[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191205
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 AM EDT Sun Aug 19 2018

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
1130 UTC.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 27W from 17N southward.
The wave is in a strong deep layer environment and is being
affected by dry and dust air intrusion in the lower levels as
depicted in GOES-16 water vapor and enhanced IR imagery. Scattered
moderate to strong monsoon trough rainshowers are from 08N to 10N
between 20W and 22W.

An Atlantic Ocean tropical wave is along 42W/43W from 20N
southward. The wave is entering a low deep layer wind shear
environment. Rainshowers are possible within 300 nm on either
side of the wave.

One Caribbean Sea tropical wave is along 66W/67W from 19N
southward. Both CIRA LPW and GOES-16 water vapor imagery show the
northern wave environment being affected by low level dry air
limiting precipitation across the Leeward Islands. Widely scattered
moderate to isolated strong rainshowers are from 12N to 16N
between 60W and 66W.

A second Caribbean Sea tropical wave is along 82W/83W from 21N
southward, in the western Caribbean Sea. Persistent upper level
cyclonic wind flow remains in the NW corner of the Caribbean Sea.
Isolated moderate to locally strong rainshowers are from 14N
northward from 75W westward.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of Guinea-
Bissau near 11N16W, to 09N18W, to 10N30W, and to 09N42W. The ITCZ
is along 08N45W 06N53W, and 06N57W near the coast of Suriname.
Isolated moderate to locally strong rainshowers are elsewhere
within 240 nm on either side of the line from 07N11W to 06N29W,
to 08N51W, to 12N60W.

...DISCUSSION...

GULF OF MEXICO...

A 1020 mb high is centered over the W Atlantic near 30N68W. A
ridge axis extends W from the high to E Texas producing 10 kt SE
return flow over the Gulf of Mexico. Widely scattered moderate
convection is over the N Gulf N of 29N between 83W-90W. A surface
trough is over the Yucatan Peninsula from 20N90W to 17N92W.
Scattered moderate convection is over the Yucatan Peninsula, S
Mexico , and the E Bay of Campeche. An upper level low is
centered over W Cuba near 23N83W producing nocturnal thunderstorms
over S Florida, and W Cuba. Expect surface ridging to prevail
across the basin through Wed. Also expect showers over the N Gulf to
continue through Mon.

A surface trough will develop along the western Yucatan
Peninsula during the late afternoons, then drift westward across
the southwest gulf waters during the overnight hours accompanied
by a fresh east to southeast wind shift with the trough
dissipating along 96W during the late mornings. Otherwise, an east
to west ridge will extend across the gulf waters between 26N and
27N accompanied by gentle to moderate anticyclonic flow which is
forecast to increase to a fresh southerly breeze across the
northwest gulf waters this evening and continue through late
tonight.

CARIBBEAN SEA...

Scattered moderate convection is noted over Hispaniola, N
Venezuela, N Colombia, Panama, Costa Rica, E Nicaragua, and E
Honduras.

Strong nocturnal easterly trades expected along the
northwest coast of Colombia and Gulf of Venezuela through the
middle of the week with the strong winds expanding as far north as
15.5N on Mon night, with seas building to 10 ft. Strong east
trades are forecast along the south coast of Hispaniola tonight. A
tropical wave along 82W will continue across the west Caribbean
today and tonight. A second tropical wave along 66W will continue
west passing through the central Caribbean early this week. A
third tropical wave in the central Atlantic will reach along 55W
on Mon night, and reach the east Caribbean during the middle of
the week.

ATLANTIC OCEAN...

A 1020 mb high is centered over the W Atlantic near 30N68W.
Widely scattered moderate convection is over the N Bahamas. A
surface trough is over the central Atlantic from 32N50W to 26N60W.
Scattered showers are within 90 nm of the trough. A 1026 mb high
is over the Azores near 39N26W producing ridging and fair weather
over the E Atlantic.

An east to west ridge will meander west from a
surface high near 30N69W to Port Canaveral Florida for the next
several days. A broad north to south orientated surface trough
along 66W will continue west passing through the Bahamas on Mon
and Tue. Gentle to locally moderate southerly winds are expected
north of ridge, a light to gentle northeast to east to southeast
wind shift is forecast along the trough, and moderate to fresh
trades are expected south of 23N, except becoming locally strong
along the north coast of Hispaniola during the late afternoon into
early evening hours.

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

$$
mrf/mt
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