347
FXPQ50 PGUM 081950
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
550 AM ChST Sat Nov 9 2024

.Marianas update...
Low-end scattered showers have moved in over Guam and Rota this
morning and look to continue through the day. To the east, another
batch of showers and isolated thunderstorms are approaching the
Marianas and is expected to move into the region later today, near
noon. This will increase showers over Tinian and Saipan to low-end
scattered as well. This pattern is expected to continue through
tonight. For Sunday on, no changes were made to the previous
forecast. Seas and winds look to remain benign until later in the
weekend as Invest 94W approaches the Marianas.

&&

.Tropical systems update...
Three disturbances remain over the region this morning. Invest 93W,
currently centered near 13.4N 161.8E, remains the subject of a
Tropical Cyclone Formation Alert from the Joint Typhoon Warning
Center (JTWC), which means development into a tropical cyclone
(Tropical Depression) is likely within 24 hours. 93W is moving west-
northwest, away from the RMI. For more information on Invest 93W, see
bulletins issued by JTWC under WMO headers WTPN21 PGTW and ABPW10
PGTW.

Invest 92W, currently centered near 14.7N 134.8E continues to move
west-northwest toward the Philippines. 92W is looking a little more
organized this morning and JTWC has bumped 92W up to "Medium". This
means 92W is expected to become a significant tropical cyclone more
than 24 hours from now.

Invest 94W is currently centered south-southeast of Chuuk near 5.0N
152.9E and is moving northeast across Chuuk State toward the
Marianas. 94W remains fairly disorganized at this time, with a "low"
rating by JTWC. This means development into a tropical cyclone is
unlikely within 24 hours.

For more information on Invest 92W and 94W, see bulletins issued by
JTWC under WMO header ABPW10 PGTW.

&&

.Eastern Micronesia update...
Invest 93W is just north-northwest of Enewetak atoll in the northern
RMI, near 13N162E, and is slowly moving west-northwest as it
generates numerous locally heavy showers and isolated thunderstorms
near the atoll. As 93W continues to pull away, the potential for
gusty winds and heavy showers and thunderstorms over the far
northern RMI will decrease, while approaching troughs and the
expected development of the ITCZ near Majuro will be increasing
showers at Majuro and nearby islands through the rest of the weekend,
with winds becoming fresh at times.

Invest 94W is still very disorganized, located southeast of Chuuk
near 5N153E, but convergent flow to the northeast is producing
numerous showers and isolated thunderstorms across Pohnpei and
surrounding islands. Meanwhile, drier air is starting to filter into
Kosrae this morning, with the CIMMS MIMIC TPW satellite product
showing precipitable water dropping from around 2.4 inches to 1.8
inches over the past 12 hours, so kept showers isolated in the
forecast at Kosrae through Sunday. As 94W moves off to the west-
northwest towards the Marianas, some of that drier air will move into
Pohnpei by Sunday. The developing ITCZ near Majuro will then push
into Kosrae Sunday night and Pohnpei Monday, increasing the potential
for showers at these locations.

Seas are around 5 to 6 feet at Pohnpei and Kosrae, and are pushing
closer to 6 to 7 feet near Majuro, and are likely slightly higher in
the far northern Marshall islands, near 93W. As 93W pulls away, seas
are expected to be around 5 to 7 feet across the region, as fresh
winds develop near the Marshall Islands and a longer period north
swell from a system well north of the region filters in early next
week.

&&

.Western Micronesia update...
Invest 94W is located southeast of Chuuk, near 5N153E, according to
latest scatterometer data and still looks very disorganized this
morning, with sustained winds around 15 kt (~17 mph). A cluster of
numerous locally heavy showers and isolated thunderstorms is
developing just east of Chuuk and should be moving in later this
morning, which will bring the potential of gusts around 25 kt or 30
mph through tonight. Models still favor 94W lifting west-northwest
towards the Marianas around Sunday, which should lift the potential
of heavy showers and gusty winds away from Chuuk Lagoon and into the
northern portions of western Chuuk State and eastern Yap State. By
early next week, expect drier weather to move into Chuuk Lagoon and
then spread westward as 94W continues to move away.

