115
FXPQ50 PGUM 280624
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
424 PM ChST Tue May 28 2024

.Marianas Synopsis...
Satellite shows fair weather across the Marianas region. Active
weather was farther south over eastern Yap State, Chuuk State and
northern Pohnpei State, along and south of 10N. Typhoon Ewiniar is
far to the northwest, south of Okinawa, and moving toward the
northeast. Local airports report gentle to moderate surface winds,
and gradient winds on the morning sounding were from the east at 12
knots.

&&

.Discussion...
Generally fair weather is still expected across the Marianas through
this week, but models do indicate occasional increase in clouds and
isolated showers, especially by Thursday. The mid-level winds are
forecast to become a little more from the southeast, with an increase
in atmospheric moisture arriving from the active weather to the
south and southeast of the Marianas. Also, we`re getting into the
time of year when island convection can develop, especially during
afternoon hours.

&&

.Marine/Surf...
A west to northwest swell coming from Typhoon Ewiniar, far to our
northwest, is expected to arrive on Thursday and Thursday night. It
should be in the 2 to 3 foot range and 12 to 13 second period, but
it`s not unusual for the first arriving swell waves to be larger that
computer models indicate. Otherwise, gentle to moderate trade-wind
conditions are expected to continue through this week.

&&

.Eastern Micronesia including Chuuk...
Numerous showers diminishing over Pohnpei this everning will
diminish over Chuuk overnight. Showers increasing over Majuro will
spread west towards Kosrae by early tomorrow. The ITCZ pattern that
brought the active, wet weather to Chuuk through Kosrae the past few
days is becoming fragmented and and less defined. The ITCZ pattern
will fluctuate north and south and transition to more of a zone of
trade-wind convergence from time to time. Multiple trade troughs and
surges in trade winds will traverse through the convergence zone,
enhancing shower and thunderstorm potential. Showers will generally
be scattered through the weekend, with periods of isolated
thunderstorms. Some guidance is suggesting the convergence zone
becoming better defined and strengthening early next week, with
shower and thunderstorm potential increasing across central and
eastern Micronesia. However, confidence this far out is too low to
introduce more than a chance of showers and slight chance of
thunderstorms.

Combined seas of 4 to 6 feet will remain as such for much of the
period, mainly influenced by the background trade swell. Gentle to
moderate winds also expected. Seas and winds may rise at Majuro over
the weekend and possibly Kosrae, Pohnpei and Chuuk early next week,
as the trade swell and trade winds look to increase.

&&

.Western Micronesia for Yap and Palau...
A surface trough currently moving through western Micronesia is
bringing increasing clouds over Yap and Palau today, but showers
remain isolated. May see a brief lull in showers, but look to
increase back up to scattered by late tonight for Yap and tomorrow
for Palau, and continuing through Thursday as multiple trade
disturbances push through. Periods of isolated thunderstorms will be
possible as well. As we head towards late week into the weekend,
shower and thunderstorm potential looks to decrease as surface
ridging builds over western Micronesia. Although there might be a
slight increase Sunday and Sunday night as models are hinting at a
weak surface trough lifting northwest through the region.

Gentle to moderate trades and seas 3 to 5 ft for Yap with light to
gentle trades and seas 2 to 4 ft for Palau through Friday. Heavier
showers may produce some fresh gusts for Yap waters tomorrow through
Thursday. Winds and seas look to diminish slightly over the weekend.

&&

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

&&

$$

Marianas: Simpson
Micronesia: Slagle