107 AXNT20 KNHC 091205 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT Thu Aug 9 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 1100 UTC. ...SPECIAL FEATURES... ...Tropical Storm Debby... The center of Tropical Storm Debby, at 09/0900 UTC, is near 43.6N 45.1W. The estimated minimum central pressure is 1002 mb. Debby is, moving northeastward 15 kt. The maximum sustained wind speeds are 40 knots with gusts to 50 knots. Debby is expected to continue moving northeastward while weakening. Debby is forecast to dissipate on Friday. Please read the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 22W/23W from 21N southward, moving W 15 knots. 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. Scattered moderate to strong rainshowers in the monsoon trough area, from 10N to 13N between 20W and 25W. An Atlantic Ocean tropical wave is along 37W/38W from 12N southward, moving W 15 to 20 knots. 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. Widely scattered moderate to isolated strong rainshowers are from 07N to 10N between 32W and 38W. An Atlantic Ocean tropical wave is along 53W/54W from 18N southward, moving W 20 knots. 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. Isolated moderate to locally strong rainshowers are within 180 nm on either side of the line that runs from 20N51W to 13N55W to 08N60W. A tropical wave is inland, in central America, along 89W/90W from 18N southward, from Guatemala southward. Scattered strong rainshowers are from 16N to 19N between 86W and 88W, in the coastal plains/coastal waters. isolated moderate to locally strong rainshowers are elsewhere from 15N to 22N between 85W and 89W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Mauritania near 17N16W, to 10N29W and 07N40W. The ITCZ continues from 07N40W to 07N50W, to 08N56W, and into northern sections of Guyana near 08N60W. enters the eastern Atlantic near 18N16W and extends southwestward to 10N28W to 08N40W. The ITCZ extends from 08N40W to 07N52W. 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 21N90W to 17N93W with scattered moderate convection within 120 nm of the trough. An upper-level low is centered over the SE Gulf near 27N84W. Another small upper level low is centered near Tamico Mexico at 23N98W. A surface trough will develop in the Yucatan Peninsula from the early evenings to overnight hours during the next several days. The surface trough will be accompanied by a surge of fresh to occasionally strong winds. A surface ridge will prevail across the area through into early next week, supporting moderate to fresh SE flow over the west central Gulf of Mexico, and off Texas early next week. CARIBBEAN SEA... A tropical wave is exiting the basin. Refer to the section above for details. Gale force winds are along the coast of N Colombia. 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. High pressure that is to the north of the area will support fresh to strong trades in the central Caribbean Sea. A tropical wave will approach the Windward and Leeward Islands later today, moving through the central Caribbean Sea by Sunday. A second tropical wave will move into the eastern Caribbean Sea and the central Caribbean Sea on Monday. The winds will pulse to fresh in the Gulf of Honduras through the week, reaching fresh to strong tonight. Winds will approach minimal gale force again on Sunday night NW of the Coast of Colombia as the pressure gradient tightens temporarily. ATLANTIC OCEAN... Tropical storm Debby is in the north-central Atlantic Ocean. Please read the SPECIAL FEATURES section for details. A 1021 mb high is centered over the west Atlantic near 26N74W. A small surface trough is over the W Atlantic from 29N64W to 26N65W. Scattered showers are within 90 nm of the trough. The remainder of the basin is under the influence of a surface ridge, anchored by a 1030 mb high centered near 41N24W. Little change is expected through the next 24-48 hours. A 27N surface ridge will shift southward to 25N today. The ridge will be to the east of a trough, that will be moving off the southeastern coast of the U.S.A. through Friday. The ridge then will move N to 28N through Monday. The wind speeds will pulse to fresh to strong offshore of the northern coast of Hispaniola through the next several days. For additional information please visit http://www.hurricanes.gov/marine $$ MT