000 AXNT20 KNHC 150511 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 111 AM EDT Fri Jun 15 2018 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...TROPICAL WAVES... A tropical wave is in the E Atlantic with axis extending from 13N27W to 03N29W, moving W at 10 kt. The CIRA LPW shows moderate moisture associated with the wave. The GOES-16 Geocolor RGB imagery shows the presence of the Saharan Air Layer dust and dry air N of the wave at 15N. Isolated moderate convection is within 120 nm of the wave axis S of 9N. A tropical wave is in the central Atlantic with axis extending from 13N44W to 03N44W, moving W at 10-15 kt. GOES SAL and Dust RGBs show the wave has dry air and dust N of 13N. Upper level diffluent flow and shallow moisture in the vicinity of the ITCZ supports widely scattered moderate convection from 04N to 11N between 35W and 43W. A tropical wave is just E of the Windward Islands with axis extending from 14N59W to 03N60W, moving W at 5-10 kt. The Saharan Air Layer dust and dry air is N of 10N. The wave is mostly void of precipitation. A tropical wave is over the W Caribbean with axis extending from 19N80W to 11N80W, moving west at 10 kt. Isolated moderate convection is within 120 nm of the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 12N15W to 08N20W. The ITCZ extends from 08N20W to 07N27W, then resumes west of a tropical wave near 07N30W continuing to 07N43W, then resumes again west of another tropical wave near 07N46W and continues to the coast of South America near 06N56W. Besides the convection mentioned in the tropical waves section, scattered moderate convection is within 120 nm either side of the axis E of 26W to the coast of Africa. Scattered moderate convection is also from 06N-11N between 36W-42W. ...DISCUSSION... GULF OF MEXICO... A surface ridge extends over the Gulf of Mexico with axis along 29N. 05-20 kt SE winds are over the Gulf with strongest winds along the N coast of the Yucatan Peninsula and the weakest winds over the NE Gulf. Scattered showers remain over the E Gulf E of 89W to include Florida and the Straits of Florida. In the upper levels, a low is centered over the SW Gulf near 26N92W. Upper level diffluence is E of the center over the E Gulf enhancing convection. A broad area of showers and thunderstorm continues over the Yucatan Peninsula. This activity is expected to persist through Friday, and then will move slowly northwestward during the weekend. Development of this disturbance, if any, should be slow to occur due to strong upper-level winds. CARIBBEAN SEA... A tropical wave is over the W Caribbean. See above. Scattered moderate to isolated strong convection is inland over Central America from the Yucatan Peninsula to Panama. Similar convection is over N Colombia. 15-30 kt tradewinds are over the Caribbean with strongest winds over the central Caribbean between 70W-85W. Mostly fair weather is over the E Caribbean. In the upper levels, diffluent flow is over the NW Caribbean enhancing convection. A large upper level ridge is over the remainder of the Caribbean with axis along 72W. The tropical wave in the central Caribbean will continue westward across the remainder of the basin through the early part of the weekend, while another tropical wave currently in the Tropical N Atlantic will move into the eastern Caribbean on Fri and Sat. Strong trades across the central Caribbean between 70W-85W will diminish this weekend. ATLANTIC OCEAN... Diffluent southwesterly upper level flow is over the W Atlantic. Scattered moderate convection is off the N Florida coast from 28N-30N between 78W-81W. Scattered showers remain over the Bahamas. A 1021 mb high is over the W Atlantic near 26N65W. The tail end of a stationary front is over the central Atlantic from 32N52W to 27N57W. Scattered showers are within 120 nm E of the front. A 1030 mb high is centered over the E Atlantic near 35N32W producing surface ridging over the E Atlantic N of 20N and E of 50W. Over the W Atlantic, a ridge along 26N will drift southward through Sun as a weak cold front sweeps eastward across the waters north of 25N. Moderate easterly winds are expected south of the ridge. Gentle to moderate southerly flow north of the ridge will moderate to fresh southwestly flow ahead of the front this weekend. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa