000 AXNT20 KNHC 131650 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Mon Dec 13 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 1630 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Sierra Leone to 07N16W. The ITCZ continues from 07N16W passing 05N35W to 01N49W. Scattered moderate convection is noted from 03N to 10N between 13W and 22W, and from 02N to 07N between 37W and 52W. GULF OF MEXICO... A weakening stationary front extends west from central Florida across the northern Gulf of Mexico to 27N95W 90 nm SE of Houston and then south into the Bay of Campeche. A moderate to fresh easterly breeze dominates majority of the basin with 2-4 ft seas except for 3-5 ft seas in the Bay of Campeche that have been decreasing over the last 12 hours. For the forecast, patchy marine fog will lower visibility along the NE Gulf coast once again Tue morning. The stationary front will dissipate today. Fresh east winds will spread westward through the Straits of Florida and into the eastern Gulf S of 26N through midweek along with building seas. CARIBBEAN SEA... High pressure across the eastern seaboard of the United States is maintaining the gradient with low pressure over Colombia. This set up is supporting strong NE winds in the Windward Passage with fresh to locally strong trades over the central Caribbean and in the lee of Cuba. Gentle to moderate winds prevail elsewhere. Seas are in the 5-7 ft range over the central Caribbean and 3-5 ft elsewhere. Scattered moderate convection is noted in the far SW Caribbean off the coast of Costa Rica, in association with the east Pacific monsoon trough. For the forecast, fresh to strong trades will prevail over the south-central Caribbean through the week. Moderate to fresh trades will prevail elsewhere. High pressure will build over the western Atlantic through the forecast period, which will result in fresh to locally strong northeast to east winds and building seas in the Windward Passage, the lee of Cuba, and south of Hispaniola through the week. ATLANTIC OCEAN... A cold front extends from the central Atlantic near 31N62W to 28N76W where it becomes stationary and extends to central Florida. Showers and thunderstorms are noted along this boundary east of 63W. There is a moderate NE breeze north of this front with gentle to moderate winds south of the boundary. These winds increase southward to moderate to fresh south of 23N. Seas in this area are in the 4-7 ft range. A 1033 mb Azores high is centered near 37N32W. The pressure gradient between this area of high pressure and lower pressure within the monsoon trough and in the vicinity of the ITCZ is supporting a large area of fresh to strong winds from 10N to 26N and between 18W to 55W. Recent altimeter data has confirmed seas in this area are 8-12 ft. Elsewhere, gentle to moderate winds and 6-8 ft seas prevail. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Medium to high ash concentrations are expected near and south of the volcano. 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/. For the forecast west of 65W, the cold front will drift southward while gradually dissipating. High pressure will build in the wake of the front. This will freshen winds over the forecast waters, mainly south of 25N, through the week. Expect moderate to fresh northeast to east trade winds to increase by mid week and prevail through Friday. $$ Flynn