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Eastern North Pacific Tropical Weather Discussion

AXPZ20 KNHC 200150

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0115 UTC Tue Aug 20 2019

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
0130 UTC. 


A 1007 mb low pressure is located near 14N98W about 200 nm S of
Oaxaca with numerous moderate and scattered strong thunderstorms
within 270 nm all quadrants from the center. Fresh to locally
strong winds are occurring with this system, especially within
about 210 nm in the SE semicircle. The system is moving WNW
around 10 kt and this motion is expected to continue over the
next several days, paralleling the coast. Locally heavy rainfall
may lead to flash flooding over Guatemala and southern Mexico 
this week. Winds and seas are expected to increase in association
with this low, and a Gale Warning is in effect Tuesday and 
Wednesday for all Mexican offshore waters from Michoacan 
southward. Mid to late week, this low will likely impact the 
waters off Baja California Sur, likely bringing gale conditions, 
as winds could approach 50 kt, with seas of 12 to 18 ft. This low
has a high chance of tropical storm formation Tuesday or 

A 1007 mb low pressure is centered near 15N121W, or about 900
miles southwest of the southern tip of Baja California. This low
is moving west at 5 to 10 kt, and this motion is expected to
continue for the next several days. Numerous moderate and
scattered strong convection is located within about 240 nm in the
SW semicircle. Early afternoon scatterometer data showed fresh to
locally strong winds in the SW semicircle from the center,
generally north of 11N. Winds and seas may increase in
associationwith this low, which has a medium chance of tropical
cyclone formation by Wednesday.

Refer to the latest NHC Tropical Weather Outlook under 
AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for more information on 
both of these lows.


A tropical wave axis is along 113W, moving west around 5 kt.
Scattered moderate convection 12N to 16N between 110W and 115W. 
This wave is expected to remain weak.


The monsoon trough extends from 10N82W to low pressure near
14N98W to another low near 15N121W to a third low near 14N131W to
11N140W. Scattered moderate isolated strong convection is noted N
of 06N and east of 90W. Scattered moderate convection is also
noted from 08N to 12N between 130W and 140W.


Please see the Special Features section for more details about 
the low pressure area S in the Gulf of Tehuantepec region.

High pressure well northwest of the area will promote fresh to 
strong NW winds offshore of Baja California Norte through Tue 
night. Low pressure over the U.S. Great Basin will induce 
moderate to fresh S winds over the Gulf of California Thu and 


A weak N-S pressure gradient across Central America will induce 
moderate to fresh offshore winds in the Gulf of Papagayo 
sporadically through Fri. Otherwise, mainly moderate W to SW 
winds will prevail S of 10N. No significant long-period swell 
will affect the seas through Fri. No tropical cyclone activity is
expected in the area through Fri.


Please see the Special Features section for more details about 
the low pressure area near 13N120W.

A 1008 mb low pressure is centered near 14N131W, moving west at 5
to 10 kt. Moderate convection is associated with this low within
about 90 nm of the center in all quadrants.

A weak ridge extends SE from 1019 mb high pressure near 36N133W
down to 20N115W. Aside from the low mentioned above, NE
tradewinds are gentle to fresh south of the ridge and north of
the monsoon trough. Southerly winds south of the monsoon trough
will remain gentle to fresh. These winds should continue for the
next few days, though the monsoon trough may lift northward to
near 15N as the two lows progress west-northwestward. SW swell of
up to 8 feet will reach the southern border of our area this 
evening, but only reach to about the equator on Tue. As the
monsoon trough pulls northward, combined SW swell and wind waves
south of the trough may produce seas of up to 10 ft Wed through
Fri in and area centered roughly around 10N110W.