[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 041758
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
158 PM EDT Wed Oct 4 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.

...SPECIAL FEATURES...
Tropical Depression Sixteen is centered near 12.3N 82.3W at
04/1800 UTC or about 40 nm WSW of San Andres Island and about 170
nm SSE of Cabo Gracias a Dios on the Nicaragua and Honduras border
moving NW at 6 kt. Estimated minimum central pressure is 1005 mb.
Maximum sustained wind speed is 30 kt with gusts to 40 kt.
Scattered moderate and isolated strong convection is from 09N-14N
between 79W-84W. See the latest NHC Intermediate Public Advisory
under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC and the full
Advisory/Forecast under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC
for more details.

...TROPICAL WAVES...
A tropical wave extends from 10N42W to 17N39W moving W at 15-20
kt. The wave remains low amplitude and coincides with subtle
troughing at 700 mb between 35W-44W. Scattered moderate
convection is from 11N-15N between 36W-45W.

A tropical wave extends from 11N65W to 18N65W to 24N63W moving W
at 15-20 kt. The wave coincides with broad 700 mb troughing
between 59W-68W and continues to interact with an upper-level low
centered near 17N63W. Divergent upper-level winds on the east
side of the upper level low are supporting scattered moderate
convection from 10N-21N between 57W-65W.

A tropical wave extends from 11N84W to 22N84W moving W at 10 kt.
This wave is also interacting with an upper level low centered
over the SW Caribbean Sea...and has recently generated Tropical
Depression Sixteen. Outside of T.D. Sixteen...widely scattered
moderate convection is elsewhere from 09N-22N between 75W-85W.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from the African coast near 12N16W to
09N20W. The Intertropical Convergence Zone axis extends from
09N20W to 07N25W to 10N42W to 10N54W. Besides the convection
associated with the tropical waves...scattered moderate
convection is from 14N-16N between 14W-20W...from 03N-12N between
10W-25W...and from 04N-09N between 30W-37W.

...DISCUSSION...

GULF OF MEXICO...
Water vapor imagery indicates an upper level anticyclone is
centered over extreme southern Texas near 27N99W with primarily
northerly flow occurring over much of the Gulf basin this
afternoon. Most moisture remains in the lower to middle levels of
the atmosphere with scattered to occasional broken clouds
prevailing within fresh to strong easterly winds. Two areas of
convective precipitation are of note with the western extent of a
shear line analyzed across the Florida Straits to 24N81W providing
widely scattered showers and isolated tstms S of 25N E of 83W...
including the Florida Keys and portions of the southern Florida
peninsula. Another area of isolated showers and tstms is occurring
along coastal Mexico in association with a surface trough analyzed
from 23N98W to 21N96W to 18N94W. Onshore winds continue to push
this activity inland across interior portions east-central Mexico.
The pressure gradient generating the strong wind regime is
expected to persist through late tonight when an area of lower
pressure is anticipated to develop in the vicinity of the Florida
Straits. Regardless of further development through tonight...the
area of lower pressure is expected to bring increased convective
precipitation to the Florida peninsula and SE Gulf through Friday.

CARIBBEAN SEA...
Primary focus remains across SW Caribbean as Tropical Depression
Sixteen track NW. In addition...a tropical wave analyzed along
84W continues to work in tandem with an upper level troughing over
Central America generating scattered showers and tstms across the
western Caribbean W of 73W. Otherwise...farther east...another
tropical wave is analyzed along 65W and continues to generate
scattered showers and tstms across the Lesser Antilles and E
Caribbean waters east of the wave axis. The wave will move across
the central through Thursday night. Finally outside of Tropical
Depression Sixteen...moderate to occasional fresh trades persist.

...HISPANIOLA...
Currently skies remain mostly fair across interior portions with
cloudiness increasing throughout the daytime hours and isolated to
scattered showers possible through the evening. The next tropical
wave is expected to approach the region by early Thursday.

ATLANTIC OCEAN...
A middle to upper level trough is noted on water vapor imagery N
of the discussion area progressing over the central North Atlc
waters. The troughing supports a cold front extending from 32N44W
SW to 28N52W becoming stationary to 26N64W then becoming a shear
line to 25N70W to the Florida Straits near 24N80W. Scattered
showers and tstms are occurring across a large portion of the SW
North Atlc waters from 22N-32N between 47W-80W. In addition...the
tropical wave along 65W is generating scattered showers and tstms
NE of the Leeward Islands from 14N-26N between 54W-64W. The area
focused around the western extent of the shear line continues to
provide heavy rainfall and convective precipitation across the
Bahamas which is forecast to move west and impact the Florida
peninsula through Thursday. Elsewhere...a broad surface ridge axis
extends SW from the Azores near 38N29W to 27N40W.

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

$$
HUFFMAN

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