- NHC East Pacific Tropical Weather Discussion
AXPZ20 KNHC 172020
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Tue May 17 2022
Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.
Based on 1800 UTC surface analysis and satellite imagery through
Global models suggest that a broad area of low pressure may form
across the western Caribbean and then shift across Central
America late this week into the weekend. This is the
climatologically favored time of year for these broad low
pressure areas, called Central American Gyres, to develop. CAG's
increase SW monsoon flow, and lift the monsoon trough well north
of its typical position, which advects abundant moisture
northward. This CAG will bring an increase in convection,
starting over the southern portions of Central America, which
will gradually lift northward across portions of Central America
and across the waters west of Central America as the monsoon
trough lifts northward. There will be the potential for locally
heavy rainfall over portions of Central America, especially in
regions of enhanced orographic lift. Please refer to products
issued by your local weather service for more information.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 10N86W to 06N106W to 10N123W to
09N128W. The ITCZ extends from 09N128W to 07N140W. Scattered
moderate isolated strong convection is noted from 04N to 10N
between 77W and 89W, from 09N to 11N between 89W and 93W, within
270 nm south-southwest of the monsoon trough between 106W and
116W, and from 10N to 12N between 120W and 124W. Scattered
moderate convection is noted from 07N to 13N between 94W and
100W, and from 06N to 09N between 116W and 124W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Moderate to fresh NW winds prevail off the coast of the Baja
California Norte. Gentle to moderate NW winds are west of Baja
California Sur. Moderate to locally fresh southerly winds are
over the Gulf of California. Moderate N to NE winds are offshore
Tehuantepec. Light to gentle winds are elsewhere over the open
waters off Mexico from Las Tres Marias to Oaxaca. Seas are in the
7-10 ft range in NW swell off Baja California Norte, 6-8 ft off
the coast of Baja California Sur, and 5-6 ft elsewhere over the
open waters off Mexico. Seas are in the 2-4 ft range over the
Gulf of California, highest near the entrance and also in the
northern Gulf. Haze is reported at coastal sites from the
southern Gulf of California southward due to agricultural fires
over Mexico, while areas of dense fog are evident in afternoon
visible satellite imagery just offshore Baja California.
For the forecast, moderate to locally fresh winds will prevail
west of Baja California through mid-week, diminishing to gentle
to moderate thereafter. Moderate to locally fresh southerly flow
in the Gulf of California will persist through Wed. Fresh to
locally strong S-SW may develop in the northern Gulf of
California early Fri through Fri night. Moderate to locally fresh
W-NW winds will develop from near Cabo San Lucas to near Cabo
Corrientes to offshore Oaxaca Wed night through the end of the
week. NW swell will prevail across the waters off Baja California
Norte through the week, subsiding late this weekend.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and
WITHIN 750 NM OF ECUADOR...
Please see the Special Features section for information on a
potential heavy rainfall event.
Gentle to locally moderate S to SW monsoon flow prevails south
of the monsoon trough. Light to gentle winds prevail north of
the monsoon trough, except moderate winds offshore southern
Nicaragua. Seas are in the 5-7 ft range in S to SW swell.
Numerous showers and scattered thunderstorms persist from
offshore Colombia to offshore eastern Costa Rica. Some haze has
been reported at coastal sights from Nicaragua northward due to
nearby agricultural fires.
For the forecast, gentle to moderate winds will prevail south of
the monsoon trough through Wed, increasing to moderate to fresh
late Wed night through Fri. Light to gentle winds will prevail
north of the monsoon trough through Fri night, except moderate to
fresh over Papagayo and offshore southern Nicaragua through Wed.
Winds may briefly pulse to fresh to strong over Papagayo and
offshore southern Nicaragua tonight. A moderate long-period
southerly swell will linger through mid-week, with a slightly
larger set of southerly swell arriving by Thu.
REMAINDER OF THE AREA...
High pressure prevails over the waters north of the ITCZ and
monsoon trough and west of 110W. The pressure gradient between
the ridge and lower pressure in the vicinity of the ITCZ and
within the monsoon trough is maintaining moderate to locally
fresh winds and seas of 6-7 ft north of the ITCZ and monsoon
trough to 26N and west of 115W, locally fresh to strong north of
27N between 120W and 127W with 7-9 ft seas in fresh northerly
swell. Gentle to moderate anticyclonic winds and 4-5 ft seas are
north of 26N and west of 129W near the high center. Gentle to
moderate southerly winds and 5-7 ft seas are noted south of the
ITCZ and monsoon trough and west of 106W, except to 8 ft south of
the Equator. East of 110W, light to gentle to winds are noted on
either side of the monsoon trough with 4-7 ft seas, except to 8
ft south of the Equator and west of 95W.
For the forecast, fresh to strong northerly winds will extend
from offshore southern California into the waters north of 27N
between 120W and 130W through mid-week, along with seas in the
7-10 ft range due to fresh northerly swell. Otherwise, little
change in conditions are expected across the open waters through
the week with rather tranquil marine conditions anticipated this