000
AXPZ20 KNHC 030246
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Wed May 3 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 
0215 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...          
A surface trough axis extends from 09N84W to 08N89W to 10N95W
to 08N106W. The ITCZ axis extends from 08N106W to 07N118W to 
06N130W to 05N140W. Scattered moderate to isolated strong 
convection is noted within 120 nm south of the axis west of 
137W, and within 30 nm of the axis between 124W and 126W. 
Scattered moderate convection is seen within 120 nm south of the 
axis between 86W and 89W, within 120 nm of axis between 105W and 
108W, within 120 nm south of axis between 108W and 110W, and 
within 120 nm north and 60 nm south of axis between 110W and 
114W.
 
...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Latest Ascat data from Tuesday afternoon and recent ship 
observations indicate light to gentle winds across these waters, 
with seas in the 5 to 6 ft range in mixed southeast and 
northwest swell. Model guidance indicates little change forecast 
through Thursday at which time a strong cold front will move 
across the Gulf of Mexico and Bay of Campeche. Strong high 
pressure building in behind this front will build a tight 
pressure gradient through the Chivela pass Thursday night 
leading to strong to near gale force winds through the Gulf of 
Tehuantepec late Thursday night and to strong north to northeast 
gale force winds of 40 kt by Friday afternoon. Wave model 
guidance forecast seas to build to 11 ft early Friday morning, 
and to around 15 ft by Friday afternoon. Winds are forecast to 
diminish below gale force by Saturday morning.

Gulf of California...light and variable are present across
the Gulf under a rather weak pressure pattern, with sea state
of 0 to 2 ft. These conditions are expected to change little 
through Thursday as the present synoptic pattern remains in 
place.

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

Light to gentle winds, with seas in the 4 to 6 ft range in a
southwest swell prevail over the forecast waters. These 
conditions are forecast to change little through Thursday. 
Scattered showers and thunderstorms were more evident over much
of Costa Rica and Panama Tuesday afternoon, and also within 300 
nm south of those coasts. This activity has since diminished, 
but is expected to reform late tonight and through Wednesday, 
with the capability of it producing heavy rainfall over the 
interior portions of those countries. 

REMAINDER OF THE AREA...

High pressure of 1025 mb centered north of the area near 36N135W
extends a ridge southeastward to 26N126W and to near 23N118W. The
pressure gradient between this area of high pressure and lower 
pressure in the vicinity of the ITCZ is supporting gentle to 
moderate trades with seas in the 5 to 7 ft range north of the 
ITCZ. A cold front is expected to approach the northwest portion
of the area on Thursday, then possibly move across those waters 
Thursday night followed by fresh north to northeast winds and 
seas 6 to 8 ft in a northwest swell. This swell is forecast to 
spread over those waters into Friday.

$$
Aguirre