000 AXNT20 KNHC 110534 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1234 AM EST Sat Mar 11 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. ...ITCZ/MONSOON TROUGH... The Monsoon Trough axis extends from the African coast near 07N11W to 03N23W. The Intertropical Convergence Zone axis extends from 03N23W to 02N29W to the Equator near 36W. Isolated moderate convection is S of 02N between the Prime Meridian and 03W. Widely scattered moderate convection is S of 07N between 13-29W. ...DISCUSSION... GULF OF MEXICO... While upper level west-southwesterly flow prevails over much of the Gulf basin this evening...mid-level energy embedded within weak shortwave troughing over the Rio Grande river valley and southern Texas is supporting scattered showers and isolated tstms N of 25N W of 90W. This activity is largely focused in the vicinity of a surface trough extending from NE Mexico near 25N98W to 29N93W. Otherwise...the remainder of the basin is under the influence of a surface ridge anchored by a 1021 mb high centered in the north-central Gulf waters near 29N88W. Mostly gentle to moderate anticyclonic winds are expected across the basin Saturday as a cold front currently across the Florida panhandle then stationary to eastern Texas sags southward into the NE Gulf waters by morning. Winds are expected to increase out of the N-NE briefly into moderate to fresh breeze levels through late Saturday morning N of the front. High pressure will then once again briefly influence the basin Saturday night as a developing area of low pressure across the far NW Gulf and the associated cold front that is forecast to emerge off the Texas and Louisiana coasts Sunday morning. The low will introduce fresh to strong E-NE winds generally N of 26N W of 89W on Sunday gradually diminishing through Monday as the low pushes eastward toward the Florida peninsula. CARIBBEAN SEA... The basin continues to be under the influence of relatively dry and stable conditions aloft due to an upper level ridge. While overall conditions at the surface remain fairly tranquil...low- level cloudiness and isolated shower activity is occurring across the Mona Passage region and Hispaniola...as well as the Gulf of Honduras region this evening. Isolated showers N of 15N between 67W-72W are occurring in the vicinity of a surface trough extending from 16N72W to 22N71W across Hispaniola and isolated showers are occurring S of 18N W of 85W...including inland portions of Honduras...Nicaragua...Belize...and Guatemala across Central America. Moderate to fresh trades are expected to continue through Tuesday. ...HISPANIOLA... Isolated shower activity continue across the region including the adjacent coastal waters in the vicinity of a surface trough analyzed from 16N72W to 22N71W. The troughing is expected to drift westward and lift N of the area by Sunday. ATLANTIC OCEAN... A middle to upper level trough is noted on water vapor imagery off the eastern US seaboard with axis extending from 38N67W to a broad base near 30N78W. This troughing supports a cold front from 32N76W to the Georgia coast near 31N81W. A pre-frontal surface trough is also noted from the cold front near 34N70W SW to the Florida peninsula near Daytona Beach. Widely scattered showers and tstms are occurring N of 29N between 65W-74W with the remainder of the SW North Atlc under the influence of a weak 1019 mb high centered near 25N79W. Farther east across the central Atlc...another ridge prevails anchored by a pair of 1030 mb highs centered near 28N47W and 31N39W. Finally across the eastern Atlc...a weakening 1015 mb low is centered near 24N28W. The associated cold front has dissipated while a dissipating stationary front extends NE from the low center to 30N22W to the Madeira Islands near 33N16W. Isolated showers are possible within 150 nm either side of the boundary. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN