[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 220005
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT Mon May 21 2018

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
2315 UTC.

...SPECIAL FEATURES...

Upper level cyclonic wind flow spans the Gulf of Mexico. A trough
extends from the Florida Panhandle, beyond the Yucatan Channel,
into the NW Caribbean Sea. This weather pattern is drawing deep
tropical moisture northward, from the SW Caribbean Sea between 76W
and 84W. A surface trough in the Gulf of Mexico extends from a
1016 mb low pressure center that is just off the coast of the
Florida Big Bend near 30N87W. A second surface trough is in the
western part of the Caribbean Sea, from 21N86W, across eastern
Honduras and NE Nicaragua, to 10N83W in the SW Caribbean Sea.
Widely scattered moderate convection and isolated strong
rainshowers cover the areas that extend from the SW Caribbean Sea,
across Cuba, to Florida, and the Bahamas and the nearby Atlantic
Ocean. This activity is expected to continue through at least
Tuesday, with heavy rainfall and possible localized flooding.
Environmental conditions are expected to be unfavorable for
development during the next few days. Some gradual development is
possible later this week while the system moves into the central
or eastern Gulf of Mexico. Locally heavy rainfall is possible
across western Cuba and Florida during the next several days.

...TROPICAL WAVES...

A tropical wave is along 33W S of 10N, moving W 10-15 kt. This
wave is embedded in a sharp 700 mb trough. Widely scattered
moderate convection is from 02S to 05N between 29W and 34W.

A tropical wave is over the E Caribbean Sea, along 62W S of 16N,
moving W at 10-15 kt. This wave continues to appear as a 700 mb
trough and has a poleward surge in moisture associated with it.
This wave most likely will weaken over the next 24-36 hours and
will be ill defined thereafter. Scattered showers are within 90 nm
of the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of
Guinea near 09N13W, to 06N14W. The ITCZ continues from 06N14W
to 04N27W, and 01N37W. Widely scattered moderate convection is
within 90 nm of the ITCZ between 14W-27W.

...DISCUSSION

GULF OF MEXICO...

Please read the Special Features section for more details about
the upper level trough and related surface weather features and
precipitation.

Scattered rainshowers are from 20N to 22N between 96W and 99W, in
the coastal sections of Mexico. This area of precipitation has
been moving southward.

A surface ridge will remain in the NW Gulf through Thursday
night. The current eastern Gulf of Mexico surface trough will
drift westward, into the central Gulf of Mexico, by Wednesday. It
is possible that a low pressure center may develop in the the NW
Caribbean Sea within the next 24 hours, and move northward along
the trough into the south central Gulf of Mexico on Friday.

CARIBBEAN SEA...

Please read the Special Features section for more details about
the upper level trough and related surface weather features and
precipitation, from the Gulf of Mexico into the NW Caribbean Sea.

Upper level cyclonic wind flow cuts across the area, to the north
of the line that curves from Hispaniola to 13N67W to 13N60W. This
upper level wind flow is around the periphery of the 23N58W
Atlantic Ocean cyclonic circulation center. Comparatively drier
air in subsidence is apparent in water vapor imagery to the north
of the Hispaniola-to-14N60W line.

The monsoon trough is along 08N/09N from N Colombia beyond SE
Costa Rica, into the eastern Pacific Ocean. Scattered moderate
convection is elsewhere from 05N to 11N between 73W and 81W.

Atlantic Ocean high pressure will maintain fresh to locally
strong trades in the central Caribbean Sea through Friday night.
Strong winds, and sea heights to 9 feet, will affect the NW coast
of Colombia. A surface trough will linger in the far western
Caribbean Sea through Thursday. It is possible that a low pressure
center may form along the trough in the Gulf of Honduras on
Tuesday, and then move northward into the Gulf of Mexico on
Friday. Fresh to strong winds will develop in the central and
western Caribbean Sea from Thursday through Friday night, between
the surface trough and the Atlantic Ocean high pressure.

ATLANTIC OCEAN...

Please read the Special Features section for more details about
the upper level trough and related surface weather features and
precipitation, from the Gulf of Mexico into the NW Caribbean Sea.
The chances for heavy rainfall in Florida, across the Bahamas,
and in the western Atlantic Ocean will continue.

An upper level cyclonic circulation center is near 23N58W.
Cyclonic wind flow covers the Atlantic Ocean and parts of the
Caribbean Sea from 13N northward between 42W and 74W.

An east-to-west oriented ridge will be along 30N through Friday
night. The ridge will support fresh to locally strong E to SE
winds mainly S of 26N, including the Old Bahama Channel, and the
approaches to the Windward Passage through Wednesday. Fresh to
occasionally strong winds will prevail N of Hispaniola, mainly at
night. It is possible that a broad area of low pressure may
develop in the NW Caribbean Sea and move northward across the
eastern Gulf of Mexico late in the week. This will cause strong SE
to S winds to develop in the waters W of 75W on Friday night.

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

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