[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211219
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Fri May 21 2021

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

...Updated at 1215 UTC for Special Features...

Based on 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...SPECIAL FEATURES...

Updated: A 1009 mb storm-force non-tropical low is located near
35.5N 58W, or about 390 nm ENE of Bermuda. Strongest winds are
in the northern semicircle. Showers and thunderstorms have
become better organized during the past several hours. If
current trends continue, advisories could be initiated on the
system later today or tonight as a subtropical storm as it moves
westward to west-southwestward to the northeast of Bermuda.
Subsequently, the low is forecast to move NE into a more hostile
environment by Saturday night or Sunday. The potential for
subtropical cyclone formation during the next two days is high.
Please see High Seas forecasts issued by the Ocean Prediction
Center at ocean.weather.gov/shtml/NFDHSFAT1.php for more details
on this developing low pressure area.

Updated: Recent satellite imagery suggests that a low-level
circulation is forming associated with the mid- to upper-level
disturbance over the western Gulf of Mexico. However, shower and
thunderstorm activity remains disorganized. Environmental
conditions are expected to be marginally conducive for
development, this system has a medium chance of becoming a
short-lived tropical depression or storm before it moves inland
over the northwestern Gulf coast tonight. Regardless of
development, the system could produce heavy rainfall over
portions of southeastern Texas and southwestern Louisiana during
the next few days. See the NHC Tropical Weather Outlook at
hurricanes.gov for more information.

Gale Warning for the Canary Islands: The forecast from Meteo-
France is for gale-force winds near the Canary Islands, starting
on 21 May, at 0600 UTC. Strong to near gale-force winds,
surrounding this area, will expand on Saturday, to cover the
area north of 26N and east of 24W, with the possibility of gale
force winds continuing near the Canary Islands. Expect seas to
build to 12-14 ft offshore Morocco this weekend, with 9-11 ft
seas elsewhere north of 22N and east of 32W. See the High Seas
Warning and High Seas Forecast products from Meteo France at
weather.gmdss.org/II.html for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal areas of Guinea
near 11N15W to 05N20W to 03N26W. The ITCZ continues from 03N26W
to 03N51W. Scattered moderate convection is noted from 02N to
06N between 38W and 52W.

GULF OF MEXICO...

A disorganized area of showers and thunderstorms over the
western Gulf of Mexico is associated with a surface trough along
95W north of 21N. Conditions are expected to be marginally
conducive for some development over the next day or so before
the disturbance moves inland over the Texas coast by tonight.
The system could produce heavy rainfall over portions of SE
Texas and SW Louisiana through Saturday. This trough is
spreading a large area of cloudiness and showers over the west-
central and NW Gulf of Mexico. East of the trough, strong E to
SE winds prevail across a large portion of the east-central Gulf
of Mexico, from the Florida Straits to the Mississippi River
delta, with seas 8 to 10 ft seas. Moderate winds prevail over
the western Gulf, west of the trough, with 5 to 7 ft seas.

For the forecast, showers and thunderstorms will continue across
the western Gulf of Mexico today, with strong gusty winds and
seas to 10 ft. A strong ridge stretching from the eastern
seaboard to the NE Gulf will continue to dominate the Gulf
waters into Sat night. The pressure gradient will support fresh
to strong SE winds and high seas across the Gulf region through
Sat. Seas will peak at around 10 to 11 ft in the north-central
Gulf this evening.

CARIBBEAN SEA...

A stationary front extends north of the region along 20N. High
pressure in the wake of the front is north of Cuba. Scattered
showers are noted across the northern Caribbean north of 17N
between the Mona Passage and 84W. Similar convection is north of
Honduras. Most of the open waters of the eastern and central
Caribbean are free of any significant precipitation. Fresh to
strong E winds are in the south-central Caribbean and in the
Gulf of Honduras, with moderate to fresh winds elsewhere. Seas
are 6-8 ft in the central Caribbean and 4-5 ft elsewhere.

For the forecast, high pressure building north of the area
across the western Atlantic will support fresh to strong winds
across the central Caribbean, and south of Cuba, through Sun
morning.

ATLANTIC OCEAN...

A cold front passes through 31N47W to 25N50W to 22N57W, then
stationary to 20N63W to 20N79W. A large area of is west of the
frontal boundary to a line from 31N56W to 21N70W. A second cold
front trails from a complex low pressure area north of the area
through 31N59W to 27N63W to 28N75W. A narrow band of showers is
along the frontal boundary. Scatterometer data shows moderate to
fresh trade winds across most of the western Atlantic. Seas are
6 to 8 ft east of the Bahamas, and 4 to 7 ft elsewhere.

For the forecast west of 65W, the stationary front along 20N
will slowly dissipate through tonight. The pressure gradient
between high pressure off the eastern seaboard and the frontal
boundary will support fresh to strong easterly winds N of the
front and W of 68W through early Sat. 6 to 8 ft seas will
prevail across the region through Sat. Large NE swell will enter
the NE forecast waters Sat, and spread across the forecast area
through Mon.

For the forecast between 35W-65W, little change in winds and
seas is expected through Saturday. See the Special Features
section above regarding the forecast east of 35W.

$$
Mundell/Hagen
This weather bulletin was brought to you by:
www.nashvilleweather.net