[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191023
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
623 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 0600 UTC surface analysis and satellite imagery through
1000 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
27N63W through the low center to 19N71W then SW to northern
Jamaica coastal waters. A diffluent wind environment aloft
generated by the upper trough that supports the low and upper
ridging over the central Atlantic support scattered heavy showers
and isolated tstms from 18N to 30N between 55W 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 today 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
today. 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 central Atlantic extending from 04N to
17N with axis near 34W, 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 areas of dry air
observed in enhanced Meteosat imagery. Shallow moisture and
divergent middle level wind flow support scattered moderate to
isolated strong convection from 01N to 16N between 24W and 45W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends across Africa into the east Tropical Atlantic
near 14N16W then along 07N25W to 07N37W. 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
1008 mb low is observed near 16N82W. 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.
Scattered showers and tstms are over central Caribbean waters
between 67W and 80W. The extension of the middle level trough to
the upper levels has its trough base across Cuba while westerlies
cover the remainder basin. Diffluent wind flow between these two
upper features is over the NE Caribbean that along with abundant
low level moisture support scattered to isolated showers and tstms
N of 10N between 61W and 71W. GOES satellite QPE data show rain
accumulations up to 3 inches in this region of the Caribbean
during the last 6 hours, with a maximum of 1 inch accumulated in 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 tonight 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 adjacent
waters. Isolated showers are elsewhere. Showers are expected to
continue today 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 dissipates. 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
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