[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 031203
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Tue Nov 03 2020

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
1145 UTC.

...SPECIAL FEATURES...

Major Hurricane Eta is centered near 13.8N 83.1W AT 03/0900 UTC,
or about 20 nm SE of Puerto Cabezas, Nicaragua moving WSW at 4
kt. Estimated minimum central pressure has lowered to 923 mb.
Maximum sustained wind speed is 130 kt with gusts to 160 kt.
Satellite imagery shows that ETA has a distinct 10 nm diameter
eye embedded within very cold cloud tops. The observed very deep
convection consists of the numerous strong type within 30 nm of
the eye, except 90 nm in the NE quadrant. Numerous moderate to
strong convection well to the northeast and east of ETA from 14N
to 18N between 76W-79W and also from 12N to 14N between 79W-81W.
Scattered moderate to isolated strong convection is elsewhere
within 120 nm of ETA in the southern semicircle and within 30 nm
of an outer rain band that extends from 15N85W to 17N84W and to
19N82W. Scattered moderate convection within 30 nm of line from
18N84W to 20N81W and to 20N79W depicts an outer fractured rain
band.

ETA will maintain its current motion through this morning, then
a westward or west-northwestward motion is forecast to begin by
this afternoon and continue through Thu. On the forecast track,
the center of Eta is expected to make landfall along the coast of
Nicaragua within the Hurricane Warning area in a few hours. The
center of Eta is forecast to move farther inland over northern
Nicaragua through Wednesday morning, and then move across central
portions of Honduras by Thu morning. Catastrophic wind damage is
expected where Eta's eyewall moves onshore within the Hurricane
Warning area within the next few hours, with tropical storm
conditions already occurring in this area. Tropical storm
conditions are expected in the Tropical Storm Warning area this
morning, and hurricane conditions are possible in the Hurricane
Watch area early today. Tropical Storm conditions are possible in
the Tropical Storm Watch area later today.

Eta is expected to produce between 15 to 25 inches of rain
over much of Nicaragua and Honduras. This rainfall will lead to
catastrophic, life-threatening flash flooding and river flooding,
along with landslides in areas of higher terrain of Central
America. Flash flooding and river flooding will be possible across
Jamaica, southeast Mexico, El Salvador, southern Haiti, and the
Cayman Islands. A dangerous storm surge will raise water levels
by as much as 14 to 21 feet above normal tide levels in areas of
onshore winds along the coast of Nicaragua within the hurricane
warning area, and 3 to 5 feet above normal tide levels along the
coast of Honduras within the tropical storm warning area. Near
the coast, the surge will be accompanied by large and destructive
waves. In addition, swell generated by Eta are expected to affect
portions of the coast of Central America and the Yucatan
Peninsula of Mexico during the next few days. For more
information on the marine hazards associated with Eta, please
refer to the High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml. Also, please refer
to the NHC Public Advisory at www.hurricanes.gov for more details.

Atlantic Gale Warning: Strong high pressure building
southeastward over the western Atlantic from the southeastern
U.S. will continue to bring northeast to east winds with frequent
gusts to gale force west of 78W and south of 27N for a few
more hours, with resultant seas to 12 ft. Similar winds also with
frequent gusts to gale force will continue over the Straits of
Florida through late tonight, with peak seas to 14 ft. These
conditions will slowly subside through the end of the week. Please
read the latest High Seas Forecast issued by the National
Hurricane Center at website www.nhc.noaa.gov/text/MIAHSFAT2.shtml
for more details and your local NWS office at wwww.weather.gov for
details on the coastal waters forecasts.

Caribbean Gale Warning: Strong pressure over the Gulf of Mexico is
combining with lower pressure over the western Caribbean
associated to Hurricane ETA and is leading to strong to near
gale force winds to occur over the northwestern Caribbean Sea.
The gradient will tighten just enough to allow for these winds
to reach gale force intensity on Wed over the waters between
Belize and the northwest part of the Gulf of Honduras. The
gradient will slacken just enough by late Wednesday allowing
for these winds diminish to strong speeds, however. seas will
be at maximum value of 12 ft at that time.

...TROPICAL WAVES...

A tropical wave has its axis along 33W/34W from 01N to 15N. It
is moving westward at 10-15 kt. This wave is located to the
southeast of a rather potent upper-level trough. This pattern is
very favorable for the enhancement of convection near the wave as
well as in the development of new convection. Satellite imagery
shows a large area of numerous moderate to strong convection from
05N to 12N between 30W-40W.

A tropical wave has its axis along 51W from 01N to 12N, moving
westward at 10-15 kt. Isolated showers and thunderstorms are
seen within 60 nm either side of the wave axis from 02N to 09N.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from 11N15W to 09N17W. Latest
scatterometer data indicates that it transitions to the ITCZ
near 08N18W and continues to 06N31W where it briefly ends.
It resumes west of a tropical wave near 06N34W to 06N43W to
02N48W. Aside from convection related to the tropical wave along
33W/34W, scattered moderate convection is within 60 nm south and
north of the ITCZ between 40W-44W.

GULF OF MEXICO...

See the Special Features section for information on a Gale
Warning for the Straits of Florida.

Strong high pressure continues to build across the basin as
the cold front that moved across the area presently stretches
from west-central Cuba southwest into the northwestern Caribbean
Sea to just northeast of Belize. The tight gradient between
it and the high pressure and lower pressure over the western
Caribbean Sea from Hurricane ETA supports fresh to strong
northeast to east winds over the central and eastern Gulf waters,
except for near gale force winds in the Bay of Campeche as were
noted in an overnight Ascat pass. Seas are in the 7-11 ft range,
with the exception of the slighter higher seas in and near the
Straits of Florida and lower seas of 5-6 ft in the far NW Gulf.

Isolated showers are over the far southeastern waters of the Gulf
to near the coast western Cuba.

The cold front will move farther away from the Gulf today. The
tight gradient in place will be slow in relaxing through the end
of the week at which time moderate to fresh east winds are
expected over the eastern Gulf.

CARIBBEAN SEA...

Please see the Special Features section above for details on
Hurricane Eta and for details on upcoming gale force winds
over a section of the northwestern Caribbean.

Outside of Hurricane Eta, the majority of the Caribbean is being
impacted by numerous showers and thunderstorms, mainly west of
about 67W. Some of this activity may at times contain strong gusty
winds and frequent lightning. Expect for this activity to change
little through the end of the week.

ATLANTIC OCEAN...

The cold front of the recent days now extends from near 28N65W to
the central Bahamas and to northwestern Cuba. Scattered to
numerous showers and thunderstorms are noted southeast and
south of the front between 65W-79W. This activity is being
enhanced and sustained by a broad upper-level trough that is
located over the western Atlantic and an upper-level dynamics
tied to a jet stream branch that rounds the base of the trough.
Strong upper- level west winds are being produced by this jet
stream branch.

The tight gradient between the cold front and strong high
pressure building east-southeastward over the western Atlantic in
its wake is resulting in strong to near gale-force northeast to
east over the western Atlantic waters, with winds reaching
frequent gusts to gale force south of 27N and west of 78W,
including the Straits of Florida. Otherwise, high pressure extends
across the basin with moderate to fresh winds in the central
Atlantic.

As for the forecast, the cold front will stall from near 27N65W to
the central Bahamas and to central Cuba tonight before gradually
dissipating through Wed night. Northeast winds with frequent gusts
to gale force south of 27N and west of 78W will diminish to
strong speeds this morning. Otherwise, strong to near gale force
northeast to east winds behind the front will continue through Thu
night, then become east mainly fresh winds Fri and increase to
fresh to strong speeds Sat and Sat night. Rough seas will continue
over the majority of the area through Thu, then begin to slowly
subside through late Fri. Seas build again over the waters north
and northeast of the Bahamas Sat and Sat night

$$
Aguirre
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