000 AXNT20 KNHC 271021 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 621 AM EDT Sat May 27 2017 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 0600 UTC surface analysis and satellite imagery through 1015 UTC. ...TROPICAL WAVES... A tropical wave is in the eastern Atlc with axis extending from 11N23W to 01N23W, moving W at 15 kt. CIRA LPW imagery shows a moderate moist environment near the ITCZ with dry air in the Saharan Air Layer N of 10N. The 700 mb analysis shows a good wave reflection. Scattered showers are within 120 nm of the wave axis. A tropical wave is in the central Atlc with axis extending from 09N36W to 01N37W, moving W at 20 kt. CIRA LPW imagery shows a moderate moist environment near the ITCZ, with dry air in the Saharan Air Layer N of 10N. The 700 mb analysis shows a good wave reflection along 38W. Scattered showers are within 120 nm of the wave axis. A tropical wave is in the W Atlc with axis extending from 13N55W to 05N56W, moving W at 20 kt. This wave shows a well defined inverted-V surface reflection on satellite imagery. CIRA LPW imagery shows a moist environment. The 700 mb analysis shows a good wave reflection. Scattered moderate convection is from 09N- 12N between 54W-58W. Scattered showers are within 120 nm of the remainder of the wave axis. A tropical wave is over the E Caribbean with axis extending from 16N62W to 08N62W, moving W at 15 kt. Unfavorable wind shear and Saharan dry air across the wave environment is hindering convection at this time. There is a very pronounced 700 mb wave reflection, however, along 62W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough enters the tropical Atlantic near 10N14W and continues to 06N18W. The ITCZ extends from 06N18W to 06N23W. The ITCZ resumes W of a tropical wave near 06N25W and continues to 04N36W. The ITCZ resumes again W of another tropical wave near 03N38W and continues to the coast of South America near 01N50W. Besides the convection associated with the tropical waves, scattered moderate convection is from 03N-08N between 15W-21W. ...DISCUSSION... GULF OF MEXICO... A 1018 mb high is located over the NE Gulf of Mexico near 28N84W. 5-10 kt anticyclonic winds are over the NE Gulf. 10-20 kt SE surface winds are over the W Gulf. In the upper levels, a ridge is over the Gulf with axis along 91W. Strong subsidence is over the Gulf. Upper level moisture is over Texas. Expect showers to advect into the Bay of Campeche from the Yucatan Peninsula, over the next 24 hours. CARIBBEAN SEA... A tropical wave is over the E Caribbean. See above. The monsoon trough extends over Costa Rica and Panama producing scattered moderate to strong convection. Further N, isolated moderate convection is along the coast of Nicaragua, and inland over Honduras and Guatemala. In the upper levels, a ridge is over the W Caribbean. An upper level trough is over the E Caribbean with strong subsidence. Expect over the next 24 hours for the tropical wave to move W over the the E Caribbean. Also expect continued convection over the SW Caribbean, and Central America. ...HISPANIOLA... Saharan dust continue to be reported across the Island and is observed in satellite enhanced imagery. Water vapor imagery shows strong subsidence over the Island, hindering convection. However, patches of low level moisture, embedded in the trade wind flow, will produce isolated showers over the next 24 hours. ...ATLANTIC OCEAN... A cold front in the SW N Atlc long 31N64W to 29N72W. A stationary front continues to 25N79W. Scattered showers are over portions of the N Bahamas. A 1024 mb high is centered over the central Atlantic near 29N48W. Three tropical waves are over the tropical Atlantic. Please refer to the Tropical Waves section for more details. Saharan dry and dust is noted across much of the Atlantic Ocean between 10N-25N. Of note in the upper levels, a small upper level low is centered near 23N59W producing upper level diffluence with scattered showers from 20N-27N between 50W- 55W. Expect over the next 24 hours for the W Atlantic front to drift E, while a new cold front will dip into the central Atlantic along 31N between 25W-40W with showers. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa