000 AXNT20 KNHC 131019 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 619 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 0600 UTC surface analysis and satellite imagery through 1000 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 late Monday N of 29N between 66W-72W and persist through Monday night across the SW North Atlc waters 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 05N09W to 03N21W. The Intertropical Convergence Zone axis extends from 03N21W to 02N29W to the Equator near 33W. Scattered moderate convection is S of 07N between 07W-17W. Isolated moderate convection is S of 05N between 22W-33W. ...DISCUSSION... GULF OF MEXICO... While upper level west-southwesterly flow prevails over much of the Gulf basin this morning...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 25N85W into a 1013 mb low centered near 26N94W then S-SW to 22N96W. The broad surface troughing associated with the low and middle to upper level diffluence is supporting scattered showers and isolated tstms generally W of a line from the northern coast of the Yucatan peninsula to the Tampa Bay region of Florida. Moderate to occasional fresh cyclonic winds are noted this morning with the low as it has deepened a few millibars during the last 6-9 hours and is forecast to move toward the Florida Big Bend region by this afternoon. The low will then merge with the Special Features low pressure area to develop off the coast of the Carolinas...with the associated cold front sweeping 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 portions of the north-central Caribbean...including Hispaniola... 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 NE 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 40N59W to a broad base near 33N64W. This troughing supports a stationary front from 32N65W to 30N74W to the Florida peninsula near 26N80W. Widely scattered showers and isolated tstms are occurring N of 26N W of 60W. 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 28N57W becoming stationary to 26N66W. Widely scattered showers and isolated tstms are occurring within 60 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