000 AXNT20 KNHC 290600 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Mon Nov 29 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 0545 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough extends axis from the coast of Sierra Leone near 09N13W and continues to 05N20W, where it transitions to the ITCZ to 04N26W to 03N35W and to 01N46W. Scattered moderate convection is seen noted from 03N to 10N between 30W-40W and within 120 nm north of the ITCZ between 42W-46W. GULF OF MEXICO... As of 03Z, a 1015 mb low is over the central Gulf near 26N90W, with a cold front extending southwest to 22N92W and to near Roca Partida, Mexico. A warm front extends from the low to 25N89W. then becomes a stationary front to 23N86W. Isolated showers are noted near the stationary front and over some areas of the eastern Gulf mainly due to an upper-level disturbance that is quickly moving eastward from the east-central Gulf toward the eastern Gulf. A recent ASCAT pass shows fresh to strong north winds to the north and northwest of the low to near 27N, and also to the northeast of the low and and north of the stationary front to 26N. Moderate to fresh northerly winds are elsewhere across the Gulf, with the exception of gentle north to northeast winds over the southeastern Gulf and Straits of Florida. Observed seas are in the 4-7 ft range, except for higher seas of 6-8 ft due to a north swell in the central Gulf area from 22N to 26N between 87W-94W, and in the SW Gulf area. Lower seas of 2-4 ft are east of 87W, and 1-2 ft in the far southeast Gulf and Straits of Florida per latest altimeter data. Broken to overcast low and mid-level clouds are confined to the SW Gulf generally along and west of the cold front. Patches of rain are possible with these clouds. For the forecast, the 1015 mb low pressure will move across the central Gulf through Mon then dissipate across the southeastern Gulf along with the front. A reinforcing cold front is expected to enter the northeast Gulf overnight and move across the eastern Gulf through Tue night, allowing high pressure to build over the northern Gulf through Fri. CARIBBEAN SEA... The pressure gradient between generally broad weak high pressure located to the northeast of the Bahamas and comparatively lower pressure over the southwester Caribbean is allowing for fresh to strong northeast to east winds to exist near the coast of Colombia along with seas of 5-7 ft. The latest ASCAT data pass shows fresh northerly winds south of 16N and west of 80W. Light to gentle northeast to east winds are elsewhere, except for gentle to moderate speeds over the central and eastern sections of the basin. Seas elsewhere are in the 2-4 ft range, except for slighter higher seas of 3-5 ft near Atlantic passages where a decaying north swell is present. Satellite imagery reveals scattered showers and thunderstorms confined to the southwestern Caribbean waters south of 16N and west of 80W. This includes the coastal waters of Nicaragua and central Panama. Diffluent flow aloft is helping to sustain this convective activity. Elsewhere, shallow moisture embedded in the trade wind flow will continue to move across the region producing isolated to scattered passing showers. A surface trough is analyzed along 67W and north of 14N to across Puerto Rico and to 20N. Some showers are possible along and near this trough. For the forecast, moderate to fresh northeast to east winds will persist over all but the northwest Caribbean through mid-week, with strong winds pulsing off Colombia, mainly at night. A weak front will move through the Yucatan Channel by late Tue, then stall and dissipate over the far northwest Caribbean through Wed. High pressure build north of the front will slightly enhance trade winds across the Caribbean later in the week. Meanwhile, moderate north to northeast swell will continue across the Atlantic waters east of 70W and through the NE Caribbean passages through Mon tonight. ATLANTIC OCEAN... As of 03Z, the previous analyzed cold front has become stationary from near 31N61W to 28N70W and to 26N75W, where it begins to dissipate to the central Bahamas. A surface trough is north of the Bahamas from near 31N77W to 27N79W. Broken to overcast low and mid-level clouds and scattered to broken high clouds are seen north of 27N and west of about 66W. Areas of rain and scattered showers are possible within this part of the area. Mainly light winds are near the frontal boundary based on scatterometer data with the exception of moderate to fresh northwest winds just off northeastern Florida. Farther east, a weak 1017 mb low is near 28N53W, with a trough to 31N53W and another trough from the low to 26N54W. No convective activity is noted with this feature as it remains under an area of moderate subsidence aloft. A recent ASCAT pass shows moderate to strong southeast to south winds within 120 nm of the low in the E and SE quadrants and gentle to moderate winds elsewhere within 240 nm of the low, except for an area of fresh to strong east to southeast winds noted north of 29N between 50W-52W. A trough is along a position from 31N44W to 25N41W. Isolated showers moving west to northwest are seen north of 25N between 43WE-46W. Recent latest altimeter data passes reveals 8-9 ft seas north of 16N between 445W-55W from north swell, and slightly higher seas of 9-11 ft over the far eastern part of the area north of 10N and east of 41W due to north to northeast that is propagating through those waters. Seas elsewhere are in the 4-7 ft range, except for lower seas of 2-4 ft south of 22N and west of 70W. For the forecast west of 65W, the aforementioned stationary front will dissipate through Mon. A reinforcing cold front will move into the waters between northeast Florida and Bermuda Mon, then continue south before stalling from 26N65W to central Cuba by late Wed, then dissipating through Thu. High pressure will settle across the northern waters along 30N north of the front Tue through Fri. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Low to medium ash concentration is noted in the vicinity of the volcano drifting towards the SW. Marine and aviation interests should monitor this ongoing situation by reading the Volcanic Ash Advisory issued by Meteo-France, at http://vaac.meteo.fr/volcanoes/la-palma/. $$ Aguirre