000
AXPZ20 KNHC 170830
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Wed Oct 17 2018

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 0600 UTC surface analysis and satellite imagery through 
0800 UTC.

...SPECIAL FEATURE...

Heavy rainfall will continue to affect portions of Central 
America and SE Mexico for the next several days as a broad area 
of low pressure centered over Guatemala near 16N91W drifts west, 
pulling in abundant tropical moisture along with it. A long 
fetch of fresh to strong SW winds are also transporting moisture 
from the tropical eastern Pacific into Central America. The 
potential for a tropical cyclone to form in this area during the 
next 48 hours is high. The combination of all this moisture and 
instability, and the potential development of yet another low 
during the next 48 hours between the Gulf of Papagayo and the 
Gulf of Tehuantepec will maintain very unsettle weather across 
the region. Consult your local meteorological service for 
details.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from the low pressure near 16N91W to 
16N98W to 11N122W. The ITCZ extends from 11N122W to 10N140W.
Scattered moderate to strong convection is found within 75 nm of 
the coastline between 84W and 85W. Scattered moderate isolated 
strong convection is from 08N to 12N between 131W and 137W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

The remnants of Tropical Depression Tara are located near 20.0N 
105.5W. Scattered moderate isolated strong convection is within 
45 nm of the center. Strong upper level winds and interaction 
with the mountainous terrain of Mexico will cause the low to 
weaken. It is expected to dissipate during the next 24 hours. 
Heavy rainfall will continue to impact coastal areas today.

High pressure ridge north of the area extending SSE to near the 
Revillagigedo Islands is maintaining moderate to locally fresh 
NW winds over the offshore forecast waters W of Baja California. 
The ridge will maintain its influence over the offshore waters W 
of Baja California throughout the week, yielding seas of 4-7 ft.

Fresh to strong NW winds continue across the Gulf of California. 
Winds will gradually subside today as high pressure over the US 
Great Basin moves E and weakens.

A gap wind event is expected in the Gulf of Tehuantepec from 
high pressure building behind a cold front in the SW Gulf of 
Mexico, with winds reaching 30 kt this morning and seas rapidly 
building to 11 ft by afternoon. Strong gap winds may continue 
for the next few days, and pulse to around 30 kt each night. 

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

Moderate to fresh SW monsoonal flow will continue across the 
region through Wed, with active showers and thunderstorms 
expected to continue across much of Central America and the 
adjacent Pacific coastal waters, spreading well inland. Long 
period cross-equatorial SW swell will maintain 5 to 8 ft seas 
across the forecast area during the next few days. As mentioned 
above, global weather models suggest the chance for low pressure 
to develop offshore of the coast between Papgayo and south of 
Gulf of Tehuantepec in the next few days, which will help to 
focus very heavy rainfall across the region. 
  
REMAINDER OF THE AREA...

A cold front extending from 30N137W to 25N140W will stall and 
weaken today. Long period NW swell behind the front and cause 
seas to build to between 8 and 10 ft generally N of 15N and W of 
132W.

Satellite-derived wind and altimeter data indicate moderate to 
fresh monsoonal flow N of 07N and south of the monsoon trough. 
An area of 7 to 9 ft seas in long period SW swell is noted 
between 95W and 108W, and is expected to continue across this 
general area through early Thu.

$$
Mundell