000
AXPZ20 KNHC 060230
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
138 UTC Fri Oct 6 2017

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
0230 UTC.

..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...         

The monsoon trough extends from 16N101W to low pres 1006 mb 
centered near 15N105W to low pres 1007 mb centered near 
11.5N115.5W to 09N124W to low pres 1011 mb centered near 11N135W 
to 10N140W. Scattered moderate and isolated strong convection is 
seen from 12N to 13N between 87W and 95W. Scattered moderate 
convection is present within 60 nm either side of a line from 
09N104W to 10N114W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

The broad cyclonic circulation constituting a Central American 
Gyre is causing an atypical NW to N gap wind event over the Gulf 
of Tehuantepec. These gap winds will diminish to speeds below 
advisory levels on Saturday, as the Central American Gyre 
gradually lifts northwestward and weakens.

A ridge covers the waters to the west of the Baja California 
Peninsula. Expect gentle to moderate N to NW winds, and seas of 
4 to 7 feet over the open waters through the weekend. A round of
NW swell will cause seas N of 25N and W of Baja to build above 8
ft by Tuesday morning.

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

The large monsoonal circulation of the Central American Gyre has
taken the monsoon trough with it northward into Central America.
This circulation has spawned Tropical Storm Nate which is 
currently centered over the NE corner of Honduras and moving
toward the Gulf of Mexico. This monsoonal surge is producing 
fresh to strong winds over an area which includes at least 
portions of the offshore zones from Panama to Guatemala. Winds 
will locally reach near gale force over the waters SW of Costa 
Rica and Nicaragua tonight and Friday. The combination of long 
period cross equatorial SW swell and wind driven waves is 
generating sea heights ranging from 8 to 15 feet in the waters 
from Panama to Guatemala. The large fetch of winds will remain 
in place until Friday afternoon. This will bring maximum sea 
heights from south of Costa Rica to Guatemala to between 15 and 
17 ft tonight and Friday. The large seas will create dangerous 
breaking surf along the coast in these areas. Winds and seas will
begin to subside on Friday night as the Central American Gyre 
gradually lifts northwestward and weakens.

The enhanced monsoonal flow will continue to push copious 
amounts of moisture into much of Central America, where 
torrential rainfall is likely to continue into the weekend. This 
extremely heavy rainfall will produce life threatening flash 
floods and mudslides.

REMAINDER OF THE AREA...Gentle to moderate winds prevail in the 
area north of the monsoon trough and west of 125W. A fresh set of
NW swell generated to the NW of a cold front currently 
approaching 30N140W are entering the NW waters. Seas experiencing
this swell will build to between 8 and 9 ft NW of a line from 
30N135W to 26N140W by late Friday. Long period SW swell are 
maintaining seas above 8 ft over all of the discussion area south
of 18N, except for the area SW of a line from 03.4S114W to 
07N131W to 15N140W. The long period swell have begun to decay and
seas in this area are expected to subside below 8 ft by Sunday 
afternoon.

$$
CAM