000
AXPZ20 KNHC 292021
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1829 UTC Sat Dec 29 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.

.INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

A surface trough extends from 05N77W to 03N81W to 04N92W. The 
ITCZ continues from 04N92W to 05N115W to beyond 06N140W. 
Scattered moderate convection is noted from 05N to 10N W of 115W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

Subsiding northerly swell is propagating across the offshore
waters of Baja California, with seas in the 6-8 ft range. Seas 
will subside below 8 ft Sun. Another set of northerly swell will
propagate into the waters off Baja California Norte building 
seas to near 10 ft Mon before subsiding through midweek.

Gulf of California: High pressure over the Great Basin of United
States is supporting fresh to strong NW winds across the entire 
length of the gulf. The strong winds and associated seas will 
diminish Sun as the high pressure weakens and shifts eastward. 
Winds will once again strengthen over the Gulf of California 
late Mon.

Gulf of Tehuantepec: Overnight drainage flow will bring a fresh 
to strong pulse of northerly gap winds into the Gulf of 
Tehuantepec tonight. A strong gap wind event is expected late 
next week. Winds will strengthen across the gulf Tue night, and
further increase to gale force Thu morning. 

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

Fresh to strong NE to E winds are expected across the Gulf of 
Papagayo through Thu. Winds will peak during the overnight and 
early morning hours with the assistance of nocturnal drainage 
flow. Moderate to fresh N winds are expected across the Gulf of 
Panama through Thu. Elsewhere, gentle to moderate NE winds will 
prevail N of 08N, while gentle to moderate southerly winds are 
expected S of 08N. 
  
REMAINDER OF THE AREA...  

High pressure of 1036 mb centered N of the area near 37N132W 
extends a ridge across the forecast waters to beyond the 
Revillagigedo Islands. The pressure gradient between this area of
high pressure and lower pressure in the vicinity of the ITCZ is 
supporting fresh to strong tradewinds N of the ITCZ to near 20N 
and W of 120W. The area of high pressure will remain in place N 
of the area helping to maintain this area of fresh to strong 
trades. Long period NW swell combined with tradewind swell is 
helping produce seas of 8 to 12 ft over much of the area north of
the ITCZ and west of 120W. 

Global models continue to indicate a cold-core upper disturbance
will dig into the base of a mid/upper level trough early next 
week, supporting the development of a sharp surface trough or 
even weak low pressure along the ITCZ near 120W by mid week. This
will likely enhance the trade winds north of the ITCZ and west 
of 120W, with near gale conditions possible on the northern end 
of the surface trough.

$$
AL