000
AXPZ20 KNHC 192139
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Sat May 19 2018

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 
2030 UTC. 
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from 09N73W TO 08.5N87W TO 10N99W TO 
10N125W. The ITCZ continues from there to beyond 07N140W. 
Scattered to locally numerous moderate to strong convection is 
from 05N to 10.5N east of 121W. Scattered moderate to strong 
convection is within 180 nm N and 120 nm S of axis between 121W 
and 140W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Moderate to fresh NW winds continue off the coast of Baja 
California this afternoon, where seas are generally 6 to 7 ft 
except to around 8 ft near and to the S of Cabo San Lucas. 
Generally light to gentle variable winds are noted over the Gulf 
of California, with slightly stronger westerly gap winds near 
low level areas over the peninsula. Light NW to W winds are 
noted farther south off the Mexican coast. The main forecast 
issue ahead will be the onset of long period SW swell in excess 
of 8 ft moving into the open Pacific waters off Mexico late on 
Sunday. Large SW swell will reach waters of southern Mexico by 
early Mon, and into the open waters off Baja California Mon 
night and Tue, mixing with NW swell off Baja California Norte.

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

Gulf of Papagayo: Light to gentle winds will dominate the gulf 
the entire forecast period as weak pressure will prevail across 
Central America. Seas of 5-8 ft are forecast over the Gulf and 
nearby waters through mid week due to strong long period SW 
swell.

Gulf of Panama: Gentle to moderate S to SW winds are forecast 
through Wed with seas of 4-6 ft in long period SW swell, 
building to 5-7 ft on Mon as the swell reaches the coasts of 
Panama and Colombia. 

Elsewhere, gentle to moderate SW winds are expected to the south 
of the monsoon trough with light to gentle variable winds north 
of trough as a weak pressure pattern remains over Central 
America. Seas of 6-7 ft in building long period SW swell west of 
the Galapagos Islands are expected to propagate northward 
tonight through late Tue next week, building 8 to 9 ft Sun 
night through Mon.

REMAINDER OF THE AREA...

A cold front is moving slowly across the eastern Pacific and has 
nearly stalled across the far northwest corner of the discussion 
area this afternoon, from 30N134W to 27N140W. The subtropical 
ridge SE of the front remains weak as the front has entered the 
area, but is sufficiently strong enough to support moderate to 
locally fresh trade winds across the tradewind belt in the deep 
tropics. Seas are 8 ft in pockets north of the monsoon 
trough/ITCZ in areas of fresh trade winds, generally from 10N to 
22N to the west of 124W. The front will weaken as it drifts SE 
through tonight. The ridge will build eastward in the wake of 
the dissipating front, allowing the areal extent of the 
tradewinds, and subsequently the areas of 8 ft seas to expand 
over the deep tropics. Meanwhile cross equatorial southerly 
swell continues to propagate into the region, with seas reaching 
8 ft as far north as 15N between 95W and 125W early in the week. 
Various wave model guidance shows the large SW swell 
encompassing most of the region south of 20N and east of 120W by 
mid week. 

$$
Stripling