253
FXPQ50 PGUM 101934
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
534 AM ChST Mon May 11 2026

.Marianas Update...
Satellite and radar observations show partly cloudy skies and
isolated showers across the Marianas. Altimetry and buoy data show
combined seas between 6 and 8 feet.

Only minor changes were made with this package. The main was to delay
the onset of scattered showers until this afternoon for Guam and
Rota. Latest guidance keeps the bulk of the showers east of island
until the early afternoon period. This aligns with current satellite
observations. Scattered showers were introduced for Saipan and Tinian
tonight with the latest guidance showing a further northward extend
to the showers.

Choppy combined seas of 6 to 8 feet will continue today, but seas are
expected to fall tonight and over the next couple of days. Benign
marine conditions will be in place by Tuesday and look to continue
through the week. A High Risk Of Rip Currents along east facing reefs
remain in effect until this afternoon.

&&

.Tropical Systems Update...
Former Tropical Depression Hagupit (05W) is located near 10N130E,
around 335 miles northwest of Koror and 505 miles west of Yap.
Overnight the JTWC issued their final warning for Hagupit based on
the exposed low-level center well west of any convection. Over the
last few hours robust convection has redeveloped near a mid-level
center that is displaced from the low-level center of Hagupit. JTWC
will continue to monitor the storm for signs of regeneration.

For more information please refer to bulletins from the Joint
Typhoon Warning Center under WMO header WTPN31 PGTW and from the
National Weather Service under WMO header WTPQ31 PGUM.

&&

.Eastern Micronesia Update...
Satellite imager shows scattered showers across Pohnpei with isolated
showers across Majuro and Kosrae. Altimetry shows combined seas
between 5 to 8 feet across the region.

Overall, very little change was made with this forecast package. A
brief lull has set up across eastern Micronesia today. This looks to
shift by Tuesday night as the ITCZ builds through the rest of the
week.

Combined seas are between 5 and 8 feet and are expected fall 1 to 2
feet over the next couple of days. Marine conditions look to remain
benign through the period, but choppy seas will be possible near
heavier showers.

&&

.Western Micronesia Update...
Satellite imagery shows isolated showers across Palau, Yap, and Weno,
with scattered showers seen across far eastern Yap State. Altimetry
data shows combined seas between 4 and 6 feet.

The only change with this forecast package was to delay scattered
showers for Palau and Yap until this afternoon. The lull in shower
and thunderstorm activity looks to be short for Yap with the remnants
of Invest 95W bringing additional showers Wednesday and Thursday.
Chuuk looks to stay active through the week, while Palau enters into
a drier stretch.

No changes were made with the marine forecast. Combined seas of 4 to
6 feet look to remain benign through the period. Some choppy seas
will be possible near heavier showers across Chuuk State this week.

&&

.Prev discussion... /issued 618 PM ChST Sun May 10 2026/

Marianas Synopsis...
Satellite and radar imagery depict an unsettled pattern across the
region, focused east and southeast of the Marianas. Patchy swaths of
cloud cover are seen over the islands, with lines of showers moving
west across the coastal waters of Guam and Rota. Buoy and altimetry
data indicate combined seas are between 6 and 9 feet.

Discussion...
A very broad trough is seen south-southeast of the Marianas,
centered over eastern Yap State. Along its northern periphery,
trade-wind convergence is generating scattered to numerous showers
and isolated thunderstorms across a broad area between Guam and
Pohnpei. Outflow along the leading edge of this convection has been
moving through Guam waters since the morning, and a Flood Advisory
was briefly issued. Models have struggled to capture this convection
and the overall pattern with good agreement on timing or general
coverage, but satellite trends point to an increase in showers
through the evening as the trough, convergence, and convective
development shift westward and closer. This pattern looks to
gradually develop over the next few days as it lurches westward
across Yap State, consolidating slightly around a broad circulation
within the trough. Convergence along the northern edge of this slow-
moving, broad disturbance will maintain a showery pattern near Guam
and Rota, potentially further north, over the next few days. Models
indicate a peak around Monday night into Tuesday morning, but the
pattern is messy and certainty remains somewhat low. The disturbance
looks to stall near Yap Proper during the latter half of the week,
maintaining a generally wetter pattern for the Marianas through
Friday.

Marine...
Moderate to fresh trade winds will continue tonight and Monday,
sustained by the pressure gradient between the subtropical ridge to
the north and the unsettled pattern over western and central
Micronesia. Trade winds and swell diminish Monday night onward as the
pressure gradient slackens, becoming light to moderate late Tuesday.
Combined seas of 6 to 9 feet will relax by several feet through the
first half of next week, becoming 3 to 5 feet around Wednesday
onward. There is a high risk of rip currents along east facing reefs
due to an elevated east-northeast trade swell, which is expected to
persist through Monday. There is also a moderate risk along north and
south facing reefs. There will be a moderate risk for lightning
tonight through Tuesday night for Guam and Rota.

