000 AXNT20 KNHC 192225 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 625 PM EDT Sun Mar 19 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...SPECIAL FEATURES... A vigorous middle to upper level low is centered offshore of the mid-Atlc seaboard near 36N73W that supports a partially occluded 1004 mb low centered near 40N67W. The associated cold front extends into the discussion area near 32N71W SW to the Florida peninsula near 27N80W. Near gale to gale force NW winds are expected in wake of the front tonight through late Monday morning generally N of 30N between the front and 74W. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 05N09W to the Equator near 20W. Widely scattered moderate and isolated strong convection is S of 06N between the Prime Meridian and 11W. Isolated moderate convection is elsewhere S of 06N between 11W- 17W...and S of 04N between 46W-52W. ...DISCUSSION... GULF OF MEXICO... Water vapor imagery indicates mostly dry air and stable conditions over much of the basin as westerly flow aloft continues to influence the upper level pattern. A middle to upper level low is centered over the mid-Atlc seaboard and supports a cold front analyzed across the Florida peninsula and into the Gulf waters near Fort Myers...continuing to 27N87W then to the SE Louisiana coast near 29N90W. While the front remains precipitation-free...a relatively cooler and drier airmass continues settling in across the eastern Gulf waters and Florida peninsula this evening. The remainder of the basin is under the influence of a surface ridge anchored by a 1027 mb high centered near 29N93W. The high is expected to provide gentle to moderate anticyclonic winds overnight into Monday as the front drifts SE and exits the region by late Monday. CARIBBEAN SEA... Mostly southwesterly upper level flow is noted on water vapor imagery over much of the Caribbean basin this evening. This southwesterly flow over western portions feeds NE into a vigorous middle to upper level low over the SW North Atlc off the coast of the Carolinas. An embedded mid-level shortwave trough is also noted in the vicinity of 28N63W that supports a 1016 mb low centered near 27N69W and the associated stationary front extending SW to eastern Cuba near 21N77W then to the NE coast of Nicaragua near 15N83W. Isolated showers continue to focus around the front occurring generally within 150 nm either side of the boundary. By Monday the front is expected to become diffuse across the western Caribbean as the surface low and upper level system move N of the discussion area into the central North Atlc waters. Otherwise...a few isolated showers are possible across the central Caribbean in the vicinity of a surface trough extending from 11N71W to 15N71W. These showers are expected to continue moving within gentle to moderate trade winds overnight into Monday. ...HISPANIOLA... West-southwesterly flow aloft over the island in addition to a stationary front analyzed across eastern Cuba is providing for isolated showers this evening. The front is expected to become diffuse tonight...however isolated afternoon showers remain possible on Monday due to the weakened remnant boundary lingering across the region. ATLANTIC OCEAN... Aside from the Special Features low pressure area and associated cold front analyzed across the northwestern SW North Atlc waters...a mid-level shortwave trough is noted on water vapor imagery in the vicinity of 28N63W supporting a 1016 mb low centered near 27N69W. The associated stationary front extends from the low to eastern Cuba near 21N76W with a warm front extending E-NE from the low to 29N58W then stationary to 32N47W. Isolated showers are occurring with the stationary front mainly S of 23N between 71W-78W while scattered showers and tstms are occurring N of 25N between 55W-67W in association with the warm front and mid-level shortwave dynamics. This low is expected to become absorbed by the cold front currently to the NW that will bring near gale to gale force NW winds to the northern waters tonight. In addition...northerly winds will filter in across the remainder of the SW North Atlc through early Monday as high pressure builds in to the region from the west. The remainder of the central and eastern Atlc is under the influence of a surface ridge anchored by a 1028 mb high centered S of the Azores near 35N27W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN