AXNT20 KNHC 221730
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Tue Jun 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 1200 UTC surface analysis and satellite imagery through
A tropical wave extends along 21W, from 16N southward, moving W
at 10 kt. Scattered moderate convection is noted from 03N to 08N
between 19W and 28W.
Another tropical wave extends along 38W from 11N southward,
moving W at 5 to 10 kt. Scattered moderate convection is within
120 nm on either side of the wave axis from 04N to 07N.
A third tropical wave runs along 53W from 14N southward, moving W
at 10 kt. Scattered moderate to isolated strong convection is
noted from 09N to 14N between 48W and 58W. Enhanced showers and
tstorms are possible over the SE Caribbean later this week.
A fourth tropical wave is along 88W, from the western Gulf of
Honduras southward to the east Pacific Ocean, and moving W at 10
to 15 kt. Convection over the southwest Caribbean is more related
to the monsoon trough, described in the Caribbean section.
The monsoon trough passes through the coastal areas of
Guinea-Bissau near 12N16W to 07N20W to 06N34W. The ITCZ continues
from 06N34W to 05N37W and then west of a tropical wave from 05N40W
to 07N52W. Scattered showers are seen within 90 nm either side of
the ITCZ between 43W and 49W.
GULF OF MEXICO...
A cold front is located just inland over Louisiana and Texas.
Upper-level diffluence is enhancing scattered moderate to strong
thunderstorms over the far northwest Gulf of Mexico out ahead of
the frontal system, north of 27N and west of 92W. A second area of
thunderstorms is located over the northeastern Gulf of Mexico
northwest of 28N and east of 89W. A surface ridge extends across
the central and southern Gulf of Mexico from the Atlantic. A
recent ASCAT pass shows fresh SE to S winds to the northwest of
the Yucatan Peninsula with generally moderately wind speeds
elsewhere across the basin. Seas are 4 to 5 feet in the western
Gulf of Mexico and 2 to 3 feet in the eastern Gulf.
A ridge from the Atlantic will continue to dominate the Gulf
region over the next several days. Pulsing fresh E to SE winds are
expected each night into the early morning hours to the NW of the
Yucatan peninsula through Thu night.
Refer to the section above for details on the tropical waves
moving across the basin.
A weak upper-level trough is inducing scattered showers and
isolated thunderstorms between Puerto Rico and eastern Cuba,
including Hispaniola and Jamaica. Scattered moderate to isolated
strong convection is seen in the southwest Caribbean south of
13.5N west of 76W in association with the monsoon trough. The
latest ASCAT pass shows fresh trade winds over the south-central
Caribbean with mainly moderate trade winds elsewhere. Fresh winds
may also be occurring in the Gulf of Honduras. Seas are 6 to 8
feet over the central Caribbean with 4 to 6-foot seas elsewhere.
The Atlantic high pressure combined with the Colombian low supports
fresh to strong trades over the south-central Caribbean mainly at
night through Wed night. Pulsing fresh to strong E to SE winds
are expected in the Gulf of Honduras at night through Wed night.
An active tropical wave with axis now along 53W is expected to
approach the Lesser Antilles by Thu. Fresh NE winds are noted
ahead of the wave axis.
Refer to the Tropical Waves section above for details on the
tropical waves moving across the basin.
West of 55W: A 1025 mb high near 29N59W extends surface ridging
towards the northwest Bahamas. A recent ASCAT pass shows fresh
southerly winds offshore north Florida and fresh trade winds north
of Puerto Rico. Winds become gentle closer to the high pressure.
Isolated showers and thunderstorms are observed between Andros
Island Bahamas and Miami Florida.
East of 55W: A surface trough is from 31N45W to 21N43W. An upper-
level low near 31N48W is inducing scattered showers north of 30N
between 43W and 48W. Ridging prevails across the remainder of the
eastern Atlantic. Winds near the coast of Morocco are strong to
near-gale force from the north. Seas of 3 to 5 feet prevail
across the subtropical Atlantic north of 23N with 5 to 7 ft seas
across the tropical Atlantic.
Forecast west of 65W: Fresh S to SW winds are expected across the
waters off NE Florida through tonight, ahead of a frontal
boundary located over the southeastern United States. Expect
scattered showers and tstorms this afternoon and evening in waters
to the east of northern Florida. A surface ridge will continue to
dominate the area during the next several days. Fresh to locally
strong winds are expected to pulse at night over Hispaniola and
adjacent waters, including approaches to the Windward Passage
through the end of the week.