072 AXNT20 KNHC 150605 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 AM EDT Sun Jul 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 0545 UTC. ...SPECIAL FEATURES... Subtropical storm Beryl is centered near 38.1N 65.4W as of 15/0300 UTC or about 345 nmi north of Bermuda, moving NNE at 11 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Little change in strength is forecast tonight. After that, Beryl should weaken as it moves over colder water, and the cyclone is expected to degenerate into a remnant low pressure area on Sunday or Sunday night. Isolated showers are within 90 nm of Beryl's center. A surface trough is ahead of Beryl, extending from 37N62W to 30N67W to Andros Island in the Bahamas. Scattered moderate to isolated strong convection is within 180 nm ahead of the trough N of 27N. Refer to the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC and high seas forecasts issued by the National Weather Service under AWIPS header NFDHSFAT1 and WMO header FZNT01 for more information. SW Caribbean gale warning off the coast of Colombia: NE gale force winds are forecast to resume near 0600 UTC today and continue through the early afternoon. The pressure gradient will tighten up again in the evening, and gale force winds will resume once more around 0600 UTC Mon from 11N to 12N between 74W and 75W. Model guidance indicates that these winds will pulse to minimal gale force at night Tue and Wed. Seas are expected to build to 11-12 ft with these wind conditions. Please read the High Seas Forecast, under the AWIPS/WMO headers HSFAT2/FZNT02 KNHC, for more details. ...TROPICAL WAVES... A tropical wave is in the E Atlantic with axis extending from a 1014 mb low near 08N27W to 15N26W, moving W at 10-15 kt. The wave is in a low to moderate deep layer wind shear environment and GOES-16 RGB's show massive Saharan dry air and dust continue to affect the wave. This is limiting convection solely to the region of the monsoon trough where scattered moderate convection is from 06N to 09N between 23W and 32W. A tropical wave is SE of the Lesser Antilles with axis extending from 05N57W to 18N55W, moving W at 15-20 kt. The wave is in a low to moderate deep layer wind shear environment, however continues to be severely impacted by Saharan dry air and dust intrusion to its environment, which is hindering convection at this time. A tropical wave is in the central Caribbean Sea with axis extending from inland Venezuela near 09N72W to central Hispaniola, moving W at 10-15 kt. CIRA LPW show abundant shallow moisture in this region of the basin, however strong deep layer wind shear in this region is limiting convection to isolated showers between 66W and 75W. A tropical wave is in the W Caribbean Sea with axis extending from 08N80W to 20N78W, moving westward at 15 kt. GOES-16 water vapor imagery at the lower levels show the wave is in a very dry environment that along with strong deep layer shear hinder convection at the time. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coastal areas of Africa near 10N15W to a 1014 mb low near 08N27W to 07N33W, where scatterometer data indicates there is a transition to the ITCZ. The ITCZ the continues along 06N41W to 04N52W. For information about convection see the tropical waves section. ...DISCUSSION... GULF OF MEXICO... High pressure ridging from a 1019 mb high center at 27N88W continues to dominate the basin allowing for generally light to gentle anticyclonic flow, which is forecast to prevail through early Wed. Seas will remain on the rather low side, generally under 5 ft. Gentle to moderate southeast to south winds will continue over the far western gulf W of 95W through the same period. GOES-16 RGB imagery continue to show African dry air and dust moving now over the Yucatan Peninsula and the Bay of Campeche. This dry air is also being captured by the CIRA LPW imagery. Otherwise, a surface trough will move westward off the Yucatan Peninsula each evening through Wednesday. It will enhance nocturnal winds in the SW corner of the Gulf and off the W Yucatan Peninsula to moderate. CARIBBEAN SEA... Two tropical waves will continue to move across the basin. Refer to the Tropical Waves section above for details. A gale warning continues in effect for the waters near the coast of Colombia. Refer to the Special Features section above for more information on this event. Scattered moderate convection and isolated tstms are occurring within 90 nm off the coasts of western Panama and Costa Rica being supported by the E Pacific monsoon trough. Except for isolated showers associated with the tropical wave along 72W, the remainder basin lacks convection due to a very dry environment at the lower levels as indicated by the GOES-16 water vapor imagery. Except for the NW Caribbean, strong deep layer shear is present, which is also supporting stable conditions. No major changes expected through the middle of the week. Otherwise, hazy conditions are expected to continue across the basin associated with the Saharan Air Layer. ATLANTIC OCEAN... See Special Features section above for the latest information on Subtropical Storm Beryl. The remainder of the Atlantic forecast area is under the influence of the Bermuda-Azores High, with a center of 1032 mb located WSW of the Azores. Its associated ridge extends southwestward to the northern Caribbean and the SE Bahamas. High pressure building westward from the central Atlantic through Tue will support fresh to strong trade winds south of 23N W of 65W. Winds will pulse to strong north of Hispaniola at night through today. High pressure building westward from the central Atlantic Ocean through Wed will support fresh to strong trade winds south of 23N. The winds will pulse to strong north of Hispaniola at night through early Mon. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos