000
AXPZ20 KNHC 012117
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2100 UTC Tue Jan 1 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURES...

...Gulf of Papagayo Gale Warning... 

The pressure gradient between a ridge of high pressure extending
westward from Atlantic high pressure and lower pressure within 
the equatorial trough is producing strong gap winds across the 
Gulf of Papagayo. Winds have been pulsing to near gale force 
during the overnight hours with the assistance of nocturnal 
drainage flow. Winds across the Papagayo region will reach 
minimal gale force tonight through Wed morning before diminishing
below gale force. 

.INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

A surface trough extends from 06N77W to 04N85W. The ITCZ continues 
from 04N85W to beyond 06N140W. Scattered moderate isolated strong 
convection was noted from 05N to 10N between 120W and 135W. 
Scattered moderate convection was noted from 12N to 20N between 110W 
and 132W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

Subsiding northwesterly swell is propagating across the waters 
off Baja California Norte, producing seas in the 7-10 ft range. 
Seas will subside below 8 ft by Wed.

Gulf of California: High pressure building across the Great 
Basin region will support strong NW winds spreading down the 
full length of the Gulf of California today through Wed night. 
Strong northerly winds will spill through the mountain gaps of 
the Baja Peninsula to produce narrow zones of strong and gusty NE
winds across the offshore Pacific waters of Baja California Tue 
night through late Wed night.

Gulf of Tehuantepec: Strong gap winds across the Gulf of 
Tehuantepec will diminish on Wed. A cold front is expected to 
move across the western Gulf of Mexico Thu and reach the Bay of 
Campeche early Fri. Winds behind the front will funnel into the 
Gulf of Tehuantepec Fri morning and increasing to gale force Fri
and Fri night.

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

Please see above for more on the Gulf of Papagayo gale force gap
wind event. In the Gulf of Panama, moderate to fresh N winds are
expected through Thu, pulsing to strong during the overnight 
hours. Elsewhere, gentle to moderate NE winds will prevail N of 
08N, while gentle to moderate southerly winds are expected S of 
08N.
  
REMAINDER OF THE AREA...  

The pressure gradient between strong high pressure N of the area 
and lower pressure in the vicinity of the ITCZ is maintaining a 
broad area of fresh to strong tradewinds N of the ITCZ to near 
21N and W of 110W. This area of high pressure will remain in 
place N of the area helping to maintain this broad area of fresh 
to strong trades. Long period NW swell is merging with this 
tradewind swell to produce seas of 8 to 12 ft over much of the 
area north of the ITCZ west of 120W. 

Global models continue to indicate a cold-core upper low will 
dig southward into the base of a mid/upper level trough between 
125W and 145W today through Fri. This will support the 
development of a sharp surface trough or even weak low pressure 
along the ITCZ between 120W and 130W by Wed. The resultant 
tightened pressure gradient will enhance trade winds north of 
the ITCZ and west of 120W, with near gale conditions possible 
developing north of the surface trough or low to near 15N.

$$
AL