000
AXPZ20 KNHC 191523
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Tue Dec 19 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 1200 UTC surface analysis and satellite imagery through 
1500 UTC.

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

The ITCZ extends from 06N98W to low pres 1011 mb near 07N113W to 
08N127W to beyond 09N140W. Scattered moderate convection is from 
07N to 14N W of 124W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Gulf of California: Gentle to moderate NWly winds prevail across 
most of the gulf and will change little through early Thu 
morning. Northerly winds will increase abruptly strong to near 
Gale force behind the next cold front expected to move through 
most of the basin early Thu through Fri. Seas will build quickly 
to 6-9 ft by late Thu. These strong winds are also forecast to 
seep through Baja California mountain passages and into the open 
Pacific waters W of the peninsula.

Elsewhere across the offshore waters of Mexico, gentle to 
moderate mainly NW winds prevail with 4-7 ft seas. A fresh pulse 
of NW swell will propagate into the waters off the coast of Baja 
California Norte Thu behind the next cold front, with seas 
building briefly 8-9 ft across the far northern waters, then 
fading to 6-7 ft early Fri.

Gulf of Tehuantepec: Northerly winds will pulse fresh to strong 
mainly during the overnight and early morning hours with seas 
occasionally building to 8 ft through Thursday. Another gap wind 
event is anticipated for Saturday morning as a tight pressure 
gradient will develop over southern Mexico. These winds will 
increase to gale force starting early next week as stronger 
high pressure builds over the state of Texas.

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

Fresh to strong NE winds will pulse mainly at night offshore of 
Gulf of Papagayo through Thu. Mainly gentle to moderate NE-E 
winds will prevail N of 08N, while gentle SW flow will dominate 
S of 08N.

REMAINDER OF THE AREA...

Northerly swell of 8 ft N of 21N continues to subside and will 
be less than 8 ft over much of this area by tonight. 

Mainly moderate winds prevail elsewhere over the forecast 
waters, except for occasional fresh winds N of the ITCZ. High 
pressure across the NE Pacific will dominate the regional waters 
through Thu morning with little change in winds.

Looking ahead, the pressure gradient will increase N of 17N and 
W of 130W between the high and low pressure moving northward W 
of 140W. SE flow around the high will increase to fresh to near 
gale force with seas building to 10 ft Thu night. A newly formed 
low W of the area will increase the pressure gradient in that 
region, thus leading to gale force winds N of 23N W of 137W by 
Fri afternoon. The low will move N-NE shifting this conditions 
to the NW forecast waters through Saturday morning. Seas are 
forecast to build to over 12 ft during that period.

$$
Ramos