Eastern Pacific Tropical Discussion

Active Tropical Systems Basin Outlooks Satellite
Eastern Pacific Basin Tropical Discussion
 
879 
AXPZ20 KNHC 290932
TWDEP 

Tropical Weather Discussion 
NWS National Hurricane Center Miami FL
1005 UTC Fri Jul 29 2016

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
0830 UTC.
  
...SPECIAL FEATURES... 

A tropical low pressure area is analyzed along the monsoon
trough near 11.5N112W, and estimated at 1009 mb. Scattered
moderate isolated strong convection is observed within 120 nm
across the north and within 90 nm across the southeast
semicircles. This low is well depicted in precipitable water
imagery as an improving cyclonic circulation. Global models
suggest a good chance for this system to become better organized
and intensify beyond 48 hours. This low center has a medium
chance of developing into a tropical cyclone in the next 48
hours. The low and associated winds and seas have been included
in the latest High Seas forecasts issued under AWIPS/WMO headers
MIAHSFEP2 FZPN03 KNHC.

...TROPICAL WAVES and REMNANT LOWS...

The remnant low of former tropical cyclone Frank is centered
near 24N126W with an estimated minimum pressure of 1010 mb. A
recent 0250 UTC RapidSCAT pass indicated 20 to 25 knot winds
within 90 nm in the NW semicircle. The remnant low is expected
to weaken further as it moves west-northwestward, with winds and
seas subsiding to less than 20 kt and 8 ft within 24 hours.  

The remnant low of former tropical cyclone Georgette is centered
near 20.5N136W with an estimated minimum central pressure of
1013 mb. A recent partial 0547 UTC ASCAT pass suggested 20 kt
winds across the northern semicircle of this weakening low, and
there may no longer be a closed low center at the surface. Seas
of up to 9 ft were noted in NE wind waves. The remnant low is
forecast to weaken further to an open trough overnight and
extend from 18N138W TO 22N140W by Fri night. 

A tropical wave is moving across Central America and into the
tropical eastern Pacific along 88W-89W early this morning, and
has been moving W at about 10 to 15 kt. Scattered moderate to
strong convection was noted from 05.5N to 11N between 89W and
101W, and mostly ahead of the wave. This wave will shift west
across the Tehuantepec region during the next 36 hours with
active convection expected to accompany it along the monsoon
trough.

..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from low pres near 10N75W to 07.5N94W
to low pres near 11.5N112W to 08.5N122W...where it transitions
to ITCZ...continuing on to 07N130W to 08N136W to beyond
07.5N140W.  

Scattered moderate to strong convection is noted from 03N to
07.5N east of 79W. Widely scattered moderate isolated strong
convection is noted within 240 NM either side of the trough
between 105W and 120W. 

...DISCUSSION...   

N of 15N E of 120W:

A west to east orientated surface ridge is building from 23N120W
to 18N107W. The pressure gradient northeast of the ridge will
support gentle to moderate nw winds across the open Pacific
waters through tonight, then the gradient will relax some with
light to gentle nw flow expected into early next week. Expect
seas of 4-6 ft to prevail.

A NNW to SSE orientated trough will meander E and W over the
Baja California Peninsula, and the northern Gulf of California
through the weekend, supporting light to gentle southerly winds
across the Gulf of California waters through tonight. Moderate
to fresh southerly flow, with 3-5 ft seas, is then forecast
across the northern Gulf of California from early Sat through
Sun afternoon before subsiding.

Fresh northerly flow is expected across the Gulf of Tehuantepec
during the overnight hours through Sat night. Guidance suggests
locally strong northerly flow on Sun, Mon and Tue nights with
seas building to 8 ft. 

S of 15N E of 120W: 

Moderate to locally fresh NE to E winds are expected across, and
just downstream of the Gulf of Papagayo during the overnight
hours through the middle of next week.

Long-period cross-equatorial SW swell, producing combined seas
of 6-9 ft, has propagated NE to along 04N between 90-120W. This
SW swell will gradually fade Sat and subside to less than 8 ft
on Sat night.

W of 120W:

See special features above for information on the remnants of
Georgette and Frank that will gradually dissipate through Fri
night.

$$
Stripling