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Eastern North Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 221600
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Tue Jun 22 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...TROPICAL WAVES...

A tropical wave extends from 05N to Honduras along 87W-88W, 
moving west at 15 kt. Scattered moderate to isolated strong 
convection is noted from 08N to 12N between 88W and 92W. Global 
models suggest that an area of low pressure associated with this 
wave is likely to form in a few days, south of the Gulf of 
Tehuantepec and southeastern Mexico. Environmental conditions 
appear conducive for gradual development of this system, and a 
tropical depression is likely to form by the end of the week or this 
weekend.  This disturbance is expected to move generally 
west-northwestward, and could be near the coast of southern Mexico 
by the weekend.  Interests in southern Mexico should monitor the 
progress of this system. 

A tropical wave extends from 05N to 16N along 103W-104W, moving 
west 10 to 15 kt. Scattered moderate convection is noted from 
11N to 14N between 105W and 108W.

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

The monsoon trough extends from 11N85W to 1011 mb low pressure
near 12N128W. ITCZ extends from 12N128W to beyond 07N140W. In
addition to the convection mentioned in the tropical wave
section, scattered moderate to isolated strong convection is
evident from 06N to 10N between 90W and 120W. Scattered moderate
convection is also evident within 60 nm north and 150 nm south 
of the ITCZ.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A weak pressure gradient persists across the Baja California
peninsula offshore waters supporting gentle to locally moderate 
NW winds. Recent ship observations and altimeter satellite data 
from around 14 UTC indicate that wave heights remain in the 4-7 
ft range. These conditions will prevail through Thu. Winds will 
increase across the Baja California Norte offshore waters Thu 
into the weekend as a ridge shift eastward and builds across the 
region.

In the Gulf of California, gentle to locally moderate S to SE 
winds will prevail through early in the weekend. Wave heights 
will be in the 3 to 4 ft range during that period.

Looking ahead, low pressure is expected to form south of the 
Gulf of Tehuantepec and southeastern Mexico in the next few days 
and move W-NW or parallel along the Mexican coast through the 
weekend. A tropical depression is likely to develop from this 
system. an area of low pressure is expected to develop south of 
southeastern Mexico and the Gulf of Tehuantepec in a few days. 
Environmental conditions are expected to be favorable for gradual
development, and a tropical depression is likely to form late 
this week or into the weekend as this systems moves WNW, or 
parallel and offshore southern Mexico. Winds to gale force are
possible off Guerrero and Michoacan from Fri night through Sat
night. 

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

Gentle to moderate SW to W winds prevail south of the monsoon 
trough, except where stronger winds are occurring near very
active convection associated with a tropical wave. Elsewhere 
light to gentle variable winds generally prevail north of the 
monsoon trough. Seas continue in the 5-8 ft range in SW swell.

Gentle to moderate SW to W winds are expected south of the
monsoon trough through Wed, while moderate SE to E winds prevail
north of the trough. Long period SW swell across the regional 
waters will gradually subside through Wed. 

Looking ahead, low pressure is expected to develop south of 
Guatemala and the Gulf of Tehuantepec Thu, increasing winds to 
moderate to fresh. Gradual development is likely as the system 
moves WNW and offshore of southern Mexico, and a tropical 
depression could form offshore of southeastern Mexico by this 
weekend.

REMAINDER OF THE AREA...

A high pressure ridge extends across the waters north of 20N and west
of 125W and is centered on a 1028 mb high near 38N144W. The 
pressure gradient between this area of high pressure and lower 
pressure within the monsoon trough/ITCZ is supporting gentle to 
moderate winds north of 08N and west of 120W. A 1012 mb low is 
along the monsoon trough along 12N128W and is nearly stationary.
Earlier scatterometer data showed NE winds 15-20 kt within 150 
nm across the NW semicircle of the low. A concurrent altimeter
satellite pass just west of the low indicated seas to 7 ft. This
is indicative of mainly moderate SW winds prevailing south of 
the monsoon trough with seas ranging between 5 to 7 ft in 
southerly swell. Wave heights are expected be 6 to 8 ft across
the tropical waters near the ITCZ west of 130W later in the week,
with 5 to 7 ft elsewhere.

$$
Christensen