000 AXNT20 KNHC 011728 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 128 PM EDT Sun Jul 1 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 1545 UTC. ...TROPICAL WAVES... The tropical wave that most recently emerged off the west coast of Africa has an axis extending from 03N23W to 16N23W and is moving W at around 20 kt. Scattered moderate and isolated strong convection is noted from 05N to 12N between 20W and 29W. A total precipitable water surge coincides with this wave. A tropical wave has an axis extending from 03N44W to 18N44W. This wave is quickly moving W at around 30 kt. This wave is well defined in model 700 and 850 mb fields and coincides with an inverted-V signature in total precipitable water data. This wave is surrounded by Saharan dust which is inhibiting deep convection. A tropical wave has an axis extending from 04N60W to 20N59W, moving westward at 15 to 20 knots. This wave is clearly defined with an inverted-V signature evident in visible satellite imagery. Scattered moderate convection is from 07N to 15N between 54W and 70W. Saharan dust surrounds the northern portion of this wave. Tropical moisture associated with this feature will continue to spread west over the southeast and south-central Caribbean, well ahead of the actual wave axis. A tropical wave has an axis extending N from central America to the Gulf of Honduras to 19N85W, as depicted in the 1500 UTC analysis. Infrared and visible satellite imagery as well as total precipitable water data confirm the location of this wave. The wave will continue across central America tonight, enhancing shower and thunderstorm activity. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean from the coast of Senegal near 14N16W and extends to 09N22W to 06N30W. The ITCZ extends from 06N30W to 05N43W, then resumes west of a tropical wave near 05N47W to 08N58W. Aside from the convection associated with the tropical waves, scattered moderate convection is observed from 06N to 10N E of 20W, and within 90 nm of the monsoon trough and ITCZ axis. ...DISCUSSION... GULF OF MEXICO... A surface trough extends over the northeastern Gulf from a 1016 mb low near 30N85W to 29N86W to 28N89W. Abundant cloudiness and numerous showers and thunderstorms are associated with the low/trough affecting mainly the waters N of 27N and E of 89W. The low is dissipating today, and the trough will drift northwestward through tonight. Scattered showers and thunderstorms will continue over much of the NE and north- central Gulf waters through at least Mon associated with this system. The remainder of the basin is under the influence of a weak high pressure center of 1016 mb located over the north-central Gulf near 28N90W. This system is producing light to gentle anticyclonic flow and seas of 1-3 ft over the eastern half of the Gulf, and gentle to moderate SE to S winds and seas of 3-5 ft over the western half of the Gulf. This weak high pressure pattern will change little through mid-week. A surface trough will emerge off the Yucatan Peninsula each evening through Wed, enhancing nocturnal winds over the SW Gulf through this period. CARIBBEAN SEA... A tropical wave is moving across the western Caribbean and central America. Please see the Tropical Waves section for details. Morning scatterometer data depicted fresh to strong winds across the south-central Caribbean south of 14N between 70W and 78W, while moderate to fresh trades prevail across the remainder of the basin S of 18N and E of 82W. Light to gentle winds are noted over the NW Caribbean. A surface ridge will remain north and northeast of the Caribbean and Tropical N Atlantic waters through the next few days. Fresh to strong winds across the south-central Caribbean will gradually diminish through Tue before strengthening again on Wed. Convection continues to flare up over the SW Caribbean mainly in the vicinity of the monsoon trough, which is just north of Panama. An upper-level low, currently just south of central Cuba, will drift westward across the NW Caribbean through Mon, and will enhance convection across the extreme western Caribbean waters and over land areas across the NW Caribbean. ATLANTIC OCEAN... Three tropical waves are moving across the waters between the coast of West Africa and the Lesser Antilles. Refer to the Tropical Waves section above for details. A weak surface high center of 1019 mb is located near 28N75W. A surface trough is just E of this high, and extends from 32N64W to 26N67W. Numerous showers and scattered thunderstorms are from 25N to 30N between 62W and 73W, and elsewhere within 90 nm of the trough axis. The high will weaken as this trough moves westward across the NW Bahamas Tue, and inland Florida Wed. Enhanced shower and thunderstorm activity is expected to continue in the vicinity of the trough. Another surface trough is over the central Atlantic and extends from 32N51W to 26N52W. Light winds are on either side of the trough axis based on scatterometer data from this morning. This trough is a surface reflection of an upper-level low spinning near 29N52W. Scattered showers and thunderstorms are associated with this system from 27N to 32N between 45W and 54W. Surface high pressure located NW of the Azores is in control of the remainder of the central and eastern Atlantic discussion waters. GOES-16 RGB Geocolor imagery continues to show an extensive area of African dust that extends from the west coast of Africa to the eastern Caribbean this morning. The Saharan dust occasionally obscures sky conditions near the Caribbean islands. The dust turns skies hazy, reducing visibility and can result in poor air quality. For additional information please visit http://www.hurricanes.gov/marine $$ Latto