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Eastern North Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 181551
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1303 UTC Mon Feb 18 2019

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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

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

Climatologically, during March and April of each year, a double 
ITCZ is usually present in the Southern Hemisphere on the eastern
Pacific basin. Based on this pattern, no monsoon trough is 
present E of 140W. 

Currently, a surface trough is analyzed from northwestern 
Colombia to 07N77W to 05N90W to 05N100W to 01N111W. The ITCZ in 
the northern Hemisphere extends from 01N111W TO 00N120W to 
00N130W to 00N140W. Isolated moderate convection is within 120 
nm N of trough between 97W and 111W. 

An early season and well defined double ITCZ is noted S of the 
Equator and extends from 06S84W to 02S100W to 04S122W. Scattered 
moderate convection is within 60 nm N and 90nm S of the ITCZ axis
between 85W and 100W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...  

A cold front has entered the forecast area and extends from 32N114W
to 28N120W to 30N131W. Fresh to strong NW winds and seas of up 
to 13 ft in NW swell follow the front, forecast to dissipate
later today as it moves across the northern Gulf of California 
and northern Baja California Peninsula. A strong and persistent 
ridge continues to dominate the offshore forecast waters W of 
Baja California, and extends to beyond the Revillagigedo Islands.
The pressure gradient between the ridge and lower surface pressure
over the SW of United States will support fresh to strong NW-N 
winds across the offshore waters W of Baja California through Tue
morning with seas of 8 to 11 ft in Nw swell. 

Gulf of California: A cold front is moving across the northern
Gulf. Fresh to strong westerly winds and seas of 8-10 ft are 
noted just ahead of the front, particularly between 29.5N and 
30.5N. Moderate to fresh NW winds are expected behind the front
today. Fresh northerly wind flow is then expected throughout 
most of the Gulf on Tue, diminishing to moderate to locally fresh
Tue night through Wed.

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

Gulf of Papagayo: Fresh to strong winds are forecast across the
Gulf of Papagayo most of the forecast period, but mainly during
the overnight and early morning hours with the assistance of the
nocturnal drainage flow, and some added enhancement from the 
easterly gradient flow from the SW Caribbean. Seas will build to 
around 8 ft Tue through Wed.

Gulf of Panama: Mainly gentle to moderate northerly winds are 
expected across the Gulf of Panama, with moderate to fresh winds 
at night tonight, and again Tue night, with seas of 3 to 5 ft.

REMAINDER OF THE AREA... 

A strong 1041 mb high pressure center, located well to the 
north-northeast of the Hawaiian Islands near 42N145W, will remain
in this general location through Wed. The associated ridge axis 
extends southeastward across the northern forecast waters to 
beyond the Revillagigedo Islands. The pressure difference between
this ridge and broad low pressure lingering across the Hawaiian 
Islands area is resulting in a tight pressure gradient across 
most of the area N of about 07N and W of 120W, where fresh to
strong NE-E winds prevail, with seas in the range of 9 to 13 ft.
The aerial extend of these winds will diminish over the next 
couple of days as the low pressure north of the Hawaiian Islands
moves westward. The area of fresh to strong northeast to east 
winds will persist, but mainly W of 130W. The seas there will 
slowly subside to around the 8 to 11ft through the next 48 hours 
as the large swell gradually propagates SE of the area.

$$
GR