523 
AXPZ20 KNHC 130902
TWDEP 

Tropical Weather Discussion 
NWS National Hurricane Center Miami FL
1005 UTC Fri Jul 13 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 0600 UTC surface analysis and satellite imagery through 
0900 UTC.  

...TROPICAL WAVES...

.A tropical wave is analyzed to the N of 09N along 91W moving W 
at 15 kt. Scattered moderate and isolated strong convection is 
observed N of 11N within 150 nm either side of the wave axis.

.A tropical wave is analyzed from 07N to 18N along 108W moving W 
at 12 kt. Scattered moderate isolated strong convection is 
observed S of 10.5N within 180 nm either side of the wave axis.

.A tropical wave is analyzed from 06N118W to 17N118W moving W at 
15 kt. Scattered moderate to strong convection is observed S of 
11N within 180 nm either side of the wave axis. 

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

The monsoon trough extends west across off the Caribbean coast 
of Colombia at 09N75W across the far SW Caribbean along 10N to 
the Pacific coast of Costa Rica at 11N86W, then dips SW to 
07N96W, then turns NW through tropical waves at 10N108W and 
10N118W to 13N122W where scatterometer winds indicate a 
transition to an ITCZ which continues SW to beyond 10N140W.

Except as mentioned near the tropical waves, scattered moderate 
isolated strong convection is observed from 03N to 09N E of 81W, 
and elsewhere within 180 nm either side of a line from 09N83W to 
10N105W to 08N118W to 15N130W to 12N140W. 

Scattered moderate isolated strong convection is observed along 
the coast of Mexico within 60 nm of 23N107W.  
  
...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Gulf of Tehuantepec: Strong to near gale force northerly 
drainage flow, with 7 to 10 ft seas, will diminish somewhat 
this morning with a strong breeze resuming this afternoon,
and then persisting through late Sun as a tropical wave passes
through the area. Brief strong nocturnal breezes are then likely
through the middle of next week. 
   
A surface ridge extends into the area from 23N117W to 14N98W. 
Light to gentle northerly winds are expected around the ridge 
axis and west of 100W for the next several days with 3 to 5 ft 
seas.   
  
Gulf of California: Light to gentle southerly flow expected for 
the next 48 hours, except moderate SW flow is expected to 
develop along 30N on Sat evening, and persist through Mon 
morning.    

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

Gulf of Papagayo: Strong nocturnal NE to E offshore winds, with 
seas to 8 ft, will occur across and within 240 nm SW of the Gulf 
of Papagayo through sunrise on Mon, followed by brief strong 
nocturnal pulses on Tue and Wed.

Gentle to occasionally moderate E winds are forecast elsewhere N 
of the monsoon trough which is meandering between 07N and 10N. 
Moderate southerly winds are forecast S of the monsoon trough 
for the next several days with 4 to 6 ft seas.  
  
REMAINDER OF THE AREA...
   
The ITCZ bulges N between 128W and 135W effectively tightening 
the pressure gradient across the deep tropics resulting in area 
of fresh to locally strong trades from roughly 11N to 18N, W of 
130W, with seas to 9 ft. A blend of model guidance leads to a 
solution of a surface trough, or surface low developing near 
11N138W this weekend, with strong E winds across the waters 
to the from about 13N to 18N W of 134W.
 
A surface ridge will meander across the discussion area from 
32N138W to 23N117W through the middle of next week, with 
moderate to locally fresh anticylonic flow forecast elsewhere 
around the ridge accompanied by 5 to 7 ft seas. 
  
$$
Nelson