AXNT20 KNHC 301714
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Tue Nov 30 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
The monsoon trough axis enters the Atlantic from the coast of
Guinea and extends to near 07N18W. The ITCZ continues from 07N18W
to 03N36W to 04N49W. Scattered moderate convection is evident from
02N to 06N between 20W and 43W.
GULF OF MEXICO...
A 1023 mb high pressure is centered over the southeast United
States. Recent scatterometer data show gentle winds covering most
of the basin, except for moderate NE winds in the southeastern
Gulf. Seas are generally 2 to 4 ft in the northern Gulf and 4 to 6
from the Yucatan Channel to the southwest Gulf. Fairly dry
weather prevails across the basin.
For the forecast, high pressure will dominate the basin for the
remainder of the week. High pressure will move eastward today into
Wed, gradually returning the east to southeast flow across the
northwest Gulf by the end of the week.
A shear line is analyzed from the W Atlantic across the central
Bahamas to the south-central coast of Cuba, and extending westward
to the Yucatan Peninsula. A 1015 mb low is along the shear line
near 20N85W producing cloudiness with possible embedded showers.
Scattered moderate to isolated strong convection is noted in the
far southwest Caribbean south of 12N near the Panama and Costa
Rica coastlines, associated with the east Pacific monsoon trough.
A westward moving surface trough is analyzed just east of the
Lesser Antilles from 17N60W to 13N60W and could bring some
showers to the islands today. Fresh trade winds are occurring
over the central Caribbean. Fresh NE winds are also noted on
scatterometer data in the Yucatan Channel, to the northwest of the
aforementioned low pressure. Seas are likely 5 to 7 ft in the
central Caribbean and 5 to 6 near the Yucatan Channel. A peak of
7 to 8 ft is noted off the coast of Colombia. Moderate winds
prevail elsewhere across the basin, with seas of 2 to 5 ft.
For the forecast, the shear line in the northwest Caribbean will
gradually dissipate today. Fresh NE winds over the Yucatan
Channel will diminish later today. Elsewhere, high pressure north
of the area will maintain moderate to fresh NE to E winds across
the Caribbean through the end of the week and into the weekend,
with strong winds pulsing off Colombia, mainly at night.
A cold front extends from 31N59W through the central Bahamas and
transitions to a shear line to central Cuba near 22N77W. A trough
extends in the wake of the front from near 30N64W to 26N73W. A
pre-frontal trough is also analyzed ahead of the front from
27N61W to 22N67W. Scattered moderate convection is ahead of the
front north of 27N between 53W and 58W. Generally moderate winds
are observed by a recent scatterometer pass on both sides of the
front, except for fresh S winds within 150 nm east of the front,
north of 28N. Seas are 8 to 9 ft north of 29N between 64W and 70W
due to a NW-N swell. Seas are 5 to 7 ft elsewhere in the W
Atlantic, NE of the Bahamas.
A surface trough is analyzed from 29N43W to 23N46W. A weak upper-
level trough in the area is enhancing scattered moderate
convection east of the surface trough north of 23N between 40W to
43W. Scattered moderate convection is also occurring from 06N to
09N between 50W to 57W, enhanced by upper-level divergence in the
area. Fresh to strong NE to E trades are observed in scatterometer
data east of 40W to the coast of Africa from the ITCZ to 30N,
where seas are 8 to 12 ft. Elsewhere, fairly tranquil weather
conditions prevail, with moderate or weaker winds and seas of 5-8
The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. Marine and
aviation interests should monitor this ongoing situation by
reading the Volcanic Ash Advisory issued by Meteo-France, at
For the forecast west of 55W, the cold front extending from
31N59W to central Cuba will stall from 31N57W to eastern Cuba
through tonight, then dissipate through mid week. High pressure
will settle across the forecast area in the wake of the front, and
dominate the region through Sat.