AXPZ20 KNHC 200333
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Tue Oct 20 2020
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
A tropical wave axis extends along 120W from 05N to 16N, moving
W at 10 to 15 kt. Associated convection is described below.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough axis extends from 12N79W to 08N83W to 13N94W
to low pres 1007 mb near 10.5N101W to 10N110W to 13N121W to
09N138W, then transitions to ITCZ continuing on beyond 08N140W.
Scattered moderate to strong convection is noted from 05N to 10N
east of 97W. Scattered moderate isolated strong convection is
noted from 08.5N to 15.5N between 113W and 134W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
The pressure gradient between a high pressure ridge to the west
of Baja California and lower pressure over southern California is
supporting moderate to fresh NW winds across the offshore waters
of northern and central Baja California. Farther south, with
exception of a small area of strong winds across the Gulf of
Tehuantepec, gentle to moderate breezes persist. Seas are
generally in the 4 to 7 ft range in mixed N and SW swell.
Winds will remain fresh through Tue night offshore the Baja
California peninsula as low pressure deepens over the SW U.S.
Locally strong winds are expected within 120 nm of Baja
California Norte and near Punta Eugenia through Tue morning,
with seas of 6-7 ft. Mostly gentle to moderate breezes and seas
5 ft or less will persist elsewhere.
Gulf of Tehuantepec: Winds across the Gulf of Tehuantepec are
expected to remain northerly for the next few days with
nocturnal pulses of 25-30 kt each late night and early morning
through Wed, and extend only 90-120 nm downwind in a relatively
narrow plume. Seas will peak each early morning at 7-9 ft.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and
WITHIN 750 NM OF ECUADOR...
Moderate to fresh SW winds prevail south of the monsoon trough,
along about 09N-10N, and east of 97W. Seas south of Costa Rica
and Panama are 7 to 9 feet in mixed SW swell. These conditions
will continue with little change through Tue night before winds
subside slightly and long period SW swell begins to slowly fade
across the region.
Broad low pressure across the western Caribbean is aiding in
producing the areas of fresh winds south of Panama and Costa
Rica, and is also helping to produce very active weather across
these eastern waters east of 90W. This active weather is expected
to continue through Tue night before beginning to diminish as the
low pressure across the western Caribbean lifts NW towards the
Gulf of Mexico.
REMAINDER OF THE AREA...
1029 mb high pressure near 36N141W extends a ridge SE to near
Clarion Island, and is supporting moderate to fresh trade winds
from roughly 13N to 25N mainly west of 125W. Seas are generally
6-7 ft across this zone. Expect little change in this pattern
Scattered moderate convection is noted from 25N to 29N between
132W and 138W, to the southeast of a deep layered upper trough
just NW of the discussion area. This trough will drift NW during
the next few days.
Farther east, seas will remain 7-8 ft near the monsoon trough
between 108W and 118W, due in part to moderate SW winds south of
the monsoon trough and longer period SW swell moving through the
area. Look for both winds and seas to diminish slightly across
this area by Tue evening.