000
AXPZ20 KNHC 202117
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Tue Apr 20 2021

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
2100 UTC.

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

The monsoon trough extends from northern Colombia near 10N74W to
08N80W to 10N87W TO 06N113W. The ITCZ axis extends from 06N113W 
to 05N120W to 04N140W. Scattered moderate isolated strong convection
can be found from 02N to 05N between 81W and 89W, from 04N to 09N
between 107W and 120W, and from 05N to 07N between 126W and 130W.
Similar convection is also noted from 11N to 13N between 102W 
and 105W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A ridge extends across the offshore forecast waters of Baja 
California producing moderate to locally fresh NW-N winds N of 
Punta Eugenia, and gentle to moderate NW-N winds between Los 
Cabos and Punta Eugenia. Seas are in the 4-6 ft range, with the 
exception of 5-7 ft N of Punta Eugenia. NW swell will impact the
waters N of Punta Eugenia beginning this evening. Seas will build
up to 8 ft on Wed. This swell event will persist on Thu with seas
to 8 ft near 30N120W. 

Gulf of California: A weak cold front is expected to push southward
across the northern part of the Gulf on Wed. Fresh to strong S to
SW winds are expected ahead of the front tonight, and again Wed 
night with seas building to 5-7 ft with the strongest winds. Moderate
to fresh southerly winds are expected to persist over the northern
Gulf through Thu night. Elsewhere, gentle to moderate southerly 
winds will prevail. 

Gulf of Tehunatepec: A weak low pressure over the SW Gulf of
Mexico and the associated cold front will support the next gap
wind event across the Tehuantepec region. Fresh to strong northerly
winds are expected late tonight into Wed morning with seas building
to 8 ft downstream of the Gulf to near 13N96W by Thu morning.

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

High pressure building across the Gulf of Mexico and the NW
Caribbean will support fresh to strong winds across the Papagayo
area Wed evening through early Fri morning. Seas will build to 8
to 9 ft by Thu. Moderate to fresh winds will prevail the remainder
of the forecast period, with seas gradually subsiding toward the
end of the week. Elsewhere, light to gentle winds will prevail. 

Large and long period cross-equatorial southerly swell will build
seas to 8 ft just S of the Galapagos Islands by Wed morning, and
across the waters between Ecuador and the Galapagos Islands by
Wed evening. These marine conditions will persist on Thu. 

REMAINDER OF THE AREA...

The pressure gradient between a strong high pressure of 1037 mb 
located well north of the forecast area and lower pressures in 
the vicinity of the ITCZ supports an area of fresh to locally 
strong NE to E trade winds from 19N to 28N W of 130W as seen on
recent satellite derived wind data. Seas are up to 9 ft across 
that region based on altimeter data. The high pressure system
will gradually weaken over the next 24-48 hours as a cold front 
approaches from the west. 

Northerly swell, with sea heights of 8 ft, are now propagating 
across the N waters N of 28N between 120W and 132W. This swell
event will continue to spread southward, with seas of 8-9 ft
dominating mainly the forecast region N of 28N between 118W and 
130W by Wed afternoon. Seas will subside to less than 8 ft Thu
night into Fri. 

$$
GR