000 AXNT20 KNHC 130521 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 121 AM EDT Tue Aug 13 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 31W/32W, from S of 12N, moving W 15 knots. This is a low amplitude wave with cyclonic turning. Scattered showers are within 120 nm on either side of the wave. An Atlantic Ocean tropical wave is along 22N50W 13N49W 03N46W, moving W 15 knots. The wave model diagnostics depict the wave well at 700 mb. The wave is embedded in dry Saharan air, which is limiting the precipitation to the north of 10N. Any nearby precipitation is with the ITCZ. A central Caribbean Sea tropical wave is along 23N71W-Haiti- 16N73W-northern Colombia near 08N73W, moving W 15 knots. The wave is embedded in dry Saharan air, which is limiting precipitation over water near the wave. The precipitation that has been in Colombia, from 07N northward, has been weakening during the last six hours. Scattered strong rainshowers are in SW Haiti and coastal waters near 20N83W. A western Caribbean Sea tropical wave is along 86W/87W, from 22N southward, moving W 10 knots. Isolated moderate rainshowers are from 16N northward from Jamaica westward. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Senegal near 15N17W, to 09N39W. The ITCZ is along 08N43W 07N50W 09N60W. Isolated moderate to locally strong rainshowers are within 180 nm on either side of the line that runs from 12N22W 10N28W 08N38W 09N46W 08N56W 11N62W. A surface trough is along 41W from 06N to 13N. No deep convective precipitation is apparent with this trough. GULF OF MEXICO... A stationary front is in the SE U.S.A., extending into the Atlantic Ocean along 32N, beyond 70W eastward. The 700 mb wind flow is cyclonic from 30N northward between 70W and 80W, and in the NE Gulf of Mexico. The middle level wind flow and the upper level wind flow in these areas is anticyclonic. The TPW imagery shows a large area of enhanced moisture in the NE Gulf of Mexico. Isolated moderate to locally strong rainshowers cover the area that extends from 23N northward in the Straits of Florida between 63W in the Atlantic Ocean and 90W in the Gulf of Mexico. Isolated moderate to locally strong rainshowers have moved into the SW corner of the Gulf of Mexico, to the north of the Isthmus of Tehuantepec of southern Mexico, from 20N southward from 94W eastward. Weak high pressure will remain across the central and eastern sections of the Gulf of Mexico. This will allow for mainly tranquil winds and slight seas through the end of the week. The wind speeds will pulse to fresh to the W-NW of the Yucatan Peninsula each evening. The wind speeds also will pulse to fresh each afternoon offshore of the Florida Panhandle and the Florida Big Bend region from Thursday through Saturday. CARIBBEAN SEA... The potential for heavy rain exists in parts of Panama, Costa Rica and Nicaragua, from Wednesday through Friday, due to favorable upper level atmospheric conditions. It is likely that the rainfall amounts may range from 1 inch to 3 inches per day, in the areas of heavy rain. Isolated flash floods are possible. Dry Saharan air covers much of the Caribbean Sea, from 11N northward, not counting the NW corner of the Caribbean Sea. GFS model data for 500 mb and for 700 mb show an inverted trough that extends from the SE Bahamas, across Hispaniola, toward the SW corner of the Caribbean Sea. The tropical wave that is along 86W/87W will move across the Gulf of Honduras tonight, and into the Yucatan Peninsula. A second tropical wave, along 71W/73W, will move across the central Caribbean Sea through Tuesday, and the W Caribbean into the middle of the week. A third tropical wave will reach the eastern Caribbean Sea by the middle of the week. The passage of these waves, along with high pressure to the north of the area, will continue to support generally fresh to strong winds in the central and southwest Caribbean Sea. ATLANTIC OCEAN... A stationary front is in the SE U.S.A., extending into the Atlantic Ocean along 32N, beyond 70W eastward. The 700 mb wind flow is cyclonic from 30N northward between 70W and 80W, and in the NE Gulf of Mexico. The middle level wind flow and the upper level wind flow in these areas is anticyclonic. Isolated moderate to locally strong rainshowers cover the area that extends from 23N northward in the Straits of Florida between 63W in the Atlantic Ocean and 90W in the Gulf of Mexico. A surface trough is along 31N40W 26N45W. Isolated moderate rainshowers cover the area that extends from 15N northward between 30W and 70W. A surface ridge extends from a 1026 mb high pressure center that is near 34N43W, through 32N46W, to 28N63W, to 26N74W. A surface ridge will persist from the central Atlantic, west- southwestward, across the central Bahamas, to the Straits of Florida, through the end of the week. This pattern will maintain gentle to moderate winds north of 22N, and moderate to fresh winds south of 22N. Active weather will continue across NE sections of the Atlantic Ocean zones through Tuesday, as an old frontal zone and an upper level trough linger there. $$ MT