000
AXPZ20 KNHC 301514
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1328 UTC Thu Nov 30 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: 1026 mb high pressure is north
of the area over central Mexico, producing a tight pressure 
gradient across the isthmus of Tehuantepec with gap winds to 
gale force over the Gulf of Tehuantepec through Sat morning.
Winds will pulse back to gale Sat night. During this extended 
gale event, seas are forecast to peak at 12-14 ft today, with 
downstream seas of 8 ft and higher reaching as far as 600 nm 
offshore. 

INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough axis extends from 09N83W TO 07N100W to 
08N108W, where it transitions to an intertropical convergence 
zone and extends from 08N117W to 08N127W to beyond 07N140W. 
Scattered moderate convection is from 06N to 09N between 77W and 
81W, and from 05N to 08N between 83W and 85W. Scattered moderate 
convection is also from 06N to 10N between 93W and 102W. 
Scattered moderate to isolated strong convection is from 06N to 
09N between 112W and 116W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see Special Feature section for detail concerning the 
gale warning in the Gulf of Tehuantepec.

Ridging extending across the region will maintain gentle to
moderate breezes across the entire area through early next week.
Long period northwest swell or 8 to 10 ft is propagating across 
the waters offshore of Baja California. A recent altimeter
satellite pass confirmed seas to as high as 10 ft off Cabo San
Lazaro in Baja California Sur. Reinforcing swell is moving south
of 30N, allowing combined seas to 12 ft off Baja California 
Norte tonight, reaching as far south as the Revillagigedo Islands
as 10 ft swell by early Sat. The swell will decay below 8 ft by 
late Mon. 

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR...
  
Gulf of Papagayo: A modest pressure gradient between high 
pressure over the western Gulf of Mexico and lower pressure 
across the southwest Caribbean is producing fresh offshore gap 
winds across the Papagayo region. These winds will be enhanced 
with overnight drainage effects for the next few days, peaking 
near 25 kt during the late night through late morning hours. 
Seas downstream will build to 6 to 8 ft during the peak winds, 
with the winds and seas diminishing slightly each late afternoon 
through evening.

Light to gentle N to NE winds, and 4 to 5 ft seas are expected 
elsewhere through Sat N of the monsoon trough. Moderate 
southerly winds, and 4 to 6 ft seas, are forecast south of the 
monsoon trough. Northerly swell generated in the Gulf of 
Tehuantepec will reach the western part of forecast zone PMZ111 
(offshore waters of Guatemala and El Salvador) today through the
end of the week.

REMAINDER OF THE AREA... 

A large area of NW swell producing seas of 8 to 15 ft across the
waters W of 120W will continue to propagate across the region, 
with the leading edge of 8 ft seas currently reaching from the 
southern Baja California peninsula to 00N140W, and will reach NW 
of a line from 18N112W to 00N140W Fri. A re- enforcing pulse of 
NW swell currently moving through the far NW waters will spread 
SE and into the central waters through Fri night. High pressure 
north of the region will enhance a broad zone of NE to E winds 
across the tradewind belt W of 130W through Fri. Seas of 8 to 12 
ft are then expected to cover nearly the entire forecast waters S
of 30N W of 110W into Sun, and will start to decay below 8 ft 
through early next week.

$$
Formosa