000
AXPZ20 KNHC 060241
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
111 UTC Thu Jul 6 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 0000 UTC surface analysis and satellite imagery through
0230 UTC.

...TROPICAL WAVES...

A surface low is analyzed near 18N119.5W, moving in tandem with 
a tropical wave along 119W/120W that extends from 11N to 21N. 
The last visible satellite images of the day continue to show a 
well defined exposed low level center well displaced from
weakening convective activity associated with the wave. An
earlier 1806 UTC ASCAT pass showed NE to E winds of 20-25 KT 
within 180 NM in the north semicircle of the low but did not 
capture the area of S to SW monsoonal flow to the southeast of 
the low. Only isolated moderate convection is noted within 120 
nm W of the wave axis from 15N to 18N. This low has moved into
an area of less favorable environmental conditions, and the 
chances of this system becoming a tropical depression are low. 
Please refer to the NHC Tropical Weather Outlook at hurricanes.gov
for more information.

In addition to the wave mentioned above along 119W/120W, a 
tropical wave is analyzed from 07N105W to 15N109W. Scattered 
moderate convection is noted FROM 07N TO 14N within 180-240 NM 
east of and 120 NM west of the wave axis. NWP model guidance 
suggests that a surface low may develop along this wave near 
10N/11N in 24 hours or so. A low pressure has been introduced 
into the High Seas forecast in 24 hours with an area of monsoonal
S to SW winds of 20 to 25 kt forecast near the low by 48 hours. 
Long term environmental conditions appear to be favorable for 
further strengthening of this low. Please refer to the NHC 
Tropical Weather Outlook at hurricanes.gov for more information.

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

The monsoon trough extends across Panama and Costa Rica into the
east Pacific near 08N83W to 11N110W to 12N117W, then resumes 
near 13N124W to 10N130W to 10N140W. Scattered moderate isolated 
strong convection was noted within 120 to 150 NM south of the 
monsoon trough axis between 79W and 100W extending to the Gulf 
of Tehuantepec, and within 120 to 180 NM either side of the axis 
between 126W and 137W. 

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A weak ridge of high pressure extends across the waters west of 
Baja California. Light to moderate anticyclonic flow prevails 
west of the Baja California peninsula, moderate to fresh N winds 
in the Gulf of Tehuantepec, and light to gentle winds over the 
Gulf of California. Seas are 4-6 ft in the open waters west of 
Mexico, with 1-2 ft seas in the Gulf of California. Nocturnal 
winds will pulse to near 25 kt each night in the Gulf of 
Tehuantepec, and diminish during the day. Little change is 
expected elsewhere.
    
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR... 

Moderate to locally fresh nocturnal winds are expected in the 
Gulf of Papagayo this week. Gentle to moderate southerly winds 
are expected south of the monsoon trough this week. Long period 
cross-equatorial S to SW swell will build seas west of Colombia 
and Ecuador Wednesday night and Thursday, then subside Friday.

REMAINDER OF THE AREA...
  
Outside the monsoonal influence of the surface low and tropical
wave along 119W/120W, gentle to moderate trade winds are expected 
to prevail north of the monsoon trough, while moderate to fresh 
southerly winds will develop south of the trough axis. Seas will 
be generally 5-7 ft. These general conditions will prevail 
through the rest of the week. Long period cross-equatorial S to 
SW swell will build seas to 8 to 9 ft south of 04N and east of 
120W by late Thursday and shrink in area by Friday. 

$$
Cobb