Rip Current in Guam, January 4 to 6, 2025

Area Forecast Discussion
National Weather Service Tiyan GU
550 PM ChST Sat Jan 4 2025

.Marianas Synopsis...
Moderate trades prevail across the region. Various buoys across the
Marianas are indicating seas of 5 to 7 feet.

&&

.Discussion...
Isolated trade showers are expected through Monday, followed by a
short stint of elevated shower coverage Monday night through Tuesday,
as a convergence zone builds ahead of a col formed near Iwo-To by a
deep low moving off the coast of Japan. Showers will quickly diminish
thereafter as drier, diffusive trades return.

&&

.Marine...
Combined seas of 5 to 7 feet are expected to increase 1 to 2 feet
through Monday night, as trade swell strengthens and another long-
period north swell makes its way across the region. Sea conditions
may become hazardous to small craft late Monday night or Tuesday as
the trade winds increase. A moderate risk of rip currents is expected
along west, north, and east facing reefs through Monday, with higher
likelihood of rip current risk becoming high along east reefs Monday
night.

&&

.Eastern Micronesia...
The Inter-Tropical Convergence Zone (ITCZ) has spawned an area of
disturbed weather and heavy showers over much of Pohnpei State and
southeastern Chuuk State. This area of showers is moving westward.
Another section of the ITCZ is causing showers and thunderstorms to
the east and southeast of Majuro. Model guidance indicates that the
areas of showers will continue westward, and unsettled weather will
persist over Eastern Micronesia the next couple days. A weak surface
ridge is seen over Kosrae this afternoon. Otherwise, the trade-wind
flow is expected to increase for the coming week with some patchy
showers developing at times.

The moderate to fresh winds that prevail southward to about 5N will
gradually increase and become fresh to strong in the coming days.
Combined seas will build over the next few days as a large north
swell, produced by a strong high pressure over the north Pacific,
continues spreading southward into the region. Seas could reach as
high as 10 feet next week for Pohnpei and Kosrae, with seas possibly
as high as 12 feet at Majuro. A Small Craft Advisory is expected as
early as Tuesday next week, and a High Surf Advisory for north facing
reefs is probable as soon as Tuesday for Pohnpei and Kosrae, and on
Wednesday for Majuro.

&&

.Western Micronesia...
Himawari visible satellite imagery earlier this afternoon revealed
scattered to numerous showers across the Republic of Palau along the
northern periphery of the Near-Equatorial Trough (NET), and across
much of Chuuk State within a broad region of troughing near the
western extent of the ITCZ. Most of the showers look to remain south
of Yap Proper, but coverage could climb to scattered at times
overnight as the NET lifts slightly north. Proximity to the NET will
keep Palau in a wetter pattern for the remainder of the weekend into
early next week, with a brief drier period around midweek before the
NET rebuilds in the area. Yap will remain on the drier side for the
rest of the weekend, but a series of surface troughs will bring
showers for the first half of next week. To the east, Chuuk will see
a gradual waning of showers through Sunday night as troughing in the
area diminishes and the ITCZ falls apart, before a trade-wind trough
crosses the area, bringing scattered showers on Monday.

Latest altimetry and buoy data show seas of around 4 to 7 feet across
the region. Combined seas and surf may increase a foot or two this
weekend into early next week as pulses of a larger northerly swell
begin to push through the region, initially for Chuuk overnight, and
for Yap and Palau Sunday night into early next week. Winds will be
moderate to occasionally fresh throughout the forecast period.

&&

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

Marianas: Montvila
East Micronesia: Simpson
West Micronesia: DeCou