AXNT20 KNHC 161020
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sun May 16 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 0600 UTC surface analysis and satellite imagery through
The monsoon trough exits western Africa near 10N14W to 05N25W.
The ITCZ continues from 05N25W to 02N39W to 04N47W. A surface
trough is along 49W/50W from the Equator to 09N. Scattered
moderate to strong is from 03N to the monsoon trough between 08N
and 25N, and within 120 nm either side of the ITCZ between 25W and
GULF OF MEXICO...
1024 mb high pressure centered over coastal Georgia extends SW to
the central Gulf, producing moderate to fresh E to SE winds across
the basin. A small area of strong easterly winds continues to
shift westward away from the Florida coast, across the Big Bend
region. Low level moisture embedded in the SE return flow across W
portions of the Gulf is producing broken multilayered clouds, and
scattered showers and isolated thunderstorms within 120 nm of the
coasts of Texas and Mexico north of 21.5N.
The high pressure across Georgia will shift slowly into the
western Atlc through Tue to support moderate to fresh E to SE
winds over the basin. Active weather will continue across the NW
Gulf today. Winds will increase to fresh to strong late Tue
through Thu as low pressure deepens across the Southern Plains.
The monsoon trough extends from NW Colombia near 11N74W through
the Colombia/Panama border and into the eastern Pacific Ocean. A
middle to upper level trough extends from the central Tropical
Atlantic SW to the central Caribbean along 75W, producing fair
weather. At the surface high pressure centered across the NE
Atlantic extends W-SW to the southern Bahamas and is supporting
fresh to strong tradewinds across the south central Caribbean
south of 14N. Gentle to model trades prevail elsewhere. Widely
scattered showers and isolated thunderstorms are seen within 120
nm of the coast of Nicaragua, and across the Yucatan Channel to
the Isle of Youth, Cuba.
The current Atlantic Ocean ridge will shift eastward and weaken,
diminishing winds and seas modestly tonight through Mon. Trade
winds will increase basin wide Wed night through Thu night as high
pressure builds across the W Atlc.
A dissipating cold front passes through 31N53W to 28.5N60W to
the central Bahamas near 24N76W. 1015 mb low pressure is just
north of the area near 32N68W and is helping to produce moderate
to locally fresh N to NE wind to the north of the front, where
seas are 6 to 8 ft in NE wind swell. The low is forecast to shift
E-NE during the next 24-36 hours and intensify, to produce gale-
force northerly winds across its western semicircle. This will
continue to spread moderate to large NE winds into the northern
waters behind the front. Scattered moderate convection is seen
along and within 150 nm SE of the front to the north of 25N.
To the east of the front, a surface ridge extends from a 1024 mb
high pressure center near 33N27W to 24N70W. This broad ridge is
supporting moderate tradewinds across the Atlantic south of 20N
where seas are 6 to 8 ft.
The current weakening frontal boundary will drift SE and dissipate
through Tue. Winds will increase north of 24N and west of 68W
late Tue through Thu as high pressure builds across the W Atlc.