[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 232345
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Fri Oct 23 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 1800 UTC surface analysis and satellite imagery through
2330 UTC.

...SPECIAL FEATURES...

Hurricane Epsilon is centered near 35.5N 61.7W at 23/2100 UTC,
or about 250 nm northeast of Bermuda is moving N or 360 degrees
at 10 kt. Estimated minimum central pressure is 968 mb. Maximum
sustained wind speed is 75 kt with gusts to 90 kt. Tropical
storm-forced winds extend within 240 nm of the center in the
northern semicircle and SE quadrant and within 120 nm of the
center in the SW quadrant. Seas of 12 ft and greater extend
outward very large distances from the center, up to 480 nm in the
NW quadrant and 420 in the SE Quadrant. Maximum seas are up to
34 ft. Latest satellite imagery shows scattered moderate
to intermittent isolated strong convection within 90 nm of the
center in the W and NW quadrants and 60 nm of the center in the
NE quadrant. Scattered moderate convection is elsewhere within
150 nm of the center in the W semicircle and within 90 nm of the
center in E semicircle. A large area of widespread rain with
embedded scattered showers and possible isolated thunderstorms are
observed well to the north and northeast of Epsilon from 39N to 42W
between 62W-66W and from 38N to 42W between 53W-62W. Epsilon is
forecast to continue on a general northward motion through early
Sat, with a very fast forward motion toward the northeast
anticipated early next week. Some fluctuations in strength could
occur for the next day or so before Epsilon begins to gradually
weaken on Sun. Epsilon could lose tropical characteristics late Sun.
Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and the
Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml
for more details.

A 1007 mb low is over the northwestern Caribbean Sea near 19N82W,
with a trough extending south-southeast to near 12N80W and
another trough that extends from the low to Cozumel, Mexico.
Scattered moderate to isolated strong convection is observed
from 18N to 20N between 80W-84W, from 15N to 18N between 77W-
80W including western and central Jamaica and also from 13N to
17N between 75W-76W. Scattered moderate to isolated strong
convection is within 30 nm of a line from 16N80W to 16N84W and
from 11N to 13N between 75W-76W. Scattered showers and isolated
thunderstorms are elsewhere between 80W-87W. Montego Bay,
Jamaica reported heavy shower and thunderstorm activity during
the early afternoon hours and .74 inches during the past 24 hours
ending at 12Z this morning. This system is part of a broad area
of low pressures that is gradually becoming better defined with
time. Atmospheric conditions appear conducive for further
development, and a tropical depression will likely form during
the next day or two while the low pressure drifts toward the
northwest. The system could move near western Cuba by Sun, then
move slowly across the southeastern Gulf of Mexico by early next
week. Interests in western Cuba, the Florida Keys, and southern
Florida should monitor the progress of this disturbance.
Regardless of development, locally heavy rainfall will be
possible over portions of the Cayman Islands, Jamaica, Cuba,
southern Florida, the Florida Keys, and the northwestern Bahamas
through the weekend. This system has a high chance of tropical
cyclone development during the next 48 hours.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis along 27W/28W
from 03N to 13N. It is moving westward at 10 kt. Scattered
moderate convection is within 180 nm east and 120 nm west of
the wave from 04N to 10N.

A central Atlantic Ocean tropical wave has its axis along 50W/51W
from 01N to 14N, moving westward at 10-15 kt. Numerous moderate
to isolated strong convection is within 180 nm east of the wave
from 09N to 13N. Scattered moderate convection is within 120 nm
west of the wave from 10N to 12N.

A tropical wave has crossed the Lesser Antilles into the eastern
Caribbean Sea, with its axis along 62W south of 19N. It is
moving westward at 10-15 kt. This wave is underneath a sharp
upper-level trough that extends from the central Atlantic to the
eastern Caribbean. Atmospheric instability aloft induced by the
trough is helping to promote scattered shower and thunderstorm
activity within 120 nm west of the wave axis and south of 14N to
within 90 nm inland the coast of Venezuela.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the coast of Guinea-Bissau
near 12N16W to 09N20W, where latest scatterometer data indicates
that it transitions to the ITCZ to 05N27W to 05N40W to 05N45W and
to 05N49W. It continues west of a tropical wave near 05N51W to
inland French Guiana near 05N54W. Scattered moderate convection
is within 180 nm north of the ITCZ between 22W-24W, within 120 nm
south of the ITCZ between 20W-26W, within 180 nm north of the
ITCZ between 30W-33W and within 60 nm north of the ITCZ between
33W-36W.

GULF OF MEXICO...

A 1010 mb low is analyzed in the southeastern Bay of Campeche
near 20N91W, with a trough extending northwestward to near
24N96W. An Ascat pass from this afternoon captured light to
gentle winds shifting from northeast to east in direction
northeast of the trough, to west to northwest in direction
southwest of trough. Isolated showers and thunderstorms are
over sections of the northern Yucatan Peninsula as well as
over some areas of southeastern Mexico. A trough is along the
Florida coast from Sarasota northward to inland northern Florida
just east of Cross City. A sub-tropical jet stream branch
stretches from the eastern Pacific Ocean eastward to over
central Mexico and east-northeastward to across central Florida.
A mid-level shortwave trough riding along this jet stream branch
in combination with deep layer moisture that is already in place
over the eastern Gulf is resulting in the development of
scattered moderate convection from 25N to 27N between 84W-87W.
Scattered showers and thunderstorms are evident elsewhere between
83W-88W. Expect for this activity to continue through the
weekend. A cold front, presently noted in satellite imagery over
eastern and central Texas, will quickly move offshore the Texas
coast this evening. A squall line rapidly surging south-southeastward
precedes the front over northeastern Texas. A line of strong
thunderstorms, with frequent lightning, is fast approaching the
NE Texas coast. Isolated showers are seen west of 88W.

