139 AXNT20 KNHC 301204 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 804 AM EDT Sun Sep 30 2018 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 1130 UTC. ...SPECIAL FEATURES... The center of Tropical Storm Leslie at 30/0900 UTC is near 33.8N 52.5W. Leslie is moving WSW, or 240 degrees, 04 knots. The estimated minimum central pressure is 991 mb. The maximum sustained wind speeds are 45 knots with gusts to 55 knots. Widely scattered moderate to isolated strong rainshowers are within 100 nm of the center in the SE quadrant. Isolated moderate rainshowers are elsewhere within 420 nm of the center in the E semicircle. The PUBLIC ADVISORIES for LESLIE are transmiteed via the WMO header WTNT33 KNHC, and via the AWIPS header MIATCPAT3. The FORECAST/ADVISORIES for LESLIE are transmitted via the WMO header WTNT23 KNHC, and via the AWIPS header MIATCMAT3. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 31W/35W from 16N southward. Widely scattered moderate to isolated strong ITCZ rainshowers are from 06N to 10N between 30W and 41W. An Atlantic Ocean tropical wave is along 51W/54W from 18N southward. Isolated moderate rainshowers, probably with the ITCZ, are from 09N to 10N between 52W and 56W, and from 10N to 20N between 43W and 50W. A Caribbean Sea tropical wave is along 72W/74W from 20N southward. The wave is moving through an area of upper level SW wind flow, and broad upper level anticyclonic wind flow. Scattered to numerous strong rainshowers were from 14N to 17N between 68W and 72W in the central Caribbean Sea at 30/0500 UTC. The cloud top temperatures in that area of precipitation have been warming during the last few hours. The precipitation has been weakening with time. Widely scattered moderate to isolated strong rainshowers remain, between 65W and 74W in the waters. Scattered to numerous strong rainshowers are in the Peninsula de la Guajira of NE Colombia, and in NW Venezuela. A SW Gulf of Mexico tropical wave is along 93W/94W from 20N southward. Isolated moderate to locally strong rainshowers are from 21N southward between 93W and 96W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Senegal near 16N17W, to 10N26W and 06N33W. The ITCZ is along 03N/05N between 36W and 51W. Widely scattered moderate to isolated strong rainshowers are within 240 nm on either side of the line that runs from 14N17W to 08N24W to 09N34W to 06N41W, and from 03N to 07N between 06W and 14W. ...DISCUSSION... GULF OF MEXICO... A surface trough is over the E Gulf of Mexico from 29N83W to 25N84W. Scattered moderate convection is within 60 nm of the trough. A surface trough is inland over the Yucatan Peninsula from 21N88W to 18N91W. Scattered moderate to isolated strong convection is from 17N-20N between 90W-92W. Currently gentle to moderate easterly surface winds are over the Gulf. Little change is expected over the gulf waters during the next couple of days. Seas will remain below 8 ft through Sunday. Of note in the upper levels, an upper level low is centered over central Texas near 31N100w. Upper level diffluence E of the centered is producing scattered moderate to isolated strong convection over the NW Gulf from 25N-31N between 89W-96W. CARIBBEAN SEA... Two tropical waves are moving across the basin. See the Tropical Waves section above for details. The eastern extent of the E Pacific monsoon trough extends over the Costa Rica and Panama along 09N producing isolated moderate convection over the SW Caribbean S of 13N. Recent scatterometer data indicate gentle to moderate trades prevail across most of the basin except in the vicinity of the tropical wave across the eastern Caribbean. Fresh winds prevail mainly east of 66W. Large northerly swell associated with Leslie will affect the tropical Atlantic waters tonight through Sunday, building seas to 10-11 ft. In the upper levels, an upper level low is centered N of E Cuba near 22N76W. This low is producing scattered moderate convection S of Cuba from 20N-21N between 77W-80W. ATLANTIC OCEAN... Two tropical waves are currently between the coast of Africa and the Lesser Antilles. See the Tropical Waves section above for details. A surface trough enters the forecast region near 30N44W then continues SSW to 20N50W. Widely scattered moderate convection is from 20N-35N between 40W-48W. This feature was formerly associated with Leslie. In the upper levels, the upper level low centered N of E Cuba near 22N76W is producing scattered showers are from 20N-27N between 70W-80W to include most of the Bahamas. Elsewhere, a large upper level low is centered over the central Atlantic near 27N49W. There is a considerable amount of upper level diffluence E of the center enhancing convection. For additional information please visit http://www.hurricanes.gov/marine $$ mrf/al/mt