321
FXPQ50 PGUM 130116 AAA
AFDGUM

Area Forecast Discussion...UPDATED
National Weather Service Tiyan GU
1116 AM ChST Thu Jun 13 2024

.Update...
Showers and cloud cover have decreased over Guam. Only isolated
showers are associated with the weakening trough approaching the
islands. Therefore, forecast was updated to partly cloudy skies and
isolated showers.

&&

.Prev discussion... /issued 413 AM ChST Thu Jun 13 2024/

Marianas Synopsis...
Satellite imagery is showing partly cloudy skies and isolated
showers over the CNMI, with mostly cloudy skies and scattered showers
over Guam. Increasing clouds and showers are approaching the
Marianas from the east. Latest altimetry passes and Ritidian buoy are
indicating seas of 3 to 5 feet.

Discussion...
Showers have become scattered over Guam and are expected to become
scattered over the CNMI later this morning as a surface trough
approaches the Marianas. Isolated thunderstorms are expected later
today as moisture deepens. Models suggest scattered showers and
isolated thunderstorms through tonight, with coverage expected to
decrease on Friday as the trough shifts west.

An upper-level low between the Marianas and Wake Island is slowly
heading west toward the Marianas. As it moves into and to the west of
the islands, upper-level winds should become more supportive for
showers and thunderstorms. Friday night and Saturday look to be the
best time frame for the unstable weather as a subtle surface trough
passes through. For late weekend, shower and thunderstorm potential
looks to decrease as surface and upper-level features push away from
the region.

Marine/Surf...
Gentle to moderate trades will prevail into the weekend. Combined
seas of 3 to 5 feet will slowly build to between 5 and 7 feet over
the weekend as trade swell strengthens. Thunderstorms possible over
the waters through Saturday and could bring some brief gusts of 20 to
25 knots.

A moderate risk of rip currents is expected to continue along east
facing reefs and expected to remain low along all other reefs. Surf
is expected to increase about a foot over the weekend as the trade
swell strengthens. This would bring a moderate risk of rip currents
to north facing reefs.

Eastern Micronesia and Chuuk...
The Inter-Tropical Convergence Zone (ITCZ) is expected to intensify
the next few days, bringing higher shower coverage across Chuuk,
Pohnpei, Kosrae and Majuro coming into the weekend. By early next
week, most of the convection is expected to shift westward, with
seasonal trade showers expected in the first half of next week.

Combined seas of 4 to 6 feet are expected to taper down by 1 to 2
feet near Pohnpei, Kosrae and Chuuk over the next few days as trade
swell weakens. Meanwhile, seas of 5 to 8 feet near Majuro may drop
by 2 to 3 feet by the weekend as both trade swell and wind waves
decrease.

Western Micronesia for Palau and Yap...
A generally unsettled weather pattern remains to be expected for
Palau and Yap through the weekend, as the waters south of Mindanao
and northeastern fringes of Indonesia continue to simmer under the
doldrums. Palau may see more intense showers and thunderstorms
tonight and Friday due to higher likelihood of localized outflow
boundaries forming. Meanwhile at Yap, on-and-off showers are
expected for much of the forecast period.

Combined seas of 2 to 4 feet are expected to last into early next
week, with some localized upticks by a foot possible near outflow
boundaries.

&&

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

$$

Marianas: Slagle
Micronesia: Montvila
Update: Kleeschulte