Over by Yap and Palau, 92W is starting to look more organized, but it
is located well north-northwest of Yap and Palau, centered near
15N135E. This has caused showers to become isolated around Palau and
western Yap State this morning, with light to gentle south to
southeast winds. Weak winds may allow for island-effect showers to
develop at Palau this afternoon, while the trough that connects 92W
to 93W, is expected to slowly move closer to Yap and redevelop
scattered showers and isolated thunderstorm later today. As 94W lifts
towards the Marianas and then passes north of Yap, a wetter pattern
is expected across most of Yap State, while models trend to be drier
across Palau over the next few days.

Marine conditions are fairly benign for the time being at western Yap
State and Palau. Babeldaob buoy data shows combined seas of 2 to 4
feet near Palau. To the east, SOFAR buoy data shows 3 to 5 foot seas
in far eastern Yap State and western Chuuk State. Choppy seas and
gusty winds are possible across Chuuk and eastern Yap State as 94W
moves towards the Marianas, and tries to become more organized.

&&

.Prev discussion... /issued 657 PM ChST Fri Nov 8 2024/

Marianas Synopsis...
Latest satellite and radar imagery are showing generally partly
cloudy skies and isolated showers. Nearby buoys are showing seas of 4
to 6 feet, comprised mainly of an elevated trade swell.

&&

Discussion...
Fairly benign weather expected through Saturday night with mainly
isolated showers expected. A tropical disturbance (Invest 94W)
southeast of Chuuk will approach the Marianas through the weekend.
The latest forecast model trend favors a passage of 94W near to
south of Guam Sunday night into Monday, possibly as a tropical
depression or weak tropical storm. Strong winds and locally heavy
rainfall leading to flash flooding possible, especially over Guam and
Rota. As this disturbance is still poorly organized, much uncertainty
remains regarding the strength, track and timing of its eventual
passage south or through the Marianas. Improving conditions expected
by around Tuesday, but another tropical disturbance (Invest 93W)
currently over the northern Marshall Islands could be a major player
mid to late next week.

&&

Marine/Surf...
Combined seas of 4 to 6 feet and gentle to moderate winds expected
through Saturday night. Seas and winds begin to increase on Sunday as
a potential tropical disturbance (Invest 94W) approaches from Chuuk
State. The general forecast model trend favors a passage of 94W near
to south of Guam Sunday night into Monday. Winds and seas could
become hazardous to small craft, especially for Guam and Rota waters.
Winds and seas looks to then decrease beginning Tuesday but another
tropical disturbance (Invest 93W) could approach the Marianas mid to
late next week.

A moderate risk of rip currents will continue along north and
especially east facing reefs as the elevated trade swell continues. A
low risk of rip currents is expected along south and west facing
reefs. Surf and rip risk could rise beginning Sunday as a potential
tropical disturbance (Invest 94W) could pass through the southern
coastal waters later Sunday into Monday, bumping up swell and wind
waves.

&&

Tropical Systems...
Invest 92W is located well west of the Marianas and well north of
Yap, centered near 15N140E, and remains fairly disorganized with a
"low" rating by the Joint Typhoon Warning Center (JTWC), meaning
development into a tropical cyclone unlikely within 24 hours. Invest
92W will continue to move west and slowly become better organized,
possibly developing into a tropical cyclone as it approaches the
northern Philippines by late weekend.

Invest 93W is centered well northwest of Majuro near 11N165E, and is
moving to the northwest. JTWC has upgraded 93W to a Tropical Cyclone
Formation Alert (TCFA), which means development into a tropical
cyclone (tropical depression) is likely within 24 hours. Invest 93W
will continue to impact the northern Marshall Islands with heavy
showers, gusty winds and choppy seas through the weekend. Further
strengthening is probable into next week as it pushes away from the
atolls of the RMI and possibly towards the Marianas.

Invest 94W is located to the southeast of Chuuk, centered near
3N156E, and remains fairly disorganized with a "low" rating by JTWC,
with development into a tropical cyclone unlikely within 24 hours.
This disturbance is favored to slowly develop and strengthen as it
shifts northwest over the next few days, likely passing just south of
Chuuk Proper tomorrow through tomorrow night, then continuing
through eastern Yap State towards the Marianas on Sunday. The
latest forecast model trend favors a passage of 94W near to south
of Guam Sunday night into Monday, possibly as a tropical depression
or weak tropical storm, and then near to north of Yap Proper Monday
night into Tuesday.

&&

Eastern Micronesia...
An active pattern continues across eastern Micronesia with JTWC
Invest 94W near Nukuoro in Pohnpei State and 93W moving across the
northern RMI. Numerous to widespread locally heavy showers extend
across most of Pohnpei State, north Kosrae State, and northern RMI.
Scattered showers and isolated thunderstorms remain near Kosrae
through tonight due to the proximity of these dual systems. 93W and
94W are expected to continue drifting northwest, maintaining numerous
locally heavy showers and isolated thunderstorms with gusts around
25 mph through tonight for Pohnpei, although gusts around 93W looks a
bit stronger, up to 35 mph or 40 mph, near northern RMI. A Special
Weather Statement has been issued for Majuro, regarding the northern
RMI. The disturbances look to pull away from the region by Saturday
night allowing for conditions to improve.

A drier airmass is pushing in behind 93W, suppressing shower
potential near Majuro tonight and quieter conditions move into
Kosrae this weekend and momentarily for Pohnpei Sunday and Sunday
night. Model guidance is showing an uptick in ITCZ showers starting
this weekend for Majuro and early next week for Kosrae and Pohnpei,
bringing another active stretch of scattered showers next week.

Kosrae and Pohnpei buoys now showing seas 5 to 6 feet this
afternoon. Combined seas are closer to 6 to 7 feet near Majuro and up
to 7 to 9 feet in the northern RMI, close to 93W. With heavier
showers across Pohnpei State, northern Kosrae State, and northern
RMI, expect choppy seas and fresh to strong gusts at times, possibly
near-gale force closer to 93W.

&&

Western Micronesia...
Satellite reveals quiet conditions over the Republic of Palau, which
sits just southeast of a broad, weak surface circulation. Palau
received some rainfall from island convection earlier this afternoon,
but showers are otherwise spotty across much of the region. To the
north and northeast, moderate to deep convection is seen in a broad
area along the southern periphery of another circulation, JTWC`s
Invest 92W. Showers are located over northern Yap State including Yap
Proper. Yap can expect scattered showers over the next few days as
92W moves away to the west and another tropical disturbance, Invest
94W, shifts northwest into the region from over Chuuk State. 94W is
currently located near Nukuoro over southwest Pohnpei State, and
looks to move northwest over the next few days, passing to the south
of Chuuk Proper tomorrow through tomorrow night before passing the
outer islands of eastern Yap State through Sunday night. This
disturbance will bring unsettled weather across Chuuk State and the
eastern outer islands of Yap State, and a Special Weather Statement
has been issued. Main impacts include widespread locally heavy
showers and strong gusty winds, which will lead to choppy seas and
could make travel between islands hazardous at times. Early next
week, 94W looks to pass northwest between the Marianas and Yap
Proper, leading to an increase in showers and gusty winds near Yap
for Monday through Tuesday.

Marine conditions are fairly benign for the time being. Babeldaob
buoy data shows combined seas of 2 to 4 feet near Palau. To the east,
SOFAR buoy data shows 3 to 5 foot seas to the south of Chuuk State.
Higher winds and choppier seas are expected for Chuuk through the
weekend as Invest 94W crosses Chuuk State.

&&

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

$$

Marianas/Tropical systems update: Kleeschulte
Micronesia update: Schank
Marianas/Tropical: Slagle
Eastern Micronesia: Cruz
Western Micronesia: DeCou