AXPZ20 KNHC 250735
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Sat Sep 25 2021
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 0600 UTC surface analysis and satellite imagery through
The axis of a tropical wave is near 129W from 06N to 14N, moving
west at 10 to 15 kt. Associated convection is described below.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 1008 mb low pressure over
northern Colombia near 11N74W to across the Papagayo region at
10N86W to 09N95W to 11N115W to 10N128W. The ITCZ extends from
10N130W to 09N140W. Scattered moderate and isolated strong
convection is noted from 11N to 14N between 87W and 93W, from 06N
to 09N between 89W and 92W, and within 16N112W to 09N112W to
06N130W to 11N130W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Fresh to near gale force N-NE winds are in the Gulf of
Tehuantepec with seas of 6 to 8 ft. Gentle to moderate NW-N
winds are noted west of Baja California and also offshore of Cabo
Corrientes. Light to gentle winds are elsewhere offshore of
Mexico. Seas are 4 to 6 ft in a mixed of long period swells
offshore of Mexico, except 3 ft or less in the central and
northern Gulf of California.
For the forecast, fresh to strong northerly gap winds will
continue in the Gulf of Tehuantepec through Sun. Mainly moderate
NW-N winds will prevail west of Baja California, pulsing locally
to fresh at times. S-SW winds will pulse to moderate to fresh in
the northern Gulf of California. Otherwise, gentle to moderate
winds will prevail. A set of large NW swell may impact the waters
west of Baja California by the middle of next week.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and
WITHIN 750 NM OF ECUADOR...
Moderate to fresh winds are in the Papagayo region, with light to
gentle winds elsewhere north of the monsoon trough. Gentle to
moderate S-SW winds are south of the monsoon trough. Seas are in
the 4 to 5 ft range from offshore of Colombia northward, and 5 to
7 ft in building SW swell offshore of Ecuador.
For the forecast, moderate to fresh offshore winds will pulse in
the Papagayo region, briefly to fresh to strong tonight and Sun
night. Otherwise, light to gentle winds will prevail north of
the monsoon trough, with mainly moderate winds south of the
monsoon trough. SW swell will propagate across the waters through
early next week.
REMAINDER OF THE AREA...
A 1011 mb low pressure area is analyzed near 20N128W. Isolated
moderate convection is noted just northeast of the trough.
Moderate to locally fresh NE-E winds are also noted near the
trough. Broad and week ridging and gentle to moderate trades
dominate the remainder of the open waters north of the
convergence zone. Gentle to moderate southerly winds prevail
south of the convergence zone. Seas are in the 5 to 7 ft range
north of 10N, and 6 to 8 ft south of 10N, except to 9 ft in
southerly swell south of the equator and west of 95W.
For the forecast, winds associated with the low north of the
convergence zone will gradually diminish over the weekend as the
low shifts westward and weakens. A cold front is expected to
move into the NW waters Mon night into early Tue and quickly
weaken as it moves southward. Associated long period NW swell is
expected to build seas to 8 to 11 ft, spreading southward
through the middle of next week.