000
AXPZ20 KNHC 152147
TWDEP 

Tropical Weather Discussion 
NWS National Hurricane Center Miami FL
2205 UTC Thu Jun 15 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 1800 UTC surface analysis and satellite imagery through 
2145 UTC.

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

The monsoon trough extends W from 12N87W to 13N102W to 12N110W 
to 06N130W where scatterometer winds indicate that the ITCZ 
forms, and then extends NW to beyond 07N140W.

Scattered moderate isolated strong convection is observed over 
and to the N of the monsoon trough within 120 nm either side of 
a line from 12N87W to 17N106W. Similar convection is observed 
mostly to the S of the monsoon trough, within 180 nm either side 
of a line from 05N80W to 08N88W to 07N117W.
 
Broad low pressure is forecast to continue for a couple of days 
across most of Central America and Eastern Mexico.  Locally 
heavy rainfall accumulations are possible as large clusters of 
tstms develop.
  
...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A nw to se orientated ridge extends across the EPAC waters well 
to the SW of the offshore zones, while a NW to SE orientated 
trough continues across the Baja Peninsula mainly during the 
late afternoons in the early evening hours. A gentle to moderate 
NW breeze is forecast across the offshore waters W of 111W 
through early Sun, then the NW flow will increase to a moderate 
to locally fresh breeze on Sun night, and continue through Tue 
night. Strong northerly drainage winds possible in the Gulf of 
Tehuantepec on Mon night into Tue. Light and variable winds 
expected elsewhere across the open Pacific offshore waters 
through early Sat, when a moderate W breeze will develop, and 
continue through Tue night. Large SW swell forecast across the 
waters s of 12N beginning early Sun, then subsiding to less than 
8 ft on Mon night. Light and variable winds forecast across the 
Gulf of California through the period. 

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

Light and variable winds are forecast to the N of 10N tonight 
and to the N of 12N early Fri. Moderate southerly flow currently 
observed to the S of 10N, will spread N with a moderate SW to W 
breeze across the entire forecast area by late Fri, with little 
change through Tue night. Long period SW swell will build seas 
to 9 ft over the upcoming weekend and continue through Mon, then 
subside to less than 8 ft by early Tue.

REMAINDER OF THE AREA...
  
A 1025 mb surface high will meander near 31N136W through Fri 
with a ridge extending SE to near 10N115W. The high should shift 
n of 32N on Fri night, but leave a ridge extending SSE across 
the discussion waters to the W of 125W. Moderate to fresh 
anticylonic flow is forecast across the discussion area through 
Tue, with seas of 7 to 9 ft to the N of the ridge between about 
120W and 127W.

An area of 6 to 8 ft seas, primarily due to SW swell, is a 
observed from 07N to 08N between 103W and 109W. The seas will 
subside below 8 ft early Fri as a batch of cross equatorial 
southwesterly swell, in the form of 7 to 9 ft seas, spreads N 
across the equator between 90W and 110W on Fri evening. Expect 7 
to 9 ft seas across the tropics to the E of 120W on Sat through 
Mon before beginning to subside on Mon night into Tue.

$$
Nelson