936
FXPQ50 PGUM 150654
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
454 PM ChST Wed May 15 2024

.Marianas Synopsis...
Satellite imagery showing partly cloudy skies and spotty trade
showers for the Marianas. Latest altimetry data is indicating seas
of 5 to 7 feet over the coastal waters.

&&

.Discussion...
The drier trade-wind pattern will persist across the Marianas
through the weekend. Expect partly cloudy skies and isolated trade
showers. May see a slight uptick in clouds and showers at times, as
wrinkles in the trades pass through. Some model guidance continues to
suggest that Invest 93W could develop into a tropical cyclone (TC)
somewhere between Yap and Chuuk and possibly approach and impact the
Marianas early to mid next week. Have introduced an increase in
showers and winds beginning Monday, but forecast confidence remains
low, as much model uncertainty in timing, location and strength of
any possible TC persists this far out. For more information on
Invest 93W, please read the Tropical Systems section below.

&&

.Marine/Surf...
Trade winds will be to fresh through Friday night, then increase
slightly over the weekend as the gradient tightens in between high
pressure passing to the north and a tropical disturbance to the
south. Combined seas of 5 to 7 feet through Saturday. Seas look to
increase by later Sunday into early next week as an elevated swell
emanating from a storm system northwest of Hawaii arrives and wind
waves increase. Depending on the location and strength of a potential
tropical cyclone early to mid next week, winds and sea conditions
could be higher and may become hazardous to small craft.

There will be a moderate risk of rip currents along east facing
reefs through at least Friday. The rip current risk will remain low
along all other reefs. Surf may build slightly for east and north
facing reefs over the weekend, possibly increasing the rip current
risk to high for east reefs and moderate for north reefs.

&&

.Tropical Systems... A weak circulation, Joint Typhoon Warning
Center (JTWC) Invest 93W, centered near 3N143E, is seen along the
Near- Equatorial Trough (NET). Latest model guidance varies
dramatically on the possible development of 93W, with the GFS again
being the most aggressive. Most of the other models show a weaker
circulation moving through the region along the NET. A key ingredient
is still lacking along the NET that would point to a more aggressive
solution, as indicated by the GFS, and that is a pronounced westerly
flow south of the NET. It is likely that this will eventually come
to fruition, and when it does, we will begin to lean more toward the
possible development of a Tropical Cyclone. As for now, everyone in
western Chuuk State, Yap State, the Republic of Palau and the
Marianas should monitor forecasts for any updates or changes noted in
the region.

&&

.Eastern Micronesia...
An active Inter-tropical Convergence Zone remains the primary
weather producer across eastern Micronesia. Along with the ITCZ, a
series of weak trade-wind troughs are evident, traversing the ITCZ.
The interaction between the ITCZ and the troughs will maintain a wet
pattern across the region for the next several days. Latest model
guidance does indicate that the ITCZ will begin to break down early
next week. As the cross-equatorial flow begins to wain, convection is
expected to decrease over Majuro as early as Monday night and at
Kosrae around Tuesday. POPs (Probability of Precipitation) looks to
remain around 30 percent for Pohnpei through midweek.

Gentle to moderate trade winds are expected to persist at Pohnpei and
Majuro through the beginning of next week, with light to gentle winds
expected at Kosrae. Combined seas of 4 to 6 feet will continue for
Pohnpei and Kosrae, with seas of 5 to 7 feet expected at Majuro.

&&

.Western Micronesia...
The NET remains the focus for western Micronesia for the next several
days, well into next week. The NET stretches east-northeastward from
near 1N130E to a weak circulation, Invest 93W, centered near 3N143E,
then continues southeast to end near EQ154E. The strong convergence
north of the trough and east of Invest 93W, is generating numerous
showers across Chuuk that look to continue through the end of the
week, though short periods of scattered showers are possible. Locally
heavy showers are a possibility through the next few days as well.
Even though little lightning is evident over the area, the potential
for isolated thunderstorms will continue for the next several days.

For Yap and Palau, the majority of the weather for the week revolves
around the possible development of Invest 93W and the movement of
the NET. Models have been persistent with moving the NET northward
over the past week or so, but it just hasn`t happened. Therefore,
until the NET actually begins to drift north, which is very likely
to occur, there will be fairly low confidence in the forecast for
both Yap and Palau. It does look good for both locations to see a
slight increase in showers Thursday night as a trade-wind trough
moving through to the north of the NET approaches the area. Showers
look to drop back to isolated by Friday at Yap, but look to remain
over Palau a bit longer. Then, a drier pattern pattern is in the
forecast, though this could change any day when the NET actually
begins to move northward.

Palau will see combined seas of 3 to 5 feet over the next several
days, along with light to gentle winds. Seas of 4 to 6 feet and
gentle to moderate winds are on tap for Yap and Chuuk, with winds
becoming light to gentle over the weekend for Chuuk. Depending on
the development of Invest 93W, seas and winds could change for all
three locations.

&&

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

&&

$$

Marianas: Slagle
Tropical: Kleeschulte
Micronesia: Kleeschulte