Tropical Weather Discussion
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000
AXNT20 KNHC 202349
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT WED JUL 20 2016

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
2315 UTC.

...TROPICAL WAVES...

Tropical wave in the east Tropical Atlantic extends along 20W
from 11N-21N moving west near 15 kt over the past 6 hours. Wave
coincides with a well defied 700 mb trough as depicted in the
global models and within a highly amplitude surge of moisture as
seen on the SSMI Total Precipitable Water imagery. No associated
deep convection.

Tropical wave in the west Tropical Atlantic extends along 60W
from 10N-18N moving west-northwest near 20 kt over the past 12
hours. Wave coincides with a weak 700 mb trough as depicted in
the global models and within a surge of moisture as seen on the
SSMI Total Precipitable Water imagery. No associated deep
convection.

Tropical wave in the Caribbean extends along 79W/80W from 13N-
22N moving west near 25 kt over the past 24 hours. Wave
coincides with a well defined 700 mb trough as depicted in the
global models and within a surge of moisture as seen on the SSMI
Total Precipitable Water imagery. No associated deep convection.

Tropical wave in the south Gulf of Mexico extends along 94W/95W
from 21N across Mexico into the east Pacific region moving west
15 to 20 kt over the past 24 hours. Wave precedes a 700 mb
trough as depicted in the global models and is embedded within a
broad area of moisture as seen on the SSMI Total Precipitable
Water imagery. Scattered showers and isolated thunderstorms are
south of 22N between 94W-97W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends across Africa into the east Tropical
Atlantic near 19N16W and continues south of the Cape Verde
Islands along 10N30W to 7N42W where the ITCZ begins and
continues to South America near 6N55W. Scattered moderate to
isolated strong convection is within 60 nm of line from 9N24W to
inland over Africa near 12N16W. Clusters of scattered moderate
to isolated strong convection are from 6N-9N between 28W-37W.

...DISCUSSION...

GULF OF MEXICO...

A large upper ridge anchored over south Arkansas covers the
north Gulf of Mexico north of 25N with a ridge axis extending
southwest to West Palm Beach, Florida. A cutoff upper low is in
the south Gulf near 22N94W covering the remainder of the Gulf
south of 25N with an upper trough axis extending east to the
Yucatan Channel. A diurnal surface trough is inland over the
west coast of the Yucatan peninsula generating scattered showers
and isolated thunderstorms within 60 nm along the coast south of
21N east of 92W. Diffluence aloft between the upper level
features is generating scattered showers and isolated
thunderstorms from 23N-26N between Florida and Mexico and from
26N-29N between 86W-92W. Isolated showers and thunderstorms are
possible across the remainder of the Gulf this evening. A
surface ridge covers the north Gulf anchored by a 1022 mb high
over northeast Louisiana. The surface ridge will persist through
the end of the week.

CARIBBEAN SEA...

An inverted upper trough extends from east Panama through the
Windward Passage into the southwest Atlantic to near 24N70W. An
upper ridge is anchored over the Virgin Islands covering the
east Caribbean and providing difflunce aloft to generate
scattered showers and isolated thunderstorms north of 12N to
over the Lesser and Greater Antilles between 60W-69W.
Afternoon/evening scattered showers and isolated thunderstorms
have developed inland over Hispaniola, Jamaica, and Cuba again
this evening. These showers are moving west-northwest into the
Caribbean waters. The remainder of the Caribbean is under fair
skies this evening. The tight pressure gradient between the west
Atlantic surface ridge and the lower pressure over South America
is producing fresh to strong trade winds across the south-
central Caribbean that will continue through the end of the
week. The tropical wave will move into the east Caribbean
tonight and into the central Caribbean by Saturday.

...HISPANIOLA...

Afternoon scattered showers and isolated thunderstorms are
moving from the Dominican Republic to over Haiti covering most
of the island this evening. Thursday will usher in additional
moisture with the tropical wave and could give the island
more showers and thunderstorms Thursday night into Friday.

ATLANTIC OCEAN...

The upper trough dips south over the the far west Atlantic to
25N between 75W-80W supporting a surface trough that extends
from 31N73W to the north Bahama Islands near 26N78W. Scattered
showers and isolated thunderstorms are north of 30N between 62W-
75W. The inverted upper trough extends from the Caribbean
through the Windward Passage 24N70W. A cutoff upper ridge is
anchored near 26N68W and is providing difflunce aloft to
generate isolated showers and thunderstorms from 23N-26N between
75W-80W. Afternoon scattered showers and isolated thunderstorms
are inland and within 60 nm along the north coast of Hispaniola
between 67W in the Mona Passage to 71W. Otherwise, high pressure
dominates the remainder of the Atlantic with a surface ridge
extending from a 1028 mb high in the north-central Atlantic near
35N44W to 31N57W then continuing west to inland over the
southeast CONUS. The west Atlantic surface trough will persist
through Friday. The surface ridge over the west Atlantic will
shift east ahead of a weak frontal boundary approaching from the
north that will dissipate through Friday off the northeast
Florida coast.

For additional information please visit
http://www.hurricanes.gov/marine

$$
PAW



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