000 AXNT20 KNHC 301031 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 631 AM 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 0600 UTC surface analysis and satellite imagery through 1030 UTC. ...SPECIAL FEATURES... Gale-force northerly winds will continue overnight over the areas of AGADIR, TARFAYA, and CANARIAS. The outlook for the 24 hours that follow the forecast that is valid until 01/0600 UTC, consists of the threat of severe northerly gale winds over AGADIR, TARFAYA, MADEIRA, 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 far eastern Atlantic tropical wave has its axis extending from 19N22W to a 1012 mb surface low near 10N22W to 01N20W, moving westward at 10-15 kt. This wave remains embedded within an envelope of southwesterly monsoonal moisture that observed in satellite imagery just offshore the coast of Africa. Isolated showers are observed in the vicinity of the low. A surface trough is from 21N35W to 17N33W. This trough is part of the energy of the northern vorticity center that accompanies this tropical wave. No significant convection is noted with this feature. A central Atlantic tropical wave has its axis from 16N48W to 03N49W, moving westward at about 15 knots. A plume of Saharan African dust is observed to the north of this wave. This appears to be suppressing deep convection from developing along and near the wave axis at this time. An area of isolated moderate convection is observed from 09N-12N between 48W-52W. This wave is forecast to enter the eastern Caribbean by Saturday. A tropical wave is moving through the eastern Caribbean with its axis extending from 20N69W to 07N71W, moving westward at about 10-15 knots. This wave maintains a good track history going back several days, and continues to mark the leading edge of an area of unsettled weather. Some of this activity is capable of producing gusty winds. At this time, isolated showers extend east of 74W. The wave will continue moving west across Caribbean enhancing convection over the Mona Passage and Hispaniola through the weekend. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from 19N16W to 15N20W. The Intertropical Convergence Zone then extends from 08N26W to 06N47W, then resumes from 07N51W to 06N57W. Aside from the convection related to the tropical waves, isolated showers are observed within 50 nm on either side of the ITCZ. ...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 trough extends over the northwest Gulf with axis along 96W and north of 24N while an anticyclonic circulation is centered over the eastern Gulf near 26N85W. At this time, fair weather prevails across the Gulf waters as a surface ridge extends across the area from the northeast. The western periphery of this ridge is controlling the wind regime keeping mainly moderate to fresh southeast to south winds through the weekend, except for lighter winds in the northeast Gulf through Saturday. Little change in the synoptic pattern is expected through the next 24-48 hours. CARIBBEAN SEA... The main feature presently in the basin is a tropical wave that is currently located over the eastern 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 across the basin, except in the east-central Caribbean near the wave's axis where moderate to strong winds prevail between 65W-72W. Convection is expected to continue across the basin as the wave moves west. 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 as subsidence aloft and resultant dry air dominates. Moisture associated with a tropical wave is moving across the Mona Passage, and is approaching the eastern portion of the island. Expect for this moisture to bring increasing shower and thunderstorm activity across the area today. Gusty winds can be expected with some of this activity. ATLANTIC OCEAN... Two tropical waves were analyzed across the basin. Refer to the section above for details. A weakening stationary front extends along 30N between 69W-74W with no significant convection. A surface trough extends from 28N58W to 24N61W without convection. The remainder of the basin is under the influence of a surface ridge, anchored by a 1033 mb high centered near 38N25W. 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 the next 24-48 hours. For additional information please visit http://www.hurricanes.gov/marine $$ ERA