000 AXNT20 KNHC 232343 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 743 PM EDT Mon Oct 23 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... A cold front is currently analyzed across the Gulf waters from the Florida Big Bend near 30N84W SW to 23N90W WSW to the Mexico coast near Tampico. A surface trough boundary extends southward from the front near 21N96W to the Mexico coast near 18N94W. Near gale to gale force NW winds are occurring S of 21N W of 95W to the west of the surface trough axis. The gale force winds are expected to be short lived as the pressure gradient weakens during the overnight hours. The wind field will once again increase into near gale to gale force conditions Tuesday afternoon as the cold front pushes through the SW Gulf waters. Please see the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...TROPICAL WAVES... A tropical wave extends from 06N57W to 17N57W moving W at 10-15 kt. The wave coincides with broad 700 mb troughing between 50W- 60W and a maximum in 850 mb relative vorticity along the wave axis near 10N. Scattered moderate convection is from 07N-18N between 52W-62W and continues to be enhanced by a middle to upper level trough with axis extending from 21N63W southward to a broad base over northeastern South America. A tropical wave extends from 10N91W to 19N93W moving W at 10-15 kt. The wave coincides with 700 mb troughing between 87W-94W and a maximum in 850 mb relative vorticity along the wave axis near 17N. Widely scattered moderate convection is from 13N-20N between 88W-96W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 14N17W to 10N21W. The Intertropical Convergence Zone axis extends from 10N21W to 07N28W to 06N45W. Scattered moderate convection is from 05N-11N between 22W-48W. ...DISCUSSION... GULF OF MEXICO... A vigorous middle to upper level trough is progressing northeastward over the Tennessee and Ohio River valleys this evening supporting a cold front extending from the Florida Big Bend region SW to 23N90W to the Mexico coast near Tampico. Scattered showers and isolated tstms are occurring within 150 nm east of the front and across interior portions of northern and central Florida. In addition...a surface trough extends from the front near 21N96W to 18N94W inducing the near gale to gale force NW winds mentioned above in the special features section. Widely scattered showers and isolated tstms are occurring generally S of 22N between 88W-97W. Otherwise...a surface ridge anchored by a 1021 mb high centered across SE Texas near 30N96W is providing moderate to fresh N to NE winds west of the front. This ridge will continue to gradually build southeastward through early Tuesday with a secondary reinforcing cold front...currently across Oklahoma and portions of western Texas...expected to surge SE Tuesday and Tuesday night increasing northerly winds across much of the basin into Wednesday. Strong high pressure in wake of the front will build in across New Mexico and Texas...and into the western Gulf Wednesday night into Thursday. CARIBBEAN SEA... An upper level anticyclonic circulation is centered over the western Caribbean near 15N82W and continues to provide an overall divergent environment aloft promoting scattered to numerous showers and scattered strong tstms from 11N-20N between 78W- 88W...including inland portions of Central America. At the surface...this activity focused on maximized moisture convergence near a surface trough analyzed from 12N82W to 18N86W. Farther south...the addition of the monsoon trough axis along 11N between northern Colombia and Costa Rica is also providing focus for scattered showers and tstms S of 11N between 71W-86W. Finally...a tropical wave is approaching the Lesser Antilles currently noted along 58W. Scattered showers and tstms are occurring from 07N-18N between 52W-62W and this area is expected to continue moving westward. Enhancing portions of this convection is an upper level low centered to the N-NW near 22N63W. Otherwise...moderate to fresh trades prevail across the basin this evening. ...HISPANIOLA... Dry air aloft within northerly flow will support fair weather across the island through Tuesday. Moderate to fresh trades are expected through Wednesday. ATLANTIC OCEAN... Much of the SW North Atlc is under the influence of a surface ridge anchored by 1032 mb high centered near 41N61W. Within the western periphery of this ridging...upper level divergence is maximized with scattered showers and isolated tstms occurring N of 27N W of 75W as a cold front approaches the eastern seaboard this evening into early Tuesday. Otherwise...within the southern periphery of the ridge...moderate to fresh E-SE winds are occurring generally W of 62W. Farther east...an upper level low is centered near 22N63W. The upper level low supports a surface trough extending from 20N58W to 26N58W with scattered showers and tstms occurring from 22N-29N between 52W-63W. This area lies SW of a cold front extending into the discussion area near 32N38W extending SW to 28N48W then stationary to N of the surface troughing near 28N57W. Widely scattered showers and isolated tstms are possible within 120 nm either side of the frontal boundary. Finally...another middle to upper level shortwave trough is noted on water vapor imagery in the vicinity of 28N28W. This feature supports another weak surface trough extending from 23N28W to 29N21W and provides focus for scattered showers and isolated tstms occurring from 19N-31N between 23W-30W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN