AXNT20 KNHC 171000
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sun Jan 17 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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.
Based on 0600 UTC surface analysis and satellite imagery through
Caribbean Gale Warning: High pressure building north of the area
will support strong to near gale force winds over the south-
central Caribbean through mid week. Overnight land breezes will
allow these winds to pulse to gale force within 90 nm off the
coast of Colombia, mainly between Cartagena and Barranquilla.
Please read the latest NWS High Seas Forecast issued by the
National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.
The monsoon trough extends from the coast of Sierra Leone near
08N13W to 06N20W. The ITCZ continues from 06N24W to 02N40W and to the
coast of Brazil near 00N50W. Scattered moderate convection is
noted within 90 nm on either sides of both boundaries.
GULF OF MEXICO...
A surface ridge extends from 1016 mb high pressure centered over
the western Gulf near 25N93W through the Straits of Florida. This
high pressure is following a cold front that moved southeast of
the basin yesterday. Light to gentle breezes cover the Gulf,
except for moderate southerly flow over the southwest and west
central Gulf. Seas are likely 5 to 7 ft in lingering NW swell over
the eastern Gulf, although these seas are subsiding quickly. Seas
are 1 to 3 ft in the northern Gulf, and are 3 to 5 ft elsewhere.
Fairly dry conditions persist for now, and no significant showers
or thunderstorms are noted.
For the forecast, a weak front will stall along the north Gulf
coast tonight, then dissipate. Southerly flow will increase across
the western Gulf through late Mon, between the high pressure
anchored over the central Gulf and lower pressure over west Texas
and northwest Mexico. Fresh to strong SW winds and seas to 8 ft
are possible over the northwest Gulf Mon night. The southerly flow
will also bring increased moisture over the cooler shelf waters
of the northwest Gulf, and patchy sea fog is possible by mid week
there. Elsewhere, fairly tranquil marine conditions will persist
through Thu as the high pressure shifts east of the area.
There is a gale warning in effect for the south-central basin.
Please see Special Features section for more details.
A stationary front extends across the northwest Caribbean from
eastern Cuba to central Honduras. A recent scatterometer shows
moderate to fresh N to NE winds are evident north of the front
over the northwest Caribbean. Seas in this plume are likely 4 to
6 ft. Grand Cayman radar is showing only a few showers along the
front moving to the southwest. High pressure north of the area
building in the wake of the front will support moderate to fresh
trade winds with 5 to 7 ft over the remainder of the basin, but
with strong trade winds and seas to 8 ft off Colombia. Other than
a few showers moving into the Windward Islands, little shower
activity is noted.
For the forecast, the stationary front reaching from eastern Cuba
to central Honduras will dissipate through Mon. The high pressure
building in the wake of the front north of the region will bring
increasing winds and building seas over the south- central
Caribbean, with winds pulsing to gale force off the coast of
Colombia mainly at night through mid week.
West of 60W, a cold front extends from west of Bermuda near 32N62W
to eastern Cuba near 21N76W. Scattered showers are observed within
90 nm ahead of the front north of 29N. The main upper dynamics
supporting the front are lifting out to the north, allowing
sustained winds and gusts to diminish over the waters north of
25N. Seas are still very high, with the buoy 41048 near 32N69W
reporting 18 ft significant wave heights. This is due to shorter
period W to NW swell. Seas in excess of 8 ft cover most of the
area north of 26N between 65W and 75W. Seas are 4 to 6 ft
elsewhere in open waters with gentle to moderate winds.
For the forecast for the waters west of 60W, the cold front from
will stall from 25N65W to eastern Cuba late today, then will
dissipate Mon. Another cold front will move southeast off the NE
Florida coast tonight, reach from Bermuda to central Cuba by late
Mon, then stall and dissipate from 23N65W to eastern Cuba through
mid week. Another cold front will move southward into the waters
between Bermuda and NE Florida Wed night, and become stationary
along 25N into the central Bahamas by late Thu.
Farther east, a cold front extends from the northwest Azores to
near 30N41W, denting a ridge that prevails north of 20N. The ridge
is supporting a broad area of moderate to fresh trade winds with 8
to 10 ft seas in mixed N and NE swell.