AXPZ20 KNHC 311546
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Wed Aug 31 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
Based on 1200 UTC surface analysis and satellite imagery through
Hurricane is centered at 17.8N 138.6W, or about 1085 statue
miles e of Hilo, Hawaii at 1500 UTC Aug 31, moving w or 270
degrees at 10 kt around the southern periphery of a sub-tropical
ridge. Estimated minimum central pressure is 954 mb. Maximum
sustained winds are 115 kt, with gusts to 140 kt. Associated
convection has been fluctuating, currently numerous moderate to
strong convection surrounds a 15 nm wide eye within 90 nm either
side of a line from 20N138W to 16N140W. A general weakening
trend is forecast with the center of Lester forecast to cross
140W later today, and all associated conditions shifting w of
140W early Fri. Refer to the latest NHC forecast/advisory under
AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC, and the latest high
seas forecast under WMO header FZPN02 KWBC for additional
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough axis extends from 09N78W to 13N95W to
11N131W. Scattered moderate isolated strong convection is
observed within 90 nm either side of a line from 03N78W to
07N82W, within 45 nm of 04N87W, within 150 nm of 11N95W, within
75 nm of 15N109W and within 150 nm either side of a line from
09N109W to 12N132W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A sub-tropical ridge will maintain moderate nw flow, with 3 to 5
ft seas, across the Pacific waters adjacent to the Baja
Peninsula today, except for moderate to fresh nw flow, with 5 to
8 ft seas, expected across the northern waters generally to the
n of 28N and w of 117W. Winds should diminish to a gentle to
moderate nw flow tonight, with 4 to 6 ft seas primarily due to
mixing long period sw and nw swell. Little change then expected
through Sun night, except for the possibility of a tropical low,
or tropical cyclone, developing s of the area on Sat, and
tracking northward on Sat night and Sun, reaching near 18N110W
on Sun night.
A thermal trough will meander over the Baja Peninsula, and
across the northern Gulf of California supporting light and
variable flow across the Gulf of California through Sun night,
except increasing to moderate southerly flow between 30N and 31N
on Fri night, and fresh to locally strong southerly flow
expected in the same area on Sat night.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Moderate to locally fresh southwesterly winds will prevail s of
the monsoon trough axis, with light to gentle w to nw winds
forecast n of the trough axis. Long period cross equatorial
southwesterly swell, with combined seas of 5 to 8 ft will begin
to subside on Fri.
REMAINDER OF THE AREA...
Except as previously mentioned, a quasi-stationary surface ridge
will extend from near 32N140W to near 13N123W through Sun night.
In the wake of Lester on Thu, moderate to fresh ne to e flow
will develop s of the ridge and n of the monsoon trough, with
combined seas of 4 to 7 ft, with little change through the
weekend. Moderate to fresh n to ne flow is forecast n of the
ridge, with 5 to 7 ft combined seas through the weekend.
An area of low pressure could form a few hundred miles sw of the
s-central coast of Mexico late this week, or early next week.
Environmental conditions are expected to be conducive for slow
development in 3 to 5 days as this system tracks northwestward.