000 AXNT20 KNHC 051227 AAA TWDAT Tropical Weather Discussion...AMENDED NWS National Hurricane Center Miami FL 825 AM EDT MON SEP 5 2016 AMENDED IN ORDER TO UPDATE INFORMATION ABOUT HERMINE 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 1030 UTC. ...SPECIAL FEATURES... Post-tropical cyclone Hermine is centered near 37.9N 68.3W, about 255 nm SE of the eastern tip of Long Island. Hermine is moving northward, or 360 degrees, 3 knots. The estimated minimum central pressure is 997 mb. Maximum sustained winds are 60 knots with gusts to 75 knots. Scattered moderate convection is mainly to the N of Hermine center from 38N to 43N between 60W and 75W. Hermine should remain near hurricane strength through tonight. Gradual weakening is forecast to begin by Tuesday morning. Large waves generated by Hermine will affect the U.S. east coast from the mid-Atlantic states and expand northward along the coast of southern New England through tonight. These waves are likely to cause life-threatening surf and rip current conditions, and significant beach erosion. Please read the latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. ...TROPICAL WAVES... A tropical wave is over the central Atlc extending from 10N to 20N with axis near 38W, moving west at 10-15 kt within the last 24 hours. The wave is in a region of favorable deep layer wind shear from 10N to 20N, however continuous intrusion of Saharan dry air and dust to the wave environment is hindering convection at the time. A tropical wave is entering the Caribbean Sea. The wave extends from 10N to 19N with axis near 61W, moving W at 15 kt within the last 24 hours. A 1009 mb center of low pressure is associated with the wave, which is located near 15N61W and is expected to move NW to near 16N66W in less than 24 hours. Abundant moisture in the vicinity of the wave along with a diffluent environment aloft support heavy showers and isolated tstms from 14N to 18N between 60W and 63W. A gale warning is in effect for the Leeward Islands and adjacent waters through later this morning. A tropical wave moved to the Yucatan Peninsula, northern Central America and NE Pacific waters. The wave extends from 07N to 20N with axis near 90W, moving at 20 kt within the last 24 hours. The wave is in a favorable deep layer wind shear environment that along with diffluent flow aloft support isolated showers across the Yucatan Channel and Gulf of Honduras. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 09N13W to 10N30W to 11N45W to 11N52W. Scattered moderate to isolated strong convection is from 04N to 11N E of 16W, from 02N to 08N between 20W and 27W and from 04N to 13N between 33W and 50W. ...DISCUSSION... ...THE GULF OF MEXICO... Weak surface ridging prevails across the Gulf waters, except for the SW basin where low level moisture convergence associated with a surface trough extending from 24N97W to 18N94W support heavy showers and tstms in the Bay of Campeche W of 93W S of 22N. The ridge provides gentle to moderate E to SE winds basin-wide. Cloudiness and isolated showers are in the N-NE Gulf coast and adjacent waters associated with the remnants of a former surface trough. A tropical wave moving across the Yucatan Peninsula support isolated showers in the Yucatan Channel. Surface ridging will remain as the main feature the next two days. ...THE CARIBBEAN SEA... The main concern for the basin is a vigorous tropical wave that is moving across the Lesser Antilles. This wave is supporting heavy showers and isolated tstms from 14N to 17N between 60W and 63W. A gale warning is in effect for the Leeward Islands and adjacent waters through later this morning. This disturbance will continue to produce locally heavy rainfall and gusty winds over portions of the Lesser Antilles today, and should spread over Puerto Rico and Hispaniola during the next day or two. Please refer to the tropical waves section for details. The monsoon trough support scattered to isolated heavy showers in the SW basin within 150 nm off the coasts from Nicaragua to Colombia. Similar convection is noted over south-central waters S of 14N between 66W and 70W. Fair weather is elsewhere. Fresh to strong winds are in the Caribbean from 11N to 17N between 61W and 79W. ...HISPANIOLA... Fair weather prevails across the island due to strong subsidence aloft as indicated by water vapor imagery. Stable and fair weather is expected to continue tonight. On Monday and Tuesday, a moist air mass associated with an approaching tropical wave will support showers. Drier weather is expected by Thursday as the wave moves away westward. ...THE ATLANTIC OCEAN... Post-tropical cyclone Hermine is N of forecast waters. Please refer to the special features section for details. Two tropical waves are moving across the basin. Please refer to the tropical waves section for details. A surface trough prevails in the SW N Atlc waters from 30N72W to 29N75W to 28N79W supporting isolated showers within 60 nm either side of its axis. Another surface trough is on the northern central Atlc from 30N43W to a 1017 mb low near 29N50W with isolated showers within 30 nm either side of its axis. Lastly, a 1013 mb low detached from the tropical wave that is in the central Atlantic and support scattered heavy showers and isolated tstms from 23N to 29N between 31W and 37W. The remainder of the basin is dominated by a weak and broad surface ridge. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS