142
AXPQ20 PGUM 120037
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1037 AM ChST Tue Nov 12 2024

Tropical Weather Discussion for the Western North Pacific between
the Equator and 25N from 130E to 180. The following information is
based on recent satellite imagery/data, weather observations, radar,
and meteorological analysis.

...SPECIAL FEATURES...

TROPICAL CYCLONES...

Tropical Storm Man-yi is currently located roughly 330 miles
east-southeast of Tinian and Saipan near 14.0N 150.5E, moving
west-southwest at around 8 mph. Himawari visible satellite imagery
this morning shows a tightly consolidated region of heavy showers
organized about and south of the center. GLD network data shows
occasional lightning along the outer south and southeast
peripheries of Man-yi. Man-yi has maintained its intensity
overnight with maximum sustained winds at around 45 mph, but is
expected to gradually intensify through tonight and Wednesday as
it turns slightly toward the west.

Man-yi is currently forecast to track near or over Guam Wednesday
afternoon as a strong tropical storm. A tropical storm warning
has been issued for Guam and Rota, which means that sustained
winds of 39 mph or greater are expected within 24 hours. Tinian
and Saipan remain under a tropical storm watch. Current forecasts
and model guidance indicate maximum sustained winds of around 60
mph with possible gusts of 75 mph near heavier showers as Man-yi
passes near Guam, with the strongest winds expected north and
northeast of the center. Given the compact nature of this storm
and the tightly-packed wind gradient, small "wobbles" in Man-yi`s
motion may lead to significant changes in expected conditions and
the severity of impacts across the Marianas. Man-yi is expected to
continue to gradually intensify as it crosses the islands,
possibly becoming a low-end typhoon (maximum sustained winds 74
mph or greater) as it passes west of the Marianas. TS Man-yi will
begin moving away from the Marianas late Wednesday night, moving
to the north of Yap State sometime Thursday or Thursday night,
before shifting northwest over the Philippine Sea by the weekend.

For more information on Tropical Storm Man-yi please refer to
bulletins from the Joint Typhoon Warning Center (JTWC) under WMO
header WTPN32 PGTW and from the National Weather Service (NWS)
under WMO header WTPQ32 PGUM.

Tropical Storm 27W is currently located roughly 355 miles
northwest of Yap near 13N 134.2E, moving west-northwest at around
17 mph. Visible satellite imagery this morning shows a broad area
of moderate to deep convection organized about the circulation
center, with the heaviest showers and thunderstorms consolidated
northwest and north of the core. A trailing band of showers and
thunderstorms is seen north of the circulation center, extending
eastward toward the Marianas. Maximum sustained winds are around
50 mph. 27W will continue to intensify over the next few days as
it tracks west-northwest toward the northern Philippines, exiting
Guam`s Area of Responsibility (AOR) sometime late Tuesday night
through Wednesday.

For more information on Tropical Storm 27W, refer to JTWC
bulletins under WMO header WTPN34 PGTW and NWS bulletins under WMO
header WTPQ34 PGUM.

...OTHER WEATHER SYSTEMS...

TRADE-WIND AND SURFACE TROUGHS...
A surface trough extends south from east of the Marianas near
17N149E, passing through Tropical Storm Man-yi to extend south-
southeast over Chuuk to near 6N151E. Numerous showers and isolated
thunderstorms are seen across Chuuk State near the trough axis,
extending northward to the southeast of Man-yi. This feature will
move in tandem with Man-yi over the next day or so, bringing
showers across Chuuk and Yap States before dissipating by Thursday
morning.

Further east, a few trade-wind troughs extend over and east of
the Marshall Islands. The first is seen extending northeast from
near 6N170E, passing north of Majuro to around 9N172E, while the
other extends from east of Majuro near 7N176E, passing northeast
across the Date Line near 9N180. Numerous showers and scattered
thunderstorms are seen over the RMI near and north of Majuro,
extending east toward the Date Line. These features will continue
to shift westward over the next few days keeping unsettled weather
across eastern Micronesia, ahead of a series of additional weak
troughs to transit the region through the coming weekend.

TRADE-WIND SURGE...
A moderate trade wind surge lingers across the region across parts
of eastern Micronesia and northward, east of Tropical Storm Man-yi.
A broad area of moderate to fresh trade winds can be seen in the
latest scatterometry data, extending from around 9N to 20N, and
from roughly 160E extending east of the Date Line. Scattered
showers and a few thunderstorms can be seen within this broad area
where trade-wind convergence is enhanced. Trade winds across the
region will continue to relax over the next day or so as the
pressure gradient weakens.

UPPER-LEVEL TROUGHS...
A pair of upper-level troughs are seen north and east of the
Marshall Islands. The first trough enters the AOR near 25N176E,
curving southwest to the east of Wake Island near 19N173E, then
continuing westward to around 18N164E, passing south of Wake. This
upper-level feature is interacting with a broad trade-wind trough
to generate showers and thunderstorms near and south of 25N176E.

The second upper-level trough extends south-southwest from around
18N180 to the east of Majuro Atoll near 7N174E. Divergent flow
aloft associated with this feature is helping to intensify showers
and thunderstorms located over and east of the Marshall Islands,
associated with trade-wind troughs over the region. These
features will consolidate into one broad upper-level trough that
will linger north of the RMI over the next day or so, extending
west and south toward Pohnpei and Kosrae for the latter half of
the week. This feature may help enhance showers and thunderstorms
across eastern Micronesia for much of the week into next week as
it lingers over the region.

$$

DeCou