000 AXNT20 KNHC 301729 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 129 PM EDT Fri Jun 30 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 1700 UTC. ...SPECIAL FEATURES... Gale-force north to northeast winds will continue today over the areas of AGADIR, TARFAYA, and CANARIAS. The outlook for the 24 hours that follow the forecast that is valid until 01/1200 UTC, consists of the threat of severe northerly gale winds over AGADIR, TARFAYA, and CANARIAS. Please refer to the METEO-FRANCE High Seas Forecast listed on the website: WWW.METEOFRANCE.COM/PREVISIONS- METEO-MARINE/BULLETIN/GRANDLARGE/METAREA2. ...TROPICAL WAVES... A tropical wave is moving westward from the African coast around 15 kt. The axis of the wave stretches NW from Sierra Leone at 05N09W to Senegal at 15N17W. TPW satellite imagery shows the wave is embedded in deep layer moisture. Scattered moderate and isolated strong convection is seen from 03N to 09N between 09W and 20W. A eastern Atlantic tropical wave has an axis extending from 03N27W to 12N25W, moving westward around 15 kt. This wave remains embedded within an envelope of deep layer moisture. Initial model fields indicate modest troughing coincides with this wave at 700 mb. Scattered moderate convection is present from 05N to 12N between 23W and 28W. A central Atlantic tropical wave has an axis reaching from 04N52W to 14N15W, moving westward around 15 knots. TPW satellite imagery shows this wave is embedded in an area of deep layer moisture. Drier Saharan air is found west of the wave over the eastern Caribbean and east of the wave in the vicinity of 40W. Initial model fields indicate subtle troughing coincides with this wave at 700 mb. This wave is forecast to enter the eastern Caribbean by Saturday. Scattered moderate and isolated strong convection is found within 120 nm either side of a line from 08N54W to 12N51W. A tropical wave entering the central Caribbean has an axis extending from 03N71W to 16N70W, moving westward around 10 knots. Initial model fields indicate well defined troughing coincides with this wave at 700 mb.This wave has produced vigorous convection during the past several days, but the areal extent and intensity of associated convection has decreased during the past 12 hours. The wave will continue moving west across the Caribbean and could produce deep convection over the Mona Passage and Hispaniola through Saturday. Scattered moderate and isolated strong convection is present from 16N to 18N between 65W and 69W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from Senegal on the African coast at 13N17W to 10N20W to 09N24W. The Intertropical Convergence Zone continues from 09N24W to 04N40W to 05N46W, then resumes from 08N52W to 07N57W. Aside from the convection associated with tropical waves, no significant convection is attributable to the ITCZ or Monsoon Trough. ...DISCUSSION... GULF OF MEXICO... A mid to upper-level trough is evident on water vapor imagery from the upper Texas coast to the Bay of Campeche. An upper-level low is embedded in the trough just to the southeast of Brownsville, TX near 27N86W. An anticyclonic circulation centered over the northeastern Gulf near 26N85W dominates the remainder of the Gulf. At this time, fair weather prevails across the Gulf waters except in the vicinity of the upper-level trough over the Bay of Campeche cloudiness and isolated showers are observed. Ridging extending SW from the NE Gulf to the Bay of campeche is generating light to moderate SE winds over the eastern Gulf and moderate to fresh SE to S winds over the western Gulf. Little change in the current synoptic pattern is expected during the next 24-48 hours. CARIBBEAN SEA... The main feature presently in the basin is a tropical wave that is currently located over the central Caribbean. This feature is discussed in the section above. Aside from the convection related to the wave, generally fair weather prevails elsewhere. Scatterometer data depicts moderate trades prevail across the basin, except over the Caribbean in the vicinity of the tropical wave to the south of Puerto Rico and Hispaniola where moderate to strong winds prevail between 64W and 72W. Convection is expected to continue in the vicinity of the wave as it moves west. However, an upper-level low to the west of the wave has begun to shear the wave and inhibit convection. The wave will likely continue to produce fresh to strong winds during the next 24 hours. ...HISPANIOLA... The relatively dry weather that prevailed across the island is ending as a tropical wave moves through. Convection associated with the tropical wave is moving W from the Mona Passage and Puerto Rico over the Dominican Republic. Expect as deep layer moisture increases over the island that shower and thunderstorm activity will increase across the area today. Gusty winds can be expected in and near showers and thunderstorms. ATLANTIC OCEAN... Two tropical waves were analyzed over the basin. Another tropical wave was emerging over the far eastern Atlantic from Africa. Refer to the tropical waves section above for details. A weak surface trough located between the Bahamas and Bermuda curves SE from 30N76W to 29N72W. No significant convection is associated with the trough. Weak surface troughs extend from 15N34W to 21N37W, from 24N48W to 29N47W and from 23N62W to 29N61W. None of these trough possessed significant convection. The remainder of the basin remains under the influence of a broad surface ridge, anchored by a 1035 mb high centered just NE of the Azores near 41N26W. Generally moderate trades will continue around the southern periphery of this high over the Atlantic from 10N and 25N between 30W and 60W through the next 24-48 hours. For additional information please visit http://www.hurricanes.gov/marine $$ McElroy