000 AXNT20 KNHC 201807 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 207 PM EDT Thu Jun 20 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 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: The pressure gradient between the Atlantic ridge and lower pressure over Colombia will continue to support minimal gale force winds in the Gulf of Venezuela and off the north coast of Colombia through the mid day Friday. Gales are expected to return off the coast of Colombia by Friday afternoon and continue through Saturday. Seas of 12-18 ft are expected across the south-central Caribbean. 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 38W S of 12N, moving W at 20-25 kt. The prevailing ridge to the north is providing strong easterly trades across the region making a favorable environment for the wave to move westward at 20 to 25 kt. A moisture maximum in the LPW is noticeable near the wave. Scattered moderate convection is seen near this wave from 03N-09N between 35W-41W. A Caribbean Sea tropical wave is along 68W S of 17N, moving W at 20-25 kt. Scattered moderate convection is seen within the northern vicinity of the wave from 14N-17N between 65W-70W. A Caribbean Sea tropical wave is along 78W S of 16N, moving W at 15-20 kt. Scattered moderate isolated strong convection is noted south of 10N near the coast of Panama and the interaction of the Pacific monsoon trough. North of 10N, no convection is noted. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal areas of Guinea near 09N13W to 08N21W. The ITCZ continues from 08N21W to 08N33W, then continues W of a tropical wave near 07N41W to the coast of Brazil near 04N51W. Aside to the convection near the tropical wave, scattered showers are moving along the monsoon trough from 05N-09N between 20W-32W, and another area of scattered showers and isolated thunderstorms are seen along the ITCZ from 05N-07N between 45W-53W. GULF OF MEXICO... An upper-level trough is exiting the Gulf and move east of FL into the western Atlantic while mid-upper level ridge builds from the west. A line of showers and thunderstorms are seen from across the Florida Panhandle from 29N-30N. There are also some dissipating showers seen 50 nm within the central coast of Louisiana. The trough along the Yucatan Peninsula is analyzed from 24N90W to 18N93W. Moderate to fresh anticyclonic flow are seen across much of the basin, with moderate to fresh southeasterly 0winds in the western Gulf. Gentle to moderate winds are in the eastern basin. A diurnal trough forming over the Yucatan Peninsula will produce fresh to strong winds each night as it moves northwestward over the SW Gulf. Otherwise, a high pressure ridge will slowly move north from the central to the northern Gulf by Sun, then persist there through Mon night leading toward generally quiescent conditions. No tropical cyclone activity is expected during the next several days. CARIBBEAN SEA... See the special features section in regards to the Caribbean Gale warning. Two tropical waves are traversing the Caribbean Sea. See the Tropical Waves section above for details. An upper level trough extends to Puerto Rico and the Leeward Islands with a mid- upper level 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, central and eastern Caribbean Sea. Strong subsidence is keeping convection at a minimum. Most of the activity in the Caribbean is associated with the tropical wave in addition to thunderstorms adjacent to the Pacific monsoon trough moving off the coasts of Panama and Costa Rica, S of 10N between 76W- 82W. There are also isolated showers approaching Puerto Rico due to the proximity of the tropical wave along 68W. Fresh to strong winds continue across the central Caribbean. Moderate to fresh trades are seen in the eastern basin, with moderate trades in the northwest Caribbean. The pressure gradient between the Bermuda high and the Colombian low will support nocturnal pulsing of minimal gales off the coasts of Colombia Fri night and Sat night. Strong winds are expected to pulse over the Gulf of Honduras each night through at least Mon night. Tropical wave near 68W will produce scattered thunderstorms with gusty winds as it moves W across the central and western Caribbean through Sat. Elsewhere, generally moderate to fresh trades will prevail through the weekend and into early next week. No tropical cyclone activity is expected during the next several days. ATLANTIC OCEAN... Scattered showers and isolated thunderstorms continue across the western Atlantic from 27N-31N between 64W-78W. 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. Otherwise, fair weather prevails across the rest of the basin as surface ridging from a 1025 mb high near 27N53W and a 1022 mb high near 26N32W dominating the area. The pressure gradient between the Bermuda high and Hispaniola will produce strong winds north of Hispaniola this afternoon and tonight before relaxing on Fri. Fresh to strong SW winds will affect the northern waters through Fri ahead of a cold front that will move off the U.S. East Coast Fri night. A high pressure ridge will dominate much of the region through Sat, then weaken Sun into Mon as the cold front continues moving E across the western Atlantic. No tropical cyclone activity is expected during the next several days. For additional information please visit http://www.hurricanes.gov/marine $$ MMTorres