000 AXNT20 KNHC 182358 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 758 PM EDT SUN SEP 18 2016 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 2345 UTC. ...SPECIAL FEATURES... Tropical Depression Julia is centered near 32.3N 78.0W at 18/2100 UTC or about 96 nm south-southeast of Myrtle Beach, South Carolina moving west at 6 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Scattered showers are from 28N-31N between 74W-80W. Please see the latest NHC Forecast/Advisory under the AWIPS/WMO headers MIATCMAT1/WTNT21KNHC for more details. Tropical Storm Karl is centered near 18.3N 45.0W at 18/2100 UTC or about 965 nm east of the Leeward Islands moving west at 13 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Scattered showers are from 18N-21N 41W-46W. Please see the latest Forecast/Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. A tropical wave is in the E Atlantic near the Cabo Verde Islands with axis extending from 18N23W to to 1 1007 mb low near 13N23W to 07N23W. These features are moving west at 5 to 10 kt over the past 24 hours. Scattered moderate convection is from 07N-16N and east of 28W. Environmental conditions are expected to be conducive for development, and a tropical depression is likely to form by mid-week. Regardless of development, locally heavy rains and gusty winds are possible in the Cabo Verde Islands during the next couple of days. This system has a medium chance of tropical formation within the next 48 hours. Please see the Tropical Weather Outlook under AWIPS/WMO Headers MIATWOAT/ABNT20 KNHC for more details. ...TROPICAL WAVES... A tropical wave is moving across the E Caribbean waters with axis extending from 21N63W to 10N63W, moving west at 15 kt over the past 24 hours. The wave is embedded in an area of light to moderate moisture as noted in TPW imagery. Isolated showers prevail in the vicinity of the wave mostly enhanced by an upper- level low currently centered south of Puerto Rico near 14N67W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the Tropical Atlantic near 17N16W then through the 1007 mb low associated with the wave in the Special Features section above, continuing to 11N36W. For convection information, please refer the tropical wave description in the Special Features section above. ...DISCUSSION... ...GULF OF MEXICO... A surface ridge extends across the basin anchored by a 1017 mg high centered 27N86W. An upper-level shortwave trough is reflected at the surface extending from 29N95W to 29N91W. Scattered moderate convection prevails north of 26N between 88W-92W. An upper-level low is centered south of the Yucatan Peninsula enhancing scattered convection across this area and reaching the Yucatan channel. Scatterometer data depicts light to gentle easterly winds across the basin. Expect a similar weather pattern through the next 24 hours. ...CARIBBEAN SEA... A tropical wave extends across the eastern Caribbean. Please refer to the section above for details. An upper-level low is centered south of the Yucatan Peninsula enhancing convection across that area and the western Caribbean waters mainly west of 84W. To the east; another upper-level low is centered near 13N67W and is reflected at the surface as a trough that extends from 21N66W to 14N67W. Isolated showers are affecting the eastern portion of the basin between 64W-70W. Scatterometer data depicts moderate to fresh trades across the basin except over the waters north of Colombia mainly south of 14N between 67W-75W where fresh to strong winds are depicted in scatterometer data. Expect for the upper-level lows to continue moving west within the next 24 hours with convection over the far western waters and east Caribbean mainly east of 70W. ...HISPANIOLA... Isolated showers are observed across the southern portion of the island at this time. An upper-level low and associated surface trough currently over Puerto Rico will move west to over the Dominican Republic by early Monday enhancing convection. A tropical wave will merge with this trough by Tuesday and will move over the island with more convection. ...ATLANTIC OCEAN... Primary features of concern in the forecast waters are Tropical Storms Karl in the central Atlantic and a tropical wave currently near the Cape Verde Islands. Please refer to the Special Features and Tropical Waves sections above for details. In the western Atlantic; scattered showers associated with Tropical Depression Julia are from 28N-31N between 74W-80W. Farther east; a surface trough extends from 25N68W to 32N57W with scattered showers and thunderstorms north of 28N between 56W-65W. The east Atlantic, the northeastern Atlantic waters north of Tropical Storm Karl are dominated by a surface ridge anchored by a 1034 mb high near 43N33W. For additional information please visit http://www.hurricanes.gov/marine $$ ERA