Drought in Guam, June 1 to 30, 2025

Area Forecast Discussion
National Weather Service Tiyan GU
526 PM ChST Sat May 31 2025

.Marianas Synopsis...
Gentle to moderate trades prevail. Satellite imagery and Doppler
Radar indicate a few lines of showers entering Guam's northeastern
waters. The buoys indicate seas are 4 to 5 feet.

&&

.Discussion...
A combination of a lingering TUTT cell overhead, southeasterlies with
increasing moisture columns, and a building ridge to the northwest,
are allowing isolated to low-end scattered showers and some
thunderstorms to move in across the Marianas for much of the first
half of next week. Showers will begin to increase moreso starting
Thursday, as a convergence zone builds across the region into next
weekend.

&&

.Marine...
Little change in the marine forecast. Combined seas of 4 to 6 feet
will taper down a foot Sunday, staying as such through at least
midweek. A moderate risk of rip currents is expected along east
facing reefs through at least the first half of next week.

&&

.Fire weather...
Only a trace of rain has fallen at the airport since midnight. More
showers are seen upstream and heading for Guam, but they are not
expected to bring a wetting rain tonight. As such, the KBDI may
either stay around the same or drop slightly, which is currently at
720. There will be a few chances for scattered showers the next few
days, but a widespread wetting rain remains unlikely the next few
days. In addition, the already stressed foliage, especially in the
southern portions of Guam, still continue to pose a high fire danger,
but Red Flag conditions are not expected to be met.

&&

.Eastern Micronesia...
An Inter-Tropical Convergence Zone (ITCZ) continues to strengthen
across eastern Micronesia. The ITCZ stretches west, currently south
of Majuro, into Kosrae. This feature is generating scattered showers
and an occasional thunderstorm over Kosrae. There is a trade-wind
trough that is still crossing the Date Line that looks to move toward
Majuro as it progresses, dragging the ITCZ a little farther north.
This will bring increasing convection to Majuro by Sunday morning.
For Pohnpei, another trade-wind trough is currently moving through
the state, producing scattered showers and isolated thunderstorms
there this afternoon. These showers look to move out this afternoon.
However, convection along the western end of the ITCZ looks to move
into Pohnpei during the afternoon hours. Latest model guidance
indicates that an overall wet, unsettled pattern will remain over the
region through the middle of next week as the developing ITCZ
remains active. There will be periods of increased convection as weak
trade-wind troughs traverse across the area and interact with the
ITCZ. Majuro should see a drier trend around Wednesday next week as
the ITCZ drifts back to the south. This drier pattern also looks to
move into Pohnpei Saturday as the ITCZ also retreats south and
weakens over the state. Kosrae, however, looks to remain in a wet
pattern for a bit longer as the ITCZ remains over the island as it
weakens and eventually dissipates.

Combined seas of 4 to 6 feet for Pohnpei and Kosrae will slowly
subside over the next few days, dropping to between 3 and 5 feet
early next week. For Majuro, seas are slightly higher, currently
between 5 and 7 feet. Seas look to subside to between 3 and 5 feet
for Majuro later next week. Gentle to moderate trade winds will
continue into the coming week, possibly becoming light around midweek
at Pohnpei and Kosrae.

&&

.Western Micronesia...
Satellite imagery this afternoon shows scattered showers over and
just south of Palau, within an area of trade-wind convergence along
the northern periphery of a broad surface trough. Yap sits in a
fairly quiet trade regime for the time being, with isolated showers
and partly cloudy skies across the area. Further southeast over Yap
State, an area of widespread showers and cloudiness is seen,
associated with a broad south-southwest to north-northeast oriented
trough centered between Sorol and Eauripik. Further east, much of
Chuuk State is fairly dry this afternoon, with just isolated showers
and a few remnant outflow boundaries seen near Chuuk Lagoon from deep
convection to the northeast. Trade winds are mostly gentle across
Yap State and the Republic of Palau, and gentle to moderate over
Chuuk. Disorganized trade-wind convergence and the approach of a
broad trade-wind trough will maintain scattered showers near Palau
tonight into early next week, and lead to increasing showers for Yap
later tonight. Although fairly quiet for now, Chuuk and Yap can
expect patchy showers from time to time through early next week, with
an increase in shower chances around the middle of next week.
Several weaker trade-wind troughs look to cross the area over the
next few days, before a more robust disturbance or two look to build
over Chuuk and eastern Yap State around Wednesday.

Benign marine conditions continue. Combined seas of 2 to 4 feet near
Palau and Yap are expected to continue through at least the first
half of this week. Combined seas of 4 to 6 feet near Chuuk will
continue through the weekend, starting to taper down early next week
as the primary swell weakens.

&&

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

Marianas: Montvila
East Micronesia: Kleeschulte
West Micronesia: DeCou