000
AXPZ20 KNHC 200302
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
300 UTC Wed Nov 20 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
meteorological analysis.

Based on |0000| UTC surface analysis and satellite imagery 
through |0230| UTC.

...TROPICAL WAVES...

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 FROM 09.5N75W TO 09.5N90W TO 09N99W
TO 11.5N110W TO 11N120W. ITCZ AXIS EXTENDS FROM 11N120W TO
11N130W TO 11.5N135W TO BEYOND 10N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 90 NM S OF TROUGH 
BETWEEN 83W AND 101W. SCATTERED MODERATE TO STRONG FROM 08N TO
15N BETWEEN 102W TO 112W...AND FROM 06.5N TO 11.5N BETWEEN 128W
TO 140W.

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.

$$
Stripling