[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200601
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Thu May 20 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 0000 UTC surface analysis and satellite imagery through
0540 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains of Guinea
near 11N15W, to 09N20W, 05N27W.
The ITCZ continues from 05N27W, to 03N34W, to 02N40W.
Precipitation:  scattered moderate to widely scattered strong is
within 390 nm to the south of the monsoon trough between 14W and
22W, and within 135 nm to the north of the ITCZ between 33W and
42W. Scattered moderate to strong is from 03N to 06N between 43W
and the coast of Brazil and French Guiana.

GULF OF MEXICO...

One surface trough extends from the SW Louisiana to the coast of
Mexico near Tampico. A second surface trough is in the Texas
coastal waters. Precipitation: scattered moderate to widely
scattered strong is covering the Gulf of Mexico from 91W
westward.

Precipitation: widely scattered moderate to isolated strong is
from 25N southward from 89W eastward.

An inland Mexico surface trough passes through the Isthmus of
Tehuantepec to the western sections of the Yucatan Peninsula.
Precipitation: scattered moderate to widely scattered strong
covers the areas of northern Guatemala and the Yucatan Peninsula
from 20N southward.

An upper level trough passes through south Texas, into the SW
corner of the Gulf of Mexico.

The scatterometer winds show that fresh-to-strong SE winds are
from 20N northward between 85W and 94W. The sea heights are
ranging from 8 feet to 9 feet from 22N northward.

The sea heights that are in the Straits of Florida, between 80W
and 84W, are ranging from 8 feet to 10 feet.

Strong to near severe thunderstorms are expected to continue
across the NW and N central Gulf of Mexico, from tonight through
Friday, and will be capable of producing gale-force wind gusts
and sea heights in excess of 12 feet. Meanwhile, a strong ridge
stretching from the eastern seaboard to the NE Gulf of Mexico,
will continue to dominate the Gulf waters during the remainder
of the week. The pressure gradient, between the ridge and
deepening low pressure in the Southern Plains and northern
Mexico, will result in fresh to strong SE winds and high seas
across the Gulf region, from tonight through Saturday. The sea
heights will peak from 10 feet to 13 feet on Thursday and Friday
in the Straits of Florida, with 12 foot seas in the central Gulf
on Friday.

CARIBBEAN SEA...

Precipitation: Isolated moderate rainshowers cover the areas
that are from 17N northward.

The monsoon trough passes through Colombia near 11N73W, through
Colombia and Panama, beyond southern Costa Rica, and into the
eastern Pacific Ocean. Precipitation: isolated to widely
scattered moderate is inland, in parts of NW Venezuela, and
elsewhere in Colombia.

Upper level westerly wind flow spans the Caribbean Sea. The GFS
model for 500 mb shows an anticyclonic circulation center is in
eastern Honduras/NE Nicaragua. The GFS model for 700 mb shows an
inverted trough that runs from Jamaica into the SW corner of the
Caribbean Sea. A ridge is along 17N/18N from 69W eastward.

Broken to overcast low level clouds, and isolated moderate
rainshowers, cover the rest of the Caribbean Sea. The clouds and
isolated moderate precipitation are moving with the
surface-to-low level wind flow.

The scatterometer winds show that moderate-to-fresh easterly
winds, and sea heights of 3 feet to 4 feet, are in the SE corner
of the Caribbean Sea. Fresh-to-strong easterly winds, and sea
heights that range from 5 feet to 7 feet, cover the central
sections of the Caribbean Sea. Fresh-to-strong, with some
possible gale-force, E-to-SE winds, and sea heights that range
from 5 feet to 6 feet, are within 180 nm to the north of
Honduras from 84W westward.

High pressure off the U.S.A. East Coast will continue to build
in the western Atlantic Ocean. Expect fresh to strong winds
tonight in the central Caribbean Sea through early next week.
Fresh to strong winds will occur also in the lee of Cuba, on
Friday and during the weekend. Expect fresh to strong easterly
winds in the Gulf of Honduras, mainly at night, through Thursday
night.

ATLANTIC OCEAN

A 1016 mb low pressure center is near 30N56W. A stationary front
extends toward the southwest from the 1016 mb low pressure
center, to 25N60W 23N70W, and to 23N76W in the Bahamas. A warm
front extends to the northeast of the 1016 mb low pressure
center, to 31N52W and 30N47W. The front is stationary from
30N47W beyond 31N41W. Strong to near-gale force winds are within
280 nm of the center in the NE semicircle. Sea heights of 9 feet
are within 200 nm of the center in the NE quadrant.
Fresh-to-strong NE-to-E winds, and sea heights ranging from 7
feet to 9 feet, cover the Atlantic Ocean, from the stationary
front northward, from 70W westward. Precipitation: widely
scattered moderate to isolated strong is within 300 nm to the E,
the SE, and the S of the 1016 mb low pressure center and the
stationary front that trails the low pressure center. Scattered
to numerous strong is to the north of the warm front. Isolated
moderate to locally strong is from Hispaniola and Cuba to 27N
from 70W westward. The low pressure center is forecast to move
westward and southwestward in warmer waters on Friday. It is
likely to become a short-lived subtropical cyclone, late on
Friday and into the weekend, near and to the northeast
of Bermuda. The system is expected to move toward the north and
northeast, into a more hostile environment, by late Sunday into
Monday.

A surface ridge passes through 31N34W, to 26N48W, to 17N64W in
the NE corner of the Caribbean Sea.

An upper level cyclonic circulation center is on top of northern
half of The Western Sahara. Comparatively drier air in
subsidence is apparent in water vapor imagery in the coastal
waters of The Western Sahara and Morocco.

N-to-NE fresh-to-strong winds are in the METEO-FRANCE forecast
area, that is called AGADIR. The sea heights are ranging from 8
feet to 9 feet.

The current stationary front extends across the western Atlantic
Ocean, from 23.5N65W to the southeast Bahamas. This front will
weaken through Thursday, as it moves southward and approaches
the Windward Passage and Hispaniola. Meanwhile, the pressure
gradient between high pressure off the eastern seaboard and the
frontal boundary will support an area of fresh to strong
easterly winds N of the front and W of 65W Wed through Fri. Seas
will peak around 10 feet, to the E of the Bahamas, from tonight
through early Thursday.

$$
mt/SS
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