000
AXPZ20 KNHC 182206
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2152 UTC Sat Jul 18 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
meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...TROPICAL WAVES...

A tropical wave is analyzed along 85W, north of 02N, moving 
westward at 10-15 kt. Scattered moderate isolated strong 
convection is noted from 04N TO 12N EAST OF 85W TO THE COAST OF
COLOMBIA, and extending into the immediate Caribbean coastal 
waters of Panama and Costa Rica.

A tropical wave is analyzed along 110W, south of 18N, moving 
westward at 10-15 kt. Scattered moderate isolated strong 
convection is noted from 07N TO 17N BETWEEN 106W AND 116W.

A tropical wave is along 124W, south of 16N, moving westward at 
15 kt. Scattered moderate isolated strong convection is noted 
from 09N TO 16N BETWEEN 120W AND 127W then continues along the 
monsoon trough as described below.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from 10N75W TO 10.5N85W TO 08N95W TO 
14N122W TO LOW PRES 1009 MB NEAR 13.5N123W TO LOW PRES 1009 MB 
NEAR 10N136W TO 11N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION is noted FROM 06.5N TO 12N BETWEEN 91W AND 109W. 
SCATTERED TO LOCALLY NUMEROUS MODERATE TO STRONG CONVECTION is
noted FROM 05N TO 13.5N W OF 127W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A deep layered upper trough west of 120W supports a weak trough 
from 30N122W to 21N132W, which is blocking high pressure across 
the NE Pacific from building into offshore waters. The resultant 
weak pressure gradient across the area is producing moderate NW 
winds west of Baja California, to the north of Punta Eugenia, and
gentle NW winds south of Punta Eugenia. The trough will weaken 
and drift west tonight through Sunday, allowing high pressure to 
build modestly into the area through early next week. Freshening 
winds and a modest increase in seas are expected Sun through Mon 
night. Gentle to moderate southerly winds will persist in the 
Gulf of California this weekend, increasing modestly during the
afternoon and evening, with seas of 2-4 ft.

High pressure building southward from the Gulf of Mexico
continues to induce moderate gap winds across the Gulf of 
Tehuantepec, which will become fresh each night. This will continue
through Sun afternoon. No significant long-period swell is 
expected across the Mexican offshore zones the next several days.

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and 
WITHIN 750 NM OF ECUADOR...

Moderate northeast to east gap winds will persist across the 
Gulf of Papagayo region through Mon, becoming fresh during 
during the night. Moderate to fresh southwest winds will prevail 
over the waters south of 08N through Tue, with fresh winds 
expected this weekend. No significant long-period swell is 
expected in Central American and equatorial offshore zones the 
next several days. 

REMAINDER OF THE AREA...

A 1036 mb high pressure center is located near 44N142W extends a
ridge across the northern waters west of the frontal trough,
while an old frontal trough extends from 30N127W to 24N134W. The
pressure gradient between the high and the monsoon trough is 
supporting moderate to fresh winds north of the convergence zone 
to 22N and west of 118W, where seas are in the 5-8 ft. Fresh NE 
to ENE winds prevail across the NW waters to the west of the 
frontal trough, and area producing seas of 6-7 ft. This area of 
winds will shift westward through Sun and weaken across the local
waters, with resultant seas diminishing to 5-7 ft.

Moderate to fresh southerly winds prevail south of the monsoon 
trough. Cross-equatorial SE swell maintains seas in the 6-7 ft 
range south of 08N and west of 115W. 

Global model continues to show development of a low pressure 
area in association with the tropical wave, presently along 124W,
during the next 2 to 3 days, as the wave it moves westward over 
open waters. Winds to 25 kt and seas to 8 ft are likely to 
develop across north and east portions of this low by tonight or 
Sun and could increase further Sun night through Mon.

$$
Stripling