000 AXNT20 KNHC 081734 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 134 PM EDT Sat Jul 8 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 1730 UTC. ...TROPICAL WAVES... A tropical wave has been introduced to this analysis. This wave extends its axis along the African coast from 14N15W to 06N14W. Abundant moisture prevails within this wave, as noted in TPW imagery. Another tropical wave is over the far eastern Atlantic with axis extending from 18N24W to 07N29W, moving westward around 10 kt. Atmospheric moisture continues to increase along and to the east of the wave. The Meteosat 9 imagery along with depicts an extensive area of African Saharan dry air and dust to its west. Convection remains limited to across the far southern extent of the wave's axis, where it intersects the monsoon trough. A tropical wave, remnants of Tropical Depression Four, is over the central Atlantic with its axis extending from 23N55W to 11N57W, moving west-northwest around 15-20 kt. The atmospheric environment surrounding the wave is very moist as observed in TPW loop series. At this time, scattered moderate convection prevails north of 18N between 52W-62W. The wave is forecast to pass to the northeast of the Leeward Islands by Sunday evening attendant with possible brief gusty winds and squalls over portions of the northeast Caribbean. It is then forecast to approach the SE Bahamas on Monday. A tropical wave is over the Caribbean Sea with axis extending from 20N70W to 10N71W, moving westward at around 5-10 kt. The latest water vapor imagery shows subsidence and associated dry air over and around the wave's environment, which is inhibiting convection at this time. A tropical wave extends from the Bay of Campeche and southeastern Mexico to the EPAC. The axis is from 23N94W to 05N96W, moving westward near 10-15 kt. The wave is embedded in a very moist and unstable atmospheric environment. Scattered moderate convection prevails over the Gulf of Mexico from 19N-25N between 93W-98W. An area of scattered moderate convection is also noted over the Pacific waters from 05N-14N between 93W-99W. The wave is forecast to move across the remainder of the SW Gulf through early this evening, then move inland Mexico tonight. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from 14N17W to 07N27W to 07N38W. The Intertropical Convergence Zone extends from 07N38W to 02N51W. Aside from the convection related to the tropical waves over the far eastern Atlantic, scattered moderate convection is along and within 50 nm on either side of the Monsoon Trough between 22W-36W. ...DISCUSSION... GULF OF MEXICO... A tropical wave is over the Bay of Campeche and extends southward to southeastern Mexico. See the section above for details. A 1019 mb high is centered over the eastern Gulf near 27N84W. It is producing light to gentle anticyclonic winds across the eastern part of the Gulf mainly north of 26N. Water vapor imagery indicates that an upper-level low is near 25N84W, and is trending to shift southward. Ample present moisture and instability to its east and southeast is bringing scattered showers and isolated thunderstorms to the E Gulf waters and Florida Peninsula. Expect for a similar weather pattern to continue through the next 24 hours. CARIBBEAN SEA... A tropical wave axis extends along 71W. See the section above for details. Scattered moderate convection is over the southwest Caribbean south of 14N and west of 79W in the vicinity of the monsoon trough that currently extends over Costa Rica and Panama. This activity will persist through the weekend. Fair weather prevails elsewhere. The pressure gradient across the area supports gentle to moderate trades across the Caribbean, except for stronger winds in the moderate to fresh range along the coast of Colombia. These conditions will continue into early next week. ...HISPANIOLA... Fair weather is observed across the island at this time. A tropical wave extends along 71W. As the wave continues moving west through the area, isolated showers could develop through the next 24 hours. ATLANTIC OCEAN... The remnants of Tropical Depression Four, now a tropical wave, is over the central tropical Atlantic while 2 tropical waves are moving over the far eastern tropical Atlantic. See the section above for details on these features. Elsewhere, a broad surface high extends across the area anchored by a stationary 1031 mb center located near 35N40W. The ridge will change little through Sunday, then begin to lift back to the north on Monday. Water vapor imagery shows an elongated upper-level low (TUTT) centered near 29N55W lifting northward. This low is reflected at the surface as a trough that extends from 31N54W to 28N55W. Isolated showers are along the trough. An extensive area of African Saharan dust is situated over the eastern and central Atlantic E of 53W, and is gradually migrating westward. For additional information please visit http://www.hurricanes.gov/marine $$ ERA