000 AXNT20 KNHC 031608 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1207 PM EDT Thu Aug 3 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 1515 UTC. ...TROPICAL WAVES... A tropical wave extends from 09N24W to 17N28W moving W at 5-10 kt. The wave coincides with 700 mb troughing between 21W-29W with a stretched maximum in 850 mb relative vorticity extending from a 1014 mb low embedded within the monsoon trough near 10N19W and the southern extent of the wave near 10N24W. Scattered moderate convection associated with the low is from 05N-11N between 15W- 23W and scattered moderate convection associated with the wave is from 05N-13N between 23W-32W. A tropical wave extends from 07N47W to 17N39W moving W at 5-10 kt. The wave coincides with relatively sharp 700 mb troughing between 36W-47W. The areal extent of the Saharan Air Layer across the central tropical Atlc is inhibiting any significant deep convection with the wave at this time. A tropical wave extends from 10N67W to 19N66W moving W at 5-10 kt. The wave continues moving within the southern periphery of a mid- level ridge anchored over the SW North Atlc near 27N68W. Scattered moderate and isolated strong convection...likely enhanced due to ample upper level diffluence...is occurring from 11N-17N between 60W-71W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 13N17W to 09N20W to 09N28W. The Intertropical Convergence Zone axis extends from 10N48W to 12N66W. Aside from convection associated with the tropical waves...isolated moderate convection is from 06N-12N between 47W-60W. ...DISCUSSION... GULF OF MEXICO... A middle to upper level trough is noted on water vapor imagery over the lower Mississippi River valley this afternoon with the base of the trough extending over the NW Gulf waters. The troughing supports a surface trough extending from SE Georgia W-SW to a weak 1015 mb low near 29N90W then to the Texas coast near 28N97W. Low-level moisture convergence is maximized along this boundary with scattered showers and tstms occurring mainly N of 27N and across inland portions of SE Louisiana...southern Alabama...and northern Florida...including the panhandle region. The boundary is expected to drift northward through the evening and overnight hours with light to gentle anticyclonic winds expected to prevail Friday. Elsewhere...a surface ridge extends across the southern Florida peninsula to the east-central coast of Mexico near 20N98W. Mostly clear skies and fair conditions are expected to persist with the ridge remaining in place across the basin through Wednesday of next week. CARIBBEAN SEA... A tropical wave is moving across the eastern Caribbean generating a broad area of scattered showers and tstms generally E of 70W...and an area N of 16N between 70W-74W in the adjacent coastal waters of Hispaniola. Elsewhere...low-level moisture convergence of moderate to fresh trades is generating scattered showers and tstms from 12N-16N between 76W-85W...including inland portions of Nicaragua. As the tropical wave along 67W moves westward...fresh to strong winds are expected to accompany the wave with continued strong convection through Sunday. ...HISPANIOLA... Scattered showers and tstms are occurring across the southern adjacent coastal waters due to an approaching tropical wave across the eastern Caribbean Sea. The tropical wave is expected to pass S of the island tonight into early Friday and then across the remainder of the central Caribbean on Friday. Continued scattered showers and tstms are expected through Friday across the region with any lingering activity moving into the western Caribbean during the upcoming weekend. ATLANTIC OCEAN... Across the SW North Atlc...an upper level ridge remains anchored in the vicinity of 28N72W supporting a ridge axis extending from near 28N73W W-SW to the southern Florida peninsula and into the southern Gulf of Mexico. Mostly fair skies and tranquil conditions prevail with only a few possible isolated showers and tstms occurring N of 30N W of 77W as a weak elongated area of low pressure extends from southern South Carolina to the north- central Gulf of Mexico. The ridge is forecast to build in during the weekend keeping any significant deep convection generally N of the discussion area. Farther east...a mid-level shortwave trough is noted on water vapor near 34N66W providing focus for scattered showers and tstms occurring from 30N-34N between 64W-69W. Otherwise...the remainder of the central and eastern Atlc are under the influence of a surface ridge anchored by a pair of 1026 mb highs...one centered S of the Azores near 34N27W and the other centered near 31N49W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN