000
AXPZ20 KNHC 131550
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Fri Apr 13 2018

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 1605 UTC surface analysis and satellite imagery through
1545 UTC.

...SPECIAL FEATURES...

Strong high pressure will surge southward along the eastern slope
of the Sierra Madre Oriental mountains on Sun in the wake of
strong spring cold front that will move across the western 
Gulf of Mexico allowing for a very tight pressure gradient to 
set up over southeastern Mexico. This will induce strong gale 
force N-NE winds into the Gulf of Tehuantepec commencing early
on Sunday. This event is expected to continue into early next 
week, while gradually diminishing. Seas as high as about 19 or
20 ft are expected Sun night into Mon, before slowly subsiding
early next week. Also of significance in regards to this 
upcoming event is that a very extensive swath of large NE to E 
swell will propagate well to the southwest and west of the Gulf 
of Tehuantepec, excepted to reach near 115W northward to 15N and 
southward to near 02N early next week. Please stay tuned to 
future E Pacific high seas forecast issued that will detail this 
upcoming strong gale. the E Pacific high seas forecast can be 
accessed under AWIPS/WMO headers HSFEP2/FZPN03 KNHC.


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

A surface trough extends from 09N84W to 06N100W. The ITCZ 
continues from 06N100W to 08N116W, where it is bisected by 
a north to south trough that extends from 11N116W to 05N118W.
The ITCZ resumes at 08N120W to 07N131W to 04N140W. Scattered 
moderate isolated strong convection is noted within 180 nm 
south of the trough between 81W and 84W. Scattered moderate 
convection is within from 60 nm south of the ITCZ between 130W
and 135W, and also within 30 nm of axis between 117W-119W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Fresh to strong NW winds and large NW swell will prevail west of 
Baja California Norte today. Strong NW winds are forecast across 
the length of the Gulf of California through early Sun. Strong N 
to NE gale force winds will begin over the Gulf of Tehuantepec 
starting Sun, continuing into Tue morning.

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

Light to gentle winds are expected through the forecast period. 
Seas in the 3 to 4 ft range will continue over most of the area. 
Fresh gap winds are likely in the Gulf of Papagayo tonight, and 
possible again starting Tue.

REMAINDER OF THE AREA... 

The pressure gradient between lower pressure in the vicinity of 
the ITCZ and high pressure centered N of the area near 35N133W 
is producing moderate to fresh trade winds north of the ITCZ and 
west of 110W. Ridging will build east-southeastward through Sat, 
with a tighter gradient increasing the trade winds across the 
tropical Pacific. Large NW swell is propagating southeastward 
through the forecast waters, with max seas to 13-14 ft, will 
slowly diminish through Mon night. A cold front will sweep into 
northwestern waters Sun, then weaken over northern waters Mon. 

$$
Aguirre