AXPZ20 KNHC 120336
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0300 UTC Tue Nov 12 2019
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 0000 UTC surface analysis and satellite imagery through
Gulf of Tehuantepec Gale Warning: A cold front over the NW Gulf
of Mexico will reach the SW Gulf of Mexico Tue. Strong high
pressure will build across the eastern slopes of the Sierra Madre
mountains in Mexico behind the cold front, and help usher in the
next gale force gap wind event in the Gulf of Tehuantepec on
Tue. Strong to minimal gale force winds will begin to funnel
through the Chivela Pass into the Gulf Tue afternoon, then winds
are expected to peak near 45 kt in the Gulf of Tehuantepec by Tue
night, with seas building to near 20 ft during this time. The
area of high pressure will shift eastward into the SE United
States Wed. This will loosen the pressure gradient over the
Tehuantepec region, and winds will diminish below gale force Wed
night. Another gale force gap wind event is possible across the
Tehuantepec region Fri and Sat. See the latest NWS High Seas
Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC or at website
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further
The axis of a tropical wave is near 99W from 03N to 14N, moving
W at around 15 kt. Convection is limited near the wave axis.
The axis of a tropical wave is near 125W from 04N to 16N, moving
W at around 10 to 15 kt. Scattered moderate convection was noted
from 08N to 11N between 121W and 132W.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 09N84W to 07.5N93W to 08N110W to
12N120W to 08N133W. Scattered moderate isolated strong
convection is noted from 09N to 15N between 110W and 121W.
Scattered moderate convection was noted from 08N to 11N between
121W and 132W. Scattered moderate convection was noted from 08N
to 12N W of 138W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Fresh to strong northerly winds will pulse in the Gulf of
Tehuantepec late tonight into early Tue morning. The next Gulf
of Tehuantepec gale force gap wind event is expected to begin
Tue afternoon. Please see the Special Feature section above for
Elsewhere, a ridge dominates the offshore forecast waters west
of Baja California, supporting gentle to moderate northerly
winds, and seas generally under 6 ft. Little change is expected
through Tue. Strong high pressure building across Mexico is
supporting fresh to strong NW to N winds near the entrance of
the Gulf of California. The fresh to strong winds will spread
south across the waters between Cabo Corriente and Los Cabos
later tonight, and farther south to near 17N between 105W and
110W by late Tue before diminishing to 20 kt or less by Tue
night. Seas are forecast to build to 8 or 9 ft over this area.
Over the Gulf of California, light to gentle winds will prevail
most of the forecast period, with the exception of moderate NW to
N winds over the southern part of the Gulf today.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Mainly fresh NE-E winds will prevail across the Gulf of Papagayo
through Wed. Farther south, mainly gentle to moderate S-SW
monsoonal flow will continue across the offshore forecast waters
of Costa Rica, Panama, Colombia, and Ecuador through the middle
of the week. Seas will remain in the 4-7 ft range. Seas generated
by the strong gale force gap wind event in the Gulf of Tehuantepec
will propagate across the offshore waters of Guatemala and El
Salvador on Wed, with seas likely building to 10 to 14 ft in
REMAINDER OF THE AREA...
A surface ridge extends from 1024 mb high pressure near 36N131W
to near the Revillagigedo Islands. The pressure gradient between
the ridge and the monsoon trough is supporting mainly moderate
to fresh NE trades N of the monsoon trough to about 20N and west
of 120W, with seas of 7 to 9 ft. These seas will gradually
subside below 8 ft by Tue night into Wed.
A cold front will reach the far NW waters tonight. The front
will extend from 30N137W to 27N140W by Tue morning and from
30N136W to 26N140W on Tue night. Seas of 8 to 9 ft in NW swell
can be expected W of the front. A larger set of long period NW
swell, with periods of 20 seconds, is forecast to enter the NW
waters on Thu. Seas associated to this swell event will peak near
15 ft over the far NW waters by Thu night.
Looking ahead, a low pressure system is expected to form during
the next few days several hundred miles south or south-southwest
of the southern tip of the Baja California peninsula. Some
gradual development will be possible thereafter while the system
moves slowly northward. The latest Tropical Weather Outlook
gives this system a low chance of tropical cyclone formation
through 5 days.