[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 212046
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sat May 22 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.

Based on 1800 UTC surface analysis and satellite imagery through
2200 UTC.

...SPECIAL FEATURES...

A 1008 mb gale-force non-tropical low is located near 35N61W,
moving WSW at 15 kt. Scattered moderate convection is within 300
nm NE semicircle and 210 nm SW semicircle. The strongest winds
of about 45 kt are located in the northern semicircle. Any
increase in organization would result in the formation of a
subtropical cyclone tonight as it moves westward to west-
southwestward to the northeast of Bermuda. By Saturday night or
Sunday, the low is forecast to move NE into a more hostile
environment. 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.

A well-defined 1009 mb surface low pressure is centered in the
western Gulf of Mexico near 26.5N95W and is moving NNW at 10 kt.
A recent ASCAT pass shows winds of 25 kt in the eastern
semicircle of the low. Scattered shower and thunderstorm activity
remains disorganized from 23N-29N between 90W-96W. Any increase
in organized thunderstorm activity near the center could result
in the formation of a short-lived tropical depression or storm.
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 through Saturday, which could
lead to flooding across the region. See the NHC Tropical Weather
Outlook at hurricanes.gov for more information.

Gale Warning for the Canary Islands: According to the forecast
from Meteo France, localized winds to gale force are possible
near and in between the Canary Islands tonight. On Saturday,
gale force winds will continue near the Canary Islands, and gales
will expand toward the coast of Morocco, including the marine
zones Agadir and Tarfaya. Outside of the gales, strong to near
gale force winds will cover the area north of 26N and east of 24W
by Saturday. 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.

...TROPICAL WAVES...

The axis of a tropical wave is near 46W south of 12N, moving
W at 20 kt. Scattered moderate convection is within 120 nm
either side of the wave axis from 03N-07N. The wave could enhance
showers over the southern Windward Islands and SE Caribbean on
Sunday.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of Africa near
11N15W to 08N19W. The ITCZ continues from 08N19W to 05N27W to
03N44W, then resumes W of a tropical wave from 04N48W to 03N51W.
Isolated moderate convection is noted from 01N to 06N between 22W
and 41W.

GULF OF MEXICO...

See the Special Features section above for information on a
tropical disturbance with a medium chance of formation.

East of 90W, scattered tstorms are noted from 23.5N-26N between
87W-90W. High pressure ridging stretching from the Carolinas to
the NE Gulf of Mexico is leading to mainly clear skies in the NE
corner of the Gulf. Fresh to strong winds prevail over the
eastern and east- central Gulf of Mexico, where seas are 8-11 ft.
Light to gentle winds, and seas of 3-5 ft prevail over the SW
Gulf of Mexico.

A strong ridge stretching from the eastern seaboard to the NE
Gulf will continue to dominate the Gulf waters this weekend. The
pressure gradient will support fresh to strong E to SE winds and
high seas across the Gulf region through late Sat. Seas will peak
at around 10 to 11 ft in the north-central Gulf through Sat
morning.

CARIBBEAN SEA...

A stationary front extends over the NW Caribbean, south of Cuba,
along 21N. Scattered moderate tstorms are along and south of the
front, from Hispaniola to Jamaica to the Yucatan Channel.
Similar convection is seen over the Gulf of Honduras. Most of
the open waters of the eastern and central Caribbean south of
17N are free of any significant precipitation. Fresh to strong E
winds prevail over the central Caribbean, as well as in the lee
of western Cuba. Moderate to fresh winds are noted elsewhere.
Seas of 6-9 ft prevail over the central Caribbean, with 4-6 ft
seas elsewhere.

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

ATLANTIC OCEAN...

See the Special Features section above for details on a low
pressure system NE of Bermuda that has a high chance of becoming
a subtropical cyclone.

A cold front extends from 31N57W to 25N65W to 26N74W. Isolated
showers are along the cold front. A stationary front extends from
31N47W to 21N64W to the Windward passage and into the NE
Caribbean. Scattered showers and isolated tstorms are within 120
nm of the stationary front. Fresh NE winds in the western
Atlantic, between Florida and 70W, with strong E winds in the
Florida Straits and south of the Bahamas. Winds are gentle to
moderate north of 20N between 30W- 65W. Fresh to locally strong
winds prevail south of 20N. Fresh to strong winds are noted north
of 25N and east of 26W, with localized areas of near gale to
gale force in between the Canary Islands.

For the forecast west of 65W, the stationary front will slowly
dissipate through Sat. 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
70W through early Sat. Large NE swell will enter the NE waters
tonight, and spread across the forecast area through Mon building
seas to 10-11 ft tonight and Sat.

$$
AL
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