000 AXNT20 KNHC 221259 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 705 AM EDT FRI JUL 22 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 0900 UTC. ...TROPICAL WAVES... A tropical wave is moving across the east Tropical Atlantic with axis that extends from 23N30W to 12N29W, moving west near 10-15 kt over the past 24 hours. The wave coincides with a well defined 700 mb trough as depicted in the global models. Scattered moderate convection is observed in the vicinity of the southern portion of the wave but it is related to the presence of the Monsoon Trough. The wave itself is surrounded by Saharan dry air and dust which is inhibiting deep convection. A tropical wave is moving across the central Caribbean with axis extending from 20N75W to 10N77W, moving west near 20-25 kt over the past 24 hours. This wave coincides with a weak 700 mb trough as depicted in the global models and within a surge of moisture as seen on the SSMI Total Precipitable Water imagery. Isolated showers and thunderstorms prevail north of 13N affecting Jamaica and adjacent waters between 71W-75W. A tropical wave is located across the west Caribbean with axis from 23N86W to 14N88W, moving west near 10-15 kt over the past 24 hours. The wave coincides with a weak 700 mb trough as depicted in the global models and is within a surge of moisture as seen on the SSMI Total Precipitable Water imagery. Isolated showers and thunderstorms are observed north of 17N between 82W-86W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 20N17W through a 1012 mb surface low near 13N22W to 07N39W. The ITCZ begins at 07N39W and extends to 05N52W. Scattered moderate convection is within 300 nm south of the Monsoon Trough between 18W-39W. ...DISCUSSION... GULF OF MEXICO... The northern portion of a tropical wave is approaching the Yucatan Channel with isolated showers/thunderstorms. Please refer to the section above for more details. A surface trough extends across the southwest Gulf from 23N94W to 18N94W. Scattered moderate convection is observed with this boundary which is moving west over the Bay of Campeche south of 21N west of 93W. A surface ridge prevails across the remainder of the basin anchored by a 1021 mb high centered near 30N82W. A diffluent flow aloft prevails across the northeast Gulf supporting scattered showers and thunderstorms mainly north of 25N. Gentle to moderate anticyclonic flow prevails across the basin. A similar weather pattern will persist during the next 24 hours. CARIBBEAN SEA... Two tropical waves are moving across the basin. Please refer to the section above for details. The presence of the Monsoon Trough supports scattered moderate to strong convection over Colombia and Panama affecting the southern waters south of 11N between 75W-80W. Dry Saharan air prevails across the eastern Caribbean inhibiting deep convection. Scatterometer data depicts moderate to fresh trades across the basin. Expect during the next 24 hours for the waves to continue moving west with isolated convection. Little change is expected elsewhere. ...HISPANIOLA... Drier conditions will prevail within the next 24 hours as a dry Saharan airmass dominates the area. ATLANTIC OCEAN... A tropical wave is moving across the eastern Atlantic. Please refer to the section above for details. An upper-level trough dips south over the the far west Atlantic between 70W-80W supporting a frontal system and surface low just north of the discussion area. A surface trough precedes these features extending from 30N60W to 28N71W. Scattered moderate convection and thunderstorms are from 26N to 31N between 66W and 77W. The remainder of the basin is dominated by a surface ridge anchored by a 1030 mb high centered near 41N25W. A similar weather pattern will prevail through the next 24 hours. For additional information please visit http://www.hurricanes.gov/marine $$ ERA/ASL