[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202344
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
743 PM EDT Thu Aug 20 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
2300 UTC.

...SPECIAL FEATURES...

Tropical Depression Thirteen is centered near 16.7N 53.9W at
20/2100 UTC or 535 nm E of the Northern Leeward Islands moving
WNW at 18 kt. Estimated minimum central pressure is 1008 mb.
Maximum sustained wind speed is 30 kt with gusts to 40 kt.
Scattered moderate to strong convection extends outward 180 nm in
the western semicircle. Scattered moderate convection is elsewhere
within 210 nm western semicircle and 150 nm SE quadrant. Seas are
up to 10 ft near the center. On the forecast track, the
depression is expected to move near or north of the northern
Leeward Islands by late Friday and near or north of the Virgin
Islands and Puerto Rico on Saturday. Please read the latest NHC
Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml
and Forecast/Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details.

Tropical Depression Fourteen is centered near 14.3N 81.0W at
20/2100 UTC or 135 nm ESE of Cabo Gracias a Dios on the Nicaragua
and Honduras border, moving W at 16 kt. Estimated minimum central
pressure is 1007 mb. Maximum sustained wind speed is 30 kt with
gusts to 40 kt. Scattered moderate to strong convection is noted
within 300 nm in the northern semicircle and 210 nm southern
semicircle, including over E Honduras, NE Nicaragua, Jamaica and
the Cayman Islands. On the forecast track, the center of the
system will move near or just north of the northeastern coast of
Honduras and the Bay Islands on Friday and will approach the east
coast of the Yucatan Peninsula of Mexico on Saturday. The center
is then expected to cross the Yucatan Peninsula Saturday night
and move into the south-central Gulf of Mexico on Sunday. This
system is expected to enhance rainfall over portions of Central
America and southern Mexico through the weekend, which may
result in some areas of significant flash flooding. Please read
the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPATA.shtml and
Forecast/Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT4.shtml for more details.

...TROPICAL WAVES...

A tropical wave near the western Africa coast is producing
disorganized showers and thunderstorms within a few hundred nm of
the coastline. This wave is expected to move over the far eastern
tropical Atlantic on Fri, and some slow development is possible
through the weekend while it moves west-northwest at 15 kt across
the eastern tropical Atlantic. Scattered moderate isolated strong
convection is noted from 11N-16N, east of 20W. Scattered moderate
convection is also noted farther S along the wave axis from 04N-
10N. This system has a low chance of tropical cyclone formation
during the next 48 hours, but a medium chance within 5 days.
Please refer to the latest NHC Tropical Weather Outlook at
www.hurricanes.gov for more details.

The tropical wave that was analyzed along 46W at 20/1200 UTC has
been removed from the analysis.

An eastern Caribbean tropical wave extends its axis along 65W from
20N southward, moving W at 15-20 kt. Scattered showers and
isolated thunderstorms are noted in the Virgin Islands and also
farther south along the wave axis between Trinidad and NE
Venezuela.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal areas of Mauritania
near 19N16W to 09N29W to 08N44W. The ITCZ extends from 12N55W to
09N61W. In addition to the convection associated with the systems
described above in the Special Features and Tropical Waves
sections, numerous moderate to scattered strong convection is
noted south of the monsoon trough from 06N-10N between 21W-25W.
Scattered moderate convection is from 06N-10N between 40W-46W.
Scattered showers and isolated tstorms are with 90 nm of the ITCZ.

GULF OF MEXICO...

A weakening stationary front extends from a 1010 mb low pressure
near New Orleans to Galveston, Texas. Ahead of it, a weak surface
trough extends from 30N87W to 24N91W. Broad ascent over the
northeast Gulf is leading to scattered moderate showers and
isolated tstorms over the eastern Gulf east of 90W. Elsewhere,
light to gentle winds and seas of less than 3 ft prevail.

Tropical Depression Thirteen is forecast to pass near or just
north of Puerto Rico on Saturday as a tropical storm. Thirteen
could strengthen to a hurricane by the time it reaches the
vicinity of South Florida or the Florida Straits on Monday.
Thereafter, it could move through the eastern Gulf of Mexico, late
Mon into late Tue, possibly at hurricane intensity.

Tropical Depression Fourteen is forecast to be a tropical storm in
the Gulf of Honduras early Saturday. It should then move NW across
Yucatan and into the south-central Gulf of Mexico on Sunday.
Fourteen could strengthen some as it continues NW to the NW Gulf
of Mexico early next week.

CARIBBEAN SEA...

Widespread shower activity covering most of the western Caribbean
is related to T.D. Fourteen. See above discussion in Special
Features for T.D. Fourteen over the Caribbean.

South of T.D. Fourteen, moderate to fresh winds are noted south
of Hispaniola in the central Caribbean, while for portions of the
eastern and western Caribbean sea away from T.D. Fourteen, gentle
to moderate trades are occurring. Scattered showers and tstorms
associated with the monsoon trough are within about 180 nm of the
Panama coast. Seas near and east of T.D. Fourteen range from 6-10
ft, with 3-6 ft seas elsewhere in the basin.

Tropical Depression Fourteen will strengthen and move into the
south-central Gulf as a Tropical Storm. Fourteen will change
little in intensity as it moves to near 25.0N 92.0W by early Mon.
Expect tropical-storm-force winds and heavy rainfall over
portions of Nicaragua, the Gulf of Honduras and the Yucatan
Peninsula.

Tropical Depression Thirteen is expected to strengthen to a
tropical storm and begin impacting the northernmost Leeward and
Virgin Islands Fri night and early Sat. The center is forecast to
pass near, or north of Puerto Rico later during the day on
Saturday. Expect a risk of squalls, strong winds and confused
seas near the NE Caribbean passages near the northernmost Leeward
and Virgin Islands, as well as the Mona Passage, as this tropical
cyclone pass through, or possibly just to the north, of these
areas.

ATLANTIC OCEAN...

See above discussion in Special Features regarding Tropical
Depression Thirteen.

Scattered moderate showers and isolated tstorms are in the waters
east of Florida. This convection is related to the eastern Gulf of
Mexico convection described above and from afternoon heating over
Florida. Farther east, a weakening cold front is sagging south
over the east-central Atlantic from 31N20W to 27N31W to 27N42W.
No convection is occurring with this front. High pressure of 1021
mb centered near 30N52W continues to dominate much of the basin.

Tropical Depression Thirteen is forecast to strengthen to a
tropical storm on Friday. After passing near, or just north of
Puerto Rico as a strengthening tropical storm on Saturday,
Thirteen could bring storm surge, heavy rainfall and wind impacts
over portions of Hispaniola, Cuba and the Bahamas. Thirteen could
strengthen to a hurricane before it reaches the vicinity of South
Florida or the Florida Straits on Monday.

$$
Hagen
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