Tropical Systems...
Tropical Depression Hagupit (05W) is located near 10N132E, around
280 miles northwest of Koror, and 445 miles west of Yap. Hagupit
continues to move west into the Philippine Sea, away from western
Micronesia. Himawari visible satellite reveals moderate to deep
convection extending outward from the center, roughly 400 miles to
the northeast and 300 miles to the east and southeast. Drier air is
entraining into the system along its western flank. TD Hagupit is
expected to continue west-northwest over the Philippine Sea through
Monday as it weakens, gradually curving to the north starting late
Monday night and potentially dissipating over the open ocean in the
next day or so. Maximum sustained winds remain at 30 mph.

For more information please refer to bulletins from the Joint
Typhoon Warning Center under WMO header WTPN31 PGTW and from the
National Weather Service under WMO header WTPQ31 PGUM.

Joint Typhoon Warning Center`s Invest 95W, located within the broad
trough over eastern Yap State, was closed earlier today owing to a
lack of a well-defined low-level circulation center and little to no
model development.

Eastern Micronesia...
A moderately active trade-wind pattern is expected to continue the
next several days, as a building convergence zone ahead of a broad
trade-wind trough induces numerous heavy showers and some
thunderstorms overnight at Pohnpei. This will be followed by a
decrease in shower coverage as convection dissipates, with lower-end
patchy showers and some thunderstorms expected thereafter. Meanwhile
at Kosrae, showers and thunderstorms have tapered down considerably
as the moisture moved toward Pohnpei to the west. This will allow the
drier trade-wind regime to last through the first half of the week,
followed by a return of on-and-off showers following another trade-
wind surge. A rebuilding ITCZ is expected to move in and persist,
producing scattered showers and some thunderstorms for much of the
forecast period at Majuro, with peak shower intensity and coverage
expected Tuesday and Tuesday night.

Combined seas of 5 to 6 feet near Pohnpei and Kosrae are expected to
taper down a few feet over the next several days, before increasing
once again as another surge in elevated trade-wind swell makes it
across the region before the next weekend. 5 to 7 foot seas are
expected to persist near Majuro through at least the midweek,
followed by a strengthening trade swell that may bring seas up
another foot or two, which are expected to remain below Small Craft
Advisory criteria for the time being.

Western Micronesia...
Tropical Depression Hagupit was about 280 miles northwest of Koror
and 445 miles west of Yap this afternoon and continues to move west,
away from the region. Farther east, a broad, disorganized tropical
disturbance, formerly known as 95W, continues to bring a large area
of showers across Chuuk State and is starting to move into eastern
Yap State. A low-level circulation has been difficult to locate,
nonetheless, this feature remains at the leading edge of the
unsettled weather pattern in central Micronesia. As Hagupit continues
to depart the region and weakens, scattered showers and isolated
thunderstorms look to linger around Palau through Monday, then a
relatively quiet pattern is expected for the remainder of the week.
At Yap, afternoon satellite imagery shows an upper-level cloud deck
still present over Yap, but showers near the surface have trended
down considerably. Isolated to scattered showers continue through
Monday night, then showers increase across Yap Proper as the
aforementioned disturbance continues to propagate westward through
Yap State. Scattered to numerous showers remain over Chuuk Lagoon
over the next day or two, then the pattern between the tropical
disturbance and the ITCZ begins to fragment momentarily around
midweek, however, mid- to high-end scattered showers look to persist
through the end of the week as the ITCZ rebuilds and extends across
Chuuk towards the weekend.

Altimetry shows combined seas have subsided to 4 to 6 feet at Palau
and 5 to 7 feet near Yap. Seas remain slightly elevated at Chuuk, at
at around 6 to 9 feet. Light to moderate winds continue tonight, then
marine conditions will continue to subside, with light to gentle
winds and seas of 3 to 5 feet expected by Tuesday night. Late week,
winds look to increase slightly, back up to gentle to moderate at
Chuuk late week as the ITCZ attempts to rebuild into the region.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...High Rip Current Risk until 4 PM ChST this afternoon for GUZ001.

MP...High Rip Current Risk until 4 PM ChST this afternoon for MPZ001>003.

Marianas Waters...None.
&&

$$


Marianas/East and West Micronesia/Tropical Update: Williams
Marianas/Tropical: DeCou
East Micronesia: Montvila
West Micronesia: Cruz