[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211756
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
156 PM EDT THU JUL 21 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...

A tropical wave is in the east Tropical Atlantic extending from
08N-20N with axis near 23W, moving W at 15 kt over the past 24
hours. Enhanced Meteosat imagery show Saharan dry air and dust
over the northern wave environment, thus hindering convection in
the Cape Verde Islands. CIRA LPW imagery from the surface to 850
mb show a moderate moist environment S of 14N that along with
divergence aloft support scattered showers from 07N-12N E of 26W.
Similar convection is from 14N-20N E of 21W.

A tropical wave is in the central Caribbean extending from 12N-18N
with axis near 68W, moving W at 20 kt over the past 24 hours. CIRA
LPW imagery from the surface to 850 mb show the wave is embedded
in a moderate to high moist environment that along with
divergent flow aloft support showers and tstms over Puerto Rico,
Hispaniola and adjacent waters southern waters to 13N.

A tropical wave is in the western Caribbean extending from 13N to
24N with axis near 83W, moving W at 20 kt over the past 24 hours.
Water vapor imagery show dry air subsidence from aloft over the
western Caribbean. Shallow moisture in the wave environment
support isolated showers N of 16N W of 76W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends across Africa into the east Tropical
Atlantic near 14N16W and then continues along 10N25W to 07N40W. The
ITCZ begins near 07N40W and then extends to 08N51W to the coast of
Venezuela near 08N60W. Aside the convection associated with the
tropical wave in the eastern Atlc, numerous moderate convection is
from 04N-10N between 27W and 43W.

...DISCUSSION...

GULF OF MEXICO...

Weak surface ridging prevails in the northern half of the basin
providing mainly gentle to moderate easterly flow, which advects
moisture from the SW N Atlc into the Gulf. This moisture is
supporting isolated heavy showers and tstms across southern and
central Florida and in the basin N of 23N. Similar convection is
across the Florida straits being enhanced by a tropical wave over
the western Caribbean. A surface trough extends over SE Mexico
coastal waters generating scattered showers and tstms S of 26N W
of 94W. The tropical wave over the Caribbean will move across the
southern Gulf Friday and enter southern Mexico late Friday night
into Saturday. Showers across the basin are expected to continue
through early Saturday.

CARIBBEAN SEA...

An inverted trough in the upper levels covers the western half of
the basin where water vapor imagery show dry air. An upper level
ridge covers the NE basin being centered near the Mona passage.
Diffluence aloft being generated by these two features along with
abundant moisture associated with a tropical wave with axis
along 68W support showers and isolated tstms over Puerto Rico,
Hispaniola and adjacent southern waters to 13N. A second tropical
wave is in the western Caribbean, however dry air subsidence from
aloft limits in part the convection to isolated showers N of 16N W
of 76W. Scattered heavy showers and tstms are in the SW basin S of
11N E of 80W associated with the monsoon trough. For further
details see tropical waves section. Scatterometer data depict
gentle to moderate trades across most of the Caribbean waters
except S of 16N between 70W and 78W where fresh to strong winds
prevail due to a tighter pressure gradient. Showers are forecast
to continue in the central and SW Caribbean through Friday. Little
change is expected elsewhere.

...HISPANIOLA...

Scattered showers and isolated tstms are across the Island and
southern adjacent waters being supported by both a tropical wave
moving into central Caribbean waters and a diffluent environment
aloft. Model guidance indicate showers will continue through
late Friday as the wave continue to move west during the next 24
hours.

ATLANTIC OCEAN...

A middle to upper level trough over W Atlc waters extends S to a
base over SW N Atlc waters. The trough aloft is supporting a weak
surface trough in the region that along with moisture being
advected by SE flow generate scattered to isolated showers W of a
line from 30N68W to 23N80W. Aside from the tropical wave in the
east Atlc, surface ridging prevails elsewhere.

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

$$
RAMOS
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