000 AXNT20 KNHC 081715 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 115 PM EDT Fri Jun 8 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...TROPICAL WAVES... Currently, three tropical waves are noted between the coast of Africa and the Lesser Antilles. A tropical wave is added to the 1200 UTC analysis/surface map along 15W from 5N-13N. The Hovmoller Diagram indicates the westward propagation of the wave, and model diagnostics guidance also suggests the presence of this system. A cluster of moderate convection is noted within about 150 nm ahead of the wave's axis from 7N-10N. A second tropical wave extends its axis along 33W south of 15N, moving westward 15 to 20 kt. Convection is limited along the wave's axis. Another tropical wave is along 53W/54W, south of 15N, moving westward 10 to 15 kt. Scattered moderate convection is noted where the wave's axis meets the ITCZ. A tropical wave is moving across the western Caribbean Sea around 10 kt. Its axis is along 84W, south of 17N. Scattered showers and tstms are behind the wave's axis over the SW Caribbean, affecting mainly the waters S of 12N. Moisture associated with the wave will spread across northern Central America the rest of today and Sat. An upper-level trough extending over the eastern Gulf of Mexico and the Yucatan Peninsula will also help to induce convection across Central America and the western Caribbean this upcoming weekend. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean through Guinea, and continues to 06N20W. The ITCZ stretches from 06N20W to 07N31W to 06N40W to 06N53W. Scattered moderate convection is from 04N-07N between 10N-21N. Similar convection is also noted within about 90 nm S of ITCZ axis W of 49W. ...DISCUSSION... GULF OF MEXICO... A weak surface low, reflection of a mid to upper level low, is analyzed over the NE Gulf near 26N87W. An area of showers and tstms is observed within about 150 nm SE semicircle of the low center. This system is helping to induce convection over Florida and adjacent coastal waters. As a result, scattered to numerous showers and thunderstorms are possible again over South Florida this afternoon and early evening. Some of the storms could become strong to even severe due to the cool temperatures aloft. Scattered showers and tstms are also noted over the SW Gulf where a diffluent pattern aloft prevails. The mid to upper low will meander over the northeast Gulf for a few more days enhancing convection over the eastern Gulf. A thermal trough will develop along the Yucatan Peninsula late each afternoon, drift westward across the southwest Gulf during the overnight hours accompanied by a fresh to locally strong wind shift, with the trough dissipating along 95W during the late mornings. An east to west ridge will meander across the northern Gulf waters through the period with moderate southeast return flow increasing to fresh breeze late Sun. CARIBBEAN SEA... Recent scatterometer data provide observations of fresh to strong trade winds from 11N-17N between 70W-82W. Moderate to locally fresh trades prevail across the remainder of the eastern Caribbean with gentle to moderate NE-E winds across the NW part of the basin. A tropical wave has reached the coast of Nicaragua and will move across Central America and the NW Caribbean the rest of today and Sat. This wave will interact with an upper-level trough. Please, see Tropical Waves section for details. Atlantic high pressure will support strong trade winds over the south central Caribbean through Sun, reaching near gale force overnight off Colombia and northwest Venezuela, diminishing early next week. Fresh to strong winds are expected in the Gulf of Honduras through tonight. Moderate to locally fresh trades will prevail elsewhere through early next week. Multi-layer clouds cover most of the Caribbean W of 78W, including Cuba. Patches of low level moisture embedded in the trade winds flow are noted elsewhere. ATLANTIC OCEAN... Abundant moisture also prevails across the west Atlantic, on the eastern side of the Gulf of Mexico-Yucatan Peninsula mid to upper level trough. Scattered showers with embedded tstms are occurring over parts of Cuba, the Bahamas and E of the Florida Peninsula to about 77W. A weak 1018 mb low is located near 31N81W. This low will dissipate by tonight. Three tropical waves are moving across the basin. Refer to the Tropical Waves section above for details. A cold front clips the northern forecast waters, mainly between 20W and 30W. A surface ridge extends across the remainder of the basin, anchored by a 1029 mb high centered near 32N39W. An east to west ridge will meander between 27N and 28N through Tue, supporting moderate to fresh winds south of 22N, pulsing to 25 kt off Hispaniola during overnight hours. Light to moderate southerly flow is expected along and north of the ridge. For additional information please visit http://www.hurricanes.gov/marine $$ GR