000 AXNT20 KNHC 201744 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 144 PM EDT Sun Aug 20 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 1615 UTC. ...SPECIAL FEATURES... A tropical wave extends from 11N76W to 20N75W moving W at 15-20 kt. The remnant circulation of Harvey continues to be analyzed as a 1006 mb low along the wave axis near 15N75W with scattered to numerous moderate and scattered strong convection occurring from 12N-17N between 73W-80W. Regardless of development...the wave will enter the SW Caribbean Sea waters tonight into early Monday and approach Central America late Monday morning into the afternoon hours. Largest impacts at this point will be the expected rainfall and strong convection the wave and low pressure area will generate across interior portions of Nicaragua and Honduras on Monday shifting westward to Guatemala...Belize... southern Mexico...and the Yucatan peninsula Monday night into Tuesday. In addition to the expected rainfall...a higher probability of flash flooding and mudslides will be an ongoing hazard across this region early in the week. ...TROPICAL WAVES... A tropical wave extends from 09N52W to 17N50W moving W at 15-20 kt. The wave coincides with 700 mb troughing between 46W-53W...and a maximum in 850 mb relative vorticity in the vicinity of a fractured portion of energy N of the wave axis analyzed as a surface trough from 18N49W to 24N47W. The fractured energy is largely due to an upper level low centered to the NW of the wave centered over the central Atlc near 26N53W. No significant deep convection is associated with the wave itself...however scattered moderate convection is occurring in the vicinity of the surface trough from 19N-25N between 45W-49W. A tropical wave extends from 09N66W to 18N66W moving W at 15-20 kt. The wave coincides with weak 850 mb relative vorticity noted in global model data in the vicinity of the wave between 65W-71W. A fractured portion of energy N of the wave axis is analyzed as a surface trough from 19N67W to 27N66W and remains the focus for most of the ongoing convection. Scattered moderate convection is from 19N-26N between 63W-69W. A tropical wave extends from 10N87W to 20N86W moving W at 15-20 kt. Subtle troughing at 700 mb is noted in global model data over the NW Caribbean Sea and portions of Central America. Isolated moderate convection is from 16N-20N between 83W-89W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 14N17W to 10N25W to 07N35W. Widely scattered moderate convection is from 08N-15N between 16W-23W...and from 03N-07N between 27W-41W. ...DISCUSSION... GULF OF MEXICO... An upper level low is centered over the eastern Gulf near 24N86W and continues to provide support for a surface trough analyzed across the adjacent coastal waters of the Florida peninsula and southern portions of the peninsula from 29N80W to 24N82W. Low- level moisture convergence along with divergence aloft is generating scattered showers and tstms generally N of 23N between 80W-86W. Farther west...a surface ridge anchored by a 1016 mb high centered near 28N93W extends an axis S-SW across the western Gulf to 20N97W. A few isolated showers and tstms are occurring across the central waters from 22N-26N between 89W-93W...however elsewhere skies remain mostly cloudy within light to gentle easterly winds. With the surface ridge axis extending east-west along 30N/31N...gentle to moderate E-SE winds are expected through Tuesday. CARIBBEAN SEA... Three tropical waves continue moving across the basin this afternoon and are highlighted above. One of these waves is the special feature wave containing the remnants of Harvey. Scattered to numerous showers and scatterer strong tstms are occurring across the area from 12N-17N between 73W-80W. This wave will reach Central America by late Monday morning into the afternoon hours. Elsewhere...Scattered showers and tstms are occurring across Puerto Rico and the adjacent coastal waters N of 16N between 63W- 67W...and across the SE Caribbean S of 12N between 59W-64W. ...HISPANIOLA... Daytime heating...local sea breezes...and mountain upslope lifting will combine with available moisture and produce scattered showers and thunderstorms across the island mainly during the afternoon and evening hours this afternoon. An approaching tropical wave currently along 67W will bring increased moisture...cloudiness...and precipitation to the island on Monday. ATLANTIC OCEAN... The SW North Atlc remains under the influence of an upper level low centered over the eastern Gulf of Mexico near 24N86W and the associated surface trough extending from the Florida Keys N-NE to 29N80W. Scattered showers and tstms are occurring from 24N-31N between 77W-82W. Otherwise...the remainder of the SW North Atlc...outside of the surface trough along 67W mentioned in the tropical wave section falls within the influence of a surface ridge anchored by 1021 mb high centered near 31N67W. Elsewhere... outside of tropical wave in the vicinity of 50W...surface ridging prevails across the central and eastern Atlc anchored by a 1025 mb high centered near 31N42W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN