000
AXPZ20 KNHC 210956
TWDEP 

Tropical Weather Discussion 
NWS National Hurricane Center Miami FL
1005 UTC Sun May 21 2017

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 0600 UTC surface analysis and satellite imagery through 
0830 UTC.

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

The monsoon trough extends from a 1008 mb surface low along the 
Caribbean coast of Colombia near 10N74W westward across Central 
America to near 08.5N81W TO 13N91W TO 11N96W TO 12.5N103W TO 
08N110W TO 06N121W. The ITCZ then begins near 07N124W and 
extends to beyond 04N140W. 

Scattered moderate to strong convection is noted from 01.5N to 
05N E of 81W. Scattered to locally numerous moderate to strong 
convection is noted from 06N TO 15N between 79W AND 100W. 
Scattered moderate isolated strong convection is noted within 60 
nm N and 150 nm S of trough between 107.5W and 114W.
 
...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

The NE Pacific surface ridge continues across the area, centered 
on a 1027 mb high near 43N133W with ridges extending SW to N of 
the Hawaiian Islands and SE to near 19N115W. The associated 
pressure gradient across the Baja peninsula waters remains 
modest tonight, and is producing gentle to moderate NW winds 
across the majority of these waters W of 100W, where seas are 
running 4-5 ft in NW swell. The ridge will begin to realign 
tonight through Mon and tighten the pressure gradient across the 
region to produce a slight increase in the NW wind flow 
throughout the upcoming week. Associated seas will build to 4-6 
ft by Tue evening. 

Gulf of California: Light to gentle NW flow will becomes light 
tonight through early Tue, and allow for afternoon seabreezes to 
produce varying winds throughout the basin. 

Gulf of Tehuantepec: A weak and broad low pressure circulation 
is beginning to develop along the monsoon trough near 11N and to 
the S of Tehuantpec tonight, and will drift slowly W and 
dissipate through Wednesday. Expect varying winds at 15 kt or 
less across the Tehuantepec region during this period, with 
active convection shifting westward into the offshore waters 
this morning through Mon night.

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

A surge in low level moisture spreading westward across the area 
will lead to active convection N of 05N through Wed.  Expect 
moderate SW to W winds S of the monsoon trough, or about 10N, 
through Wed, while gentle to moderate E to SE winds prevail N of 
the trough. Look for freshening offshore flow from the Papgayo 
area across the waters of Nicaragua tonight through Tuesday 
evening, producing areas of 20 kt winds. A strong pulse of SSW 
swell is moving into the waters tonight and will build seas 6 to 
9 ft E of Papagayo and 6 to 7 ft W of Papagayo through Sun night 
before slowly fading through Tuesday. 

REMAINDER OF THE AREA...
  
The NE Pacific ridge will generally meander from through 30N130W 
to 15N107W through Wednesday. Moderate anticyclonic flow with 
combined seas of 4-6 ft is expected through late Monday, except 
5-7 ft in the trade wind belt S of 15N. A weak trough will sweep 
eastward across the waters north of 30N Monday night and 
Tuesday. Cross-equatorial southerly swell to 8 ft will prevail 
elsewhere south of 10N east of 110W through early Sunday night, 
then gradually subside to less than 8 ft Sunday night and Monday.

$$
Stripling