000 AXNT20 KNHC 271746 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 146 PM EDT Wed Jun 27 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... A tropical wave has an axis from 01N to 20N along 27W. Scattered moderate and isolated strong convection is observed from 04N-10N between 25W-32W. While no surface observations were in the vicinity of the wave, visible satellite imagery suggests that either a distinct surface trough or broad low is present. A distinct maximum in total precipitable water (TPW) exists along and east of the wave's axis. Expect a fresh northeast to east to southeast wind shift along the wave axis as it progresses westward across the tropical Atlantic. A tropical wave extends its axis along 50W from 01N to 19N, and is estimated to be progressing west at 15-20 kt. No significant convection is related to this wave at this time. The wave also has negligible surface signature, though it is well-present in the 700 mb model diagnostics and TPW. A tropical wave is analyzed across the central Caribbean and South America along 78W from 02N to 19N, and is moving west about 15-20 kt. Scattered moderate and isolated strong convection exists south of 13N within 300 nm west of the wave's axis. The wave has negligible surface signature and cannot be easily identified in TPW, though it is present in the 700 mb model diagnostics A tropical wave is progressing west through Central America and is currently analyzed with axis along 90W and extends south from 22N into the east Pacific near 09N. Scattered moderate and isolated strong convection is occurring east of the wave axis over portions of Central America. The wave does have some surface circulation as well as being apparent in the TPW imagery. This tropical wave has the potential to develop into an east Pacific tropical cyclone later this week. ...MONSOON TROUGH/ITCZ... The monsoon trough extends southwest off the coast of western Africa at 18N16W to 15N21W. West of a tropical wave, the ITCZ forms at 06N31W and continues to 06N47W, then resumes west of a tropical wave near 07N52W to 06N58W. Aside from the convection described in the Tropical Waves section above, scattered moderate convection is observed within 60 nm of the ITCZ. ...DISCUSSION... GULF OF MEXICO... A surface ridge prevails across the northern portion of the Gulf, anchored by a 1019 mb high centered over the Florida peninsula. With this, a gentle to moderate anticyclonic flow dominates the Gulf waters. A surface trough will develop during the late afternoons and early evenings over the Yucatan Peninsula, then shift westward across the southwest gulf waters during the overnight hours and dissipate by late each morning. The trough will be accompanied by a fresh to locally moderate wind shift each night. CARIBBEAN SEA... See tropical wave section above for details on two waves progressing west through the Caribbean. Fresh to locally strong winds are noted across the west Caribbean, generally from 11N to 18N between 68W and 82W. Winds up to 30 kt were observed by the ASCAT scatterometer at 1410 UTC this morning. These winds will diminish from the north, but continue across the southwest Caribbean this week. Nocturnal winds will pulse to fresh to strong through tonight in the Gulf of Honduras. ATLANTIC OCEAN... A broad ridge of high pressure dominates across the tropical North Atlantic from 27N near the Bahamas to near 30N in the far eastern Atlantic. Moderate scattered convection is located near 28N-32N from 55W-75W just south of a stationary front. Weak surface troughs are centered near 30N34W and 30N42W though these have minimal convection and no significant winds. Two tropical waves are moving across the tropical Atlantic. Refer to the section above for more information. Moderate to fresh trades are noted across the tropics with little change forecast this week. Moderate winds are forecast for the next few days during the late afternoons into the early evening hours along the north coast of Hispaniola. For additional information please visit http://www.hurricanes.gov/marine $$ Landsea