000 AXNT20 KNHC 181627 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1226 PM 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 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...TROPICAL WAVES... A tropical wave is in the central Atlc with axis extending from 13N27W to 06N29W, moving W at 10 kt. The wave came off the coast of Africa a couple of days ago very weak, however disorganized convection has augmented and latest scatterometer data show fresh to strong winds associated with it. Satellite derived data indicate the wave is in a strong vertical wind shear environment. However, shallow moisture and middle to upper level diffluence support scattered moderate convection and isolated tstms from 08N-13N between 22W-31W. A tropical wave is in the E Caribbean with axis extending from 17N61W to 07N61W, moving W at 20 kt within the last 24 hours. The wave is in a region of moderate to strong vertical wind shear. However, shallow moisture in the E basin along with upper level diffluent flow support scattered heavy showers and tstms from 09N-15N between 60W-65W. A tropical wave is in the E Caribbean with axis extending from 18N66W to inland Venezuela near 08N66W, moving W at 10-15 kt. The wave is in a region of moderate to strong vertical wind shear. The wave is underneath an upper level low that supports scattered heavy showers and isolated tstms from 14N to 18.5N between 65W-68W, including eastern Puerto Rico. A tropical wave is moving across Central America with axis extending from 16N83W across Nicaragua to 06N83W, moving W at 15 kt. The wave is in a region of low to moderate vertical wind shear and CIRA LPW is showing abundant moisture associated with it at the lower levels. This environment is supporting numerous heavy showers and scattered tstms from 08N-14N between 80W-86W, including Nicaragua. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 08N13W to 07N19W. The Intertropical Convergence Zone axis extends from 07N19W to 09N27W, then resumes near 08N32W continuing along to 06N47W to 08N57W. Aside convection associated with the tropical wave in the central Atlc, scattered moderate convection is from 07N-14N between 52W-60W. ...DISCUSSION... GULF OF MEXICO... A stationary front extends from the southern Florida peninsula near 26N81W westward to 25N90W then curves SW to the Bay of Campeche near 18N94W. The front is supported aloft by a middle to upper level trough progressing eastward over the E CONUS seaboard and SW N Atlc waters. Scattered moderate convection is within 240 nm S of the boundary between 80W-86W and in the eastern Bay of Campeche. Isolated showers are within 210 nm N of the boundary E of 87W. High pressure builds behind the front supporting northerly fresh to strong winds in the western half Bay of Campeche and in the NE Gulf. The front is expected to weaken today and gradually become diffuse by early Thu. Fresh to strong winds will prevail through tonight and then decrease into moderate to occasional fresh through the end of the week. CARIBBEAN SEA... A middle to upper level high covers the western half of the basin proving stability and fair weather, except S of 18N W of 80W where a tropical weather support numerous to scattered heavy showers and tstms. An upper level low covers a great portion of the eastern half of the Caribbean supporting scattered heavy showers in the vicinity of two tropical waves, one along 67W and another near 62W. See tropical waves section for further details. Convection associated with these waves is forecast to impact the Lesser Antilles, Puerto Rico and Hispaniola today through early Thursday. Otherwise, moderate to fresh trades across the central and eastern basin are expected to gradually increase through the end of the week as high pressure N of the are strengthens. ...HISPANIOLA... Dry air subsidence from aloft support mainly fair weather across the Island. However, isolated showers and tstms are starting to enter the Dominican Republic and adjacent waters as a tropical wave, currently moving across Puerto Rico, continue to move west. Scattered heavy showers and tstms associated with the wave are forecast to affect the Island this evening through Thursday afternoon. ATLANTIC OCEAN... A stationary front extends from 30N72W SW to the southern Florida peninsula near 25N80W, which is expected to meander while gradually dissipating through early Thursday. The front is supported aloft by a middle to upper level trough. Isolated showers are occurring W if the front and within 75 nm E of it. Farther east, an upper level low support a pre-frontal surface trough from 30N65W to 25N70W as well as scattered showers from 22N-32N between 60W-70W. The remainder of the central and eastern Atlc are under the influence of a surface ridge anchored by a 1030 mb high centered near 32N35W. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos