[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201745
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
145 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 1200 UTC surface analysis and satellite imagery through
1745 UTC.

...TROPICAL WAVES...

Tropical wave came off the coast of West Africa this morning and
extends from 9N-18N with axis near 18.5W. Global model guidance
indicates the wave will move at 10 kt within the next 24 hours.
The wave is being engulfed by Saharan dry air and dust, which is
limiting the convection to scattered showers from 7N-14N E of 22W.

Tropical wave is east of the Lesser Antilles extending from 10N-
18N with axis near 58W, moving W at 20 kt within the last 24
hours. The wave has been moved further west from the former
position per the latest tropical wave diagnostics guidance. Low
level moisture convergence supports scattered showers from 11N-16N
between 58W and 63W, including the Windward Islands. Strong deep
layer wind shear and dry air limits the convection to isolated
showers across the Leeward Islands.

Tropical wave in the central Caribbean extending from 12N-22N with
axis near 77W, moving W at 20 kt within the past 24 hours. Wave
coincides with a weak 700 mb trough depicted in global model
guidance and is embedded in shallow moisture as indicated by CIRA
LPW imagery. Isolated showers and tstms are mainly over southern
Cuba adjacent waters.

Tropical wave in the Bay of Campeche extending from 11N-22N with
axis near 93W, moving W at 15 kt over the past 24 hours. Wave
coincides with a 700 mb trough as indicated in global model
guidance and is embedded within a surge of moderate moisture at
the lower levels according to CIRA LPW imagery. Deep layer wind
shear limits the convection to isolated showers S of 25N E of 95W.
Scattered showers and isolated tstms are between the wave axis and
the eastern coast of Mexico S of Tampico.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends across Africa into the east Tropical
Atlantic near 16N16W and then continues along 10N24W to 08N40W.
The ITCZ begins near 08N40W and then extends to 07N48W to the
coast of Guyana near 07N58W. Aside from the convection associated
with the tropical waves, scattered moderate convection is within
245 nm south of the monsoon trough east of 35W.

...DISCUSSION...

GULF OF MEXICO...

Weak surface ridging continues to dominate across the central and
northern Gulf waters, thus providing gentle to moderate easterly
flow. A tropical wave moves over the SW basin with axis near
central Bay of Campeche. Convection associated with this wave lies
mainly W of its axis to the eastern coast of Mexico south of
Tampico. See tropical waves section for further details. The
tropical wave will move inland Mexico and into east Pacific waters
by Thursday morning. A surface trough currently over the NW
Caribbean will move across the Yucatan Peninsula and then over
the SW Gulf by Thu afternoon. Weak ridging will persist elsewhere.

CARIBBEAN SEA...

A surface trough, remnant of a tropical wave currently over the
Bay of Campeche extends from 21N81W to Honduras near 15N85W
generating scattered showers W of 80W. Over the central Caribbean,
a tropical wave extends from 21N75W to 11N79W generating scattered
to isolated showers over eastern Cuba and southern Hispaniola
adjacent waters. A third tropical wave is east of the Lesser
Antilles with axis near 58W. Moisture associated with this wave
and a diffluent environment aloft support scattered showers N of
11N E of 66W, including the Windward and Leeward Islands. 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 week. The tropical wave E of the Lesser
Antilles will move into the eastern Caribbean tonight and into the
central basin Friday morning.

...HISPANIOLA...

An upper level inverted trough in the central Caribbean and an
upper level ridge centered NE of Puerto Rico generate a diffluent
environment aloft. This environment in the upper levels along
with moisture associated with the passage of a tropical wave currently
with axis near 77W support scattered showers and isolated tstms
over Hispaniola adjacent waters W of 70W. Showers will increase
and extend inland Thursday as a tropical wave moves across the
Eastern Caribbean.

ATLANTIC OCEAN...

A middle to upper level trough along the eastern seaboard with
base extending into the SW N Atlc waters along with shallow
moisture being advected by southeasterly flow support isolated
showers and tstms W of 70W. Otherwise, besides the tropical waves
already discussed, surface ridging dominates elsewhere. No major
changes are expected in the next two days.

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

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