000 AXNT20 KNHC 300523 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 123 AM EDT Thu Mar 30 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 0000 UTC surface analysis and satellite imagery through 0445 UTC. ...SPECIAL FEATURES... A middle to upper level shortwave trough is noted on water vapor imagery in the vicinity of 34N54W supporting a 991 mb surface low centered near 33N53W. The occlusion associated with the low extends to a triple point near 33N50W and a warm front SE to 31N46W. The cold front extends from the triple point S-SW to 30N50W to 20N59W into the NE Caribbean Sea near 17N68W. Near gale to gale force winds are occurring across the discussion area generally N of 27N between 59W and the cold front with storm force winds occurring N of the area within 180 nm of center within the W quadrant. The low is forecast to move N-NE through Thursday night and become absorbed with a forecast storm force 970 mb low centered near 43N52W. By late Thursday night into early Friday morning...the fully absorbed low pressure area is forecast to be producing hurricane force winds within 300 nm of center in the S and SW semicircles well N of the discussion area. Please see the latest NWS High Seas Forecasts under AWIPS/WMO headers MIAHSFAT2/ FZNT02 KNHC and HSFAT1/FZNT01 KWBC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 13N17W to the Equator near 24W. Widely scattered moderate and isolated strong convection is S of 10N between 05W-20W. ...DISCUSSION... GULF OF MEXICO... Middle to upper level southwesterly flow aloft prevails over the Gulf this evening with a vigorous middle to upper level low noted on water vapor imagery over the central CONUS. The approaching upper level troughing dips southward over much of Texas and the Rio Grande river valley. While the associated cold front remains across interior portions of Texas...a leading surface trough axis extends from Lake Charles Louisiana SW to NE Mexico near 26N97W. This pre-frontal troughing is providing focus for scattered showers and tstms occurring across the NW Gulf waters N of 28N between 91W-94W...and within 15 nm either side of the trough axis. Otherwise...the remainder of the basin is under the influence of southerly return flow on the western periphery of a surface ridge anchored by a 1018 mb high centered near the Florida Big Bend. Moderate to fresh S-SE winds prevail and by Thursday afternoon... as the cold front emerges off the Texas and Louisiana coasts... winds will shift northerly through Thursday night. The front is then forecast to gradually weaken as it moves eastward and become diffuse during the weekend. CARIBBEAN SEA... Conditions remain relatively tranquil across the basin this evening as mostly dry west-southwesterly flow aloft prevails. One exception is a weak cold front extending from the central Atlc into the NE Caribbean from 19N60W to 17N68W. Low-level moisture convergence is maximized across the eastern Caribbean S of the front generating isolated showers generally S of 16N between 62W-76W. Otherwise...moderate to fresh trades continue and are expected to persist through the upcoming weekend into Monday. ...HISPANIOLA... Strong subsidence is noted on water vapor imagery over the island this evening...however low-level moisture and cloudiness continues to impact western portions of the island with possible isolated shower activity generally E of 72W. ATLANTIC OCEAN... The main feature in the Atlc is the Special Features low centered near 33N53W. Aside from the gale force wind field associated with it across the discussion area...scattered showers and isolated tstms are occurring within 120 nm of a line from 32N44W to 22N55W. The remainder of the SW North Atlc remains under the influence of a surface ridge anchored by a 1019 mb high centered across the central Bahamas near 26N76W. To the north...the next frontal boundary is analyzed along 31N between 74W and the Georgia coast. Isolated showers are possible within 30 nm either side of the front. The eastern Atlc remains under the influence of a surface ridge anchored by a 1023 mb high centered near 28N27W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN