000 AXNT20 KNHC 090605 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 AM EDT FRI SEP 9 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. Based on 0000 UTC surface analysis and satellite imagery through 0545 UTC. ...TROPICAL WAVES... A tropical wave is in the central Atlantic extending from 05N to 19N with axis near 36W, moving W at 20 kt within the last 24 hours. There is a center of low pressure associated with the wave centered near 11N36W, which is forecast to move WNW to near 13N41W within the next 24 hours. The wave is in a region of mainly favorable to neutral deep layer wind shear and abundant moisture from the surface to 850 mb as shown by CIRA LPW imagery. That environment along with divergent flow aloft support scattered showers and tstms from 07N to 17N between 30W and 42W. Some gradual development of this system is possible during the next several days, and a tropical depression could form while this system moves WNW into the central Atlantic by early next week. A tropical wave is in the E Caribbean waters extending from 10N to 17N with axis near 67W, moving W at 15 kt within the last 24 hours. The wave is in a region of neutral to unfavorable deep layer wind shear and water vapor imagery continue to show strong dry air subsidence, which hinder shower activity at the time. A tropical wave is in the western Caribbean extending from 13N to 23N with axis near 87W, moving W at 15 kt within the last 24 hours. Abundant moisture in the wave environment, favorable deep layer wind shear and diffluence at the middle levels support isolated showers from 15N to 23N between 78W and 88W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 18N16W to 12N30W to 07N43W. The ITCZ begins near 07N43W and continues to 04N52W. Aside from the convection related to the tropical wave along 36W, scattered moderate convection is observed south of the Monsoon Trough from 06N to 12N E of 28W. ...DISCUSSION... ...GULF OF MEXICO... A broad surface ridge across the Atlantic extends WSW across the Florida Peninsula and covers the Gulf waters, thus providing ESE gentle flow. The exception to this is the Bay of Campeche where winds are from the NE due to a tropical wave that is expected to move across the Yucatan Peninsula later this morning. Mainly unfavorable deep layer wind shear and strong dry air subsidence across the entire basin continue to favor fair weather. The tropical wave will move across into the Bay of Campeche Friday night through Saturday with possible showers. Little changes expected elsewhere. ...CARIBBEAN SEA... The main feature in the basin continues to be a tropical wave that is moving across the NW Caribbean generating scattered to isolated showers over central and eastern Cuba and adjacent waters N of 15N. A second tropical wave is just S of Puerto Rico. However, no shower activity is associated with it. Please refer to the tropical waves section for details. In the SW basin, scattered to isolated showers are S of 12N. Fair weather and moderate trades dominate elsewhere. The tropical wave will move to the Yucatan Peninsula today. A surface trough will move WNW across the NE Caribbean Friday evening generating showers across Puerto Rico and adjacent waters. Shower activity associated with this trough will impact Hispaniola Saturday through Sunday. ...HISPANIOLA... Fair weather conditions prevail across the island supported by both unfavorable deep layer wind shear and strong dry air subsidence from aloft. A surface trough moving WNW around the periphery of the Atlantic surface ridge will approach the Island Saturday through Sunday. Showers are expected during the weekend associated with this area of low pressure. ...ATLANTIC OCEAN... Diffluent flow between an elongated upper low over the NW Atlantic and a broad upper anticyclone centered over the Straits of Florida support scattered to isolated heavy showers across the central Bahamas and the Great Bahama Bank. That shower activity is also associated with a surface trough that extends from 27N73W to 22N78W. Lastly, a surface low of 1014 mb in the deep tropics supports scattered showers and tstms from 16N to 20N between 54W and 60W. The remainder of the basin is dominated by a broad surface ridge. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS