000
AXPZ20 KNHC 101532
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1532 UTC Sat Nov 10 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
1500 UTC. 

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: A cold front currently moving
across the Gulf of Mexico is in the process of approaching the
Bay of Campeche this morning. Strong high pressure ridging along
the eastern slopes of Mexico is outrunning the leading edge of 
the front with a tight pressure gradient already in place, and 
thus gale force northerly winds have already commenced in the 
Gulf of Tehuantepec. Winds will further increase to 35-40 kt by 
early this evening as the actual front manages to pass E-SE of 
the Chivela Pass. Seas are expected to build in and downstream of
the Gulf of Tehuantepec up to 13-14 ft with the strongest winds.
Winds will diminish below gale force by Sun morning, then 
further diminish to 20 kt or less by early Mon morning.

Looking ahead, model guidance continues to suggest a gale to 
minimal storm force gap wind event across the Gulf of Tehuantepec
on Tue. This will be associated with a strong cold front moving 
across the western Gulf of Mexico. Winds are forecast to reach 
minimal gale force by Tue morning, then suddenly increase to 
40-45 kt by early Tue afternoon as a strong high pressure of 1037
mb over NE Mexico extends a ridge southward across the Mexican 
coastal plains. A very tight pressure gradient across the Isthmus
of Tehunatepec is forecast to support these very strong winds 
forecast to reach near 50 kt by early Tue evening. Seas are 
expected to build up to 26-28 ft by Tue night.

...TROPICAL WAVES...

The axis of a tropical wave is located near 106W N of 08N. 
Isolated showers are near the southern end of the wave axis.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from 09N75W to 08N100W to 07N110W to
10N120W. The ITCZ extends from 10N120W to 08N130W to 04N140W.
Scattered moderate and isolated strong convection is from 08N to
08N between 78W and 81W, from 09N to 12N between 98W and 100W,
within 60 nm either side of the axis between 122W and 130W, and
also within 60 nm either side of the axis between 133W and 140W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

Gulf of California: High pressure over the Great Basin region
has weakened slightly with now moderate to fresh northerly winds
in the Gulf of California N of 29N. Winds will diminish further
and become variable by tonight. Strong high pressure will then
build again N the area Sun night and Monday, resulting in fresh 
to strong winds N of 30N beginning Sun evening. Fresh to strong 
winds will spread S across the entire length of the Gulf of 
California and likely across the waters between Las Marias 
Islands and Los Cabos by Mon evening. Seas are forecast to build 
to 8-9 ft before starting to subside Tue morning as the ridge 
slightly shift eastward. 

Weak inverted troughing extends from SE to NW across the offshore
waters W of Baja California with high pressure ridging W of
there. Mainly light to gentle anticyclonic flow and seas of 3-5 
ft prevail over these offshore waters and will persist through 
Sun. Strong high pressure will build over the SW of United States
and Mexico on Monday. Strong winds in the northern Gulf of 
California will funnel across Baja California Norte into the Bay 
of Sebastian-Vizcaino and other regions W of the Baja California
Peninsula Mon evening into Tue. Model guidance indicates the
slight potential for minimal gale force winds near 29.5N115W late
Tue morning into early afternoon with the enhanced funneling 
from the northern Gulf of California. 

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

Fresh to occasionally strong winds will pulse over the Gulf of 
Papagayo beginning tonight through Mon morning, with moderate to
fresh thereafter.

Otherwise, light to gentle winds are forecast N of the monsoon 
trough, with gentle to moderate SW winds S of the monsoon 
trough through the next several days. Cross equatorial long 
period SW swell will keep seas in the 6-7 ft range between 
Ecuador and the Galapagos Islands this weekend into early next
week, reaching the waters near the Azuero Peninsula by early Sun
morning.
   
REMAINDER OF THE AREA...  

High pressure of 1033 mb located well N of the area extends a 
ridge SE across the forecast waters to near 14N126W. A weak
surface trough is noted from 12N121W to 19N120W. Scattered
moderate convection is noted from 17N to 19N between 118W and the
trough axis. Mainly light to moderate trades and 5-7 ft combined
seas prevail across the open waters.

The trough is forecast to drift W while gradually dissipating.
The pressure gradient is forecast to tighten Mon night into Tue
morning with trades increasing to moderate to fresh just N of the
ITCZ. A cold front will attempt to approach 30N140W early next
week but will stall and weaken just W-NW of the area.

$$
Lewitsky