737 AXNT20 KNHC 060006 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 806 PM EDT Sun Aug 5 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... A tropical wave is in the E Atlc with axis extending from 08N- 18N along 27W, moving W at 10 kt. CIRA LPW imagery show abundant shallow moisture in the wave environment. However, the wave is being severely affected by Saharan dry air and dust, which is limiting convection to isolated shower within 150 nm either side of the wave axis. A tropical wave is in the central Atlc with axis extending from 06N-20N along 37W, moving W at 15 kt. The wave continues to be affected by intrusion of Saharan dry air and dust as indicated by GOES-16 RGB and water vapor imagery at the lower levels. Shallow moisture in the vicinity of the monsoon trough support scattered moderate convection from 07N-11N between 31W-38W. A tropical wave is in the E Caribbean with axis S of 20N along 67W, moving W at 10 kt. The wave is in a very moist environment at the lower levels as indicated by CIRA LPW and GOES-16 water vapor imagery. The wave is underneath a diffluent environment between an elongated upper level low over Hispaniola and adjacent waters and SW flow, which is supporting scattered showers and tstms N of 13N between 61W and 74W. A tropical wave is in the W Caribbean with axis S of 20N along 78W, moving W at 15 kt. CIRA LPW imagery shows shallow moisture associated with the wave. However, strong deep layer wind shear and a thin layer of Saharan dust hinder convection at the time. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from 16N16W to 12N26W to 09N36W. The ITCZ begins W of a tropical wave near 07N38W and continues to 05N52W. Besides the convection mentioned in the tropical wave section, heavy showers and tstms are from 07N-10N between 43W- 46W. ...DISCUSSION... GULF OF MEXICO... The Bermuda high extends a ridge axis SW across the Florida Peninsula to the NW Gulf of Mexico providing light to locally moderate SE to E winds. A surface trough is embedded over the W Gulf from 26N90W to 23N96W. A tropical wave is also over the Bay of Campeche. See above. CIRA LPW imagery shows shallow moisture across the basin. Patches of scattered moderate convection are over the W Gulf W of 88W. In the upper levels, the western half of the Gulf is under a diffluent environment enhancing showers and tstms W of 90W. Elsewhere, over the E gulf, upper level diffluence supports showers from 23N-28N E of 86W. Expect convection and showers over the western Gulf to continue through Monday. Otherwise, surface ridging will prevail through early next week. CARIBBEAN SEA... Two tropical waves are over the Caribbean Sea. See above. Presently scattered showers are over the Leeward Islands. More showers are along the coasts of Honduras and Nicaragua. GOES-16 RGBs indicates a thin layer of Saharan dust is over the basin. This along with strong deep layer wind shear is suppressing convection over the remainder of the Caribbean. Expect a strong surface pressure gradient area N of Colombia to support fresh to near gale force winds through Friday. ATLANTIC OCEAN... A non-tropical 1011 mb low centered over the central Atlantic near 32N46W continues to produce limited shower activity. Environmental conditions are expected to be only marginally conducive for the low to acquire subtropical or tropical characteristics while it moves little over the next day or so, and then moves north-northeastward through Tuesday. A cold front extends SW from the low along 30N45W to 37N50W to 25N60W to 27N73W. Scattered moderate convection is from 26N-29N between 44W-48W. Aside from the tropical waves, the remainder the Atlc is under the influence of a surface ridges that supports fair weather. For additional information please visit http://www.hurricanes.gov/marine $$ MF/NR