Tropical Weather Discussion

000 
axpz20 knhc 110346
twdep

Tropical weather discussion
NWS National Hurricane Center Miami FL
053 UTC Mon Dec 11 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 0000 UTC surface analysis and satellite imagery through
0230 UTC.

...Special features...

Gulf of Tehuantepec storm warning: a very tight pressure gradient
is sustained across The Isthmus of Tehuantepec by 1031 mb high 
pres centered just west of Monterrey Mexico. This pressure 
gradient will be augmented by nocturnal drainage flow to maintain 
storm force winds of 40-50 kt over the Gulf of Tehuantepec until
around dawn on Mon, with seas in the 14-21 ft range. A swath of 
30 to 40 kt gale force winds surrounds the area of storm force 
winds within 60 nm either side of a line from 16n95w to 14n96w 
to 13n97w, with corresponding seas in the 12-18 ft range. Fresh 
to strong NE-E winds extend downstream from the Gulf to near 10n
and 100w, where seas run 8 to 11 ft primarily in NE swell. Seas 
8 ft or greater are propagating well away from the Gulf to near 
106w this evening. The area seas 8 ft or higher will spread even
farther W to near 110w on Monday. Gales are forecast to continue
over the Gulf of Tehuantepec through Wednesday night, then
abruptly subside to below 20 kt by noon on Thu.

Gulf of papagayo gale warning: strong high pres ridging SSE over
Central America and the SW Caribbean Sea has induced NE gale 
force winds of 30 to 35 kt over the Gulf of papagayo. N to NE 
winds of 20 to 30 kt are occurring elsewhere downstream from the 
gale force winds over an area from 06.5n to 11n between 85.5w 
and 90w. The pres gradient will loosen enough to allow for these 
gale conditions to diminish to strong to near gale force NE winds
late Monday morning and then to strong NE winds Tuesday evening.
Seas of 8 to 10 ft will propagate to the SW well away from the 
fetch area and reaching from 05n to 11n between 86w and 91w 
by Monday evening. The area of seas 8 ft or greater will begin to
diminish on Tuesday as winds subside and the swell decay.

 
...Intertropical convergence zone/monsoon trough... 

The monsoon trough axis extends from southern Nicaragua at 
11n85w to 07n98w to 08n112w. The ITCZ continues from 07n121w to
06n128w to beyond 08n140w. Scattered moderate convection is 
present from 05n to 09n between 122w and 132w.

 
...Discussion...

Offshore waters within 250 nm of Mexico...

Gulf of tehuantepec: please see special features section above 
for details the ongoing storm event. 

High pressure over the Great Basin has weakened enough to allow 
fresh to strong northerly winds over the northern Gulf of 
California to subside. N to NE winds funneling through the Baja 
California peninsula into the Pacific waters have diminished to 
light and variable. High pres ridging to the NW will maintain 
gentle to moderate winds and 4-6 ft seas will persist through Thu
night.

Offshore waters within 250 nm of Central America, Colombia, and 
within 750 nm of Ecuador...

Gulf of papagayo: see the special features section above for 
details on the ongoing gale event. 

Strong high pressure ridging southeastward over Central America
and the NW Caribbean is generating strong to gale force NE winds
over the Gulf of papagayo and nearby waters. 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 expected off the coast of El 
Salvador and Guatemala, including Gulf of fonseca through Mon
morning.

Remainder of the area...

A cold front crosses the NW corner of the area from 32n136w to 
27n140w. Strong S to SW winds ahead of the front and N of 29n 
have subsided as the front begins to weaken. Seas will run 8 to 
15 ft in NW swell N of a line from 32n132w to 24n140w. The front 
will dissipate by late Monday night, however, long period NW 
swell will maintain seas of 8-11 ft W of a line from 32n126w to 
20n132w to 15n128w to 09n138w. The swell will gradually decay 
through Wed morning, with seas of 8-10 ft expected W of a line 
from 20n121w to 00n135w. The pressure difference between a trough
near 136w and the high pressure over the northern waters is 
forecast to result in strong NE to E winds beginning late Monday 
night from 13n to 18n, and to the W of 129w along with seas of 8 
to 10 ft. This area of strong winds will shift W of 130w by noon 
on Tuesday, then diminish to between 15 and 20 kt late Tuesday.

$$
Cam


		
		

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