000
AXPZ20 KNHC 130242
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
048 UTC Thu Apr 13 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 FEATURES...

...Gulf of Tehuantepec Gale Warning...

The pressure gradient between the high pressure ridging surging 
down eastern Mexico and lower pressures prevailing to the south 
of the Tehuantepec region will tightened enough tonight to 
support minimal gale-force north to northeast winds across the 
Isthmus of Tehuantepec. Seas associated with these wind 
conditions are in the 8 to 12 ft range. Strong to near-gale force
north to northeast winds will be within 45 nm either side of a 
line from 16N95W to 14N96W with seas up to 9 ft. These winds 
will diminish to just below gale-force by Thursday morning as the
gradient relaxes again, with fresh to strong northerly flow 
pulsing thereafter through the remainder of the week and the 
upcoming weekend, mainly at night with nocturnal drainage flow.
Seas will will prevail from 8 to 12 ft through the next 24 hours.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The Intertropical Convergence Zone extends from 03N110W to
04N136W. Surface trough extends from 09N138W to 05N138W. 
Scattered moderate/isolated strong convection is within 200 nm 
north of the axis between 119W and 131W. 

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

See the Special Features section for details on the Gulf of 
Tehuantepec Gale Warning.

A 1028 mb surface high center is analyzed north of the area at 
42N150W, with a ridge axis extending from northwest to southeast
across the offshore waters. Moderate anticyclonic winds prevail 
along the Pacific coast of Baja with long period northwest swell 
contributing to combined seas of 6 to 9 ft. The pressure gradient
between the ridge and troughing along Baja California will 
tighten tonight supporting an increase in the winds along Baja 
California Norte to mostly the strong category by Thursday 
morning. These winds are expected to persist through Friday with 
combined seas of about 7 to 9 ft. These conditions are also 
expected to expand westward to near 116W during this forecast 
time.

In the Gulf of California, light to gentle variable flow will 
prevail through the week and into the upcoming weekend with seas
mainly 2 ft or less, except 3 to 4 ft near the entrance to the 
Gulf.

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

In the Gulf of Papagayo, fresh to locally strong nocturnal 
drainage winds are expected to pulse through the week and the 
upcoming weekend. These winds may possible max out to near 25 kt
tonight, with seas expected to build to around 8 ft downstream 
of the gulf waters during and shortly after the pulsing 
conditions.

In the Gulf of Panama, a small area of moderate to fresh 
nocturnal northerly flow is expected to develop during the 
overnight hours through the remainder of the week and the 
upcoming weekend. Seas are will build to 5 to 7 ft downstream of
the gulf waters during this time.
  
Elsewhere, light to gentle winds and combined seas of 3 to 6 ft 
will prevail during the next several days.

REMAINDER OF THE AREA...

A weakening cold front is analyzed over the northwest portion of
the area from near 30N125W to 25N140W. A secondary front extends
from 30N132W to 28N140W. The weakening front will become 
stationary and dissipate during the next 24-30 hours. The second
and stronger cold front will remain north of the area but its 
associated northwest swell will move across the northern portion 
of the basin. Seas up to 11 ft are forecast to be north of 19N 
and west of a line from 30N122W TO 19N134W at that time. Wave 
model guidance indicates that these seas will slowly subside on 
the weekend.

Elsewhere, a ridge extends from the 1028 mb high centered north 
of the area to near 13N105W. The pressure gradient between the 
ridge and lower pressure in the tropical belt region has resulted
in moderate to fresh winds from 06N to 16N west of 120W, with 
seas to 9 ft. These conditions will vary little through the next
48 hours.
  
$$

NATIONAL HURRICANE CENTER