647
FXPQ50 PGUM 080841
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
641 PM ChST Wed May 8 2024

.Marianas Synopsis...
Partly cloudy skies with isolated showers and gentle to moderate
trade winds prevail across the Marianas this evening. Altimetry
shows seas between 4 and 6 feet.

&&

.Discussion...
A weak trade-wind trough is evident on the latest ASCAT analysis to
the east of the Marianas. With this trough, the CIMMS MIMIC
Precipitable Water product shows PWATs increasing above 2 inches.
Therefore, expect isolated showers to become scattered through the
evening as the trough nears the islands, with scattered showers
continuing through around noon on Thursday. By Thursday afternoon, a
dry trade-wind pattern will return to the region. Latest model
guidance has backed off on the unstable pattern moving into the
region Friday, on through the weekend.

&&

.Marine...
Gentle to moderate trade winds look to continue through the weekend.
Combined seas will remain in the 4 to 6 foot range through the
weekend. As the northeast swell diminishes over the next couple of
days, the east trade-wind swell is expected to build.

There is a moderate risk of rip currents along north and east facing
reefs. As the northeast swell diminishes, the rip current risk will
become low along north facing reefs, but will remain moderate along
east facing reefs into the weekend.

&&

.Tropical systems...
A Near-Equatorial Trough (NET) is evident on the latest ASCAT
analysis to the south of Yap and Palau. Along the NET, there are 2
areas of interest being monitored by the Joint Typhoon Warning Center
(JTWC). The first is Invest 92W, a weak circulation centered near
3N149E, the second one is Invest 90W, an area of enhanced convection
centered near 4N140E. Latest model guidance shows both Invest 90W and
92W drifting off to the west-northwest over the next several days,
with no development for 90W, while 92W looks to very slowly organize
over the next several days, though it looks unlikely that 92W will
develop into a significant Tropical Cyclone (TC) before passing
through Palau. Residents of Palau and western Yap State should
continue to monitor forecasts over the next few days for any possible
change in the expectations for Invest 90W and 92W.

&&

.Eastern Micronesia...
Trade-wind convergence along and behind a pair of troughs are
generating scattered showers and isolated thunderstorms within
the region. The first trough is located between Majuro and Kosrae,
while the second trough is pushing over Pohnpei. Both deterministic
and ensemble models still on board with shifting the trade
convergence north and over Majuro, Kosrae, and Pohnpei around Friday
in response to weak circulations lifting the Near-Equatorial Trough
(NET) northward in western Micronesia. Scattered showers and
isolated thunderstorms are expected at Majuro, Kosrae, and Pohnpei as
weak trade-wind troughs traverse the area of trade convergence over
the islands. For early next week, models show the NET moving back
southward over western Micronesia and trade-wind pattern setting over
the region with weak trade-wind troughs moving through the region
leading to periods of showers and thunderstorms.

Moderate trades with up to fresh gusts are expected at Majuro,
Kosrae, and Pohnpei through Thursday, then weakening to gentle to
moderate through early next week. Combined seas of 6 to 8 feet are
expected to drop a foot or two by the weekend and persist through
early next week.

&&

.Western Micronesia...
A trade-wind trough between Pohnpei and Chuuk is expected to impinge
the NET with scattered showers and isolated thunderstorms expected on
Thursday. Model analysis shows convergence along trade-wind troughs
impinge into the NET will keep scattered showers and isolated
thunderstorms in the forecast through at least early next week. For
Palau and Yap, the latest model guidance continues to show the NET
lifting northward with weak circulations embedded in the trough
breaking off and moving west-northwest. For more information related
to the circulations, please see the Tropical Systems section above.
Both the GFS and ECMWF move the NET to just south of the main island
of the Republic of Palau. There is still a bit of model spread and
track of the weak circulations. Therefore, putting in chances for
scattered showers and isolated thunderstorms for now.

Gentle to moderate trades and combined seas of 4 to 6 feet are
expected at Chuuk, Yap, and Palau. Some fresh gusts are possible at
Chuuk through Thursday.

&&

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

$$

Marianas: Kleeschulte
Micronesia: Kelly