211
FXPQ50 PGUM 082034
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
634 AM ChST Tue Jul 9 2024

.Update...
Very little change in forecast philosophy for the Marianas overnight.
The only substantial shift is based on a lead time analysis on
infrared satellite imagery. This showed that the showers we had in
for Wednesday could in fact arrive late tonight, so inserted after
midnight wording into the forecast to reflect that. Otherwise no
significant changes.

Seas will remain at 3 to 5 feet through the period, although they
will be at the lower end of that range through Friday, then toward
the upper end of that range Saturday. East winds will be mainly 10
knots, with some 10 to 15 knot values Saturday. These are still
benign marine conditions, which will continue all this week and
probably into next week as well.

&&

.Eastern Micronesia...
Slight changes were made to the forecasts but shower coverage
remains the same from the previous. The majority of the shower
activity today is expected near Majuro and Kosrae with scattered
showers as trade winds converge and move west across the region.
Expect the line of showers associated with the convergence zone to
lift north throughout the day today, and by Wednesday expect an
increase in shower potential for Pohnpei.

Combined seas of 4 to 6 feet are near Majuro and 3 to 5 feet are
near Kosrae and Pohnpei. Seas are expected to rise another foot or so
by tonight before gradually decreasing later this week.

&&

.Western Micronesia...
In Chuuk, reduced showers and eliminated thunderstorms today and
tonight, and reduced showers Wednesday. Also reduced winds slightly
at Chuuk through Wednesday. At Yap, introduced thunderstorms today.
At Koror Palau, introduced scattered showers through Wednesday. This
really just amounts to short term updates based on satellite and
model trends since yesterday.

Combined seas will remain 3 to 5 feet at Chuuk through the period.
Likewise, at Yap, seas will remain 2 to 4 feet at Yap through the
period. At Palau, seas will remain 2 to 4 feet through Friday, then
could build to between 3 and 5 feet Saturday. Winds will be 5 to 10
knots across all the major islands of Western Micronesia, from the
east at Yap and Chuuk, and from the northwest shifting toward
southwest at Koror, Palau. Altogether, benign marine conditions will
continue.

&&

.Prev discussion... /issued 504 PM ChST Mon Jul 8 2024/

Discussion...
Not much has changed since the previous forecast. Satellite shows
very little shower active to the east of the Marianas, so expecting
partly cloudy skies and isolated showers to continue through Tuesday
night. A disturbance is expected to pass just south of the Marianas
starting around Wednesday. As this disturbance passes near the
Marianas, there will be an increased potential for scattered
Wednesday through Friday. Decided to add isolated thunderstorms to
the forecast for Wednesday through Thursday as newer model data
suggests that an upper-level trough will develop over the Marianas
around that time, and given the expected increase in shower activity,
it will not take much upper-level instability to get thunderstorms
to develop.

Marine...
Gentle to moderate trade winds and combined seas of 3 to 5 feet will
continue through the week as the primary swell remains from the east.
Shower and thunderstorm activity will start to increase Wednesday as
an disturbance passes south of the Marianas and into western
Micronesia.

Eastern Micronesia...
Satellite imagery shows scattered showers just to the east of Majuro
with isolated showers present across much of eastern Micronesia.
There is little change in thought from the previous discussions.
Shower coverage should increase to scattered for Kosrae and Pohnpei
tonight as a trade-wind trough moves through the region. Trade-wind
convergence looks to increase towards the second half of the week,
leading towards likely PoPs for Pohnpei, Kosrae, and Majuro.

Combined seas of 4 to 6 feet are near Majuro and 3 to 5 feet are
near Kosrae and Pohnpei. Seas are expected to rise another foot or so
by Tuesday for Kosrae before gradually decreasing later this week
across eastern Micronesia.

Western Micronesia...
Satellite imagery shows isolated showers for Chuuk and Yap with some
scattered showers just west and east of Palau. Isolated showers are
expected on Tuesday for Yap and Palau as the weak circulation and
trough responsible for scattered showers has shifted westward. The
next weather system will begin to impact Chuuk on Tuesday with
scattered showers as a NET moves into western Micronesia. Likely
showers will be possible Wednesday night for Chuuk and Saturday night
for Palau as the NET moves through the region this week.

Gentle westerly winds should continue through much of the week for
Palau, but outside of that marine conditions should remain benign
through the week. Combined seas of 2 to 4 feet will persist for
Palau and Yap this week, while Chuuk may briefly see 3 to 5 foot seas
towards the middle of the week.

$$

&&

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

$$

Marianas: Stanko
Western Micronesia: Stanko
Eastern Micronesia: Hong