000
AXPZ20 KNHC 111515
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1321 UTC Wed Oct 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 1200 UTC surface analysis and satellite imagery through
1430 UTC.

INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from 10N76W to 09N81W to low pres 
1009 mb near 11N88W to 08N94W to low pres 1007 mb near 13N102W to
low pres 1007 mb near 14N107W to 12N113W to low pres 1009 mb 
near 14N118W to 10N128W to 12N136W to 12N140W. Scattered moderate
and isolated strong convection is observed from 04N to 08N 
between 89W and 110W, from 12N to 18N between 94W and 111W, from 
12N to 18N between 94W and 111W and from 08N to 10N between 121W 
and 124W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A surface ridge extends from 32N136W SE to 24N127W to 22N120W. 
Latest satellite-derived wind data indicate moderate NW to N 
winds prevail across the offshore waters of Baja California east 
of 118W, and also over the northern half of the Gulf of 
California. NW swell moving through the regional waters are 
producing seas of 5 to 7 ft across the waters N of 20N and 3 to 5
ft seas between Cabo Corrientes and the entrance to the Gulf of 
California. This swell will continue to subside throughout the 
early morning hours, with seas becoming 4 to 6 ft by late 
afternoon. Another pulse of NW swell is crossing 30N and will 
propagate into the area early Thursday and cause seas to build to
between 6 and 9 feet N of 23N by Friday evening.

Strong N to NE winds have begun to spill across the W half of 
the Gulf of Tehuantepec overnight and are expected to increase to
20-30 kt by early tonight. Seas across and downstream of the 
gulf will increase to between 7 and 10 ft ft during this time. 
The strong N to NE winds are then expected to persist across the 
Gulf of Tehuantepec through Saturday morning, and maximize in 
tandem with nocturnal drainage to around 30 kt during the early 
morning hours each day. Seas will build to 10 ft downstream of 
the gulf waters near 15N95W during the morning hours just after 
sunrise Thursday through Saturday.


OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR...
    
Light and variable winds and 4 to 5 ft seas are expected to the 
N of 08N through tonight. Seas will increase slightly to around 5
to 6 ft Thursday through Friday as a new round of cross 
equatorial SW swell reaches the region. Gentle to moderate SW to 
W winds, and 4 to 7 ft seas are currently observed across the 
area S of 08N, except S winds eastward of 84W, with a slight 
increase in seas with this new pulse of SW swell. 

REMAINDER OF THE AREA...

Mainly gentle to moderate winds prevail north of the monsoon 
trough and west of 120W. Long period NW to N swell are producing 
seas of 7 to 8 ft in the waters from 18N to 30N to the W of 120W.
Seas will subside to 6-7 ft across this area this afternoon 
before the next pulse of long period northerly swell currently 
crossing 30N this morning causes seas to build. The leading edge 
of the long period swell will reach 25N by Thursday morning and 
will continue propagating southward, with seas building to 8 to 
12 ft north of 23N W of 117W early on Friday morning. Strong high
pressure will build across NW portions of the area tonight 
through Friday and bring strong NE to E winds across the 
northwest portions of the area generally N of 23N and W of 124W. 
The high will weaken on Sat and Sun, allowing winds to subside to
fresh, but 8 to 10 ft seas will cover almost all of the area N 
of 13N and W of 120W by Sat morning.

$$
CAM