000 AXNT20 KNHC 141735 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 135 PM EDT Wed Jun 14 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 1715 UTC. ...TROPICAL WAVES... A strong tropical wave is over the far eastern Atlantic Ocean producing a large area of showers and thunderstorms well south of the Cabo Verde Islands. Its axis extends from 10N23W to a 1012 mb low pressure located near 05N24W to 02N24W. Development, if any, of this system is expected to be slow to occur over the next several days while the wave moves westward at 15 to 20 kt over the tropical Atlantic. A tropical wave extends from 14N34W to 06N35W moving westward at 15-20 kt. The wave remains embedded within an area of deep-layer moisture as depicted on the TPW product. The wave also coincides with an inverted trough at 700 mb. Visible satellite imagery indicates some inverted-V pattern in association with this feature. Scattered showers are from 08N to 10N between 35W and 38W. A tropical wave is over the far eastern Caribbean and extends from Barbuda and Antigua to the coast of Venezuela near 10N62W. The wave is producing locally heavy showers and some areas of rain, mainly over the Windward Islands and regional waters. The wave is very well depicted in the moisture product and will continue to affect the Windward Islands tonight into Thurssay. Another tropical wave is over the central Caribbean with axis from 18N76W to 09N76W moving westward at 10 kt. This wave is associated with weak 700 mb inverted trough. TPW imagery shows a surge of moistened air in association with this wave. An area of showers and thunderstorms is near the northern end of the wave axis affecting most of Jamaica and surrounding coastal waters. ...MONSOON TROUGH/ITCZ... The Monsoon Trough extends from the coast of west Africa near 11N15W to 05N22W, then resumes west of a tropical wave at 05N25W to 08N34W. The ITCZ extends from 08N37W to 07N48W to 06N54W to 07N58W. Two tropical waves are embedded within the Monsoon trough/ITCZ. Most of the convective activity is associated with these tropical waves. Scattered moderate convection is from 03N to 05N between 10W and 17W. ...DISCUSSION... GULF OF MEXICO... High pressure of 1019 mb located over the SE CONUS extends a ridge across much of Gulf region producing gentle to moderate E to SE winds across the area. Winds increase near the Yucatan Peninsula, where scatterometer data indicate moderate to fresh NE to E winds in association with a thermal trough, that normally develops during the evening hours over the Yucatan Peninsula and moves across the SW Gulf during the overnight and early morning hours. Water vapor imagery reveals the presence of an upper- level low spinning over the SE Gulf, with a trough extending SW across the northern Yucatan Peninsula into the Bay of Campeche. Upper diffluence on the east side of the low combined with a moist and humid SE flow at low levels, is helping to induce showers and thunderstorms over parts of south and central Florida. Mosaic Doppler radar from the SE U.S. shows bands of showers and thunderstorms across south Florida, the Florida Keys and the SE Gulf. Plenty of moisture and the risk of some heavy showers and thunderstorms will be very possible across south Florida through the weekend. Abundant moisture are also expected to persist over the SE Gulf and the Yucatan Peninsula through the weekend. This weather pattern will be associated with a broad area of low pressure forecast to form over the northwestern Caribbean Sea and adjacent land areas by the weekend. Some gradual development of this system is possible thereafter while it moves slowly northwestward toward the southwestern Gulf of Mexico. Winds are expected to increase over the SW Gulf by late Saturday ahead of the low pressure expected to approach the region through northern Central America. CARIBBEAN SEA... Two tropical waves are moving across the Caribbean Sea. Please see the tropical waves section for more details. These tropical waves will become absorbed in a broad area of low pressure forecast to form over the NW Caribbean during the upcoming weekend. A 1009 mb low pressure is analyzed on the 1200 UTC map over the SW Gulf near 12N81.5W. This low is producing some shower and thunderstorm activity, and is forecast to remain nearly stationary over the next 24 hours. Scatterometer data show moderate to fresh trades across the east and central Caribbean, particularly south of 18N, and fresh to locally strong winds across the Gulf of Honduras. Gentle to moderate winds are seen over the NW Caribbean. This wind pattern will continue on Thursday. As previously mentioned, an upper-level low located over the SE Gulf is also helping to induce some shower and thunderstorm activity over western Cuba. Looking ahead, a broad area of low pressure is expected to form over the northwestern Caribbean Sea and adjacent land areas by the weekend bringing more rain to the area. In fact, computer model indicates plenty of moisture across the western and central Caribbean Sea, and over most of Cuba during the upcoming weekend. ...HISPANIOLA... An upper-level trough in the SW Atlantic and extend south to a base over Hispaniola. This trough, combined with a E to SE winds at low levels will support scattered showers and tstms mainly in the afternoon and evening hours. Late tomorrow, expect a gradual increase in moisture as a tropical wave approaches from the east. ATLANTIC OCEAN... Two tropical waves are moving westward between the coast of Africa and the Lesser Antilles. Please refer to the Tropical Waves section above for details. A surface trough extends from 31N62W to 24N68W. This trough is likely a reflection of an upper-level trough extending from 31N62W to Hispaniola. Some shower and thunderstorm activity is ahead of the trough axis, covering the waters from 26N to 31N between 57W and 61W. A recent ASCAT pass shows the wind shift associated with the trough axis. Otherwise, broad high pressure covers the Atlantic from the Azores to the Bahamas. Moderate to locally fresh trades are around the southern periphery of the ridge between the Windward Islands and 30W. A surge of African dust is just in the wake of the tropical wave located along 34W/35W as noted in the Saharan Air Layer Tracking Product from CIMSS. For additional information please visit http://www.hurricanes.gov/marine $$ GR