[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 292221
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
621 PM EDT SAT OCT 29 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 1800 UTC surface analysis and satellite imagery through
2200 UTC.

...TROPICAL WAVES...
Tropical wave extends from 09N55W to 18N54W moving W at 10-15 kt.
The wave remains relatively difficult to track and is based on
interpolation and continuity. Subtle 700 mb troughing is noted in
global model fields between 51W-58W. No significant deep
convection is associated by the wave at this time.

...ITCZ/MONSOON TROUGH...
The Monsoon Trough extends from near 13N17W to 08N21W. The
Intertropical Convergence Zone axis extends from 08N21W to
05N30W to 10N40W to 11N50W. Scattered moderate and isolated
strong convection is from 05N-12N between 09W-17W. Scattered
moderate convection is from 01N-10N between 21W-34W.

...DISCUSSION...

GULF OF MEXICO...
A relatively narrow area of upper level troughing is noted on
water vapor imagery over the western Gulf with axis extending from
30N93W S-SW to an upper level low centered over the eastern
Pacific waters near 14N102W. This troughing aloft is inducing a
weak surface trough analyzed across the SW Gulf from 16N93W to
24N98W providing focus for widely scattered showers and isolated
tstms generally S of 25N W of 94W. Elsewhere to the east of the
upper level troughing...south-southwesterly flow aloft prevails
with ample middle to upper level diffluence aloft supporting an
area of scattered showers and isolated tstms across much of the
central and eastern Gulf from 23N-28N between 80W-94W...including
the Florida Straits and portions of the Florida peninsula. Aside
from convection...a strong pressure gradient exists between
surface ridging anchored across the SE CONUS and an area of low
pressure across the NW Caribbean Sea. Fresh to strong east-
northeasterly winds are expected to continue across the eastern
Gulf through Wednesday with slightly weaker winds...moderate to
fresh E-NE winds occurring W of 90W.

CARIBBEAN SEA...
Southerly flow aloft prevails on the western periphery of an upper
level anticyclonic circulation centered over the central
Caribbean near 16N76W. Within this area...a 1010 mb surface low
is centered in the NW Caribbean near 19N85W with a surface trough
analyzed NW to the Yucatan Channel near 21N86W and S-SE from the
low to 16N82W to 12N81W. As the wind shear across this region
remains unfavorable for organized deep convection in the vicinity
of the low...scattered showers and isolated tstms are occurring
to the NE of the low from 18N-22N between 86W-88W...and within 60
nm either side of the trough axis S of 18N. Other isolated
showers and tstms are occurring across portions of Cuba in
association with the upper level diffluent environment.
Otherwise...outside of the influence of the area of lower
pressure across the western portion of the basin...gentle to
moderate trades are expected to persist through Monday.

...HISPANIOLA...
Northwesterly flow aloft prevails over the island with scattered
showers and tstms occurring this evening within the northern
periphery of an upper level anticyclonic circulation centered over
the central Caribbean Sea near 16N76W. The favorable upper level
diffluent pattern is expected to persist through Monday.

ATLANTIC OCEAN...
Upper level west-southwesterly flow prevails aloft over much of
the SW North Atlc this evening. Moisture and cloudiness stretch as
far E as 45W on the northern periphery of a broad upper level
anticyclonic circulation centered over the central Caribbean Sea
near 17N76W. While a frontal boundary has dissipated across the
waters within the last 24 hours...a pair of surface troughs are
analyzed highlighting areas of low-level moisture convergence. The
first is analyzed across the central Bahamas and the other is
analyzed from N of Puerto Rico near 20N66W into a 1012 mb low near
22N64W to 30N60W. The most intense convection currently occurring
is in the vicinity of the low with scattered showers and strong
tstms from 20N-24N between 59W-65W. Elsewhere scattered showers
and widely scattered tstms are occurring across the remainder of
the discussion waters W of 50W. Much of the eastern-most activity
is beginning to come under the influence of a middle to upper
level shortwave trough noted on water vapor imagery near 33N63W.
This shortwave also supports a cold front analyzed from Bermuda
near 32N65W to 31N70W. Finally...across the NE portion of the
discussion area...a 1013 mb low is centered SE of the Azores near
36N23W with a surface trough analyzed from 32N22W to 26N28W.
Another surface trough is analyzed S of this low pressure area
from 15N30W to 23N27W and remains within southwesterly upper
level flow on the eastern periphery of an upper level trough axis
extending from 24N37W to 09N52W. Scattered showers and isolated
tstms are occurring mainly from 13N-20N between 24W-32W.

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

$$
HUFFMAN
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