000 AXNT20 KNHC 221038 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 638 AM EDT Tue Aug 22 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 1015 UTC. ...SPECIAL FEATURES... A tropical wave extends from 24N87W to 13N88W moving W-NW at 10-15 kt. The remnant circulation of Harvey continues to be analyzed as a 1011 mb low pressure along the wave axis near 18N88W. Scattered moderate to isolated strong convection is from 18N-23N between 79W-89W. Satellite images and surface observations indicates the low is along the coast of N Belize. Tropical cyclone development is expected when the system moves over the Bay of Campeche tonight or early Wednesday, and a tropical depression is likely to form over the southwestern Gulf of Mexico on Wednesday or Thursday. Regardless of development, locally heavy rainfall and gusty winds are expected to spread westward across Belize and the Yucatan peninsula during the next day or so. There is a high chance for this system to become a tropical cyclone within 48 hours. ...TROPICAL WAVES... A tropical wave extends from 24N29W to 10N32W moving W at 15-20 kt. A 1011 mb low pressure precedes the wave centered near 12N38W. Scattered moderate convection is from 09N-14N between 25W-33W. This wave in a moist area based on TPW imagery and has a well pronounced 700 mb trough. A tropical wave extends from Puerto Rico near 19N67W to Venezuela near 10N68W, moving W at 20-25 kt. Isolated showers are within 120 nm of the wave axis. Subtle troughing is noted on 700 mb streamline analysis. Some moisture is observed on either side of the wave axis based on the SSMI TPW animation. This wave will cross the central Caribbean through mid-week. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 18N16W to 18N27W to 12N38W to 07N42W to 07N46W. The Intertropical Convergence Zone axis continues from 07N46W to 06N58W. Besides the convection mentioned in the tropical wave section, scattered moderate to isolated strong convection is along the coast of W Africa from 08N-14N between 12W-17W. Isolated moderate convection is from 05N-08N between 35W-43W. ...DISCUSSION... GULF OF MEXICO... Weak surface ridging is over the Gulf of Mexico with axis along 30N. 10-15 kt easterly surface flow is over the N Gulf. The northern extent of a tropical wave is producing scattered moderate to isolated strong convection over the SE Gulf of Mexico, Yucatan Channel, and the N Yucatan Peninsula. Scattered showers and isolated thunderstorms are also advecting over S Florida from the Atlantic. In the upper levels, an upper level low is centered over the W Gulf near 27N91W enhancing showers. Expect over the next 24 hours for the upper level low to remain quasi-stationary and continue to produce showers. Looking ahead, the remnant low of Harvey and tropical wave, will traverse the Yucatan Peninsula today, and then move into the Bay of Campeche Wednesday, where redevelopment to a tropical cyclone appears likely. CARIBBEAN SEA... The remnant low of Harvey currently located over N Belize continues to be the primary area of concern across the basin. Please, see Special Features section for more details. A tropical wave is over the eastern Caribbean. Please, see the Tropical Waves section for details. Patches of low-level moisture embedded in the trade wind flow are noted over parts of the east and central Caribbean. Fresh SE winds are observed per scatterometer data across the central Caribbean, but mainly N of 13N. These winds are the result of the pressure gradient between the Atlantic ridge and the remnant low of Harvey. ...HISPANIOLA... Presently, showers are over SW Haiti. However,daytime heating, local sea breezes and mountain upslope lifting will combined with available moisture to produce scattered showers and thunderstorms during the afternoon and evening hours today. The next tropical wave is forecast to pass just south of the island tonight into Wednesday. ATLANTIC OCEAN... A trough of low pressure continues to move westward across the Bahamas and now extends from 29N77W across the N Bahamas to central Cuba near 22N79W. This system continues to produce disorganized showers and thunderstorms, with fresh to strong winds mainly on its NW side based on scatterometer data. Only slow development of this system is anticipated today while it moves west-northwestward towards Florida. Farther east, there is another surface trough that extends 24N55W to 16N55W. Scattered moderate convection is from 23N-25N between 51W-54W. An upper- level low is also centered near 27N59W. A 1022 mb high is centered W of Bermuda near 32N72W. Another 1022 mb high is centered over the central Atlantic near 32N48W. The tail end of a cold front is over the E Atlantic from 31N32W to 28N40W. Scattered showers are within 90 nm of the front. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa