000
AXPZ20 KNHC 171008
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Sat Sep 17 2022

Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
0910 UTC.

...SPECIAL FEATURES...

Tropical Storm Lester is centered near 15.4N 98.6W, or 215 km SE
of Acapulco, Mexico at 17/0900 UTC, moving NW at 9 kt. Estimated
minimum central pressure is 1002 mb. Maximum sustained wind 
speed 40 kt with gusts to 50 kt. Scattered to numerous moderate 
to strong convection within 360 nm NW quadrant. Scattered 
moderate isolated strong elsewhere N of 12N between 97W and 103W.
Lester is expected to continue moving NW today, with the center 
of Lester expected to cross the coast of southwestern Mexico 
early tonight, along the coast of Guerrero to the west of 
Acapulco, near 18.1W 101.3W and dissipate over southwestern 
Mexico on Sunday. Some minor strengthening is forecast today with
rapid weakening is expected after the center crosses the coast 
of Mexico. Heavy rains have already begun to impact most of the 
coastal zones of Guerrero. These rains may produce flash and 
urban flooding, along with possible mudslides in areas of higher 
coastal terrain. Swells generated by Lester are affecting 
portions of the coast of southern Mexico and this will continue 
into Sunday. These swells will cause life-threatening surf and 
rip current conditions. Please consult products from your local 
weather office.

Please read the latest HIGH SEAS FORECAST issued by the National
Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest 
T.D. Thirteen-E NHC Forecast/Advisory and Public Advisory at 
www.hurricanes.gov for more details.

Southwest of Southwestern Mexico:
An area of low pressure located near 15N106.5W or a few hundred
miles southwest of Manzanillo, Mexico, continues to produce
disorganized showers and thunderstorms. Environmental conditions
are forecast to become more conducive for development, and a
tropical depression is likely to form within the next couple of
days. This disturbance is forecast to meander off the
southwestern coast of Mexico through the end of this week, and
then begin to move north to northwestward early next week.
Numerous moderate to strong convection is occurring within 210 nm
across the W semicircle. Scattered moderate isolated strong
convection is elsewhere from 12N TO 17.5N between 106W AND 112W.
A broad area of fresh to strong SW-W winds is S of the monsoon
trough and across the SE semicircle of the low center, covering
the waters from 08N to 15N between 100W and 112W. Seas of 8-15 ft
in long period S to SW swell are occurring across this area.
Winds will increase across the southeast semicircle this morning
and reach gale force, then are expected to persist through Mon. A
gale warning has been issued for this area. The latest Tropical 
Weather Outlook gives this system a high chance of tropical 
cyclone formation within the next 48 hours.

Refer to the latest NHC Tropical Weather Outlook at 
www.hurricanes.gov for more details on both areas.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough extends from 10.5N77W to 10N85W to 14.5N93W, 
then resumes from near 14N112W to 11.5N121W to 13N128W to low 
pres near 11.5N139W. Aside from the convection associated with 
Lester and the low pressure near 14.5N106.5W, scattered moderate 
to strong convection is noted from 06N northward to the coasts E 
of 95W to the coast of Colombia. Scattered moderate isolated 
strong convection is elsewhere within 30 nm N and 90 nm S of the 
trough between 118W and 140W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Refer to the Special Features section for details on T.S. Lester
and a low pressure area located a few hundred miles southwest of
Manzanillo, Mexico.

A ridge dominates the offshore of Baja California producing moderate
to locally fresh NW to N winds N of Cabo San Lazaro, and gentle
to moderate NW winds between Cabo San Lazaro and Los Cabos. Seas
are generally in the 6-7 ft range except to 8 ft offshore of Baja
Norte. Light to gentle winds and seas of 1-3 ft prevail in the 
Gulf of California. Marine conditions S of Cabo Corrientes are 
dominated by long period SW swell and swell being generate by 
 the above mentioned low pressure area with a high chance of 
tropical cyclone formation.

For the forecast, Lester will continue moving NW and reach near
16.7N 99.7W early this afternoon, and move inland near 18.1N 
101.3W tonight, and weaken to a tropical depression as it 
continues moving inland overnight Sat through Sun morning before 
dissipating Sun afternoon. A Tropical Storm Warning remains in 
effect across the offshore waters from Oaxaca to Michoacan. A 
ridge will remain in place across the offshore waters of Baja 
California through the weekend and maintain moderate to fresh 
winds. Gentle to occasionally moderate mainly southerly winds and
1-3 ft seas are expected in the Gulf of California. Marine 
conditions will begin to deteriorate between Los Cabos and Cabo 
Corrientes on Sat night, as the low pressure currently located a 
few hundred miles southwest of Manzanillo, Mexico moves 
northward.

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR...

Moderate to fresh W-SW winds prevail south of the monsoon 
trough, while light and variable winds are north of the trough 
from the Gulf of Papagayo region to Guatemala coastal waters. 
Seas are 6-8 ft in SW swell across the offshore waters, with the
exception of 8-9 ft well offshore of Guatemala. A moist and 
unstable environment interacting with the monsoon trough persists
across the area, mainly N of 05N, resulting in active showers 
and thunderstorms.

For the forecast, mainly gentle to moderate winds will persist
across the offshore forecast waters, with seas of 6-9 ft in SW
swell through Sun. Winds could increase to moderate to fresh 
between northern Costa Rica and Guatemala over the weekend as a 
broad area of low pressure develops along the monsoon trough. A 
very moist and unstable atmospheric environment will help 
maintain active weather across most of the offshore waters over 
the next few days. 

REMAINDER OF THE AREA...

Refer to the Special Features section for details on T.S. Lester
and a low pressure area located a few hundred miles southwest of
Manzanillo, Mexico.

High pressure dominates the waters north of the monsoon trough 
and west of about 118W, centered on a 1034 mb high near 45N155W.
The pressure gradient between this system and a 1011 mb low 
pressure located near 11N139W supports an area of fresh NE winds
from 11N to 20N between 124W and 140W based on recent satellite 
derived wind data. Seas are 7-8 ft within these winds. Gentle to 
moderate winds prevail elsewhere north of the monsoon trough. 
Moderate to locally fresh southerly winds are south of the 
monsoon trough along with 5-8 ft seas, outside of T.S. Lester and
a low pressure area located a few hundred miles southwest of 
Manzanillo, Mexico. A broad area of fresh to strong SW-W winds 
prevail S of these tropical systems to 06N. Cross equatorial SW
swell continues to move into the region and is maintaining seas
of 6-8 ft to the south of the monsoon trough and west of the
Galapagos Islands. 

For the forecast, high pressure will continue to dominate the
northern forecast waters. A weak cold front is forecast to enter
the discussion area on Sun, extending roughly from 30N125W to
27N135W to 28N140W by Sun night. Seas of 8-10 ft in northerly
swell will follow the front reaching the waters N of 28N and W 
of 125W by Mon morning. An area of fresh NE winds with seas to 8
ft will move westward in tandem with the low pressure located 
near 11N139W. Additional pulses of cross-equatorial SW swell 
will continue to propagate across the forecast waters east of 
130W. 

$$
Stripling