[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 111039
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
639 AM EDT Tue Jul 11 2017

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
1115 UTC.

A tropical wave is analyzed over the far eastern Atlantic off the
coast of Africa along 20N. Deep layer moisture is associated with
the tropical wave south of 11N, with Saharan dust prevalent
farther north. Scattered moderate to isolated strong convection is
noted from 06N to 11N between 15W and 27W.

An Atlantic Ocean tropical wave is along 34W/35W from 05N to 15N
southward, moving westward 15 knots. This tropical wave remains
well defined in satellite derived wind fields. Scattered moderate
convection is noted from 03N to 07N between 32W and 35W.

An Atlantic Ocean tropical wave from 16N45W to 07N41W, moving
westward around 10 knots. A fairly well defined and amplified
surface trough is noted in satellite derived winds to the north of
the tropical wave, while the tropical wave itself remains poorly
defined. This feature continues to move slowly west, and will
likely come in phase with the more rapid moving tropical wave
farther east in the deep tropics. No significant convection is
noted with this tropical wave.

A broad trough along roughly 55W remains fairly well defined in
the lower to mid levels of the atmosphere, and to a lesser extent
at the surface, moving west at 10 to 15 kt. This feature emerged
out of the mid latitude areas of the eastern Atlantic a few days
ago, and will continue westward in the deep tropics toward the
Windward and Leeward Islands into the eastern Caribbean later
today. This feature exhibits no deep layer moisture or sensible
weather at this time.

A tropical wave reaches across the central Caribbean Sea from the
Guajira peninsula of northeast Colombia to the Windward Passage
and is moving west at 10 to 15 kt. Fairly dry air follows this
wave across the eastern Caribbean. No significant convection is
noted with it.

...ITCZ/MONSOON TROUGH...

The monsoon trough passes through Senegal near 14N16W, to 07N30W,
08N40W. The ITCZ extends from 08N43W to 06N56W. Scattered
moderate to isolated strong convection is observed from from 06N
to 11N between 15W and 27W, associated with the tropical wave
off the African coast. Scattered moderate convection is noted
within 180 nm of the ITCZ.

...DISCUSSION...

...THE GULF OF MEXICO...

Broad ridging reaches from the Big Bend area of Florida in the
northeast Gulf through the coast of south Texas. The northern
extent of a tropical wave is moving into the Yucatan peninsula,
and will move across the far southwest Gulf through mid week,
enhancing resident overnight troughing. This will support moderate
to fresh overnight winds across the southwest Gulf will clusters
of showers and a few thunderstorms. A broad upper low over the
north central Gulf will continue to support showers and
thunderstorms across the Straits of Florida, where moderate to
fresh east winds persist south of the ridge. Elsewhere, gentle
winds and slight seas will persist.

...THE CARIBBEAN SEA...

Strong trade winds persist over the south central Caribbean ahead
of and in the wake of a passing tropical wave. The area of strong
trade winds is shrinking slightly however as high pressure north
of the region weakens. Trade wind convergence continues to
support clusters of showers and thunderstorms along the monsoon
trough over the southwest Caribbean. Little convection is noted
elsewhere with moderate trade wind flow.

...HISPANIOLA...

A few overnight showers are forming off the northern coast of the
Dominican Republic. However, showers and thunderstorms from the
late afternoon and evening appear to have dissipated completely at
the end of daytime heating, despite a tropical wave moving across
the region. This is due in part to diminishing divergence aloft
as an upper low west of the area weakens. Scattered showers and a
few thunderstorms are likely once again later today over interior
areas with afternoon heating.

...THE ATLANTIC OCEAN...

Showers and thunderstorms associated with the remnants of T.D.
Four near 22N65W are weakening. A trough remains situated
northeast of the Leeward Islands, from 19N68W to 23N65W.
Convection is diminishing but a weak lower level circulation is
still visible in satellite imagery. Farther northeast, an upper
low is centered near 28N58W, supporting possible scattered showers
from 25N to 29N between 54W and 57W. Elsewhere, broad ridging
dominates the Atlantic Ocean north of 22N.

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

$$
Christensen
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