000 AXNT20 KNHC 180505 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 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 0000 UTC surface analysis and satellite imagery through 0415 UTC. ...TROPICAL WAVES... A tropical wave extends from 06N58W to 14N57W 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 and isolated strong convection is from 09N-14N between 52W-61W. A tropical wave extends from 07N65W to 15N65W moving W at 10-15 kt. The wave coincides with shortwave 700 mb troughing between 63W-67W and a maximum in 850 mb relative vorticity along the wave axis near 14N. Isolated moderate convection is from 13N-16N between 63W-68W. A tropical wave extends from 04N82W to 14N83W 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 18N81W. Widely scattered moderate convection is from 08N-16N between 80W-86W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 10N14W to 06N20W. The Intertropical Convergence Zone axis extends from 06N20W to 07N27W to 06N33W to 08N39W to 05N52W. Widely scattered moderate convection is from 07N-12N between 21W-29W. Scattered moderate convection is from 05N-10N between 32W-42W. ...DISCUSSION... GULF OF MEXICO... A stationary front extends from Lake Okeechobee westward to 27N88W then curves SW to 24N93W to the coast of southern Mexico near 18N94W. The front is supported aloft by a middle to upper level trough progressing eastward over the NE Gulf waters and northern Florida this evening. Most convection...scattered showers and isolated tstms...are occurring across eastern portions of the basin S of 28N E of 87W...including the central and southern Florida peninsula. Other isolated showers and tstms are occurring across the SW Gulf S of 21N between 93W-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 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 18N81W and is providing mostly dry air aloft between 69W- 80W. Widely scattered showers and isolated tstms are occurring S of 18N W of 80W in association with a tropical wave along 83W...and N of 18N W of 85W in association with a surface trough offshore of the Yucatan peninsula along 87W. Farther east... another tropical wave along 66W is providing for isolated showers and tstms E of 68W...while a third tropical wave remains to the E of Windward Islands along 57W. 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. ...HISPANIOLA... A narrow upper level trough axis extends along 69W over the island between two upper level anticyclonic circulations...one centered near 21N63W and the other centered over the western Caribbean Sea near 18N81W. Most of the island is under fair skies and tranquil weather for the overnight period...but looking ahead...a tropical wave will skirt S of the island Wednesday into Wednesday night and bring a higher potential for shower and tstm activity into Thursday. ATLANTIC OCEAN... A stationary front extends from 32N70W SW to the Florida peninsula near 27N80W 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 77W south of the front. A pre-frontal surface trough is analyzed from 23N71W to 32N66W and continues to provide focus for widely scattered showers and isolated tstms from 22N-32N between 63W-70W. The remainder of the central and eastern Atlc are under the influence of a surface ridge anchored by a 1031 mb high centered near 33N37W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN