000 AXNT20 KNHC 181005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 605 AM EDT Wed Oct 18 2017 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 0915 UTC. ...TROPICAL WAVES... A tropical wave extends from 06N59W to 15N59W moving W at 10-15 kt. The wave coincides with shortwave 700 mb troughing between 56W-61W and a maximum in 850 mb relative vorticity along the wave axis near 10N. Scattered moderate convection is from 08N-13N between 52W-61W. A tropical wave extends from 08N66W to 17N66W moving W at 10-15 kt. The wave coincides with shortwave 700 mb troughing between 64W-68W and a maximum in 850 mb relative vorticity along the wave axis near 15N. Isolated moderate convection is from 11N-18N between 62W-69W. A tropical wave extends from 06N83W to 16N83W moving W at 10-15 kt. The wave coincides with subtle 700 mb troughing over the SW Caribbean Sea. Dry NE to E flow aloft is noted on water vapor imagery on the southeastern periphery of an upper level ridge anchored near 17N80W. Scattered moderate and isolated strong convection is from 06N-14N between 76W-85W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 07N12W to 07N20W. The Intertropical Convergence Zone axis extends from 07N20W to 09N26W to 06N38W to 07N54W. Scattered moderate convection is from 05N-12N between 22W-43W. ...DISCUSSION... GULF OF MEXICO... A stationary front extends from the southern Florida peninsula near 26N81W westward to 27N90W then curves SW to 23N94W to the coast of southern Mexico near 18N94W. The front is supported aloft by a middle to upper level trough progressing eastward over the offshore waters of the far northwestern SW North Atlc waters this morning. Most convection...scattered showers and isolated tstms...are occurring across eastern portions of the basin S of 28N E of 87W...including the southern Florida peninsula. Other isolated showers and tstms are occurring across the SW Gulf S of 22N between 91W-95W in the vicinity of the front. The front is expected to drift SE through the next couple of days and gradually become diffuse by Wednesday night. Fresh to strong N-NE winds will prevail through Wednesday night and then weaken slightly into moderate to occasional fresh through early Thursday. Surface ridging is expected to remain in place across the SE CONUS the remainder of the week. CARIBBEAN SEA... An upper level anticyclone is centered over the western Caribbean near 17N80W and is providing mostly dry air aloft between 70W- 80W. Scattered showers and strong tstms are occurring S of 14N W of 79W in association with a tropical wave along 83W. Widely scattered showers and isolated tstms are also N of 16N W of 84W. Farther east...another tropical wave along 66W is providing for widely scattered showers and tstms between 62W-67W...while a third tropical wave remains to the E of Windward Islands along 59W. The third wave carries more active convection that is expected to impact the Lesser Antilles Wednesday through early Thursday. Elsewhere...moderate to fresh trades prevail and are expected to persist through Wednesday...gradually increasing across the eastern and central Caribbean by Wednesday night as the pressure gradient strengthens. ...HISPANIOLA... A narrow upper level trough axis extends along 69W over the island between two upper level anticyclonic circulations...one centered near 18N64W and the other centered over the western Caribbean Sea near 17N80W. Most of the island is under fair skies this morning. Looking ahead...a tropical wave will skirt S of the island Wednesday night and bring a higher potential for shower and tstm activity through Thursday night. ATLANTIC OCEAN... A stationary front extends from 32N70W SW to the southern Florida peninsula near 26N80W and continues to slowly drift eastward. The front is supported aloft by a middle to upper level trough axis extending from over the offshore waters of the Carolinas southwestward to over the NE Gulf of Mexico waters. Scattered showers and isolated tstms are occurring primarily N of the front and W of 76W south of the front. A pre-frontal surface trough is analyzed from 25N71W to 32N65W and continues to provide focus for widely scattered showers and isolated tstms from 22N-32N between 59W-67W. The remainder of the central and eastern Atlc are under the influence of a surface ridge anchored by a 1029 mb high centered near 33N37W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN