000
AXPZ20 KNHC 260217 CCA
TWDEP 

Tropical Weather Discussion...corrected
NWS National Hurricane Center Miami FL
2205 UTC Tue Apr 25 2017

corrected ITCZ/Monsoon Trough section

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
2145 UTC.

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

A surface trough axis extends from 09N84W to 06N95W to 06N101W, 
where ASCAT winds indicate that the ITCZ forms and continues 
west to 05N109W to 03N115W to beyond 05N124W. Scattered moderate 
isolated strong convection is within 180 nm south of the trough 
axis between 90W and 97W. Scattered moderate convection is 
within 60 nm south of the trough axis between 97W and 101W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A tight pressure gradient over the northeast portion of the
area is producing strong northwest winds within 60 nm west of the 
Baja California Peninsula from 25N to 29N, and also north of 29N
east of 123W to the coast of the Baja California Peninsula. Seas
with these winds are in the 8 to 10 ft range, except for 10 to 11
ft seas north of 28N. Long period northwest swell elsewhere 
north of 21N between 111W and 124W is allowing for combined seas
of 8 to 10 ft within this area. The pressure gradient will relax
some tonight through Wednesday, then tighten again on Thursday.
Expect strong NW winds to spread southward to along 28N and
east of 125W on Thursday with seas building to 10 to 13 ft by 
early Friday. The gradient should relax Friday night with seas 
subsiding to less than 8 ft on Sunday.

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

A gentle onshore breeze is expected during the day, becoming 
offshore along the coast at night. Combined seas of 3 to 5 ft in
mixed SW and NW swell is forecast through Thursday.
 
REMAINDER OF THE AREA...
  
A 1029 mb high pressure center analyzed at 32N136W extends a 
ridge southeastward to near 21N115W. Associated high pressure
covers the area north of 15N west of 115W. The pressure gradient
between the ridge and lower pressure over Baja California with 
the typical thermal trough that develops is supporting strong 
northwest winds, with seas of 8 to 10 ft in the northeast part of
the area west of the offshore waters situated within 250 nm of 
the Mexican coast. These winds and seas will change little 
through Wednesday, then shift west-southwest Wednesday night 
through Thursday as the high pressure strengthens and the 
aforementioned ridging builds further to the east. Fresh 
northeast trades are expected south of the ridge and north of
the ITCZ, with seas building to 8 ft west of 130W later in the 
week. Southern hemispheric will approach the equator near
the area between 105W and 125W Thursday night and Friday, with 
seas of 8 to 9 ft.

$$
Aguirre