000 AXNT20 KNHC 251806 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 PM EDT SUN SEP 25 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. ...SPECIAL FEATURES... Post-tropical cyclone Karl is centered near 39.9N 47.9W at 25/1500 UTC or about 552 nm south of Cape Race Newfoundland, moving NE at 43 kt. Estimated minimum central pressure is 986 mb. Maximum sustained winds are 60 kt with gusts to 75 kt. Numerous moderate and scattered strong convection is being sheared to the NE of the center from 40N to 43N between 45W and 48W. Please see the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. ...TROPICAL WAVES... A tropical wave in the east Tropical Atlantic extends from 06N37W to a 1010 mb surface low centered near 08N37W to 14N35W. The wave is moving W near 20 kt over the past 24 hours. This wave still coincides with a 700 mb trough noted in model guidance. The wave is the leading edge of a surge of deep moisture reaching all the way E to the African coast in TPW imagery. Scattered moderate and isolated strong convection is seen within 90 nm either side of a line from 09N41W to 14N37W. A tropical wave in the west-central Tropical Atlantic extends from 12N59W to 22N58W, moving W around 15 kt over the past 24 hours. The wave is still tracking with a 700 mb trough depicted in model guidance and a surge of moderate moisture as seen in TPW imagery. Isolated moderate convection is present in a small area on the S side of the wave from 12N to 14N between 60W and 62W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 13N16W to the 1010 mb low described above centered near 08N39W to 06N43W. The ITCZ extends from 06N39W to 07N50W. Aside from the convection related to the tropical wave and low along 35W, isolated moderate convection is present from 07N-12N between 20W-32W. ...DISCUSSION... GULF OF MEXICO... An upper-level low remains centered over the Florida Panhandle near 31N87W. Divergent upper-level winds on the SW side of the low are triggering moderate convection E of Texas and S of Louisiana from 26N to 29N between 90W and 97W. A surface trough reaches over the Bay of Campeche from 19N94W to 22N94W. A surface ridge N of the United States gulf coast will generally maintain light to moderate E to SE winds across the basin through Monday. A weak cold front will reach the NW Gulf by late Monday, then stall and dissipate by Tuesday. CARIBBEAN SEA... An upper-level low is centered just SE of Puerto Rico near17N65W. Convergent NW to W flow aloft on the W side of the low is suppressing convection over most of the basin. Divergent upper-level winds are supporting cloudiness and scattered moderate convection across the western Caribbean W of 85W over Belize and the Yucatan Peninsula. The Monsoon Trough passes over Costa Rica and Panama. Low-level convergence near the trough is generating scattered moderate and isolated strong convection over the Caribbean waters S of 12N. Satellite-derived wind data show moderate to fresh trades across the basin except south of 15N between 68W-75W where fresh to strong winds prevail. Little change is expected within the next 24 hours. A tropical wave will approach from the E with isolated showers affecting the Lesser Antilles Sunday night. ...HISPANIOLA... Only isolated showers are observed across the island at this time. Upper-level convergence associated with an upper-level low centered SE of Puerto Rico is the culprit. However, the upper- level low will provide enough instability to enhance afternoon and evening showers and thunderstorms through Tuesday. ATLANTIC OCEAN... Karl has become post-tropical over the N Atlc. Two tropical waves are moving across the basin. Please refer to the special features and tropical waves sections for details. To the E of this activity; a weak 1017 surface high is located NE of the Bahamas near 27N74W. The remnants of T.D Lisa were analyzed as a 1011 mb low centered near 28N42W. Isolated moderate convection associated with the monsoon trough spreads from 04N to 13N between 19W and 35W. The remainder of the basin remains under the influence of a surface ridge anchored by a 1026 mb high centered near 38N21W and a 1025mb high centered near 32N28W. Expect for Karl to continue moving NE and become a hurricane by Sunday. A cold front will drop S into the central Atlantic on Monday, accompanied by convection. The front will become stationary by Tuesday. For additional information please visit http://www.hurricanes.gov/marine $$ CAM