[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301705
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
105 PM EDT SUN OCT 30 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
1500 UTC.

...TROPICAL WAVES...

A tropical wave is east of the east Caribbean Islands extending
from 15N58W to 08.5N61W moving west at 10 to 15 kt. The tropical
wave coincides with a 700 mb trough and is embedded within an
area of deep moisture. Scattered moderate convection is within 120
nm east of the tropical wave axis. The wave is expected to
gradually become diffuse during the next 24 to 48 hours.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends across Africa to 1008 mb low pressure
at the coast near 15N17W to 04N25W to 04N35W. The intertropical
convergence zone axis extends from 04N35W to 06N45W to the coast
of South America near 05N52W. Scattered moderate convection is
within 210 nm either side of the monsoon trough axis east of 31W.

GULF OF MEXICO...
A relatively narrow area of upper level troughing is noted on
water vapor imagery over the far northwestern Gulf, with an axis
extending from an upper level cyclone near 27N96W south-southwest
to an upper level cyclone centered over the eastern Pacific waters
near 16N101W. This troughing aloft is inducing a weak surface
trough analyzed across the SW Gulf from 26N95W to 19N91W. Numerous
moderate and isolated strong convection is in the central Gulf
within 120 nm of 25N91W, with scattered moderate convection within
60 nm of 24.5N86W, under an area of ample middle to upper level
diffluence, along with moist south-southwesterly flow present.
Aside from convection, a relatively 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 the early part of the week, with slightly
weaker winds at moderate to fresh occurring west of 90W.

CARIBBEAN SEA...
Southerly flow aloft prevails on the western periphery of an
upper level anticyclonic circulation centered over the western
Caribbean near 15N78W. Within this area, a 1010 mb surface low is
centered in the NW Caribbean near 18.5N84W. A surface trough
extends northwest from the low to the northeast tip of the Yucatan
Peninsula near 21N86.5W. Strong wind shear is present across the
area, however, an area of scattered moderate convection is to the
west-southwest of the low, within 60 nm of 17.5N86.5W. Isolated
showers and thunderstorms are occurring between Cuba and Jamaica
towards the Windward passage, in association with an upper level
diffluent environment. Aside from convection, fresh to strong
northeast flow will develop in the lee of Cuba as well as near and
downwind of the Windward Passage by Tuesday. Otherwise, gentle to
moderate trades are expected to persist through the early part of
the week.

...HISPANIOLA...
Northwesterly flow aloft prevails over the island, with scattered
showers and isolated thunderstorms occurring within the northern
periphery of an upper level anticyclonic circulation centered over
the western Caribbean Sea near 15N78W. The currently favorable
upper level diffluent pattern is expected to persist through the
early part of the week, allowing for the continuation of present
weather conditions.

ATLANTIC OCEAN...

Upper level northwest-west flow prevails aloft over much of the
SW North Atlc. A middle to upper level trough extends across the
northern portion from 32N51W to 27N65W to 27N73W. Dry and stable
air continues to fill in from the north behind the troughing. A
moist environment is present south and east of this trough. A cold
front is supported by the trough extending from east of Bermuda
near 32N62W to 28N78.5W, with the western portion expected to
become diffuse shortly. An elongated surface trough is located to
the east, extending from 32N49W to 1011 mb surface low pressure
near 22N64.5W, continuing to the southwest near the northern coast
of the Dominican Republic. Active convection is present with
numerous moderate and isolated strong found within 180 to 360 nm
east-southeast of the surface trough. Across the eastern portion
of the basin, a surface trough extends from 1013 mb low pressure
near 34N22W to 27N26W, with a weak surface trough across the
tropical Atlantic from 16N31W to 11N38W. Mainly gentle to moderate
trades will prevail east of 60W, outside of any areas of deep
convection. Meanwhile, the surface low near 22N64.5W is forecast
to drift to the west-southwest with an area of fresh to near gale
force winds on the northern side persisting through the early part
of the week. A tight pressure gradient between this low and high
pressure ridging anchored over the SE CONUS will maintain a
relatively tight pressure gradient south of 27N west of 65W,
supporting fresh to occasionally strong northeast flow.

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

$$
LEWITSKY
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