000
AXPZ20 KNHC 161616
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 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 1200 UTC surface analysis and satellite imagery through 
1515 UTC.

...SPECIAL FEATURES...

The center of Tropical Storm Tara is located near 18.6N 104.5W 
at 1500 UTC, or ABOUT 26 nm SSW of Manzanillo Mexico, drifting 
NNW or 335 degrees at 1 kt. Estimated minimum central pressure 
is 1001 mb. Maximum sustained wind speed is 40 kt with gusts to 
50 kt. Scattered to numerous moderate to strong convection is 
noted surrounding Tara from 17.5N TO 21.5N and within 75 nm of 
the Mexican coast, and extending inland up to 30 nm. Upper level 
southeast winds have sheared Tara significantly overnight, with 
convection recently making a come back. However the proximity to 
the coast and weakened state of the system will likely lead to 
gradual weakening during the next 24-48 hours as it moves slowly 
toward the northwest. Tara is now forecast to weaken t a 30 kt 
tropical depression within 24 hours, a 25 kt post-tropical low 
within 48 hours, and then dissipate by 72 hours. See latest NHC 
forecast/advisory under AWIPS/WMO headers MIATCPEP2/WTPZ32 KNHC 
for more details.

Gulf of California: Strong NNW winds continue across the far 
northern Gulf of California and extends southward into central 
portions along 26N. High pressure over the Great Basin of the 
United States is forcing this wind flow. One last pulse of 
strong northerly winds are expected this evening before winds 
begin to subside by Wed morning as the high moves E and weakens.
   
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from 19N87W TO LOW PRES 1008 MB NEAR 
16N88.5W TO 09.5N120W TO 10.5N136W to beyond 08N140W. Numerous 
moderate and scattered strong convection is found from 04N to 
07N E of 80W. Scattered moderate isolated strong convection is 
seen N of a line from 07N82W to 11N92W and within 180 nm of the 
monsoon trough axis W of 95W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

High pressure off the northern California coast extends SSE into 
the region and is maintaining moderate to locally fresh NW winds 
over the offshore forecast waters W of Baja California. The 
ridge currently extends from a 1022 mb high to near the 
Revillagigedo Islands and 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 Tehuantepec: The next gap wind event is forecast to 
start this afternoon, 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.

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 Tue, with active showers and thunderstorms 
expected to continue across much of Central America and the 
adjacent Pacific coastal waters. Long period cross-equatorial SW 
swell will maintain 5 to 8 ft seas across the forecast area 
during the next few days. Global weather models suggest the 
chance for low pressure to develop offshore of the coast of 
Guatemala or south of Gulf of Tehuantepec in the next few days, 
which will help to focus very heavy rainfall across the region.
In the medium range, this low  pressure system has a high chance 
of becoming a tropical cyclone during the next 5 days as it 
tracks WNW along the southern coast of Mexico.
  
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 27N 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 a 
position from 30N138W to 27N140W today, and then 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