AXPZ20 KNHC 231015
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Sun Oct 23 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 0600 UTC surface analysis and satellite imagery through
The low pressure center moving W-NW and away from the
Tehuantepec region the past 24 hours has improved in
organization overnight, and this system has been initiated as
Tropical Depression Twenty-E, located near 13.1N103.6W at 0900
UTC, moving W-NW or 290 deg at 14 KT. Maximum sustained winds
are 30 kt with gusts to 40 KT, and minimum central pressure is
1007 mb. Satellite and microwave imagery overnight have shown
increased deep convection near and within 210 nm across the NW
semicircle of the center. Also, a partial ASCAT pass overnight
showed winds to 28 kt occurring within 120 nm across the NE
quadrant. Oceanic and atmospheric conditions appear favorable
for gradual strengthening of the T.D. during the next few days,
as it moves W-NW at 10-15 kt, and is expected to reach hurricane
strength within 48 hours. Based on the current forecast track,
strong to tropical storm force winds will brush across outer
portions of the offshore waters from SW of Acapulco to Cabo
Corrientes through Monday afternoon, then the cyclone will move
slightly more westward and remain outside the offshore waters of
Baja California Sur Monday night and Tuesday. See the latest NHC
forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 for
A gale warning remains in effect for the Gulf of Tehuantepec.
A narrow north to south aligned ridge across eastern Mexico will
maintain strong northerly winds across the Gulf of Tehuantepec
for most of the upcoming week. Winds are expected to increase
late each night through early morning to minimal gale force,
then diminish to 20-30 kt during the day. Peak seas downstream
of these gales will build to around 9-12 ft by sunrise each
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 10N74W to 10N86W to 09N92W to
T.D. TWENTY-E near 13.1N103.6W to low pres near 15N115.5W to low
pres near 13.5N128W to beyond 11.5N140W. Widely scattered to
scattered moderate to strong convection is noted from 02.5N to
09.5N E of 85W. Scattered moderate to strong convection is noted
within 120 nm N and 180 nm S of the trough between 93W and 130W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
For the Gulf of Tehuantepec area, see special features section
above. A weak sub-tropical ridge axis extends from NW to SE
across the offshore waters of Baja California Sur to near
23N113W. Light to gentle NW winds are expected across the
Pacific waters of Baja California today before weak troughing
develops just offshore of Baja California Sur tonight to produce
light and variable winds. Combined seas of 4 to 6 ft in NW swell
are expected this morning before seas build to 5-8 ft this
afternoon through Mon in a new pulse of NW swell. NW winds will
freshen modestly Mon night through Tue as the ridge strengthens
Inside the Gulf of California, mainly gentle southerly winds are
noted based on scatterometer and surface data. This general wind
direction will persist on Sun, then light and variable winds are
expected on Mon.
Light and variable winds are also expected elsewhere within
about 100 nm of the Mexican coast from W of the Gulf of
Tehuantepec through tonight, except for freshening E to SE winds
across the outer waters between Acapulco and Cabo Corrientes due
to T.D. Twenty-E.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gulf of Papagayo: fresh to locally strong NE winds are expected
across and just downstream of the Gulf of Papagayo early Sun
morning and again on Monday morning. Gentle to moderate S to SW
winds are noted S of 05N, while gentle to moderate W to NW winds
are N of 05N. Combined seas of 4 to 6 ft, primarily in long-
period SW swell dominate the offshore waters. These marine
conditions will persist over the few days.
REMAINDER OF THE AREA...
A weak ridge dominates most of the north waters N of 20N W of
118W. Under the influence of this system, mainly gentle to
moderate winds are noted per scatterometer data. Winds will
increase to 15-20 kt near the monsoon trough due to the presence
of a string of weak low pres systems along the trough, and
their associated convection.
A new pulse of long period NW swell is spreading SE across the
NW waters. This swell is expected to reach the waters of Baja
California today then gradually subside below 8 ft by Mon night.
A cold front will enter the NW waters near 30N140W tonight and
will move across the NW waters on Monday, stretching from
30N133W by Monday evening. This front will be reinforcing by a
second cold front reaching the same area on Tue. The merging
cold front is forecast to extend from 30N134W to beyond 26N140W
by Tue night.