[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 111745
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
145 PM 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 1200 UTC surface analysis and satellite imagery through
1730 UTC.

...SPECIAL FEATURES...

Atlantic Gale Warning: A broad 1010 mb low pressure centered
near 12N39W along a tropical wave. Scattered moderate convection
is noted from 06N-15N between 39W-45W. 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 30
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. Please refer to the latest High
Seas Forecast product found at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml.

...TROPICAL WAVES...

An eastern Atlantic tropical wave axis is along 24N from 04N-
18N, moving W at 10-15 kt. Scattered moderate convection is
noted from 09N-14N between 17W-27W.

A central Atlantic tropical wave axis is along 57W from 02N-22N,
moving W at 10-15 kt. This wave is well depicted in satellite
imagery, despite the lack of significant convection. At this
time, scattered showers are noted over the northern portion of
the wave.

A west-central Caribbean tropical wave axis is along 75W south
of 20N, moving W at about 10 kt. Scattered showers are noted in
the vicinity of the wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa near 21N17W
to 12N26W to the Special Features low near 12N39W. The ITCZ
extends west of the tropical wave near 10N42W to 10N54W. Aside
from the convection related to the tropical waves described
above, scattered showers are noted along the monsoon trough
mainly east of 30W.

GULF OF MEXICO...

Surface ridging prevails across the basin, anchored by a 1017 mb
high centered near 27N87W. Light to gentle winds persist across
the waters N of 25N, while moderate winds are noted offshore of
the Yucatan peninsula in the Bay of Campeche.

High pressure will maintain a ridge across the northern waters
this week, resulting in gentle to moderate winds with slight
seas across 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...

Refer to the section above for details on the tropical wave
moving across the basin.

Recent GOES-16 satellite imagery show scattered moderate
convection over the southwest Caribbean, related to the
extension of the EPAC's monsoon trough. Fresh to strong trade
winds persist in the south-central waters near the coast of
Colombia and in the Gulf of Venezuela. Elsewhere, gentle to
moderate winds prevail.

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 across the SW Caribbean. This could result in
localized flooding over Central America and northwest South
America.

ATLANTIC OCEAN...

Please see the sections above for more details on a gale warning
for the Atlantic high seas and the tropical waves moving across
the basin.

A surface trough lingers offshore of the NW Bahamas, with
scattered showers noted west of 69W. 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 1024 mb high pressure near 32N42W. 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.

The trough well offshore of the NW Bahamas will dissipate later
today. 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.

$$

ERA
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