000 AXNT20 KNHC 121801 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 201 PM EDT Sun Mar 12 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 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...SPECIAL FEATURES... An area of low pressure is forecast to develop across the offshore waters of the Carolinas Monday night leading to an increase in the pressure gradient between the low and high pressure anchored across much of the NE CONUS and over NW Atlc waters. Near gale to gale force E-SE winds are expected to develop across the SW North Atlc waters N of 30N between 68W and 73W Monday evening, continuing through Tuesday morning. 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 coast of Liberia Africa near 05N09W then continues along 05N13W to 03N20W to 02N34W. The Intertropical Convergence Zone axis extends from 02N34W SW to the coast of Brazil near 02S43W. Scattered moderate to isolated strong convection is from 01N-06N E of 23W. Isolated moderate convection is within 120 nm S of the remainder monsoon trough and within either side of the ITCZ. ...DISCUSSION... GULF OF MEXICO... Middle to upper level troughing over the E CONUS extending SW across Texas to northern Mexico supports a cold front across the northern Gulf of Mexico. The front extends across northern Florida SW to a 1018 mb low near 28N83W to 28N88W to 1016 mb low near 27N92W then SW to the southern tip of Texas where it stalls. Fresh to near gale force N-NE winds are N of the front along with scattered showers and isolated tstms as indicated by Dopler radar and GOES experimental lighting density product. A surface trough is over the Bay of Campeche from 23N92W to 18N94W with isolated showers in its vicinity. Otherwise...the remainder of the basin is under the influence of gentle to moderate E-SE winds and mostly clear skies. The area of low pressure in the NW Gulf waters is forecast to stall through Monday morning and then move to the NE basin where is going to be absorbed by a cold front that is forecast to move across the remainder Florida Peninsula Tuesday. High pressure will then build in Wednesday providing moderate N-NE winds. CARIBBEAN SEA... A middle level short-wave trough extends from Hispaniola to the SW basin and along with shallow moisture depicted by CIRA LPW imagery support scattered to isolated showers over SE Dominican Republic adjacent waters as well as across Jamaica and coastal waters. Fresh to strong winds continue along the coast of Colombia and Venezuela, however gentle to moderate winds prevail elsewhere and are expected to continue through Wednesday. Strong dry air subsidence support fair weather across the remainder basin. ...HISPANIOLA... A middle level short-wave trough extending from Hispaniola to the SW Caribbean along with shallow moisture support scattered to isolated showers over SE Dominican Republic adjacent waters. Conditions are expected to improve tonight into Monday as a frontal boundary to the N across the SW North Atlc region moves eastward and then N of the area. ATLANTIC OCEAN... A broad middle to upper level trough over the western North Atlc supports a 1018 mb low off the coast of Georgia from which a cold front extends SW across northern Florida. The upper trough also supports a cold front from 31N55W to 27N65W where it stalls and progressively weakens to the northern Bahamas. Widely scattered showers and isolated tstms are occurring within 210 nm of the low. The low and cold front will stall through Monday night and then will transition back to a cold front that will move across the Bahamas through Wednesday. The second front is forecast to move eastward and eventually become diffuse across the central Atlc waters between 50W-60W by Monday. Otherwise, surface ridging prevails across the remainder of the central Atlc and much of the eastern waters anchored by a 1037 mb high centered NE of the Azores. Embedded within the southeastern periphery of the ridge...a surface trough is analyzed from 29N30W to 24N25W supported aloft by a mid-level low centered near 28N27W. No significant convection is occurring with the trough...however strong to near gale force NE winds are noted on earlier ASCAT data N of 26N between 19W-27W. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos