000
AXPZ20 KNHC 060918
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Sat May 6 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 0600 UTC surface analysis and satellite imagery through 
0900 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning...High pressure in the western 
Gulf of Mexico supports a tight pressure gradient in southern 
Mexico, with gale force winds in the Gulf of Tehuantepec mainly 
north of 14N, with peak seas 12-13 ft. The area of high pressure 
will shift eastward today and winds will veer over the southwest 
Gulf and start to diminish over the Gulf of Tehuantepec. Winds 
will be below gale force early Saturday morning, and less than 
20 kt by early Sunday. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
         
A monsoon trough extends from 10N83W to 08N107W to 06N115W to 
08N122W, quickly transitions to a ITCZ, then continues to beyond 
04N140W. Scattered moderate isolated strong convection is 
occurring from 03N TO 12N east of 107W. Scattered moderate 
convection is within 150 nm of the axis between 123W and 128W. 

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

See the special features section for more information on the 
latest Gulf of Tehuantepec gale force gap wind event.

A cold front will approach the SW United States and NW Mexico 
this evening, then move across NW Mexico tonight through Sunday. 
Winds will increase across the Pacific waters of Baja California 
through Saturday night ahead of the front, then become fresh to 
near gale force in the northern Gulf of California ahead of the 
front late tonight into early Saturday. Behind the front, fresh 
to strong winds are forecast offshore of Baja California Norte 
and in the northern Gulf of California. Seas will build to 8-15 
ft in N swell in Pacific waters north of 22N west of the front 
through early next week. Seas will build to 5-8 ft north of 29N 
in the Gulf of California tonight through Saturday night. Light 
to gentle winds prevail elsewhere in Gulf of California south of 
29N, with seas 1-3 ft. Gentle to moderate NW to W winds and seas 
in the 4-6 ft range prevail over the remaining forecast waters.

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

Gentle to moderate winds prevail over the forecast waters with 
seas in the 5-7 ft range. Only minor fluctuations in winds are 
expected across the area through Saturday, then uncertainty in 
the forecast increases Sunday through the middle of next week. 
Global models continue to show an elongated cyclonic circulation 
likely to develop and extend over the region. Upper atmospheric 
conditions will be conducive for sustained deep convection this 
weekend through the middle of next week across central America 
and adjacent offshore waters to southeastern Mexico. Models are 
not in very good agreement in the development of a low pressure 
system within the larger elongated gyre, but do suggest that a 
surface low or two will eventually develop across the tropical 
eastern Pacific between Central America and 95W by the middle of 
next week. Slow movement of this low pressure area could lead to 
periods of very heavy rainfall across portions of the region 
from Costa Rica to SW Guatemala. 

REMAINDER OF THE AREA...

A dissipating cold front moving through northern waters extends 
from 30N121W TO 26N126W. Fresh to strong winds prevail northwest 
of the front with 8-11 ft seas. Fresh to strong winds will 
spread eastward as the front shifts across the northern forecast 
waters. Large NW swell, with seas to near 15 ft along 30N, will 
also accompany the front with 8 ft or greater seas likely to 
cover much of the area of north of 20N this weekend. 

$$
Mundell