000 AXNT20 KNHC 131205 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT Wed Jun 13 2018 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 1145 UTC. ...TROPICAL WAVES... A tropical wave is along 21W from 04N-14N, moving west at 10-15 kt. Saharan dry air and dust are in the northern wave environment, thus limiting convection. Isolated showers are in the southern portion of the wave being enhanced by the monsoon trough and ITCZ. A tropical wave is along 36W from 01N-11N, moving west at 10-15 kt. CIRA LPW imagery show high moisture in the wave environment, which is supporting scattered moderate convection from 02N-08N between 32W and 44W. A tropical wave is along 54W from 04N-14N, moving west at 10-15 kt. Moisture associated with the ITCZ and upper level diffluent flow support scattered showers within 300 nm west of the wave axis south of 10N and isolated showers east of it. A tropical wave is over the E Caribbean along 67W south of 18N, moving west at 10-15 kt. Strong wind shear in the region and Saharan dry air in the wave environment hinder deep convection at the time. A tropical wave is over the W Caribbean along 85W south of 20N, moving west at 10-15 kt. Scattered showers are W of 82W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 12N16W to 08N17W. The ITCZ extends from 07N23W to 04N35W, then resumes west of a tropical wave at 04N39W and continues to 03N51W. Besides the convection mentioned in the tropical wave section, scattered moderate convection is from 03N-07N between 38W-51W. Scattered moderate convection is also from 06N-10N between 56W- 60W. ...DISCUSSION... GULF OF MEXICO... A 1019 mb high is centered over the NE Gulf near 28N84W. 5-10 kt anticyclonic winds are noted around the high. 10-15 kt SE surface flow is over the remainder of the Gulf. Isolated moderate convection is noted over the Florida Peninsula, over the S Bay of Campeche, and over S Louisiana. An upper-level trough is over the Gulf with axis along 87W. An embedded upper level low is centered over the NW Gulf near 29N95W. A surface trough will develop along the Yucatan Peninsula late Wed and Thu afternoons, and drift westward across the southwest Gulf waters during the overnight hours accompanied by a strong east to southeast wind shift with the trough dissipating along 96W during the late mornings. The pressure gradient is tightening in association with a tropical wave moving through the Yucatan Channel on Wed. The wave will pass through the southwest gulf waters on Thu and Fri accompanied by a weak low pressure center along the wave axis. A fresh southeast breeze is expected across the central waters through Sat with locally strong conditions developing on Sat night into Sun. CARIBBEAN SEA... Two tropical waves are over the Caribbean. See above. Elsewhere, scattered moderate convection is inland from S Guatemala to Panama. An upper-level trough extends across the NW Caribbean with axis along 87W. Diffluent flow east of this trough is enhancing convection over the W Caribbean and central Cuba. A large upper- level ridge is over the remainder of the Caribbean with axis along 72W. A tropical wave will move west across the western Caribbean through Wed night with a surface low developing along the wave axis. A second tropical wave across the east Caribbean will pass through the central Caribbean on Thu and Fri. A third tropical wave will pass west through the tropical waters east of windwards on Wed, and pass through the east Caribbean on Thu and Fri. Strong trades currently across the south-central and southwest Caribbean will spread north across the central Caribbean on Wed and Thu, while fresh to locally strong southeast pulses will continue across the northwest Caribbean. Locally strong trades will continue across the tropical waters east of the Windwards through late Wed. ATLANTIC OCEAN... Abundant deep layer moisture continues to prevail in the western Atlantic and Bahamas, E of a deep upper-level trough with axis along 87W. Scattered moderate convection is observed west of 75W. A surface ridge dominates the remainder of the Atlantic, anchored by a 1029 mb high centered near 34N26W, producing fair weather. Moderate to locally fresh winds are noted along the southern periphery of the ridge from scatterometer data. The surface ridge will meander between 27N-29N through the week. A weak cold front is expected to pass east through the waters north of 26N on Sat. Fresh to locally strong easterly winds are forecast along the northern coast of Hispaniola during the late afternoons and evenings through Thu, with moderate easterly flow forecast elsewhere south of the ridge. Gentle to moderate southerly flow is expected north of the ridge, with a brief moderate northeast breeze expected to the north of the cold front on Sat. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa/Ramos