000
AXPZ20 KNHC 220404
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Tue Sep 22 2020

Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 140W. The following information is
based on satellite imagery, weather observations, radar, and
meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0345 UTC. 

...SPECIAL FEATURES...

Tropical Storm Lowell is centered near 17.7N 114.5W at 22/0300 
UTC or about 400 nm southwest of the southern tip of Baja 
California moving west at 11 kt. The estimated minimum central 
pressure is 1001 mb. Maximum sustained wind speed is 40 kt with 
gusts to 50 kt. Last available GOES-17 visible satellite imagery
showed that Lowell remains a sheared system, with its poorly 
defined and mainly exposed cloud system center oriented in a 
northeast to southwest fashion. Present infra-red satellite 
imagery shows numerous moderate to strong convection increasing 
within 180 nm of the center of Lowell in the SW quadrant. 
Scattered moderate to isolated strong convection is within 60 nm 
of 16N117W. A recent altimeter data pass revealed seas up to 8 ft 
east of Lowell to near 107W and from 13N to 18N, mainly due to
the persistent fetch of fresh to strong southeast to south winds
pre-Lowell. Lowell is forecast to maintain its current motion 
through Wed, followed by a turn toward the west- northwest Wed 
night. Slow strengthening is anticipated during the next few 
days, and Lowell could reach near hurricane strength by Wed night
near 20N122W. Please read the latest HIGH SEAS FORECAST issued 
by the National Hurricane Center at website- 
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest 
Tropical Depression Seventeen-E NHC Forecast/Advisory and Public 
Advisory at www.hurricanes.gov for more details.

...TROPICAL WAVES...

A tropical wave has its axis along 139W from 03N to 18N. It is
moving westward at 10-15 kt. Scattered moderate convection is
seen near and along the monsoon trough within 180 nm east 
of the wave axis from 09N to 10N and within 60 nm west of 
the wave axis from 09N to 10N.

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

The monsoon trough axis extends from northwestern Colombia to
across Panama to 09N84W to 09N92W to 09N100W and to 13N107W.
It resumes at 15N118W to 11N130W to 10N140W. Scattered moderate
to isolated strong convection is within 120 nm south of the
trough between 78W-82W. Scattered moderate convection is within
60 nm south of the trough between 133W-136W and within 30 nm of 
the trough between 89W-95W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

The gradient induced by weak deep layer ridging between Baja 
California and 125W is supporting mainly moderate northwest 
to north winds off Baja California Norte with combined seas to
6 or 7 ft. Winds and seas will diminish some through Tue, except 
within about 300 nm southwest of the southern tip of Baja
California, where much high winds and seas on the periphery of 
Tropical Storm Lowell can be expected.

Farther south, fresh to strong winds will pulse in the Gulf of 
Tehuantepec region through the next couple of days. Elsewhere, a
weak pressure pattern across the region will result in mainly 
gentle to moderate winds and slight seas. 

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

Gentle to moderate south to southwest winds continue south of 
the monsoon trough. Elsewhere, gentle winds prevail north of the 
monsoon trough. Combined seas are currently in the 5-6 ft range 
in a mix of wind waves and southerly swell.

REMAINDER OF THE AREA...

The gradient between the subtropical ridge and lower pressure in
the tropics is allowing for generally gentle to moderate trades 
to exist well into the deep tropics. The ridge will build 
southward some north of 20N and to the west of Lowell through 
mid-week.

Farther east, seas of 8-9 ft are within an area along the 
monsoon trough between 111W-119W. These seas are a result of the
fresh to strong southwest to west winds that are occurring in 
the southern part of the broad cyclonic circulation associated to
Tropical Storm Lowell. In addition, persistent long-period 
southwesterly is present within this area as well further 
contributing to the build up of these seas.

$$
Aguirre