000
AXPZ20 KNHC 312146
TWDEP 

Tropical Weather Discussion 
NWS National Hurricane Center Miami FL
2205 UTC Thu May 31 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 
1545 UTC.  
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends west off the Caribbean coast of 
Colombia at 10N76W across the extreme southwest caribbean and 
across northern Costa Rica to the Pacific Coast of Costa Rica at 
11N86W to 13N94W, then turns southwest 09N120W where 
scatterometer winds indicate a transition to an ITCZ which 
continues west to beyond 08N140W. Scattered moderate and 
isolated strong convection is observed within 120 nm either side 
of a line from 06N85W to 06N93W to 12N95W to 08N128W to 08N137W.
 
...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Northwest swell, in the form of 7 to 8 ft seas, currently N of 
30N west of 119W, will subside to less than 8 ft tonight. A 
northwest to southeast orientated low level ridge continues 
across the East Pacific well beyond 250 nm seaward, with the 
associated pressure gradient forecast to support a moderate to 
fresh northwest breeze west of the Baja Peninsula through late 
Sun night, then diminish to a gentle northwest breeze on Mon and 
Tue. Another round of large northwest swell, in the form of 7 to 
10 ft seas, will arrive at 32N120W on Mon, with seas 8 ft of 
greater forecast north of 27N west of 117W by the middle of next 
week.
   
Gulf of California: Moderate southerly winds are forecast across 
the gulf waters north of 30N through tonight, then light and 
variable winds are expected through Sun night when moderate to 
fresh southerly flow will set up, and then persist through the 
middle of next week. A moderate to fresh northwest breeze is 
setting up across the gulf waters south of 26N, with these 
conditions forecast to spread north to along 27.5N on Fri, with 
little change then through early Sat. Light and variable 
conditions are forecast for the central and southern gulf waters 
on Sun, then moderate southerly flow is forecast on Mon and Tue.

Gulf of Tehuantepec: Moderate nocturnal drainage is forecast to 
resume on Sat night as a surface low is forecast to develop 
along the monsoon trough near 12N101W. The low should move west 
of the area on Sun night. 
    
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR... 

Gulf of Papagayo: Moderate to locally fresh nocturnal 
drainage flow is forecast through Sat night. 

Otherwise, light to gentle onshore winds are forecast during the 
daylight hours, and gentle to occasionally moderate offshore 
nocturnal flow, with 3 to 5 ft seas throughout.
  
REMAINDER OF THE AREA...
   
A surface ridge extends into the area from 32N140W to 11N113W.
Fresh trades, and 6 to 8 ft seas, are observed across the 
tropics south of the ridge from 09N to 12N west of 136W. These 
conditions will gradually diminish by tonight, then redevelop 
again on Sat through Mon night.  

Fresh north winds, and long period N swell in the form of 7 to 
10 ft seas, is observed north of 25N between 120W and 140W.
These seas will gradually subside to less than 8 ft by late Fri. 

The next round of fresh to locally strong north winds, and 
northerly swell to 8 ft will reach along 32N between 122W and 
128W late Sun. Although the the north winds will diminish to a 
moderate to fresh breeze early next week, the associated swell 
will propagate south to along 25N between 118W and 128W on 
Tue before beginning to subside.
  
$$
Nelson