Latest Ascat data indicates generally light to moderate east to
southeast winds over the eastern Gulf, except for fresh wind
speeds over the southeastern Gulf where a tighter gradient
exists between the broad low pressure over the northwestern
Caribbean Sea and high pressure that ridges south-southwestward
from the eastern U.S. to the NE Gulf. Seas throughout per current
buoy observations and latest altimeter data are in the range of
3-5 ft, with the highest of the range found in southeastern
Gulf.

As for the forecast, the broad low pressure over the northwestern
Caribbean Sea will continue to gradually become better defined
over the next couple of days, with a high chance of it developing
into to a tropical depression. It is expected that this area of
low pressure will move across western Cuba into the southeastern
Gulf of Mexico, then move northward through the eastern Gulf
through mid-week. Regardless of development, heavy rain is
possible over western Cuba and South Florida into early next
week. A weak cold front will move into the NW Gulf Sat morning,
stall, then lift back north as a warm front through Sun.

CARIBBEAN SEA

See the Special Features section for details relating to broad
low pressure are in the northwestern Caribbean.

Aside from convection associated with the Special Features area
of broad low pressure in the northwestern Caribbean Sea consisting
of A 1007 mb low near 19N82W, with a trough extending south-
southeast to near 12N80W and another trough to Cozumel, Mexico
and the convection related to the eastern Caribbean tropical
wave, clusters of scattered moderate to strong convection are
occurring from 15N to 18N between 74W- 80W. This activity is
being aided by an inverted mid-level trough axis that extends
from near 14N75W to 12N80W. Isolated showers moving quickly
westward are seen elsewhere across the basin, with the exception
of scattered showers and thunderstorms that are along and just
offshore the coasts of Panama and southern Costa Rica.

Latest Ascat data depicts moderate to fresh trades in the south-
central Caribbean and light to gentle trades elsewhere, with the
exception of moderate to fresh east to southeast winds north and
northeast of area of broad low pressure. Seas throughout are in
the range of 4-6 ft, except for up to 8 ft east of 80W including
the Mona Passage region.

As for the forecast, the Special Features area of broad low
pressure in the northwestern Caribbean will continue to gradually
become better defined over the next couple of days, with a high
chance that it will develop into a tropical depression as it
moves near western Cuba by Sun, then move slowly across the
southeastern Gulf of Mexico by early next week. Interests in
western Cuba, the Florida Keys, and southern Florida should
monitor the progress of this disturbance. Regardless of
development, locally heavy rainfall will be possible over
portions of the Cayman Islands, Jamaica, Cuba, southern Florida,
the Florida Keys, and the northwestern Bahamas through the
weekend. Winds and seas will increase east of the Windward
Islands and in the eastern Caribbean through early next week
between this low and higher pressure over the Atlantic.

ATLANTIC OCEAN...

Please see the Special Features section above for details
on Hurricane Epsilon. Also, please see the Tropical Waves
section above for information on the two Atlantic tropical waves.

A trough extends from near 25N68W southwestward to northwest
Haiti. Scattered moderate convection west of the trough south of
24N, including the southeastern Bahamas and the eastern part of
the Straits of Florida. Scattered showers and isolated
thunderstorms are within 60 to 90 nm either side of the trough
from 24N to 25N. Similar convection is within 120 nm southeast
of a trough analyzed south of Epsilon that extends from 30N60W
to 27N65W and to 26N70W. Latest Ascat data shows fresh to strong
west to northwest winds west of the trough to 67W and north of
28N. Seas there are in the range of 8-12 ft.

Scattered showers and thunderstorms, moving eastward are within
30 nm of a line from 23N61W to 24N65W.

High pressure is present elsewhere across the Atlantic east of
60W, with the culprit high pressure center anchored north of
the area at 35N34W. Weaker high pressure is over the western
Atlantic north of 28N and west of 70W. Latest Ascat data shows
generally gentle to moderate east winds over the western
Atlantic and mainly moderate to fresh east winds south of 22N
between 55W and 60W, with seas of 6-8 ft in NE swell.

Hurricane Epsilon is well north of the area to the northeast
of Bermuda and is expected to continue northward through
early Sat, with a very fast forward motion toward the northeast
anticipated early next week. Epsilon could lose tropical
characteristics late Sun.

Long-period northeast swell generated from Hurricane Epsilon,
now well north of the area, will continue to impact the waters
north and northeast of the Bahamas through Sat. Low pressure
moving northeast from Central Cuba has a high chance of tropical
formation early next week over waters near South Florida and the
northern and central Bahamas. Regardless of development, heavy
rain and gusty winds are possible across South Florida and the
Bahamas this weekend through early next week.

$$
Aguirre
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