000 AXNT20 KNHC 292349 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 749 PM EDT Mon May 29 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...TROPICAL WAVES... A tropical wave is located over the eastern Atlantic off the coast of west Africa. The axis of the wave extends from 16N22W to 05N24W. The wave is moving west at 20 kt. TPW satellite imagery shows the wave is embedded in moderately moist environment near the ITCZ/Monsoon Trough. This wave possesses a good signature in the 700 mb wind flow field. There is no significant convection currently associated with this wave. A tropical wave located over the eastern Atlantic has an axis extending from 11N35W to 01N38W. The wave is moving west at 10 to 15 kt. TPW satellite imagery shows the wave is embedded in a moderately moist environment near the ITCZ. The wave lies just to the southeast of large area of dry air associated with the Saharan Air Layer mainly north of 10N. This wave possesses a weak signature in the 700 mb wind flow field. Scattered moderate convection is seen south of 10N between 30W-44W. A tropical wave over the western Atlantic has an axis extending from 12N59W to 02N58W. The wave is moving west at 15 to 20 kt. TPW satellite imagery shows the wave is embedded a moderately moist environment. Dry air associated with the Saharan Air Layer north of 10N is inhibiting convection along the northern portion of the wave. This wave possesses a weak signature in the 700 mb wind flow field. Scattered moderate convection is seen south of 10N between 50W-62W. A tropical wave over the eastern Caribbean and has an axis extending from 15N69W to 02N70W. The wave is moving west at 15 to 20 kt. TPW satellite imagery shows the wave is embedded in a moderately moist environment. This wave possesses a good signature in the 700 mb wind flow field. Scattered moderate convection is sheared NE of the wave's axis south of 11N between 70W-75W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends SW into the tropical Atlantic from 16N16W to 13N20W. The ITCZ begins near 08N25W to 05N36W then resumes west of a tropical wave near 04N39W to 03N51W. Isolated showers are observed along the ITCZ. ...DISCUSSION... GULF OF MEXICO... A frontal boundary stalling along the Rio Grande and SE Texas has served as the primary focus for the development of showers and thunderstorms today. A squall line moved into the west Gulf extending from 28N94W to 24N94W to 22N98W. Aside from the squall line, scattered moderate convection prevails across the western half of the basin supported by a diffluent flow aloft. A surface ridge prevails across the eastern Gulf anchored by a pair of highs centered near 29N90W and 28N84W. Expect convection to persist over the NW Gulf as the stalled frontal boundary remains inland just to the NW. Also expect showers to persist over the Bay of Campeche during the next 24 hours as upper-level divergence associated with the upper-level trough serves as a catalyst for deep convection. CARIBBEAN SEA... A tropical wave is passing over the E Caribbean. See the Tropical Waves section for more details. The Monsoon Trough extends over Costa Rica, Panama and Northern Colombia supporting scattered moderate convection associated S of 11N. A broad upper-level ridge extends north over the Caribbean from Central and South America. An upper level trough passes just north of the Caribbean from the Bahamas to Puerto Rico. Subsident flow between the ridge and trough will generally inhibit convection, except over the islands where diurnal heating and orographic lifting is generations scattered showers and thunderstorms. Little change is expected during the next 24 hours. HISPANIOLA... Water vapor imagery shows strong subsidence over the island, hindering convection. However, patches of low-level moisture, embedded in the trade wind flow, will maintain isolated showers through the evening hours. A similar scenario will continue through the next 24 hours. ATLANTIC OCEAN... Three tropical waves are moving across the basin. Please refer to the section above for details. A surface trough extends across the west Atlantic from 31N78W to 27N79W. No convection is related to this feature at this time. A broad 1027 mb high is centered over the east Atlantic near 33N30W. This high extends across the whole basin. Saharan dry air is noted across much of the Atlantic Ocean north of 10N and east of 50W inhibiting significant convection. Expect during the next 24 hours for showers to form over the Atlantic in the vicinity of the Lesser Antilles as a tropical wave approaches. For additional information please visit http://www.hurricanes.gov/marine $$ ERA