AXPZ20 KNHC 231545

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sun Oct 23 2016

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
1545 UTC.


Tropical Depression 20-E: centered near 13.5N 105.0W or about
385 sm s of Manzanillo Mexico at 1500 UTC, is moving W-NW or 290
deg at 14 KT. Maximum sustained winds are 30 kt with gusts to 40
KT, and minimum central pressure is 1007 mb. Currently scattered
strong convection is observed along a band over the w semicircle
within 120 nm either side of a line from 17.5N102W to 10.5N107W.
Oceanic and atmospheric conditions are favorable for gradual
strengthening and the system is forecast to reach minimal
tropical storm force near 14.1N 106.6W at 0000 UTC on Mon, then
continue to strengthen reaching minimum hurricane force early
Tue. Although the forecast track keeps the tropical storm force
winds beyond 250 nm from the coast, strong, mainly ne to e winds
are expected to pass across the offshore waters beyond 200 nm
from 13N to 17N today through midday on Mon when the cyclone
turns more westward. For additional details, refer to the latest
NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25.

Gulf of Tehuantepec gale warning: minimal gale force winds and
seas to 14 ft will continue till late morning, then diminish to
strong to near gale force strength this afternoon with these
conditions continuing through late morning on Mon. Guidance has
backed off the strength of the drainage flow, and now expect a
30 kt max through early Thu, and then minimal gale force again
late Thu.


The monsoon trough forms over the Gulf of Panama near 09N79W
and extends sw to 07N81W, then turns nw to 12N96W where it loses
identity in the broad cyclonic circulation associated with
tropical cyclone 20-E. Scatterometer winds indicate that the
monsoon trough forms again w of 20-E at 15N110W, and extends w
through an embedded 1010 mb low at 16N115W to another embedded
low at 12.5N127W 1009 mb, with the trough continuing sw to
11N133W, then nw to beyond 12N140W.

Isolated moderate and strong convection is over and along the
eastern segment of the monsoon trough within 120 nm either
side of a line from 05N77W to 12N95W. Scattered moderate to
strong convection is noted along the w segment of the monsoon
trough within 60 nm either side of a line from 13N110W to 16N114W.
Scattered moderate isolated strong is noted within 90 nm either
side of a line from 13.5N125W to 11N131W.



See special features for the Gulf of Tehuantepec area and for
T.D. 20-E affecting the far offshore waters. A 1015 mb surface
high is analyzed at 26N120W surrounded by light anticyclonic
winds across the waters w of the Baja Peninsula. Combined seas
are in the 3 to 6 ft range, except 7 to 8 ft n of 28N w of 118W
due to long period nw swell that will subside below 8 ft
tonight. The high will shift w leaving a ridge extending nne to
southern California on Mon resulting in light n flow to the n of

Light to gentle southerly winds expected across the Gulf of
California through tonight except gentle to moderate winds to
the n of 30N. The low level winds will veer to the n late
tonight and Mon.

Light to gentle winds expected elsewhere n of the Gulf of
Tehuantepec area, except moderate to fresh e to se winds are
forecast beyond 200 nm, with a small area of strong winds at 250
nm seaward across offshore zones PMZ025 today and across
the se portion of PMZ023 late tonight into Mon.


Gulf of Papagayo: moderate to fresh ne winds are expected across
and just downstream of the Gulf of Papagayo tonight into early
Mon morning.

Gentle nw to n winds are expected through mid week elsewhere n
of the monsoon trough which is meandering e to w along about
09N, while moderate sw flow is expected s of the monsoon trough
except increasing to fresh across the waters beyond 200 nm.
Combined seas of 3 to 6 ft, primarily in long-period sw swell is
expected across the offshore waters for the next 3 days.


See special features concerning TD 20-E.

A ridge will meander across the e portion blocking the eastward
progression of a series of weak cold fronts moving into the nw
waters. A cold front on Mon will be accompanied by a fresh sw to
w to nw wind shift with seas building to 8 ft n of 31N just
ahead and everywhere and the discussion area w of front.
Southwesterly winds will increase to 20 to 25 kt with seas
building 8 to 12 ft early Tue near 30N140W, with these
conditions spreading e to along 130W Tue night as the cold front
enters the area. The front will reach along 125W to the n of 27N
early Fri, then begin to stall and weaken.