000
AXPZ20 KNHC 232200
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Mon Aug 23 2021

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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURES...

Tropical Storm Marty is centered near 20.9N 114.1W at 23/2100
UTC moving W at 13 kt. Estimated minimum central pressure is
1002 mb. Maximum sustained wind speed is 40 kt with gusts to 50 
kt. Peak seas are currently 11 ft. Scattered moderate and 
isolated strong convection is noted within 30 nm N semicircle 
and 90 nm S semicircle. Scattered moderate convection is noted 
elsewhere within 120 nm S semicircle. Gradual weakening is 
forecast to begin on Tuesday, and Marty is expected to weaken to 
a tropical depression by early Wednesday and degenerate into a 
remnant low Wednesday night or early Thursday. Please read the 
latest NHC Public Advisory at 
https://www.nhc.noaa.gov/text/MIATCPEP3.shtml and Forecast/ 
Advisory at https://www.nhc.noaa.gov/text/MIATCMEP3.shtml for 
more details.

An area of disturbed weather centered less than 200 miles south of 
Guatemala and southeastern Mexico is producing a broad area of 
disorganized showers and thunderstorms. Environmental conditions are 
forecast to be favorable for gradual development of this system, and 
a tropical depression is likely to form by the middle to latter
part of this week.  The disturbance is expected to move westward to
west-northwestward at 10 to 15 kt, remaining offshore the coast 
of southwestern Mexico through this week. This system has a 
medium chance for tropical development within the next 48 hours, 
and a high chance within the next 5 days. Refer to the National 
Hurricane Center Tropical Weather Outlook for details. 

...TROPICAL WAVES...

The southern portion of a tropical wave extends along 85W and N 
of 07N, moving W at 10 to 15 kt. Scattered moderate and isolated
strong convection is noted N of 03N and E of 85W.

A tropical wave is along 92W and N of 09N, moving W at 10 to 15 
kt. Scattered moderate convection is noted N of 07N between 88W 
and 98W.

A tropical wave is along 112W from 01N to 15N, moving W at 5 to 
10 kt. Scattered showers are noted in the vicinity of the wave, 
mainly N of 10N.

A tropical wave is along 128W from 01N to 18N, moving W at 10 to
15 kt. Scattered moderate convection is noted along 12N, where 
the wave meets the monsoon trough.

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

The monsoon trough extends from 10N86W to 12N98W, then resumes 
from 13N116W to beyond 11N140W. Aside from the convection 
described in the Tropical Waves section above, scattered moderate
convection is noted from 07N to 14N and E of 100W, from 12N to
21N between 101W and 110W, from 10N to 13N between 108W and 
118W, and from 08N to 12N and W of 119W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Refer to the Special Features section above for details on
Tropical Storm Marty and the other area of interest.

Gentle to moderate winds prevail in the Gulf of California, with
gentle to moderate NW-N winds offshore of Baja California outside
of Marty. Moderate to fresh SE winds are being funneled along 
the coast and across the offshore waters of Guerrero and 
Michoacan. Seas across the offshore waters of Mexico outside of
Marty are 4 to 7 ft, except 3 ft or less in the Gulf of 
California. Fresh to strong N-NE winds are in the Gulf of
Tehuantepec along with 5 to 7 ft seas.

For the forecast, aside from Marty and the area of disturbed 
weather off the coast of southern Mexico, gentle to moderate 
southerly flow will prevail in the Gulf of California. Fresh to 
strong N-NE winds will continue to pulse in the Gulf of 
Tehuantepec through the week.

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

Scattered showers and isolated thunderstorms continue along and 
within 90 nm of the coast of Central America from Panama 
northward under the influence of moist monsoonal winds, and the 
passage of two tropical waves across the region. Moderate E-SE 
winds prevail offshore of Nicaragua northward. Moderate S-SW 
winds prevail south of the monsoon trough. Seas of 4 to 7 ft in 
mixed long period swell dominate the offshore waters.

For the forecast, gentle to moderate winds will prevail north of
the monsoon trough. Moderate S to SW winds south of the monsoon 
trough will freshen through mid-week, diminishing by the end of 
the week. Long period SW swell will reach the coast of Central 
America tonight.

REMAINDER OF THE AREA...

Refer to the Special Features section above for details on
Tropical Storm Marty.

Broad surface ridging dominates the waters north of the monsoon
trough. Gentle to moderate N-NE winds prevail north of the 
monsoon trough, with mainly moderate to fresh southerly winds 
south of the monsoon trough, locally to strong. Seas of 4 to 7 ft
dominate most of the waters, except W of 130W where seas are ranging
from 8 to 10 ft near the strong winds.

For the forecast, trades north of the monsoon trough will 
gradually increase to moderate to fresh as the pressure gradient 
tightens. Otherwise, little change in marine conditions is 
forecast through the week.

$$
ERA