000 AXNT20 KNHC 220004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT MAY 21 2016 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. ...TROPICAL WAVES... Tropical wave extends from 03N38W to 08N35W moving W at 15 kt. The wave coincides with a mid-level 700 mb trough and associated positive relative vorticity in the vicinity of the wave axis. Both the CIRA layer precipitable water imagery from the surface to 850 mb and the Saharan Air Layer imagery show dry air in the northern wave environment, which is in part is hindering convection at the time. Tropical wave extends from 08N53W to 03N55W moving W at 10 kt. This wave coincides with a weaker 700 mb trough across Suriname and adjacent coastal waters. Moderate moisture from the surface to the middle levels along with a diffluent environment aloft support isolated showers in the vicinity of the wave. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 07N12W to 04N24W. The Intertropical Convergence Zone axis extends from 04N24W to 04N30W to 06N35W. It then resumes west of a tropical wave from 04N39W to 03N51W. Scattered moderate convection is from 02N to 11N east of 20W. ...DISCUSSION... GULF OF MEXICO... A cold front extends across the SE CONUS and transitions to a stationary front from 30N87W to 29N92W. Shallow moisture over the western Gulf advected from the Caribbean by SE flow support scattered showers within 90 NM either side of the front. Otherwise...the remainder of the Gulf is under the influence of gentle to moderate anticyclonic flow associated with a ridge anchored by a 1017 mb high over the NE basin near 28N87W. The high will dissipate by early Sunday morning while the front transitions into a cold front to move across the eastern Gulf and the Florida Peninsula the remainder Sunday through Monday near sunrise. CARIBBEAN SEA... The surface pressure gradient across the Caribbean Sea remains relatively strong due to a nearly stationary ridge anchored across the central Atlc and lower pressure noted across northern South America. The gradient is resulting in fresh to strong trades across the central and eastern basin with winds strong to near gale force within close proximity to the coast of Colombia. Strong high pressure persisting over the Atlantic will allow for this winds to remain in place through at least late Monday. Otherwise...an upper level trough is noted on water vapor imagery across the eastern Caribbean with axis along 67W. East of the axis in the region of maximum lifting dynamics...scattered showers and tstms are occurring across the Windward Islands S of 15N east of 63W. Diffluence aloft along with moisture inflow from the tropical Atlantic support showers along Cuba and central Hispaniola. ...HISPANIOLA... A diffluent environment aloft between a short-wave trough over the SW N Atlantic waters and NW flow from a ridge over the western Caribbean along with moisture inflow from the tropical Atlantic support showers across central Hispaniola. These conditions are forecast to persist through the remainder weekend. ATLANTIC OCEAN... A middle to upper level trough over the eastern CONUS extending to W Atlantic waters W of 70W support a surface trough from 30N76W to 25N80W that enhances scattered moderate convection and isolated thunderstorms N of 25N W of 72W. Farther east...a deep layered low centered over the central North Atlc supports a cold front analyzed from 30N58W to 29N61W where is becomes stationary to 30N67W. Otherwise...the remainder of the central and eastern Atlc is under the influence of a surface ridge anchored by a 1025 mb high centered near 29N34W. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos