[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 190553
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
153 AM EDT WED OCT 19 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...

A non-tropical 1004 mb surface low is centered northeast of the
Turks and Caicos near 24N68W with a surface trough extending from
27N62W through the low center to 19N70W then SW across Hispaniola.
A diffluent wind environment aloft generated by the upper trough
that supports the low and upper ridging over the central Atlantic
support numerous heavy showers and tstms from 20N to 25N between
62W and 65W and from 20N to 23N between 59W and 63W. Scattered
heavy showers and tstms are also across Puerto Rico and adjacent
waters from 14N to 20N between 63W and 69W. Scattered showers are
elsewhere from 14N to 30N between 56W and 70W. Upper-level winds
are forecast to become more conducive for this system to acquire
some tropical characteristics, and a subtropical or tropical
cyclone is likely to form within the next few days. The low is
forecast to move northward to north-northwestward on Wednesday and
Thursday, before turning north-northeastward and merging with a
cold front over the western Atlantic by the weekend. Regardless
of development, locally heavy rainfall is possible over the
Dominican Republic, Puerto Rico, and the U.S. and British Virgin
Islands tonight and Wednesday. There is a medium chance of
development over the next 48 hours. Please see the Tropical
Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for
more details.

...TROPICAL WAVES...

Tropical wave is in the eastern Atlantic extending from 04N to
15N with axis near 32W, moving W at 10 kt over the past 24 hours.
The wave continues in a region of unfavorable deep layer wind
shear and CIRA LPW imagery from surface to 850 mb show pockets of
dry air in the wave environment coinciding with enhanced Meteosat
imagery. Shallow moisture and divergent middle level wind flow support
scattered showers and isolated tstms from 01N to 15N between 23W
and 44W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends across Africa into the east Tropical Atlantic
near 14N17W then along 08N28W to 08N42W. For convection
information see the tropical waves section.

...DISCUSSION...

...GULF OF MEXICO...

Surface ridging continues to extend from the NW Atlantic waters SW
across the SE CONUS and in the Gulf. This provides mainly E-SE
gentle to moderate flow basin-wide, except over the E Bay of
Campeche where winds are from the 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. NE wind flow then
will dominate across the basin ahead of the next cold front to
enter the NW Gulf waters early Friday morning.

...CARIBBEAN SEA...

A middle level trough over the W Atlantic extends SSW across the
NW Caribbean to a base near coastal waters of NE Honduras where a
1009 mb low is observed near 16N81W. A surface trough extends from
the low SW to 13N83W then inland Nicaragua, El Salvador and
southern Guatemala. Scattered showers are within 90 nm off the
coast of Nicaragua associated with this area of low pressure. The
extension of this middle level trough to the upper levels where
the base of the trough lies across Cuba and westerlies over the
remainder basin generate a diffluent wind environment over the NE
Caribbean. This wind regime aloft along with abundant low level
moisture across the region support scattered heavy showers and
isolated tstms N of 13N between 63W and 68W. GOES QPE show rain
accumulations up to 3 inches in this region in the last 6 hours,
with a maximum of 1 inch for W and S regions of Puerto Rico. The
area of low pressure discussed in the special features section
support SE gentle to moderate wind E of 70W and NE flow of the
same magnitude in the NW basin. Showers will continue across
Puerto Rico and adjacent waters through Wednesday night when
showers will shift W to Hispaniola as the area of low pressure in
the SW Atlantic moves NW.

...HISPANIOLA...

An area of low pressure centered NE of the Turks and Caicos
extends SSW across the Island, thus supporting scattered heavy
showers and tstms over the eastern Dominican Republic and
isolated showers elsewhere. Showers are expected to continue
Wednesday and amplify Thursday as the low N of the area moves NW
over SW N Atlantic waters.

...ATLANTIC OCEAN...

The main feature of interest in the basin is an area of low
pressure centered NE of Turks and Caicos, which is generating
scattered heavy showers and tstms between 55W and 70W. There is a
medium chance this area of low pressure intensifies and become a
cyclone. See special features for further details. In the central
Atlantic, with lack of support aloft, a stationary front extending
from 30N37W to 21N48W starts to dissipate. The remainder basin N
of 16N is being influenced by a weak surface ridge. A cold front
will come off the NE Florida Peninsula Friday.

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

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