000
AXPZ20 KNHC 070247
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
138 UTC Fri Jul 7 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.

...SPECIAL FEATURE...

A broad low pressure area in the monsoon trough was located near 
11N108W. It is moving slowly westward at about 10 kt. Scattered 
moderate isolated strong convection is observed within 180-240 NM
of the circulation center, roughly from 08N to 14N between 106W 
and 112W. Recent infrared satellite imagery shows increasingly 
cyclonically curved convective bands around the circulation 
center in an area of low vertical shear. This environment is 
expected to remain favorable for the low to strengthen, and it 
is likely to become a tropical cyclone within the next day or so.
Please refer to the NHC Tropical Weather Outlook at hurricanes.gov
for more information. An earlier 1606 UTC ASCAT scatterometer 
pass indicated southwesterly 20-25 kt monsoonal flow within 180 
NM in the SE semicircle of the low. This in conjunction with long
period cross-equatorial swell has produced a band of 8 to locally
10 ft seas. 

...TROPICAL WAVES...

The tropical wave along 96W/97W N of 13N earlier has moved over
Mexico with no impact on the East Pacific basin. 

A tropical wave along 124W/125W from 14N to 22N moving west at 
10 kt has a weakening exposed low level center near 18N125W
lacing deep convection. The low is expected to degenerate into a
trough within 24 hours, with the trough continuing westward, and
crossing 140W by late Sunday or Monday.

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

The monsoon trough extends from Costa Rica near 09N83W and
continues through 09N91W to 12N105W through the low pressure 
near 11N108W to 14N117W. The monsoon trough then resumes from 
12N127W to 09N140W. Scattered moderate isolated strong 
convection is observed elsewhere along the monsoon trough within 
120 to 180 NM south of the trough axis between 87W and 106W. 
Scattered moderate convection was observed within 90-120 NM 
either side of axis between 125W and 140W. 

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A 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 a max of 20 kt each night in the Gulf of Tehuantepec, 
then diminish during the day. Little change 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 for the remainder of this week. Gentle to 
moderate southerly winds are expected south of the monsoon trough
as well. Long period cross-equatorial S to SW swell and seas to 
8-9 ft W of Colombia and Ecuador will subside Friday into the
weekend. 

REMAINDER OF THE AREA...
  
See special feature section for more information on the low 
centered near 11N108W. Outside the influence of this area, 
gentle to moderate trade winds will prevail north of the monsoon 
trough, while moderate to fresh southerly winds will be south of 
the trough axis. Seas will be generally 5-7 ft. These general 
conditions are expected to prevail through the rest of the week.

$$
Cobb