected to remain below hazardous
levels of 9 feet. This southeast swell will also weaken later this
week, as winds south of the Equator diminish. Altimetry shows seas
around 4 to 6 feet across eastern Micronesia, and seas are not
expected to change much this week. Winds are gentle to moderate,
becoming fresh near heavier showers.

&&

.Western Micronesia...
Showers remained fairly isolated across western Micronesia overnight
as Chuuk remains west of the ITCZ in eastern Micronesia and Palau
and Yap were in a pattern of light winds surface winds and fairer
weather, also known as the Doldrums. The overall weather pattern is
expected to change today however. A TUTT cell has developed north of
Yap and west of the Marianas, and this TUTT cell will help to
destabilize the atmosphere across Palau and Yap, increasing the risk
for showers and thunderstorms. The destabilizing of the atmosphere,
along with light winds, will also increase the potential of island-
effect showers as island heating will promote increased convection
over the islands, especially during the afternoon hours. Models have
this TUTT cell slowly drifting southwest and weakening through
Wednesday, allowing the potential of showers and thunderstorms to
decrease around Wednesday or Thursday.

For Chuuk, models have a trough breaking off the western edge of the
ITCZ and pushing into Chuuk State as early as this afternoon. This
will help to keep easterly winds moderate to fresh across Chuuk,
bring scattered showers and isolated thunderstorms to Chuuk through
Thursday. Showers are then expected to decrease back down to
isolated around Friday as the trough moves into Yap and Palau,
increasing the potential for showers across these islands.

Benign sea conditions are expected to continue across the region
through the end of the week. Buoys near Yap and Palau show combined
seas mainly 1 to 2 feet due to light swell and winds. Around Chuuk,
altimetry is showing seas around 3 to 4 feet, and seas are expected
to build 1 to 2 feet as the easterly swell builds slightly.

&&

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

$$

Marianas: Montvila
Micronesia: Schank