000 AXNT20 KNHC 130506 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 106 AM EDT Mon Mar 13 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 0415 UTC. ...SPECIAL FEATURES... An area of low pressure is forecast to develop across the offshore waters of the Carolinas Monday increasing the pressure gradient between the low and high pressure anchored to the N across much of the NE CONUS and adjacent NW North Atlc waters. Near gale to gale force SE winds are expected to materialize by Monday afternoon and persist through Monday night across the SW North Atlc waters N of 29N between 68W-73W in association with a frontal boundary. See latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough axis extends from the African coast near 08N13W to 05N16W to 03N22W. The Intertropical Convergence Zone axis extends from 03N22W to 01N31W to the Equator near 38W. Scattered to numerous moderate and widely scattered strong convection is S of 07N between 03W-13W. Isolated moderate convection is S of 04N between 22W-30W. ...DISCUSSION... GULF OF MEXICO... While upper level west-southwesterly flow prevails over much of the Gulf basin this evening...pockets of mid-level energy are noted on water vapor imagery embedded within weak shortwave troughing over the Gulf basin supporting a stationary front extending from the southern Florida peninsula to 25N84W into a 1014 mb low centered near 27N94W then S-SW to 23N96W. The broad surface troughing associated with the low and middle to upper level diffluence is supporting scattered showers and isolated tstms generally NW of a line from 19N96W to 25N85W. Fresh to strong E-NE winds occurring within the northern periphery of the low are expected to gradually diminish through the overnight hours. By Monday afternoon...the low is forecast to begin moving eastward as upper level dynamics provide transition of the front to a cold front...sweeping the front east of the basin by Tuesday. High pressure will build in Monday night into Tuesday behind the front providing moderate to fresh northerly winds. 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 north-central Caribbean...including Hispaniola...eastern Cuba...Jamaica...and the adjacent coastal waters. Moderate to fresh trades are expected to continue through Tuesday night. A weakening cold front is expected to bring moderate to fresh northerlies to the NW Caribbean by Tuesday night into Wednesday. ...HISPANIOLA... Isolated shower activity continues across the region including the adjacent coastal waters. Conditions are expected to improve Monday as a frontal boundary to the N across the SW North Atlc region moves eastward and then N of the area. ATLANTIC OCEAN... Middle to upper level trough is noted on water vapor imagery over the western North Atlc with axis extending from 39N64W to a broad base near 34N72W. This troughing supports a stationary front from 31N74W to the Florida peninsula near 26N80W. Widely scattered showers and isolated tstms are occurring N of 27N W of 70W. As mentioned above...an area of low pressure is forecast to develop offshore of the Carolinas by Monday night with the current stationary front becoming the focus for warm and cold front development within the system. Aside from the strong wind field forecast...the cold front will move eastward to 60W by Friday with a trailing stationary front lingering SW toward the Windward Passage region. High pressure will build in W of the front providing strong to near gale N-NW winds Tuesday night through Wednesday night. Farther east...another cold front extends into the discussion area near 32N51W SW to 27N60W becoming stationary to 26N70W. Widely scattered showers and isolated tstms are occurring within 45 nm either side of the cold front with isolated showers occurring elsewhere N of the front. Finally...the remainder of the eastern Atlc is under the influence of a surface ridge anchored by a 1040 mb high centered NE of the Azores near 42N20W. No significant convection is occurring...however near gale force E-NE winds were noted on earlier ASCAT data from 26N- 34N E of 30W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN