708 AXNT20 KNHC 181708 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sun Oct 18 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 1200 UTC surface analysis and satellite imagery through 1640 UTC. ...SPECIAL FEATURES... A 1004 mb low is near 27.4N 56.5W, or about 478 nm ESE of Bermuda. Scattered moderate convection is noted from 22N-31N between 44W-54W. Convection associated with this low has gradually increased in both coverage and organization during the past 24 hours. Further development is expected, and a subtropical depression or storm is very likely to form during the next day or so while the low meanders well to the southeast of Bermuda. There is a high chance of formation during the next 48 hours. At this time, gale conditions are expected to begin on Mon night and follow the low as it moves northward. Please read the latest Tropical Weather Outlook and the High Seas Forecast product for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave has an axis along 30W, from 14N southward, moving westward at 10 kt. Scattered moderate to strong convection is noted from 07N-14N between 26W-33W. An Atlantic Ocean tropical wave has an axis along 45W, from 15N southward, moving westward at 10-15 kt. No significant convection is associated with this wave at this time. An eastern Caribbean tropical wave has an axis along 65W, from 19N southward, moving westward at 10 kt. No significant convection is associated with this wave at this time. A western Caribbean tropical wave has an axis along 81W, from 22N southward, moving westward at 10 kt. Scattered moderate convection is noted near the wave from 09N-20N between 78W-82W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal region of Senegal near 14N17W to 08N24W to 07N34W. The ITCZ continues from 07N34W to 07N43W, then continues west of a tropical wave near 07N45W to the coast of French Guiana near 06N54W. Scattered moderate convection is along and south of the monsoon trough from 03N- 09N between 13W-28W. Isolated convection is seen within 70 nm of the ITCZ. GULF OF MEXICO... Upper level and surface ridging is sprawled across the Gulf of Mexico. Isolated thunderstorms are noted in the SE Gulf in association with a stationary front in the Straits of Florida from 22N-24N between 83W-88W. A trough is in the Bay of Campeche, stretching from 22N97W to the coast of Mexico near 19N93W. Moderate easterly winds are noted in the eastern Gulf with gentle to moderate southeasterly winds in the western Gulf. Seas average 3 to 6 ft. High pressure will continue building across the basin producing moderate to fresh easterly winds over eastern Gulf and gentle to moderate winds elsewhere. The pressure gradient will tighten across the eastern Gulf tonight bringing fresh to strong easterly winds. CARIBBEAN SEA... Please refer to the Tropical Waves section for information on the two tropical waves in this basin. The monsoon trough extends off the coast of Panama to a 1008 mb low near 10N79W. Scattered moderate to isolated strong convection is noted near this low and tropical wave from 08N-11N between 76W-82W. Scattered moderate to strong convection is moving across Jamaica and eastern Cuba from 16N-22N between 74W- 79W. Scattered moderate convection is also seen in the NW Caribbean, including the Gulf of Honduras, from 14N-21N between 82W-88W. The eastern Caribbean does not have any significant convection at this time. Moderate to fresh trades are north of Colombia/Venezuela with light to gentle trades elsewhere. Seas average 3-6 ft with up to 7 ft north of Colombia. A tropical wave moving across the W Caribbean will reach the Yucatan Peninsula by Tue morning enhancing winds and convection over the area. A broad area of low pressure is expected to form in a couple of days over the southwestern Caribbean Sea. Some gradual development of this system will be possible through the middle of the week as it moves slowly northward or north- northwestward over the western Caribbean Sea. ATLANTIC OCEAN... Please refer to the Special Features section for information on the low in the central Atlantic and the Tropical Waves section for information on the two tropical waves in this basin. A stationary front extends across the western Atlantic off the coast of Florida to the Straits of Florida, from 31N71W to 24N83W. Scattered moderate convection extends from off the north- central coast of Florida to eastern Cuba, including the Bahamas, from 20N-30N between 72W-81W. North of the front, fresh ENE winds are noted with light to gentle winds south of the front. Seas are up to 9 ft off the coast of Florida. Moderate to fresh northerly winds are noted to the east of the low in the central Atlantic. Seas average 6-10 ft. A trough is east of the Lesser Antilles from 17N54W to 10N57W. Scattered moderate convection is from 12N-18N between 47W-54W. Another trough extends from 22N37W to 15N42W. Isolated thunderstorms are within 90 nm. A pre-frontal trough is noted in the eastern Atlantic from 31N28W to 30N33W. Moderate to fresh northerly winds are north of the trough with fresh to strong SW winds south of the trough. Seas are averaging 3-5 ft across the rest of the basin. The stationary front will dissipate on Mon. A non-tropical low pressure system is located about 550 miles east-southeast of Bermuda. Further development is expected, and a subtropical depression or storm is very likely to form during the next day or so while the low meanders well to the southeast of Bermuda. The pressure gradient between high pressure to the north and the low will increase winds and seas across the NE waters beginning tonight. $$ AReinhart