000
AXNT20 KNHC 151741
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
141 PM EDT Thu Aug 15 2019

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
1720 UTC.

…SPECIAL FEATURES…

Potential for Heavy to Extreme Rain/Flooding from southern Mexico
to Central America

Numerous moderate to strong convection is moving across the SW
Caribbean and Costa Rica/Nicaragua from 08N-14N between 77W-86W.
The most intense convection on land is currently moving across
eastern and central Nicaragua. A large surge of moisture will
bring continuous heavy rainfall across southern Nicaragua and
northern Costa Rica today then shift to central/northeast
Nicaragua on Friday. Flash floods and mudslides will be the
biggest hazard during this event.

…TROPICAL WAVES…

An tropical wave is along the west African coast along 12W S of
17N. Scattered moderate convection is seen near this wave from
08N-17N between 13W-18W.

An Atlantic Ocean tropical wave is along 46W S of 15N and moving
W at 15-20 kts. This wave is well depicted in model guidance.
Showers with isolated thunderstorms are seen within 170 nm of the
wave axis from 07N-11N.

A Caribbean Sea tropical wave is along 72W S of 20N, moving W at
10 kt. Scattered showers and isolated thunderstorms are seen E of
the wave axis from 14N-18N and W of 68W.

…MONSOON TROUGH/ITCZ…

The monsoon trough passes through the coastal sections of Senegal,
just to the north of its border with The Gambia, near 13N17W to
09N22W to 10N33W to 09N43W. The ITCZ begins near 09N47W to 06N54W.
Scattered showers with embedded thunderstorms are seen south of
the monsoon trough from 05N-10N between 18W-36W. A small cluster
of convection is seen north of the ITCZ from 08N-09N between
49W-61W.

GULF OF MEXICO…

A mid-level trough continues to push east across the SE U.S.,
extending into the northern Gulf of Mexico. At the surface, a
stationary front remains well inland with a trough seen from
31N84W to 27N87W. Another trough is seen in the western Gulf from
29N91W to 29N96W. These troughs, along with mid-level forcing, is
leading to scattered moderate convection across the northern Gulf
from 24N-30N between 82W-95W. Isolated thunderstorms are also
igniting just 50 nm off the west Florida coast from the Florida
Keys to southern Tampa Bay. The Yucatan trough is analyzed from
22N91W to 18N94W. The latest scatterometer data shows light to
gentle winds across the basin.

The stationary front over the northern Gulf states could bring
higher winds and seas near the ongoing convective activity.
Moderate to fresh SW winds are expected over the NE Gulf ahead of
the front. Winds will pulse to fresh over the western Yucatan
Peninsula adjacent waters each evening associated with a surface
trough. Otherwise, surface high pressure will establish in the
region Friday and prevail through Monday.

CARIBBEAN SEA…

An upper level low is over the northern Caribbean and extends
south and west into the western Caribbean. For now, isolated
thunderstorms are seen south of SE Cuba and some thunderstorms are
moving across the eastern Caribbean. See the Special Features
section for more information on the heavy rainfall in Central
America. The latest scatterometer data indicates fresh to strong
trades north of Colombia. Moderate to fresh trades are seen across
most of the Caribbean, with gentle trades in the NW basin.

A tropical wave with axis near 72W will move across the western
Caribbean Friday and Saturday. The passage of the wave along with
high pressure north of the area will continue to support fresh to
strong tradewinds in the central and southwest Caribbean through
Friday and in the NW Caribbean Saturday and Sunday. Fresh to
strong winds will resume in the south-central basin Monday
evening supported by a new tropical wave that will move across the
region.

ATLANTIC OCEAN…

An upper level trough is leading to scattered moderate convection
across the western Atlantic, including the Bahamas, from 23N-31N
between 74W-79W. A mid-level low near 18N50W is producing
scattered showers with isolated thunderstorms from 21N-29N between
41W-58W. Otherwise, the rest of the basin is under surface ridging
anchored by a 1027 mb high near 34N48W.

Surface ridging extending from the Bermuda High will persist
across the forecast waters through Monday. This pattern will
maintain mainly gentle to moderate winds north of 22N and
moderate to fresh winds south of 22N through most of the period.
Fresh to strong winds are expected between Turks and Caicos and
Hispaniola during the evening and night hours through Friday
night.

$$
AKR