[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 040557
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Wed Nov 4 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 0000 UTC surface analysis and satellite imagery through
0515 UTC.

...SPECIAL FEATURES...

Hurricane Eta is near 13.8N 84.0W at 04/0300 UTC, or about 39 nm
WSW of Puerto Cabezas, Nicaragua, moving W at 5 kt. Estimated
minimum central pressure is 970 mb. Maximum sustained wind speed
is 90 kt with gusts to 110 kt. Numerous strong convection is
within 60 nm of the center. More numerous strong convection is
E of the center over the Caribbean from 13N-18N between 78W-81W.
Scattered moderate to isolated strong convection is elsewhere
from 10N-22N between 77W-89W. A faster west-northwestward motion
is expected through early Thursday.  A turn toward the north,
and then north-northeast is forecast Thursday night and Friday.
On the forecast track, the center of Eta is expected to move
farther inland over northern Nicaragua through Wednesday morning,
and then move across the central portions of Honduras through
Thursday morning.  The system is forecast to emerge over the
northwestern Caribbean Sea Thursday night or Friday. Rapid
weakening will occur over the next couple of days as the center
of Eta moves farther inland over Nicaragua and Honduras.
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. Please refer
to the NHC Public Advisory at www.hurricanes.gov for more
details. Please refer to the High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for details on the
marine hazards associated with Eta.

Caribbean Gale Warning: Strong high pressure over the northern
Gulf of Mexico is combining with lower pressure over the
western Caribbean associated with Hurricane Eta and is leading
to near gale force winds over the northwestern Caribbean Sea.
The gradient will tighten just enough to allow for these winds
to reach gale force on Wed over the Gulf of Honduras. The
gradient will slacken just enough by late Wed allowing for these
winds to diminish to strong speeds. Seas will be at maximum value
of 12 ft at that time.

...TROPICAL WAVES...

A tropical wave axis is along 35W from 01N-15N, moving W at 10
kt. This wave is located to the southeast of a rather potent
upper-level trough. This pattern is favorable for the enhancement
of convection near the wave. Satellite imagery shows a large area
of scattered moderate isolated strong convection E of the axis
from 05N-11N between 26W-34W.

A tropical wave axis is along 53W from 01N-12N, moving W at 10
kt. Isolated showers are within 90 nm of the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends off the west coast of Africa near
12N16W to 10N20W. The ITCZ is from 10N20W to 07N34W, then
continues west of a tropical wave from 06N37W to 02N51W.

GULF OF MEXICO...

A surface ridge extends from a 1027 mb high pressure over Alabama
and Georgia southwest across SE Texas and then southward to
southern Mexico. The pressure gradient between Hurricane Eta
and the high pressure is currently causing near gale force NE
winds across the southeast Gulf of Mexico. This includes the
Florida Straits and the Yucatan Channel, where an ASCAT pass
suggested that NE winds were in the 28 to 33 kt range. Winds
are only moderate over the northwest Gulf of Mexico. Strong
N winds are in the Bay of Campeche south of 20N. Little to no
significant precipitation is noted, although scattered stratus
clouds are seen in the southern half of the Gulf.

Fresh to near gale force NE winds will continue over the SE Gulf
and the Bay of Campeche, with near gale force NE winds over the
Straits of Florida. Winds will remain moderate to fresh over the
NE Gulf waters by the end of the week and into the weekend.

CARIBBEAN SEA...

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

Convection in the western Caribbean west of 73W is due to
Hurricane Eta and its interaction with an old lingering frontal
zone. Clusters of scattered moderate to strong convection are
over E Cuba and Hispaniola. An ASCAT pass showed moderate to
fresh trades across the eastern and central Caribbean, east of
75W. Near gales extend northwestward from Eta's tropical storm
force wind field, all the way through the Yucatan Channel into
the SE Gulf. The entire area north of 18N and west of 80W is
experiencing NE winds of 25 to 33 kt.

ATLANTIC OCEAN...

As of 04/0300 UTC, a stationary front extends from near 31N55W to
26N65W through the central Bahamas near 24N75W to central Cuba
near 22.5N80W. Scattered moderate convection is within 90 nm of
the front. Near gale force winds are north of the front west of
74W, and extend from the Florida Straits through the central and
northwest Bahamas to near 25N74W. Fresh to strong winds are
elsewhere behind the front, except for moderate anticyclonic
winds seen north of 29N and west of 70W.

Farther east, a potent upper-level trough stretches across the
central Atlantic, generally from 15N-30N between 35W-50W. This
upper trough is enhancing scattered convection aloft that extends
N from the tropical wave along 35W to 30N, between 28W-35W.

The stationary front over the western Atlantic will remain over
the region tonight into Wed before gradually dissipating Wed
night. Strong to near gale force NE to E winds behind the front
will continue through Thu night, then become east mainly fresh
winds Fri and increase to fresh to strong Sat and Sun. 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 Sun.

$$
Formosa
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