AXPZ20 KNHC 290231
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Thu Jul 28 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 0000 UTC surface analysis and satellite imagery through
A tropical low pressure 1009 mb is analyzed along the monsoon
trough near 11N111W. Scattered moderate convection is observed
mainly NE of the low in an area generally from 10N to 13N
between 107 and 110W. This low has a medium chance of developing
into a tropical cyclone in the next 48 hours. The low and
associated winds have been included in the latest High Seas
forecasts issued under AWIPS/WMO headers MIAHSFEP2 FZPN03 KNHC.
...TROPICAL WAVES and REMNANT LOWS...
The remnant low of former tropical cyclone Frank is centered
near 24N125W with an estimated minimum pressure of 1008 mb. An
earlier 1834 UTC ASCAT pass indicated 20 to 25 knot winds within
120 nm in the N semicircle and 45 nm in the S semicircle. The
remnant low is expected to weaken further with winds and seas
less than 20 kt and 8 ft within 24 hours.
The remnant low of former tropical cyclone Georgette is centered
near 21N135W with an estimated minimum central pressure of 1011
mb. An earlier RapidSCAT pass indicated 20 to 25 kt ENE winds
within 150 nm N of the center and suggested the system may be
opening up into a trough. Seas of up to 9 ft were noted. The
remnant low is forecast to weaken to an open trough overnight
and extend from 20N139W to 23N139W by late Fri.
A tropical wave is analyzed from 10N to 17N along 115W/116w, and
has been moving W at about 10 to 15 kt. Scattered moderate to
strong convection was noted within 120 nm either side of the
wave axis from 12.5N to 15N.
A second tropical wave analyzed over the w Caribbean from 11-22N
along 82W will move w off the Central American coast tonight, then
slow it's forward speed as it continues w through the Gulf of
Tehuantepec area Fri night into early Sat enhancing the northerly
drainage flow around sunrise Sat.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
A monsoon trough extends WNW from the Pacific coast of Costa
Rica near 10N85W to 10N95W through an embedded 1009 mb low
pressure near 11N111W, then continues W to 10N120W, where
scatterometer winds indicate a transition to an ITCZ, which
continues SW to through 07N133W to beyond 08N140W.
Scattered moderate to strong convection was noted within 180 nm
south of the the monsoon trough between 88W and 97W.
Scattered moderate isolated strong convection was noted within
120 NM S of the axis between 104W and 108W.
N of 15N E of 120W:
A west to east orientated surface ridge is building from 21N120W
to 17N104W. The pressure gradient northeast of the ridge will
support gentle to moderate nw winds across the open Pacific
waters through Fri night, then the gradient will relax some with
light to gentle nw flow expected into early next week. Mostly
expect seas of 4-6 ft.
A NNW to SSE orientated trough will meander E and W over the
Baja California Peninsula, and the northern Gulf of California
this week, supporting light to gentle southerly winds across the
Gulf of California waters through Fri. Moderate to fresh
southerly flow, with 3-5 ft seas, is then forecast across the
northern Gulf of California from Fri night to late Sat night.
Fresh northerly flow is expected across the Gulf of Tehuantepec
during the overnight hours through Sat night. Guidance suggests
locally strong northerly flow on Sun, Mon and Tue nights with
seas building to 8 ft.
S of 15N E of 120W:
See section on tropical wave and lows.
Moderate to locally fresh NE to E winds are expected across, and
just downstream of the Gulf of Papagayo during the overnight
hours through the middle of next week.
Long-period cross-equatorial SW swell, in the form of combined
seas of 6-9 ft, has propagated n to along 10N between 90-115W.
These seas are forecast to subside to less than 8 ft on Sat
W of 120W:
See special features above for information on the remnants of
Georgette and Frank that will gradually dissipate through Fri
night. A tropical low will move w into the area near 11N120W on
Fri night with the possibility of tropical cyclone development.