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Eastern North Pacific Tropical Weather Discussion

AXPZ20 KNHC 231531

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1339 UTC Mon Sep 23 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.


Tropical Storm Kiko is centered near 15.7N 135.8W at 23/1500 UTC
moving WNW at 7 kt. This general motion is expected today, 
followed by a turn toward the northwest on Tuesday. Kiko could 
begin to turn back toward the west in a few days as it weakens. 
Estimated minimum central pressure is 1002 mb. Maximum sustained 
wind speed is 45 kt with gusts to 55 kt. Some additional 
strengthening is possible today, but weakening is forecast to 
begin by Tuesday and Kiko is forecast to become a remnant low 
later this week. See latest NHC forecast/advisory under 
AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details.

The last advisory on Mario is issued by the National Hurricane
Center at 23/1500 UTC. At this time, the remnant low of Mario is
centered near 25.0N 114.3W moving N at 7 kt. Mario will likely 
continue to move generally northward at a slightly slower forward
speed for the next day or so. Estimated minimum central pressure
is 1007 mb. Maximum sustained wind speed is 25 kt with gusts to 
35 kt. Gradual weakening is anticipated through Tuesday. This
morning, some ship observations and surface data showed the 
cyclonic circulation associated with Mario near and to the W of 
Cabo San Lazaro, while an altimeter pass indicated seas to 8 ft 
within about 60 nm on the NE quadrant of the remnant low. See 
latest NHC forecast/advisory under AWIPS/WMO headers 
MIATCMEP4/WTPZ24 KNHC for more details.


A tropical wave is along 96W N of 05N moving west at 10 to 15 
kt. Scattered moderate convection is from 12N to 16N between 91W
and 98W. 

A tropical wave is along 107W from 05N to 16N moving west around
10 kt. Scattered moderate convection is from 11N to 16N between 
103W and 108W.


The monsoon trough extends from 08N84W to 1012 mb low pressure 
near 12N99.5W to 14N112W to 13N125W, then resumes west of T.S. 
Kiko from 13N137W to 12N140W. Scattered moderate isolated strong 
convection is from 02N to 07N E of 81W, and within about 150 nm S
of monsoon trough between 110W and 121W.


Tropical Depression Mario has weakened to a remnant low over the
offshore waters W of Baja California Sur. Seas to 8 ft in mixed 
swell from Mario will gradually subside by later today. Please 
see the Special Features section above for more information on 

A weakening cold front will move southward across the Baja 
California Norte waters late today into Tue. Expect a brief 
period of fresh southerly flow over the northern Gulf of 
California ahead of the front, followed by moderate to fresh 
northerly winds over the northern Gulf on Tue. 

Looking ahead, SW monsoon flow will likely strengthen south of 
the Tehuantepec region Wed through Fri as the monsoon trough 
lifts northward. Low pressure may develop along the monsoon 
trough off the southern coast of Mexico by late week, which would
further enhance wind speeds and build offshore seas in excess of
8 ft.


Moderate SW winds will prevail south of the monsoon trough 
through Wed night, then become moderate to fresh through Fri as 
the monsoon trough lifts northward. Seas will generally remain 
in the 6-8 ft range, then build to 8 ft or greater by late week 
across the offshore waters from Guatemala to northern Costa 


The pressure gradient between T.S. Kiko and a 1020 mb high 
pressure located near 38N139W is supporting an area of fresh to 
locally strong NE to E winds to the N of Kiko from 19N to 26N W 
of 133W as indicated by the most recent satellite wind data. 
Mixed swell from Kiko is producing a broad area of 8 ft seas or 
greater roughly from 10N to 27N W of 132W. Moderate to rough 
seas will persist around the periphery of Kiko through Wed when
it is forecast to be just W of the forecast region. Please see 
the Special Features section above for information on T.S. Kiko.

A weakening cold front is forecast to move across the northern 
forecast waters late today into Tue. Long period NW swell will 
follow the front, with seas building to 9 or 10 ft across the N
waters, particularly N of 28N W of 125W by Wed morning, and N of
26N W of 125W by Thu morning. 

A small low pressure system is analyzed along the monsoon trough
near 12N99.5W or several hundred miles south of the southwestern
coast of Mexico. A cluster of moderate to isolated strong convection
is within about 60 nm SW quadrant of low center. This system is 
expected to drift northward or northwestward during the next few 
days, and significant development is unlikely due to strong 
upper-level winds.