[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200558
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
158 AM EDT THU OCT 20 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 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...SPECIAL FEATURES...

An elongated non-tropical 1005 mb surface low is centered northeast
of the southeastern Bahamas near 25N70W with a surface trough
extending from 29N61W through the low to 19N76W. Scattered
moderate convection and isolated tstms are mainly E of the surface
trough from 20N to 30N between 58W and 71W. Isolated showers and
tstms are within 180 nm W of the surface trough. Although the
associated shower and thunderstorm activity remains disorganized,
environmental conditions could become a little more conducive for
the low to acquire some tropical characteristics during the next
day or so, and this system could still become a subtropical or
tropical cyclone before it merges with a cold front over the
western Atlantic late Friday. Regardless of development, locally
heavy rainfall is possible over Hispaniola, Puerto Rico, and
portions of the northern Leeward Islands through Thursday. Please
see the Tropical Weather Outlook under AWIPS/WMO headers
MIATWOAT/ABNT20 KNHC for more details.

Gale force winds are expected to develop in the Gulf of Mexico
Friday night associated with a cold front that will enter the NW
waters of the Gulf early Friday morning. NW to N gale force winds
are forecast for the area S of 25N W of the front with seas to 10
ft. Please see the High Seas Forecast under AWIPS/WMO headers
MIAHSFAT2/FZNT02 KNHC for more details.

...TROPICAL WAVES...

Tropical wave is in the central Atlantic extending from 05N to
15N with axis near 38W, moving W at 15 kt over the past 24 hours.
The wave continues in a region of unfavorable deep layer wind
shear. However, CIRA LPW imagery from surface to 850 mb show the
wave is in an abundant moist environment that along with divergent
upper level wind flow support scattered moderate convection from
01N to 15N between 30W and 44W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends across Africa into the east Tropical
Atlantic near 17N16W to 09N30W to 08N40W. The ITCZ begins from
that last coordinate and continues to 07N49W to 07N55W. Aside
from the convection related to the tropical wave, scattered
moderate convection is from 02N to 07N between 20W and 30W.

...DISCUSSION...

...GULF OF MEXICO...

Surface ridging across the eastern CONUS extends SW into the
Gulf, thus providing E-SE gentle to moderate flow basin-wide,
except for the Bay of Campeche where winds are from the N-NE.
Middle to upper level ridging and strong dry air subsidence
persist across the basin supporting stable and fair weather
conditions. The current wind regime will persist through Thursday
afternoon, then NE wind flow will dominate ahead of a cold front
forecast to enter the NW Gulf waters early Friday morning. The
front is expected to reach S Florida Saturday near sunrise. Gale
force winds are expected to develop W of the front S of 25N Friday
night. See special features section for further details.

...CARIBBEAN SEA...

An elongated area of low pressure in the SW N Atlantic waters
centered northeast of the southeastern Bahamas and upper
divergence generated by the upper trough that support the low and
a ridge over the central Atlantic continue to support scattered
showers across Puerto Rico, Hispaniola and adjacent waters.
Scattered showers are within 60 nm off the coast of Central
America from Honduras to northern Panama. The low in the special
features section continue to support gentle to moderate SE wind E
of 70W and NE flow of the same magnitude W of 78W. Showers will
cease for Puerto Rico Friday and will continue across Hispaniola
through the weekend. A center of low pressure will develop in the
central basin today and will persist through Saturday. A cold
front will reach the NW basin Saturday night.

...HISPANIOLA...

An elongated area of low pressure centered northeast of the
southeastern Bahamas and upper divergence continue to support
scattered showers across Hispaniola and adjacent waters. Showers
associated with this low will continue across Hispaniola through
the weekend.

...ATLANTIC OCEAN...

The main feature of interest in the basin is an area of low
pressure centered northeast of the southeastern Bahamas, which is
generating scattered showers and tstms from 20N to 30N between 58W
and 71W. There is a medium chance this area of low pressure
intensifies and become a cyclone. See special features for further
details. Fresh to near gale force winds are in the SW N Atlantic
waters associated with this low. Please see the High Seas
Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more
details. The other feature of interest is a tropical wave in the
central Atlantic. See the tropical waves section for further
details. In the central Atlantic, the remnants of a stationary
front are analyzed as a surface trough extending from 30N36W to
26N44W. Scattered showers are within 120 nm W of the trough axis.
The remainder basin is under the influence of a surface ridge. A
cold front will come off the NE Florida Peninsula Friday night.

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

$$
RAMOS
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