000 AXNT20 KNHC 192341 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 741 PM EDT Wed Jun 19 2019 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 1800 UTC surface analysis and satellite imagery through 2320 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: The pressure gradient between the Atlantic ridge and 1007 mb low pressure over Colombia will support gale force winds tonight in the Gulf of Venezuela and off the north coast of Colombia. Winds will then be just below gale force Thu morning until late Friday, when gales are again expected off the coast of Colombia. Elsewhere across the south-central Caribbean, winds of 25-33 kt should persist continuously through Saturday night. Seas of 12-15 ft are expected across the south-central Caribbean, and to 8 ft in the Gulf of Venezuela tonight. See the latest NWS High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers HSFAT2/FZNT02 KNHC, or at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further details. ...TROPICAL WAVES... A tropical wave is along 32W from 13N southward, moving W at 20-25 kt. Upper-level diffluence in the area is supporting scattered showers from 03N-11N between 27W-34W. A moisture maximum along with curvature in the moisture field is clearly noted in the CIRA Layered Precipitable Water product in the surface to 700 mb layer. A model diagnosed 700 mb trough also supports the analysis of this tropical wave. The wave is likely to enhance rainfall over the Lesser Antilles this weekend. A tropical wave is moving through the Lesser Antilles along 62W from 05N-16N, moving W around 20 kt. Upper-level divergence from the latest CIMSS-NESDIS analysis and abundant low to mid level moisture seen in the latest TPW product support scattered moderate convection south of 15N between 59W-63W, including over the Windward Islands. Wind gusts ranging between 30-40 kt were recently observed Wednesday afternoon across the Windward Islands. The gusts are due to the combined effects of the tropical wave and the strong pressure gradient across the region. A central Caribbean Sea tropical wave is along 74W from 07N-18N, moving W at 20-25 kt. The wave is currently being engulfed by dry Saharan air, with little convection noted. Convection associated with this wave could become reinvigorated when it reaches Central America Thursday night or Friday. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal areas of Guinea- Bissau near 12N16W to 09N20W. The ITCZ begins near 09N20W to 05N30W, then resumes west of the tropical wave from 05N34W to 04N52W. In addition to the convection associated with the tropical wave along 32W described above, scattered moderate convection is noted along the ITCZ between 39W-43W. GULF OF MEXICO... An upper-level trough is over Florida, whereas mid-upper level ridging covers the western Gulf of Mexico. Scattered moderate convection is over Florida, with scattered showers and isolated tstorms in the NE Gulf. Fair weather prevails in the central and western Gulf of Mexico, west of 88W. Moderate anticyclonic winds prevail across much of the Gulf. A diurnal trough forming over the Yucatan Peninsula will produce fresh to strong winds each night as it moves NW into the SW Gulf of Mexico. Otherwise, a high pressure ridge will slowly move northward over the Gulf through the weekend, then persist over the NE Gulf through Monday night. CARIBBEAN SEA... Two tropical waves are traversing the Caribbean Sea. See the Tropical Waves section above for details. The upper level pattern consists of a shortwave trough across the NW Caribbean Sea and a weak upper ridge over the central and eastern Caribbean. The GOES-16 Saharan Air Layer tracking product shows that a plume of African dust has reached the western and central Caribbean Sea. In the SW Caribbean, the Colombian low and the East Pacific monsoon trough are inducing scattered moderate to strong convection over Panama and the far SW Caribbean, south of 10N. Strong trades continue to cover the central Caribbean with near gales in the south-central Caribbean due to the strong pressure gradient between the Bermuda high and the Colombian low. Nocturnal pulsing of minimal gale force winds will continue tonight through Sat night in the Gulf of Venezuela and off the coast of Colombia, except Thu night. See the Special Features section above for details. Strong winds are expected to pulse in the Gulf of Honduras each night through Sun night. Generally moderate to fresh trades will prevail elsewhere through the weekend and into early next week. ATLANTIC OCEAN... An upper level trough over Florida supports a surface trough from 29N77W to beyond 32N75W. The diffluent flow associated with the upper trough is enhancing scattered moderate convection over the Florida Peninsula and the Atlantic waters within 60 nm of the east coast of central and northern Florida. Elsewhere north of 26N and west of 70W, scattered showers and isolated tstorms are present. The GOES-16 Saharan Air Layer tracking product shows that a plume of African dust extends from Puerto Rico to the Central Bahamas, including Hispaniola and eastern and central Cuba. Surface high pressure ridging covers the remainder of the Atlantic, anchored by a 1024 mb high near 28N53W. This is supporting fair weather across much of the Atlantic. The surface trough from 32N75W to 29N77W will dissipate tonight as it moves eastward. Strong winds will pulse north of Hispaniola tonight and Thu night. Winds will strengthen over the northern waters Thu through Fri ahead of a cold front that will move off the U.S. East Coast late week. A high pressure ridge will dominate much of the region through Fri, then weaken this weekend as the cold front continues moving across the western Atlantic. For additional information please visit http://www.hurricanes.gov/marine $$ Hagen