000
AXPZ20 KNHC 311552
TWDEP 

Tropical Weather Discussion 
NWS National Hurricane Center Miami FL
1605 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 Pacific coast of 
Colombia at 09N78W across the extreme northern Gulf of Panama, 
and then continues northwest across interior Panama to along the 
Pacific coast of Costa Rica then offshore to 13N94W, then turns 
southwest to 09N116W 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 lines from 10N93W to 14N96W and 
from 11N104W to 07N127W. Isolated moderate and strong convection 
is noted elsewhere to the north of 04N east of 97W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Northwest swell, in the form of 7 to 9 ft seas, currently west 
of a line from 32N118W to 27.5N119.5W, is subsiding from the 
south, and forecast 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.
    
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 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 during the upcoming weekend.  

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