000
AXPZ20 KNHC 162213
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Tue Oct 16 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 1800 UTC surface analysis and satellite imagery through 
2100 UTC.

...SPECIAL FEATURES...

The center of Tropical Depression Tara is located near 19.0N 
105.0W at 2100 UTC, or about 40 nm W of Manzanillo Mexico, 
drifting NW or 325 degrees at 2 kt. Estimated minimum central 
pressure is 1005 mb. Maximum sustained wind speed is 30 kt with 
gusts to 40 kt. Scattered moderate to strong convection is noted 
surrounding Tara from 18N TO 22N and within 75 nm of the Mexican 
coast, and extending inland up to 30 nm. Upper level southeast 
winds and interaction with the mountainous coastal zone of 
Mexico have continued to weaken the small circulation of Tara 
today. Tara is not expected to re-strengthen and is now forecast 
to weaken to a 25 kt post-tropical remnant low within 24 hours, 
and then dissipate by 48 hours. Heavy rainfall will continue to 
impact the adjacent coastal areas through Wednesday. See latest 
NHC forecast/advisory under AWIPS/WMO headers MIATCPEP2/WTPZ32 
KNHC for more details.
 
Heavy rainfall will also continue to affect portions of Central 
America and southeast Mexico from western Panama to Oaxaca, 
Mexico for the next few days as broad low pressure prevails in 
the lower levels of the atmosphere. A Caribbean low pressure 
center moved inland this morning across Honduras and Belize and 
is pulling abundant tropical moisture with it. A long fetch of 
fresh to strong SW winds are also transporting tropical moisture 
from the tropical eastern Pacific into Central America. 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 over land from Panama to LOW PRES 
1007 MB NEAR 16N89.5W TO 08.5N122W TO 11N129W to beyond 
08.5N140W. Scattered moderate to strong convection is found from 
03.5N to 12N E of 89W, and from 10N to 14.5N between 89W and 
115W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

A 1023 mb high pressure system off the northern California coast 
extends SSE into the region to near the Revillagigedo Islands, 
and 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 4-6 ft. A new 
pulse of NW swell will arrive late Thu through Fri to raise seas 
to 5-7 ft.

Gulf of California: Strong NNW winds continue across the far 
northern Gulf of California and extends southward to about 30N, 
as strong high pressure persists over the Great Basin region of 
the United States. One last pulse of strong northerly winds are 
expected this evening before winds begin to gradually subside 
through Wed as the high moves E and weakens.

Gulf of Tehuantepec: The next gap wind event is forecast to 
start this evening, with winds then quickly blasting to 30 kt 
late tonight through Wed with seas rapidly building to 11 ft by 
Wed afternoon. This event will be associated with a ridge 
building behind a cold front sliding S along the eastern slopes 
of the Sierra Madre Mountains in Mexico and the western Gulf of 
Mexico. These strong gap winds may continue for the next few 
days, and pulse to around 30 kt each night. Global models 
continue to suggest that another low pressure center will likely 
develop near the Pacific coast of Central America in the next 
few days, somewhere between the Papagayo region and Tehuantepec. 
The gap wind event across Tehuantepec will act to enhance this 
low level circulation as it shifts westward Wed or Thu...and 
there is a medium chance for a tropical cyclone to develop 
across this area within the next 48 hours, and a high chance to 
form within the next 5 days.

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 and spread 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...

The pressure gradient between the high pressure ridge to the W 
of the Baja Peninsula and a cold front approaching from the W is 
generating fresh to strong southerly winds across the far NW 
waters, mainly N of 28N and within 150 nm east of the front. 
Moderate to locally fresh trades are noted S of 15N and N of the 
monsoon trough W of 125W. The cold front is forecast to reach 
from 30N138W to 27N138W to 25N140W as a weakening stationary 
front on Wed. Long period NW swell will follow 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 confirmed the presence
of moderate to fresh monsoonal flow over the forecast waters N 
of 07N and S of the monsoon trough. An area of 7 to 9 ft in long 
period SW swell is noted south of the monsoon trough and mainly 
between 97W and 115W, and is expected to prevail across this 
general area through through early Thu.

$$
Stripling