000
AXPZ20 KNHC 100946
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
843 UTC Sun Dec 10 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 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Storm Warning: A very tight pressure gradient
across the Isthmus of Tehuantepec will support storm force winds
of 40-50 kt across the Gulf of Tehuantepec through late this 
morning. Seas are in the 14-22 ft range. A large area of gale 
force winds of 30-40 kt is elsewhere N of 13N between 94W-97W.
Fresh to strong NE-E winds extends downwind to beyond 100W, N of
10N. Seas 8 ft or greater are expected to propagate well away 
from the Gulf to near 105W today, and farther W to near 110W on 
Monday. Gale conditions are forecast to continue into early next 
week.

Gulf of Papagayo Gale Warning: Strong high pressure building 
N of the area will induce a gale gap wind event across the Gulf 
of Papagayo today. N-NE winds of 20-30 kt are expected elsewhere 
downstream from the gale force winds over an area from 07N-11N 
between 85W-88W this morning, and from 06N-10N between 86W-90W 
early on Monday with sea heights to 9 ft in NE swell. 

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

The Monsoon Trough extends from 09N77W to 08N90W to 07N100W to 
09N115W to 11N127W TO 09N140W. Scattered moderate convection is 
from 07N to 10N between 95W and 100W. Similar convection is from 
08N to 12N between 115W and 140W.
 
...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Gulf of Tehuantepec: Please see Special Features section above 
for details. 

High pressure over the Great Basin will continue to support fresh
to strong northerly winds over the northern Gulf of California
today. N-NE winds funneling through the Baja California 
peninsula into the Pacific waters have diminished to 15-20 kt, 
with seas subsiding below 8 ft off the coast of Baja California 
tonight. Elsewhere gentle to moderate winds and 4-6 ft seas will
persist through next week.

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

Gulf of Papagayo: Please, see Special Features section above 
for details.  

Strong high pressure building across northern central America 
will induce a strong Papagayo gap wind today, and again Mon. 
Large NE swell from a Tehuantepec gap wind event will spread 
across the offshore waters of Guatemala and El Salvador through 
Mon. Localized gap pulses of strong NE winds are possible off the
coast of El Salvador and Guatemala, including Gulf of Fonseca 
beginning early today.

REMAINDER OF THE AREA...

Long period NW swell has spread across the forecast waters 
W of a line from 30N127W to 16N113W to 05N130W to 02N140W. A 
weak cold front has crossed into the far NW part of the area. 
This front will dissipate by early today. The pressure gradient 
between it and high pressure over the northern is expected to 
develop strong S to SW winds N of 28N W of 135W with waveheights
of 8-12 ft in NW swell. These conditions will continue into 
Monday, then gradually decay through the middle part of next 
week.

$$
Formosa