921 AXNT20 KNHC 090005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Wed Aug 8 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... ...Tropical Storm Debby... Debby is located near 42.0N/47.2W as of 08/2100 UTC. Estimated minimum pressure is 1004 mb, moving northeast at 13 kt. Maximum sustained winds are 35 kt with gusts to 45 kt. Debby is expected to continue moving northeast while weakening. Debby is forecast to dissipate on Thursday. See the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. ...Caribbean Gale Warning... Gale force winds will develop once again by 09/00Z over the area north of Colombia from 11N-13N between 70W-76W. These conditions will continue through Thursday morning. Please see the Atlantic High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for further details. ...TROPICAL WAVES... A tropical wave axis off W Africa extends from 20N20W to 06N20W, moving W at 10-15 kt. The wave is associated with a 700 mb trough, and an embedded 700 mb low centered near 13N20W. SSMI TPW shows a moist area S of 14N, and dry air N of 14N. Widely scattered moderate convection is from 07N-14N between 12W-22W. A tropical wave axis in the eastern Atlantic extends from 12N33W to 06N33W, moving W at 10-15 kt. This is a low amplitude and low latitude wave with Saharan dry air N of the wave. SSMI TPW shows a moist area along the wave axis. Scattered showers are noted from 09N-11N between 29W-32W. A tropical wave axis in the central Atlantic extends from 18N52W to 06N52W, moving W at 10-15 kt. This wave has a well defined inverted V surface pattern noted on satellite imagery. The wave also has a large 700 mb trough associated with the wave. The wave is affected by Saharan dry air intrusion W of the wave axis and N of 12N. Scattered moderate convection is from 09N-11N between 52W-56W. A tropical wave axis in the W Caribbean extends from 18N87W to 05N87W, moving W at 10-15 kt. The wave is in a moist environment as indicated by SSMI TPW imagery, especially the southern portion of the wave that is over the E Pacific. The northern portion of the wave over the Gulf of Honduras is under an upper level diffluent environment. Scattered moderate to isolated strong convection is noted within 180 nm of the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the eastern Atlantic near 18N16W and extends southwestward to 11N31W. The ITCZ begins W of a tropical wave near 09N38W and continues to 08N47W. Besides the convection mentioned in the tropical wave section, scattered showers are observed within 180 nm S of the ITCZ. ...DISCUSSION... GULF OF MEXICO... An area of high pressure extends from the western Atlantic into the basin. A surface trough extends over the Bay of Campeche from 24N97W to 20N96W with scattered showers prevailing mainly west of 94W. An upper-level low centered over the Straits of Florida near 24N82W, enhancing convection across the Yucatan Channel. A thermal trough will develop over the Yucatan Peninsula from the early evenings to overnight hours for the next several days. A surge of fresh to occasionally strong winds will be associated with this trough. High pressure ridging will prevail across the area through the week. CARIBBEAN SEA... A tropical wave is moving across the basin. Refer to the section above for details. Gale force winds will develop again this evening. Please read the Special Features section above for details. The monsoon trough in the SW Caribbean supports scattered moderate convection south of 10N and west of 80W. This pattern will continue through the week. The next tropical wave is forecast to reach the waters east of the Lesser Antilles by early Friday, and move across these islands this weekend. ATLANTIC OCEAN... Tropical storm Debby is over the north-central Atlantic. Refer to the section above for details. Two tropical waves are moving across the basin. See the section above for details. A 1019 mb high is centered over the west Atlantic near 28N74W. The remainder of the basin is under the influence of a surface ridge, anchored by a 1028 mb high centered near 42N25W. Little change is expected through the next 24-48 hours. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa