AXPZ20 KNHC 192210
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Tue Nov 19 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 1800 UTC surface analysis and satellite imagery through
The axis of a tropical wave is along 90W N of 04N, moving W at
10 to 15 kt. A low to middle level cloud swirl is evident in
satellite imagery along about 08.5N in the vicinity of the wave.
Small clusters of moderate convection are noted behind the wave
within 120 nm S of the monsoon trough between 90W and 82W.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 09.5N75W TO 10N89W TO 08.5N94W
TO 1010 MB low pressure near 12N108W TO 11N121W. THE ITCZ
extends from 11N121W TO beyond 10.5N140W. Scattered moderate
isolated strong convection is observed within 75 NM N and 120 NM
S of the trough between 82W AND 107W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Gentle to moderate southerly winds across the northern Gulf of
California will back to the SW and increase to near gale force
N of 30N tonight, ahead of a cold front approaching the area
from the northwest. Seas will quickly build to 8-10 ft across
this area buy around sunrise. Additionally, SW gap winds are
forecast to accelerate through the prominent low ridges in the
mountainous terrain of Baja California Norte and produce very
gusty conditions downstream across the Gulf. Associated
deepening low pressure across the desert SW of the U.S.
supporting the cold front will linger N of the area through Thu
and help to maintain strong to periods of near gale force SW
across the northern Gulf of California through Wed night before
diminishing Thu afternoon.
This cold front just N of the area will sink southward into the
outer offshore waters later tonight and reach along 27N to the W
of 120W by Wed night. This system will usher in new long period
NW swell into the offshore waters west of the Baja California
Norte, with building seas in the 8 to 12 ft range on Wed. This
swell event will spread southward, with seas 8 ft or greater
spreading as far south as 21N by Fri before subsiding.
Low level moisture ahead of the cold front and entrained in the
SW winds forecast across Baja California and the Gulf tonight
through Wed will spread across north portions of the Gulf and
along the western slopes of the Sierra Madre Occidentales,
leading to very active convection late this afternoon through
Wed morning, and then again Wed afternoon and evening.
Moderate high pressure across the Gulf of Mexico will continue
to support moderate to strong northerly gap winds across the
Gulf of Tehuantepec through Wed afternoon before winds across
the Bay of Campeche and the western Gulf of Mexico veer
southerly and shut down the northerly flow across Tehuantepec.
Light to gentle breezes and slight seas will then persist
through the remainder of the week.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Fresh to strong NE-E winds are expected across the Gulf of
Papagayo Wed through Thu with seas building to around 7 ft.
Elsewhere, gentle to moderate southwest monsoonal flow will
continue across the offshore waters of Costa Rica, Panama,
Colombia, and Ecuador for the next several days.
REMAINDER OF THE AREA...
The remnant low of Tropical Depression Twenty-One-E is near
12N108W. Widely scattered moderate convection is noted within
120 nm on the E side of the low. These remnants are forecast to
gradually merge with broad and weak low pressure in that
vicinity, and gradually shift W across the tropics for the next
few days. Easterly winds to around 20 kt could persist across
the N semicircle of this broad low pressure during this time.
Elsewhere a ridge dominates the north waters mainly N of 16N W
of 122W. The pressure gradient between the ridge and lower
pressure in the vicinity of the ITCZ is supporting moderate to
locally fresh winds north of the ITCZ and west of 125W.
Additional pulses of long period NW swell will continue to
impact the west-central waters today with seas of 8 to 9 ft from
10N to 15N W of 135W. An altimeter pass confirmed the presence
of these sea heights. A new pulse of large, long period NW swell
is forecast to reach the forecast waters north of 20N west of
130W Thu night, with seas peaking 12 or 13 ft by Fri.