000
AXPZ20 KNHC 272145
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1927 UTC Fri Apr 27 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 1800 UTC surface analysis and satellite imagery through
2045 UTC.
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from 08N77W to 07N84W to 07N100W. The
intertropical convergence zone continues from 07N100W to 06N117W
to 07N129W to beyond 06N140W. Scattered moderate and isolated 
strong convection is present from 03N to 09N between 78W and 
92W, from 04N to 09N between 103W and 112W and within 90 nm of 
the ITCZ axis W of 125W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A mid to upper-level trough extends SW from near 30N130W to near
20N140W. Divergent upper-level winds on the east side of the 
trough are inducing surface troughing and lower pressure over the
Gulf of California and northwest Mexico, tightening the gradient
between the surface trough and surface high pressure ridging 
southeastward to near the Revillagigedo Islands. Fresh to strong 
NW winds will continue along the coast of Baja California N of 
25N as ridging continues to build southeastward into the area and
a trough deepens over the Colorado River valley through the 
northern Gulf of California. Altimeter passes from very early 
this morning showed seas to 8 ft between the Revillagigedo 
Islands and Cabo San Lazaro, likely due to a dominant NW swell 
component. NW winds off Baja California Norte will remain fresh 
to strong through Sun night as the mid to upper-level trough 
swings E toward the Baja Peninsula and causes the surface low 
pressure to deepen. Seas will build north of Cabo San Lazaro due 
to the increased winds. Seas will peak between 8 and 10 ft on 
Sat, but subside farther south. Winds and seas will then diminish
overall through early next week as the mid to upper-level trough
continues eastward and high pressure builds into the region.

Pulses of strong westerly gap winds are possible over the 
northern Gulf of California as the trough shifts eastward late
Sun through Tue. 

Farther south, pulses of fresh to strong northerly winds are 
possible over the Gulf of Tehuantepec this weekend, particularly 
during Sat morning as nocturnal drainage flow augments the winds
generated by high pressure building over the western Gulf of 
Mexico.

Elsewhere, light to gentle winds will generally prevail through 
Mon, accompanied by 4 to 6 ft seas.

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

Fresh northeast nocturnal winds over and downstream of the Gulf 
of Papagayo will begin Sun night, then continue through at least 
Wed night. Gentle to moderate offshore flow will prevail 
elsewhere N of 09N, and light to gentle SW winds are expected S 
of 09N along with seas of 4 to 6 ft.

REMAINDER OF THE AREA... 

A ridge extends SE from 1027 mb high pressure centered over the 
north central Pacific near 32N140W to near the Revillagigedo 
Islands. Moderate to locally fresh northeast trade winds and 7 to
8 ft seas are observed across the tropical waters W of 115W 
between 08N and 20N, or south of the subtropical ridge and north 
of the ITCZ. These winds will increase to fresh to locally strong
as the pressure gradient increases over this region through Sun.
This will lead to an increase in the areal coverage of 8 to 9 ft
seas in this region. Winds and seas in this area will then 
decrease on Mon and Tue as the high centered N of the area shifts
northward and slowly weakens.
   
$$
CAM