934 AXNT20 KNHC 240002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 802 PM EDT Thu Aug 23 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...TROPICAL WAVES... An east-central Atlantic tropical wave has its axis along 35W from 02N-20N, moving westward at 15 kt. The wave is embedded within a very dry and stable environment which is inhibiting significant convection at this time. Scattered showers are noted where the wave meets the monsoon trough along and south of 08N. A central Atlantic tropical wave has its axis extending along 55W from 02N-20N, moving westward at 10-15 kt. This wave is also embedded within a very dry and stable environment caused by Saharan Air Layer that is spreading westward across the Atlantic. No convection is related to this wave at this time. A west-central Caribbean tropical wave has its axis along 77W south of 20N to northwest Colombia. It is moving westward at 15-20 kt. Scattered moderate convection is observed with the portion of the wave south of 11N, and over the northern portion of the wave affecting east Cuba, Jamaica and adjacent waters. A tropical wave has its axis along 90W south of 20N, moving westward near 10-15 kt. Scattered moderate convection is over the portion of the wave affecting the Yucatan Peninsula. Scattered showers are noted between 05N-10N due to the monsoon trough's interaction with the wave. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the African coast near 13N16W to 09N21W to 09N51W. Scattered moderate convection is observed over Africa and east of 20W. ...DISCUSSION... GULF OF MEXICO... A stationary front extends across the northern gulf waters along 28N. This front is related to a 1015 mb low centered near 29N83W. A pre-frontal trough extends from central Florida near 27N83W to the NE Gulf near 25N86W. Scattered moderate convection is within 90 nm of this trough affecting mainly the Florida Peninsula. A 1019 mb high is located over the northwest Gulf near 26N96W. To the southwest, a tropical wave is enhancing convection across the Yucatan Peninsula. Refer to the section above for details. The pressure gradient across the Gulf supports light winds throughout, with a wind shift along the frontal system. In the upper levels, an upper level high centered over Texas is producing NE upper level winds over the Gulf with upper level moisture. Expect the front to dissipate this weekend. CARIBBEAN SEA... Two tropical waves are moving across the basin. Refer to the section above for details. An upper-level low is centered over the Cayman Islands near 19N81W. The low is enhancing scattered showers near the upper-low center and the tropical wave along 77W. Scattered moderate convection is over the SW Caribbean S of 12N to include Panama and Costa Rica. Expect strong nocturnal pulses of winds through the upcoming weekend along the coast of NE Colombia and W Venezuela with seas building to 9 ft. ATLANTIC OCEAN... Two tropical waves are moving across the basin. Refer to the section above for details. A stationary front is off the coast of N Florida from 32N79W to 31N80W. Scattered moderate convection is from 27N-32N west of 75W. To the east, scattered showers are over the west Atlantic from 25N-30N between 67W-73W due to an upper- level low centered near 26N72W. A surface trough extends over the central Atlantic from 26N58W to 17N59W. Scattered showers are within 120 nm of the trough. A 1024 mb high is analyzed near 38N50W. Saharan dust and associated dry air, although not as dense as in previous days, is noted mainly east of 60W on GOES-16 GEO color dust imagery. The dust is keeping convection limited to non- existent across the eastern and central Atlantic waters. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa/ERA