AXPZ20 KNHC 212145
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Fri Oct 21 2016
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
Based on 1800 UTC surface analysis and satellite imagery through
Showers and thunderstorms located a few hundred miles south-
southwest of the Gulf of Tehuantepec are associated with a broad
area of low pressure located near 11N97W. Satellite imagery
indicates scattered moderate isolated strong convection mainly w
of the low center from 10N to 13N between 96W and 100W. Environmental
conditions are forecast to be generally conducive for development
of this disturbance over the next few days, and a tropical
depression will likely form early next week while the system moves
toward the west-northwest at about 10 kt.
A gale warning remains in effect for the Gulf of Tehuantepec. The
latest marine guidance suggests that the current minimal gale
force winds will increase to 30 to 40 kt tonight, then diminish
to 30 to 35 kt on Sat and continue into the early morning hours on
Sun before diminishing below gale force by late sun morning.
Minimal gale force conditions are expected to develop again late
Mon and continue through Tue night.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 11N86W to 1008 mb low pres near
11N97W to 12N105W to 1007 mb low pres near 13N115.5W to 10N124W to
low pres near 09N131W to 13N140W. Scattered moderate isolated
strong convection is from 09N to 12N between 117W and 124.5W.
Similar convection is N of 04N E of 80W...including the Gulf of
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
See special features for Gulf of Tehuantepec. A sub-tropical
ridge axis extends from NW to SE across the offshore waters of
Baja California. Light to gentle NW flow with combined seas of 5
to 7 ft are expected through Sat night. Seas are forecast to then
build to 7 to 9 ft across the waters N of 27N W of 118W on Sat
night, and continue through Sun.
Gentle to moderate NW winds are blowing across the Gulf of
California, and are forecast to become light and variable on Sat,
then light southerly flow expected across the entire gulf waters
Light and variable winds expected elsewhere within 250 nm of the
Mexican coast N of the Gulf of Tehuantepec through Sat, except
moderate E to SE winds are forecast beyond 200 nm on Sun and Mon.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gentle to moderate S to SW winds are noted per scatterometer data
S of 06N, while gentle to moderate W to NW winds are N of 06N.
Combined seas of 4 to 7 ft, primarily in long- period SW swell is
expected across the offshore waters for the next 3 to 5 days.
REMAINDER OF THE AREA...
A ridge dominates most of the north waters N of 15N W of 115W. The
pres gradient between the ridge and lower pres in the vicinity of
the monsoon trough is resulting in an area of moderate to fresh
winds between 14N and 18N W of 135W based on an Ascat pass. seas
in this area are near 8 ft according to an altimeter pass. A cold
front is expected to approach 30N140W tonight while gradually
dissipating through late Saturday. A new set of long period NW
swell follows the front. This swell event will propagate SE across
the NW waters Sat and Sun, reaching the waters W of Baja on Sun.