000 AXNT20 KNHC 292315 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Tue Jun 30 2020 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 2300 UTC. ...TROPICAL WAVES... A tropical wave is along 30W S of 10N, moving westward at around 15 kt. The tropical wave is primarily identified via GFS-based 700 mb wave diagnostics. Scattered moderate and isolated strong convection is present from 03N-06N between 28W-30W, and from 06N-08N between 30W-32W. A tropical wave extends from 19N46W to 06N53W, moving westward around 15 kt. The wave is well-defined at the surface based on the most recent scatterometer passes. Scattered moderate isolated strong convection is occurring near the northern end of the wave axis from 17-19N between 44W-46W. Scattered moderate convection is observed from 10N-13N between 49W-53W. Some slight development of this system is possible during the next day or so. Strong upper-level winds are forecast to inhibit further development by mid-week. This wave is forecast to reach the Lesser Antilles late Tue night into Wed morning. A tropical wave has entered the Caribbean Seas and extends along 63W, moving westward around 15 kt. No significant convection is evident in association with the wave. A low amplitude tropical wave is along 81W S of 14N, moving westward around 10 kt. The tropical wave is primarily identified via GFS- based 700 mb wave diagnostics. This system, combined with the eastward extent of the NE Pacific monsoon trough, is helping to induce convection over parts of Panama and Costa Rica. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from inland in Mauritania near 18N16W to 14N20W to 09N24W. The ITCZ continues from 09N24W to 06N43W. Aside from the convection associated with the tropical waves, scattered moderate convection from 06N-09N between 16W-19W and 03N-08N between 32W-40W. GULF OF MEXICO... A ridge dominates the Gulf waters anchored on a 1019 mb high pressure located near 28N85W. A thermal trough will develop this evening near the NW of the Yucatan Peninsula and will drift westward across the SW Gulf at night where it will eventually dissipate in the morning. Little change in the weather pattern and associated features is expected during the week. Under this pattern, moderate to fresh SE to S winds are expected over the western Gulf with light to gentle winds over the eastern Gulf. Fresh to strong winds will pulse each night into the early morning hours over the SW Gulf in association with the aforementioned thermal trough. Some Saharan Air Layer/African dust has moved into the SW Gulf of Mexico, though this is less extensive than the previous outbreak. CARIBBEAN SEA... A pair of tropical waves are moving across the Caribbean Sea. Please, refer to the Tropical Waves section for details. The pressure gradient between the Atlantic high pressure and the Colombian/Panamanian low is supporting fresh to strong trades across the south-central Caribbean. This is forecast to persist into the middle of the week. Winds will briefly diminish by mid- week as the area of high pressure weakens. Daytime heating, local sea breezes and available moisture are combined to produce scattered showers and thunderstorms over the Greater Antilles late this afternoon. Scattered showers and thunderstorms are also noted over much of central America. Most of the basin is covered by a moderate Saharan Air Layer/African Dust event, though visibilities are only slightly inhibited. Aside from some convection in the SW Caribbean in connection with a tropical wave and the NE Pacific monsoon trough, no other significant convection is occurring today. ATLANTIC OCEAN... Refer to the section above for details on the tropical waves moving across the area. The 1032 mb Bermuda-Azores High is located near 37N37W with a ridge extending to just north of the Bahamas. Moderate to fresh trades are noted along the southern periphery of the ridge. Some of the big Saharan Air Layer/African dust outbreak from earlier days still remains north of 25N west of 70W, though this should disperse tonight. The Saharan Air Layer from CIMSS shows African dust dominating the eastern Atlantic, just behind the tropical wave currently extending from 19N46W to 06N53W. However, this is not nearly as dense as the one from a few days ago. $$ GR