341
FXPQ50 PGUM 042056
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
656 AM ChST Wed Jun 5 2024

.Marianas Synopsis...
Satellite shows mostly cloudy skies with scattered showers moving
through the Marianas Waters. Cloud tops have been cooling so isolated
thunderstorms are possible. Combined seas of 3 to 5 feet are composed
mainly of trade-wind swell and wind waves.

&&

.Discussion...
The Tropical Upper Tropospheric Trough (TUTT) will be our main
weather maker for the next day or two. We have an area of enhanced
activity bearing down on us, so went with scattered showers and
isolated thunderstorms today, then backed it off gradually at this
time.

Once this TUTT cell moves away, weather will quiet down a bit, have
reflected this in the forecast. The next TUTT cell will likely stir
things up a bit again. Have worked to reflect this as well, the main
uncertainties are in the timing.

&&

.Marine...
Seas will build 1 foot to between 4 and 6 feet tonight. They could
just brush 5 to 7 feet Thursday night, then by Friday they will be
starting to diminish. By Saturday, they could be back down to between
3 and 5 feet. Winds will remain 10 to 15 knots, which allows benign
marine conditions to continue to reign over the Marianas. So, as long
as mariners are watching for lightning, they should be fine weather-
wise.

&&

.Eastern Micronesia...
The ITCZ has nearly fallen apart due to the lack of southeasterly
wind near Kosrae and Majuro, and most of the convection is currently
near and west of Pohnpei, developing along the remaining convergence
and under the upper-level support of the TUTT cell just east of the
Marianas. Looking at satellite imagery showers look to be fairly
isolated across at Pohnpei, Kosrae and Majuro this morning, and while
showers are expected to remain isolated at Kosrae and Majuro today,
given the proximity of the convection near Pohnpei, expect scattered
showers and isolated thunderstorms to move back over the island this
afternoon. Models show southeasterly winds redeveloping south of
Kosrae and Majuro by Thursday, suggesting the redevelopment of the
ITCZ or a Near-Equatorial Trough. This should increase convergence
across the region and increase showers once again, until the feature
falls apart again this weekend.

Altimetry shows seas around 4 to 6 feet across eastern Micronesia,
and seas are not expected to change much through the weekend. Winds
are gentle to moderate, becoming fresh near heavier showers. Gentle to
moderate trades are expected through at least Thursday at Majuro and
Pohnpei before becoming light to gentle and continue through the
weekend. For Kosrae, gentle to moderate trades will become light to
gentle tonight and remain light to gentle through the weekend.

&&

.Western Micronesia...
The Tropical Upper Tropospheric Trough (TUTT) cell that was north of
Yap has been drifting southwest and very near Yap Proper this
morning. The TUTT`s upper-level support is helping to produce
scattered showers and isolated thunderstorms across western Yap State
and especially Palau. The TUTT is expected to continue to drift
southwest and slowly dissipate allowing the potential for showers
and thunderstorms to decrease at Yap Thursday and at Palau by Friday.

For Chuuk, a trade-wind trough, along with upper-level support of the
TUTT near the Marianas is producing scattered showers and isolated
thunderstorms around Chuuk, with the heaviest convection currently
south of Chuuk Lagoon. With the collapse of the ITCZ in eastern
Micronesia, expect the potential for showers to decrease as the
trough pushes west of Chuuk Thursday, and are not expected to
increase again until late this weekend as another trough moves into
Chuuk State.

Benign seas conditions are expected to continue across the region
through the end of the week. Buoys near Yap and Palau show combined
seas around 2 to 3 feet due to light swell and winds. Around Chuuk,
altimetry is showing seas around 3 to 5 feet. Winds are expected to
remain light to gentle across Palau and Yap, while moderate to fresh
winds at Chuuk will become light to gentle later this week.

&&
&&

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

$$

Marianas: Stanko
Micronesia: Schank