[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 111021
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
621 AM EDT Tue Aug 11 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
1000 UTC.

...SPECIAL FEATURES...

Atlc Gale Warning: A broad 1009 mb low pressure centered near
11.5N37W at 06 UTC is analyzed along a nearby tropical wave.
Scattered moderate isolated strong convection is noted within 180
nm NW quadrant of the low. Environmental conditions are expected
to be conducive for development to occur, and a tropical
depression is likely to form during the next day or so while the
disturbance moves westward to west-northwestward at around 10-15
kt across the tropical Atlantic. This system has a high chance of
tropical cyclone formation during the next 48 hours. Please see
the latest North Atlantic Tropical Weather Outlook for more
information. A gale warning has been issued over the Atlantic high
seas, as this system is expected to develop gale-force winds in
its N semicircle within the next 36-48 hours as seas build to 8-11
ft. Note that a tropical storm warning will replace the gale
warning if/when this system becomes a tropical depression.

...TROPICAL WAVES...

An eastern Atlantic tropical wave axis is along 21N south of 18N,
moving W at 10-15 kt. Numerous moderate isolated strong convection
is noted from 10N to 13N between 19W and 23W.

An eastern Atlantic tropical wave axis is along 37W south of 16N,
moving W at 10-15 kt. Please see the Special Features section for
more details about this wave and the potential for tropical
cyclone formation.

A central Atlantic tropical wave axis is along 55W south of 21N,
moving W at 15 kt. Isolated showers are occurring N of 15N within
90 nm of the wave axis.

A central Caribbean tropical wave axis is along 74W south of 20N,
moving W at 15-20 kt. Isolated thunderstorms are noted from 17N to
19N within 60 nm of the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Mauritania near
19N16W to 12N21W to 11N36W to 09N45W. The ITCZ extends from 09N45W
to 10N55W, then continues from 10N56W to the coast of Venezuela
near 09N61W. Scattered weak convection is occurring within 360 nm
S of the monsoon trough between 37W and 43W.

GULF OF MEXICO...

Surface ridging prevails across the eastern and central Gulf this
morning, anchored by a 1018 mb high near 28N84W. Light to gentle
winds persist across the waters N of 25N, with moderate winds
noted offshore of the Yucatan peninsula in the Bay of Campeche.
Isolated thunderstorms continue over portions of the SW Gulf near
a trough analyzed from 23N98W to 19N96W. Isolated convection is
also noted in the coastal waters near the Florida Panhandle and
the Tampa Bay region. Seas range from 3-5 ft in the SW Gulf, to
1-3 ft elsewhere across the basin.

High pressure centered over the NE Gulf will maintain a ridge
across the northern waters this week, resulting in gentle to
moderate winds with slight seas across much of the area. Fresh to
locally strong winds are expected each evening for the next
several nights in the eastern Bay of Campeche near the Yucatan
peninsula due to local effects.

CARIBBEAN SEA...

Recent GOES-16 satellite imagery and lightning data show scattered
moderate convection continues north of the eastern Pacific monsoon
trough, over the far SW Caribbean. Strong trade winds persist in
the south-central waters near the coast of Colombia and in the
Gulf of Venezuela. Elsewhere, moderate to fresh trades prevail
across much of the basin, except for gentle to moderate winds in
the NW Caribbean. Seas are 7-11 ft within the strong trades off
Colombia, and 7-9 ft in NE swell offshore of Nicaragua.

Fresh to strong trade winds will prevail across the south-central
Caribbean waters through Fri night, with near gale-force winds
expected to pulse near the coast of Colombia and in the Gulf of
Venezuela for the next couple nights. Fresh winds will pulse for
the next several nights through the Windward Passage. Winds and
seas will increase over the Tropical N Atlantic waters tonight and
Wed as a tropical wave crosses the region. A low pressure system,
possibly a tropical cyclone, could increase winds and seas over
the waters E of the Leeward Islands Fri through Sat as it moves
W-NW across the tropical Atlantic waters.

A tropical wave approaching the eastern extent of an active phase
of the Madden-Julian Oscillation (MJO) later this week will
support enhanced moist low-level convergence and the potential for
heavy rainfall. This could result in localized flooding over
portions of Panama, Costa Rica and Nicaragua.

ATLANTIC OCEAN...

Please see the Special Features section above for more details on
a gale warning for the Atlantic high seas, as well as the high
potential for tropical cyclone formation.

A weak low pressure trough lingers offshore of the NW Bahamas,
with isolated thunderstorms noted east of the trough roughly between
68W and 72W. Scattered convection is also occurring near another
trough analyzed from 31N62W to 26N63W. Overall, the pressure
pattern remains weak across the subtropical Atlantic, with light
to gentle winds over the waters N of 25N. Moderate to locally
fresh trades prevail across the central tropical Atlantic, south
of 1022 mb high pressure near 32N44W. Earlier altimeter data
indicated seas were 6-8 ft in this region. Farther east, fresh
northerly winds are noted from the Canary Islands southward to
20N off the coast of Africa.

A weak low pressure trough well offshore of the NW Bahamas will
dissipate later today or tonight. Fresh winds will pulse each
night near the coast of Hispaniola and over the approach to the
Windward Passage. Winds and seas will increase E of 65W tonight
and Wed as a tropical wave crosses the region. A low pressure
system, possibly a tropical cyclone, could increase winds and seas
E of 65W Fri night through Sat night as it moves W-NW across the
tropical Atlantic waters.

$$
B Reinhart
This weather bulletin was brought to you by:
www.nashvilleweather.net