000 AXNT20 KNHC 302320 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Wed Sep 30 2020 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...Special Features A tropical wave located over the west-central Caribbean Sea near 79W is moving west around 10-15 kt. Scattered moderate to strong convection is noted from 11N-17N between 73W-83W. This system is expected to continue moving westward over the next couple of days and produce a broad area of low pressure over the western Caribbean Sea by Thursday night or Friday. Environmental conditions are forecast to be conducive for some development thereafter, and a tropical depression could form over the weekend while the system moves slowly west- northwestward over the northwestern Caribbean Sea. There is a medium chance of development in the next 5 days. ...TROPICAL WAVES... A tropical wave extends its axis along 30W southward from 15N, moving west at 10-15 kt. Scattered moderate convection is noted from 08N- 13N between 27W-31W. A tropical wave axis is along 55W southward from 17N, moving west at 10-15 kt. Scattered moderate convection prevails along and east of the wave's axis from 09N-17N between 52W-60W. A tropical wave axis is along 70W southward from 20N, moving west at 10-15 kt. Scattered moderate convection is noted from 12N-19N between 67W- 71W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Guinea-Bissau near 11N15W to 10N24W to 08N38W. The ITCZ continues from 08N38W to 10N50W. Outside of the convection associated with the tropical waves, an area of scattered moderate to isolated strong convection is moving off the coast of Africa from 07N-15N E of 20W. Scattered moderate convection is noted from 07N-10N between 34W-37W and along the ITCZ from 06N-09N between 40W-50W. Gulf of Mexico... At 2100 UTC, a stationary front draped across the southern Gulf and eastern Bay of Campeche, extending off the SW Florida coast near 26N81W to the northern Yucatan near 21N90W to the southern coast of Mexico near 19N92W. Scattered moderate convection is noted within 50 nm of the front. Behind the frontal boundary, ridging from a 1021 mb high pressure near 31N91W is building across the NW and central Gulf and bringing dry, tranquil conditions with it. Light to gentle winds and seas 4-6 are noted in the northern Gulf. Fresh to strong N to NE winds are behind the front in the eastern Gulf with seas up to 8 ft. Fresh to strong N winds are in the western Bay of Campeche with seas up to 12 ft. The stationary front will support strong to near gale force N winds in the Bay of Campeche through tonight and moderate to fresh NNE winds in the SE and SW basin through Thu. Moderate to fresh winds in these portions of the basin will prevail thereafter as surface ridging in the basin strengthen and an area of low pressure develops over the far NW Caribbean. These winds may reach near gale force speeds Thu night through Mon along with building seas. CARIBBEAN SEA... Please refer to the Special Features Tropical Waves section above for details on the tropical waves. The monsoon trough extends across the SW Caribbean from 12N76W to 10N83W. Scattered moderate convection is from 09N-14N between 74W-84W. Scattered moderate convection is also moving across the Lesser Antilles. Diurnally driven convection is seen across the Greater Antilles with some of the activity moving into adjacent waters. Light to gentle winds are noted in the NW Caribbean with fresh winds in the eastern Caribbean with seas 3-6 ft. Fresh to strong easterly winds are noted in the central Caribbean with seas up to 9 ft. Moderate to fresh winds are expected over the central and eastern Caribbean through Sat, and will decrease to gentle to moderate for the remaining period. A tropical wave located over the western Caribbean Sea is expected to move westward over the next couple of days and interact with the remnants of a frontal system, producing a broad area of low pressure over the far western Caribbean Sea by Thursday night or Friday. Environmental conditions are forecast to be conducive for some development thereafter, and a tropical depression could form over the weekend. ATLANTIC OCEAN... Refer to the section above for details on the tropical waves moving across the tropical Atlantic. Surface ridging prevails across the basin, anchored by a 1036 mb high is centered over the central Atlantic near 41N43W. A surface trough is seen in the latest ASCAT pass from 30N45W to 25N38W and a second trough further east extending south from a low pressure near 32N31W to 25N29W. A stationary front extends off the Florida coast in the SW Atlantic from 30N75W to the SE Florida coast near 26N80W. Scattered moderate convection is within 60 nm of the front with an area of scattered moderate to isolated strong convection from 25N-31N between 74W-76W. Fresh N to NW winds are behind the front with moderate S to SE winds ahead of the front. A surface trough is analyzed in the central Atlantic from 31N47W to 25N40W. A second trough farther east extends along a 1019 mb low near 32N32W from 33N33W to 28N30W. Surface ridging extends across the rest of the basin anchored by a 1036 mb high in the north- central Atlantic. Gentle to moderate winds prevail across most of the basin. Fresh easterly winds are noted north of Puerto Rico. Moderate SSE winds ahead of a stationary front will prevail to the E of the Bahamas through Thu as the front dissipates. A tropical wave will move across the eastern and central Caribbean Thu through Sun and will support moderate to fresh winds over the SE offshore waters, increasing to strong N of Hispaniola at night. $$ AReinhart