000 AXNT20 KNHC 210002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 802 PM EDT TUE SEP 20 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 2315 UTC. ...SPECIAL FEATURES... The center of Tropical Storm Karl was located near 20.1N 55.2W at 20/2100 UTC moving westward, or 275 degrees at 12 knots. The estimated minimum central pressure is 1005 mb. The maximum sustained wind speeds are 35 knots with gusts to 45 knots. Scattered moderate isolated strong convection was noted within 180 nm of the center in the NE semicircle. Karl is expected to gradually intensify over the next several days. Please read the latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT2/WTNT32 KNHC and the Forecast/Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. Tropical Storm Lisa was located near 16.4N 31.0W at 20/2100 UTC. moving northwestward, or 315 degrees at 10 knots. The estimated minimum central pressure is 1004 mb. The maximum sustained winds have increased to 40 knots with gusts to 50 knots. Scattered moderate to strong convection was noted within 180 nm of the center of Lisa in the N and within 90 nm in the S semicircles. Please read the latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT3/WTNT33 KNHC and the Forecast/Advisory under the AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC for more details. ...TROPICAL WAVES... A Caribbean Sea tropical wave is along 73W/74W from 18N southward, moving westward 10 to 15 knots. Isolated moderate convection was noted over the Caribbean from 15N to 23N between 67W and 80W. More concentrated activity was located over Hispaniola. ...ITCZ/MONSOON TROUGH... The Monsoon Trough passes through coastal sections of Mauritania near 16N17W to near 13N20W, and is rather diffuse along 07N30W 07N40W to 08N45W. Scattered moderate convection was noted from 07N to 10N between 23W and 27W. Isolated moderate convection was noted from 05N to 07N between 32W and 41W. ...DISCUSSION... ...THE GULF OF MEXICO... An upper level cyclonic circulation center was located just to the west of the Isthmus of Tehuantepec of southern Mexico near 17N95W. Cyclonic wind flow covers the area from 20N southward between western Guatemala and 100W. An upper level shear axis was noted over the NW Gulf extending from southeastern Louisiana to near Tampico Mexico. Strong mid-to upper level subsidence was noted along and to the NW of the shear axis along the coast of Texas and Louisiana. Weak anticyclonic flow was noted over the remainder of the Gulf. At the surface...a weak 1014 mb low was centered near 27N88W and was in the process of dissipating. the low was located along a surface trough which extended from near Cedar Key Florida through the low to near 22N96W. Scattered showers and thunderstorms were noted over the Bay of Campeche and the Yucatan Peninsula. isolated thunderstorms have developed along the Texas coastal plain between Houston and Corpus Christi. ...THE CARIBBEAN SEA... A large elongated upper level cyclonic circulation covers most of the Caribbean Sea with the broad center extending from southeast Cuba to 15N66W. Upper level cyclonic wind flow spans the entire Caribbean Sea. Scattered moderate to strong convection was noted over interior portions of Cuba, Hispaniola and over orographically favored regions in central America. The monsoon trough is along 09N/10N from 74W beyond 86W, into the eastern Pacific Ocean. Scattered strong convection was noted from 10N to 12N between 78W and 81W. ...HISPANIOLA... An upper level cyclonic circulation center is just off the SE coast of Jamaica. Upper level SE wind flow is moving across Hispaniola. A surface trough is along 73W/74W, from 19N to 23N, cutting across the SE Bahamas and into the Windward Passage. A tropical wave also is along 73W/74W from 18N southward, moving westward 10 to 15 knots. ...THE ATLANTIC OCEAN... A cold front passes through 32N75W to 31N79W. A surface trough continues from 31N79W across north-central Florida to near Cedar Key. An upper level cyclonic circulation center is near 36N57W, to the north of the area. Cyclonic wind flow that is moving around this center reaches 32N. A surface trough is along 32N64W to 30N64W. An upper level cyclonic circulation center is near 23N62W. Cyclonic wind flow covers the area from 18N to 29N between 57W and 67W. Widely scattered moderate in the area of cyclonic wind flow from 21N northward. Tropical Storm Karl is about 310 nm to the ESE of this feature. Broad surface anticyclonic wind flow covers the Atlantic Ocean from 24N northward between Africa and 50W. For additional information please visit http://www.hurricanes.gov/marine $$ COBB