000 AXNT20 KNHC 061204 AAA TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 631 AM EDT TUE SEP 6 2016 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 39.6N 71.7W at 06/1200 UTC, or about 82 nm S of the eastern tip of Long Island. Hermine is moving W at 5 knots. The estimated minimum central pressure is 996 mb. Maximum sustained winds are 55 knots with gusts to 65 knots. Scattered showers are within 390 nm from the center to the NE and SW quadrants. A decrease in forward speed is expected later today, and Hermine will likely become nearly stationary by tonight. A turn toward the northeast is forecast to occur on Wednesday. Hermine is expected to produce additional light rainfall amounts not exceeding 1 inch along the mid- Atlantic and southern New England coastline from New Jersey to eastern Long Island to southeastern Massachusetts. Large waves generated by Hermine will continue to affect the U.S. east coast from the mid-Atlantic states through New England for another couple of days. 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 came off the West African coast earlier this morning. The wave extends from 06N to 18N with axis near 17W, expected to move at 10 kt within the next 24 hours. The wave is in a region of favorable deep layer wind shear and abundant low level moisture that along with diffluent flow aloft support heavy showers and tstms from 06N to 18N E of 20W. A tropical wave is over the central Atlc extending from 07N to 20N with axis near 38W, moving W at 5-10 kt within the last 24 hours. The wave is in a region of favorable deep layer wind shear and Saharan dry air and dust is not evident in its immediate environment anymore. However, both CIRA LPW show the wave axis is mainly in a dry environment, which is hindering convection and any development at the time. A tropical wave is over the central Caribbean Sea extending from 09N to 18N with axis near 70W, moving W at 20 kt within the last 24 hours. A 1010 mb center of low pressure is associated with the wave, located near 15N70W and expected to dissipate in less than 24 hours. Abundant moisture in the vicinity of the wave and a diffluent environment aloft support scattered heavy showers and isolated tstms from 15N to 18N between 68W and 70W and isolated showers elsewhere from 13N to 20N between 65W and 75W. A tropical wave extends from the Bay of Campeche to southern Mexico into the NE Pacific waters. The wave extends from 12N to 21N with axis near 94W, moving W at 15 kt within the last 24 hours. The wave is in a favorable deep layer wind shear environment that along with abundant low level moisture support scattered to isolated heavy showers and tstms across the W Bay of Campeche. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 10N14W to 05N25W to 07N35W. The ITCZ begins near 08N49W to 09N55W to 10N62W. See the tropical waves section for convection information. Otherwise, scattered moderate to isolated strong convection is from 03N to 09N between 25W and 38W. Isolated showers are within 60 nm either side of the ITCZ. ...DISCUSSION... ...THE GULF OF MEXICO... Weak surface ridging prevails across the Gulf waters, except for the far SW portion of the basin where a tropical wave along 94W is supporting scattered to isolated heavy showers in the W Bay of Campeche. Surface observations and scatterometer data indicate moderate E to SE winds basin-wide, except for locally fresh E-NE winds in the vicinity of the tropical wave axis. Cloudiness and isolated showers over the SE basin are being supported by middle to upper level diffluence. The tropical wave moving across the Bay of Campeche over the next few days will support enhanced winds and showers there. Elsewhere surface ridging will remain as the main feature the next two days. ...THE CARIBBEAN SEA... The main concern for the basin is a tropical wave that is moving across the central Caribbean. Abundant moisture in the vicinity of the wave and a diffluent environment aloft support scattered heavy showers and isolated tstms from 15N to 18N between 68W and 70W and isolated showers elsewhere from 13N to 20N between 65W and 75W. Locally strong winds are possible in some of the heavier squalls passing south of Dominican Republic. This disturbance could produce periods of locally heavy rainfall and gusty winds over portions of Hispaniola tonight and on Tuesday. Development of the wave is unlikely while it moves westward across the Caribbean Sea for the next few days. Upper-level winds could become a little more conducive for development when the wave approaches the Yucatan peninsula late this week. Please refer to the tropical waves section for details. ...HISPANIOLA... Increasing multilayered cloudiness has spread across the Dominican Republic in advance of the tropical wave along 70W. The potential for very heavy rainfall exists on Tue into Wed across the island as the strong tropical wave continues westward in the Caribbean. Drier weather is expected by Thursday as the wave moves away from the island. ...THE ATLANTIC OCEAN... Post-tropical cyclone Hermine is N of forecast waters. Please refer to the special features section for details. A surface trough, remnants of a frontal boundary, prevails across SW N Atlantic waters extending from 30N70W to 26N77W to 23N82W. Isolated showers and tstms are within 60 nm either side of the trough axis. Farther east, a second surface trough extends from 29N52W to 23N56W, however no convection is associated with it a the time. A third surface trough extends from 30N30W to 28N32W with scattered showers within 60 nm either side of its axis N of 28N. Isolated showers are within 120 nm N of the Dominican Republic and Puerto Rico coasts associated with a tropical wave in the Caribbean with axis near 68W. Lastly, a 1012 mb low in the deep tropics near 13N45W supports scattered showers from 07N to 15N between 40W and 47W. The remainder of the basin is dominated by a broad but weak surface ridge. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS/PAW