000 AXNT20 KNHC 051022 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 622 AM EDT Sat Aug 5 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 1011 mb low is several hundred miles southwest of the Cabo Verde Islands near 10N33W. The low is moving west at 10 kt. The low is in a region of low vertical wind shear. CIRA LPW imagery shows a very moist environment around the low. Scattered showers are within 90 nm of the low center. There is a medium chance for this system to become a tropical depression by early next week across the eastern or central tropical Atlc. ...TROPICAL WAVES... A tropical wave is over the E Atlantic with axis extending from 18N34W to 08N35W, moving W at 15 kt. This wave has broken away from the special feature low mentioned above. The wave is in a moist environment. Dry Saharan air is noted N of 18N. A surface trough depicts the wave axis. Widely scattered moderate convection is from 07N-12N between 35W-43W. A tropical wave is in the central Atlantic with axis extending from 20N47W to 11N48W, moving west at 10 kt. The wave is in a moist environment as seen on SSMI TPW imagery. The wave has a 700 mb trough W of the current position. The wave is in a region of low vertical wind shear. No significant convection is noted at this time. A tropical wave is in the central Caribbean with axis extending from 19N74W to 09N74W, moving west at 10 kt. The wave is in a very moist environment as seen on SSMI TPW imagery. The wave is under a distinct 700 mb trough. The wave is in a region of strong vertical wind shear. Clusters of scattered moderate to isolated strong convection are over the S Caribbean and N Colombia from 07N-16N between 71W-79W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 13N16W to 13N25W to 08N35W to 11N45W. The Intertropical Convergence Zone axis extends from 12N49W to 07N58W. Aside from convection associated with the tropical waves, scattered moderate convection is from 11N-15N between 52W-56W. ...DISCUSSION... GULF OF MEXICO... Weak surface ridging is over the N Gulf of Mexico. Scattered showers linger over the NE Gulf of Mexico N of 28N and E of 90W. Further S, a surface trough is over the Yucatan Peninsula from 21N89W to Guatemala near 14N92W. Scattered moderate convection is over the Bay of Campeche from 17N-20N between 91W-94W. In the upper levels, a broad upper level trough is over the N Gulf N of 27N with upper level moisture and cloudiness. Expect over the next 24 hours for airmass showers and thunderstorms to A 1014 mb low is centered inland over S Mississippi near 32N90W reform over the N Gulf during the afternoon and evening hours Sat. CARIBBEAN SEA... A tropical wave is moving across the central Caribbean. See above. Fresh to strong winds are in the vicinity of this wave. Scattered showers and isolated thunderstorms linger over the W Caribbean and Central America. In addition the extension of the Pacific monsoon trough is producing scattered moderate convection over the SW Caribbean, Panama, and Costa Rica, S of 11N. Further more, scattered showers are over the NE Caribbean between 62W-73W. Of note in the upper levels, a small upper level low is centered over Hispaniola near 18N72W. Upper level diffluence E of the center is enhancing the showers over the NE Caribbean. Expect over the next 24 hours for the Caribbean and Central America to remain in a very moist environment S of 18N, and thus showers and thunderstorms will build during the afternoon and evening hours Sat. ...HISPANIOLA... Scattered showers are occurring across the Island mainly S of 19N. This shower activity is associated with a tropical wave moving over the central Caribbean. The tropical wave is expected to be W of the island by Saturday night, however shower activity is forecast to linger through early Sunday morning. ATLANTIC OCEAN... A tropical low and two tropical waves are over the tropical Atlantic. See above. Scattered showers linger along the N Florida coast N of 29N W of 79W. Otherwise, the remainder of the Atlantic is under the influence of surface highs anchored near 29N69W, and 30N50W. Of note in the upper levels, an upper level low is centered near 24N56W with upper level diffluence S and W of the center producing scattered showers. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa