000 AXNT20 KNHC 290548 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 148 AM EDT Thu Jun 29 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 0530 UTC. ...SPECIAL FEATURES... Northerly winds will increase to gale-force tonight in AGADIR AND TARFAYA through 30/0000 UTC. The outlook for the 24 hours that follow the forecast that is valid until 01/0000 UTC, consists of the threat of severe northerly gale winds over AGADIR and TARFAYA. Gale-force winds are also expected over eastern MADERIA 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 extends across the coast of Africa from 20N17W to 07N11W. This wave was introduced after analyzing Hovmoller diagrams, satellite imagery, and model diagnostics. It is moving westward at 10-15 kt. The wave is embedded within a rather large envelope of deep moisture as seen in the latest satellite animation. Scattered showers and thunderstorms are observed south of 12N between 15W- 20W. A tropical wave over the central Atlantic has its axis extending from 14N38W to near 00N39W, moving westward at about 10-15 kt. Satellite imagery and TPW data indicate that moisture around the wave is not as deep as 24 hours ago due to a large area of Saharan dust that intruded from the north towards the wave. The last visible imagery showed elongated cyclonic turning of the low clouds around the vicinity of the wave. No significant convection is present at this time. A tropical wave is moving across the Lesser Antilles with its axis extending 16N61W to 06N62W, moving west at about 15 kt during the past 24 hours. This wave continues to be easily identifiable on satellite imagery as having the typical configuration of those waves observed later during the season. It is detected in the model fields, and is supported by the latest diagnostic model analysis. This wave is accompanied by scattered moderate convection within 100 nm to its east from 06N-12N between 62W-66W, and lighter activity extending along the wave's axis affecting the Windward Islands. Some of this activity may most likely be attendant by strong gusty winds. The wave is forecast to continue moving west across the eastern Caribbean tonight through Friday. Expect increasing showers and thunderstorms with gusty winds to move across these waters. A tropical wave over the western Caribbean has its axis along 87W south of 21N, moving westward at about 10 kt. The axis of this wave continues to mark the leading edge of a surge of deep tropical moisture. Scattered moderate convection remains inland affecting portions of Honduras and Nicaragua. Some of this convection may contain locally heavy rainfall. The shower and thunderstorm activity approaching those same countries from offshore may bring gusty winds and locally heavy rainfall tonight through the afternoon hours. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the coast of Africa near 08N13W to 07N18W. The Intertropical Convergence Zone then extends from 07N18W to 10N30W to 06N39W, then resumes west of a tropical wave near 06N41W to 04N51W. Aside from the convection related to the tropical wave along the African coast discussed above, no significant convection is observed at this time. ...DISCUSSION... ...GULF OF MEXICO... A mid to upper-level trough is evident on water vapor imagery to be just inland the Texas and southwest Louisiana coasts. An upper-level low has developed over the north-central Gulf supporting a cluster of moderate convection from 26N-30N between 88W-91W. To the east, a stationary boundary extends northward from inland Louisiana to just along the Florida panhandle coastline. Isolated showers are expected along the frontal boundary. The surface analysis reveals a weak pressure pattern present over the remainder of the basin. With little changes to the present synoptic pattern forecast through Friday, the convection described over the north-central Gulf is expected to continue through at least the next 24 hours. ...CARIBBEAN SEA... The main feature presently in the basin is a strong tropical wave that is currently entering the southeastern Caribbean. Another tropical wave over the western Caribbean. These features are discussed in the section above. Aside from the convection related to these features, generally fair weather prevails elsewhere. Scatterometer data depicts moderate to fresh trades across the basin, except in the south-central Caribbean south of 15N between 72W-76W where a stronger pressure gradient present there is supporting strong northeast to east winds. Little change is expected with these winds through Friday. The tropical wave entering the southeastern Caribbean will be the main feature during the next 48 hours. Isolated showers and abundant cloudiness are noted east of 70W. The strongest convection remains over land at this time affecting portions of Venezuela. Convection is expected to develop as the wave continues moving west across the eastern Caribbean through the day. The impacts of this wave as related to marine interests will be mainly highlighted in the Offshore Waters Forecast and High Seas Forecast products. ...HISPANIOLA... Fair weather prevails across the island at this time. Guidance suggests that little change is expected in the present weather pattern through the next 24 hours, then increasing moisture along with scattered showers and thunderstorms are expected on Friday as a strong tropical wave approaches from the southeast. ...ATLANTIC OCEAN... Two tropical waves were analyzed across the basin. Refer to the section above for details. A stationary front extends across the west Atlantic from 31N70W to 29N81W. A pre-frontal trough is located from 30N71W to 26N78W. Isolated showers are expected along these boundaries. To the east, an upper-level low is reflected at the surface as a trough that extends from 30N58W to 22N60W. The remainder of the basin is under the influence of a surface ridge, anchored by a stationary 1033 mb high centered near 39N31W. The wind flow pattern around the southern periphery of this high pressure will continue to transport Saharan African dust westward to the the central Atlantic through Friday. 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