[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141735
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
135 PM EDT Wed Jun 14 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...TROPICAL WAVES...

A strong tropical wave is over the far eastern Atlantic Ocean
producing a large area of showers and thunderstorms well south of
the Cabo Verde Islands. Its axis extends from 10N23W to a 1012 mb
low pressure located near 05N24W to 02N24W. Development, if any,
of this system is expected to be slow to occur over the next
several days while the wave moves westward at 15 to 20 kt over the
tropical Atlantic.

A tropical wave extends from 14N34W to 06N35W moving westward at
15-20 kt. The wave remains embedded within an area of deep-layer
moisture as depicted on the TPW product. The wave also coincides
with an inverted trough at 700 mb. Visible satellite imagery
indicates some inverted-V pattern in association with this
feature. Scattered showers are from 08N to 10N between 35W and
38W.

A tropical wave is over the far eastern Caribbean and extends
from Barbuda and Antigua to the coast of Venezuela near 10N62W.
The wave is producing locally heavy showers and some areas of
rain, mainly over the Windward Islands and regional waters. The
wave is very well depicted in the moisture product and will
continue to affect the Windward Islands tonight into Thurssay.

Another tropical wave is over the central Caribbean with axis
from 18N76W to 09N76W moving westward at 10 kt. This wave is
associated with weak 700 mb inverted trough. TPW imagery shows a
surge of moistened air in association with this wave. An area of
showers and thunderstorms is near the northern end of the wave
axis affecting most of Jamaica and surrounding coastal waters.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the coast of west Africa near
11N15W to 05N22W, then resumes west of a tropical wave at 05N25W
to 08N34W. The ITCZ extends from 08N37W to 07N48W to 06N54W to
07N58W. Two tropical waves are embedded within the Monsoon
trough/ITCZ. Most of the convective activity is associated with
these tropical waves. Scattered moderate convection is from 03N
to 05N between 10W and 17W.

...DISCUSSION...

GULF OF MEXICO...

High pressure of 1019 mb located over the SE CONUS extends a
ridge across much of Gulf region producing gentle to moderate E
to SE winds across the area. Winds increase near the Yucatan
Peninsula, where scatterometer data indicate moderate to fresh NE
to E winds in association with a thermal trough, that normally
develops during the evening hours over the Yucatan Peninsula and
moves across the SW Gulf during the overnight and early morning
hours. Water vapor imagery reveals the presence of an upper-
level low spinning over the SE Gulf, with a trough extending SW
across the northern Yucatan Peninsula into the Bay of Campeche.
Upper diffluence on the east side of the low combined with a moist
and humid SE flow at low levels, is helping to induce showers and
thunderstorms over parts of south and central Florida. Mosaic
Doppler radar from the SE U.S. shows bands of showers and
thunderstorms across south Florida, the Florida Keys and the SE
Gulf. Plenty of moisture and the risk of some heavy showers and
thunderstorms will be very possible across south Florida through
the weekend. Abundant moisture are also expected to persist over
the SE Gulf and the Yucatan Peninsula through the weekend. This
weather pattern will be associated with a broad area of low
pressure forecast to form over the northwestern Caribbean Sea and
adjacent land areas by the weekend. Some gradual development of
this system is possible thereafter while it moves slowly
northwestward toward the southwestern Gulf of Mexico. Winds are
expected to increase over the SW Gulf by late Saturday ahead of
the low pressure expected to approach the region through northern
Central America.

CARIBBEAN SEA...

Two tropical waves are moving across the Caribbean Sea. Please
see the tropical waves section for more details. These tropical
waves will become absorbed in a broad area of low pressure
forecast to form over the NW Caribbean during the upcoming weekend.
A 1009 mb low pressure is analyzed on the 1200 UTC map over the
SW Gulf near 12N81.5W. This low is producing some shower and
thunderstorm activity, and is forecast to remain nearly stationary
over the next 24 hours. Scatterometer data show moderate to fresh
trades across the east and central Caribbean, particularly south
of 18N, and fresh to locally strong winds across the Gulf of
Honduras. Gentle to moderate winds are seen over the NW Caribbean.
This wind pattern will continue on Thursday. As previously mentioned,
an upper-level low located over the SE Gulf is also helping to
induce some shower and thunderstorm activity over western Cuba.
Looking ahead, a broad area of low pressure is expected to form
over the northwestern Caribbean Sea and adjacent land areas by the
weekend bringing more rain to the area. In fact, computer model
indicates plenty of moisture across the western and central
Caribbean Sea, and over most of Cuba during the upcoming weekend.

...HISPANIOLA...

An upper-level trough in the SW Atlantic and extend south to a
base over Hispaniola. This trough, combined with a E to SE winds
at low levels will support scattered showers and tstms mainly in
the afternoon and evening hours. Late tomorrow, expect a gradual
increase in moisture as a tropical wave approaches from the east.

ATLANTIC OCEAN...

Two tropical waves are moving westward between the coast of
Africa and the Lesser Antilles. Please refer to the Tropical Waves
section above for details. A surface trough extends from 31N62W
to 24N68W. This trough is likely a reflection of an upper-level
trough extending from 31N62W to Hispaniola. Some shower and
thunderstorm activity is ahead of the trough axis, covering the
waters from 26N to 31N between 57W and 61W. A recent ASCAT pass
shows the wind shift associated with the trough axis. Otherwise,
broad high pressure covers the Atlantic from the Azores to the
Bahamas. Moderate to locally fresh trades are around the southern
periphery of the ridge between the Windward Islands and 30W. A
surge of African dust is just in the wake of the tropical wave
located along 34W/35W as noted in the Saharan Air Layer Tracking
Product from CIMSS.

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

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