AXPZ20 KNHC 270932
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0932 UTC Wed Jul 27 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 0600 UTC surface analysis and satellite imagery through
Hurricane Frank is centered near 22.5N 119.7W, or about 500 nm
west of the southern tip of the Baja California Peninsula, at
0900 UTC, moving slowly west-northwest, or 295 degrees at 10 kt.
The maximum sustained winds have increased to 70 kt with gusts to
85 kt. The estimated minimum central pressure is 985 mb.
Currently, scattered moderate isolated strong convection is
observed within 120 nm of the center. The eye has disappeared,
and Frank appears to be starting a weakening trend that will
persist through the next couple of days as Frank moves west-
northwest. Refer to the latest NHC forecast advisory under
AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details.
Tropical Storm Georgette is centered near 19.1N 129.2W at 0900
UTC, moving northwest at 5 kt. Maximum sustained winds are 35 kt
with gusts to 45 kt. Estimated minimum central pressure is 1006
mb. Significant convection has dissipated as Georgette moves over
cooler water. However, a recent scatterometer pass confirmed winds
to minimal tropical storm force persist in the northeast quadrant
of the storm. A gale warning may be required in the next several
hours if Georgette is no longer considered a tropical storm but
winds to gale force persist. Rapid weakening will follow as
Georgette continues to move west later today as a remnant low
pressure area. Refer to the latest NHC forecast advisory under
AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details.
Also refer to the latest high seas forecast under AWIPS/WMO
headers MIAHSFEP2/FZPN03 KNHC for more details on the wave
forecasts associated with these systems.
A tropical wave north of 10N along roughly 106W/107W is supporting
a 1009 mb low pressure area along the monsoon trough near 09N104W.
No significant convection is associated with the tropical wave
outside of the monsoon trough.
A second tropical wave will move west across Central America
tonight, and enter the Pacific off Costa Rica by early Thursday.
Expect a slight increase in convection along the coast of Central
America early Thursday as the wave moves across the region.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
A monsoon trough extends from 07N78W to 07N80W to 11N95W to 1009
mb low pressure near 09N104W to 11N114W to 07N125W. The ITCZ
continues from 07N125W to 07N140W. Scattered moderate to isolated
strong convection is noted within 120 nm south of the monsoon
trough axis between 95W and 105W. Scattered moderate convection is
also noted within 90 nm either side of axis between 115W and 125W.
North of 15N and east of 120W:
Tropical storm force winds associated with Hurricane Frank will
move west of 120W on through this afternoon, and associated seas
of 8 ft or greater will shift west of 120W tonight. See special
features above additional information on Frank.
Elsewhere the pressure gradient remains weak between troughing
over the Gulf of California and the tropical wave moving westward
between 105W and 110W, resulting in gentle to moderate breezes
overall. Little change is expected into late this week. Looking
ahead, the gradient will tighten slightly by Saturday after Frank
has dissipated west of the area, which will allow the subtropical
ridge to build. This may result in fresh southerly flow over the
northern Gulf of California by early Saturday between the local
trough and the ridge to the west.
South of 15N and east of 120W:
Fresh gap winds are expected through the Gulf of Papagayo later
today and tonight ahead of a tropical wave approaching from the
southwest Caribbean. Fresh gap flow will again briefly impact the
Gulf of Papagayo Thursday night in the wake of the tropical wave.
The wave will help develop a surface low along the monsoon trough
by Thursday night near 10N90W, with increasing chance of tropical
cyclone formation later in the week.
Long-period cross-equatorial southwest swell, in the formed of
combined seas of 6-8 ft, is forecast to propagate north across
the equator between 100-115W on Thursday, and reach along 08N
between 90W and 115W on Saturday before beginning to subside.
Combined seas are forecast to less than 8 ft on Sunday.
West of 120W:
See special features above for information on tropical cyclones
Georgette and Frank that will pass westward through the northern
portion of this discussion area through this upcoming weekend.
Moderate to fresh northeast winds are noted on scatterometer data
this morning between the tropical cyclones and high pressure to
the north of the area. Resultant wind waves are combining with
longer period northerly swell still propagating into the area to
support combined seas to 9 ft mainly north of 20N and west of
125W. This is also mixing with southerly swell generated from the
Frank and Georgette. Although the areal extent of the these higher
seas will shrink slightly to the northwest over the next couple of
days as Frank and Georgette weaken, seas to 9 ft will persist over
the far northwest portion of the discussion through late week.
Farther south, the presence of the Georgette and Frank are keeping
the pressure gradient fairly week, limiting both trade winds and
their resultant areas of convection along the ITCZ.