159 AXNT20 KNHC 141557 TWDAT Tropical Weather Discussion...Updated NWS National Hurricane Center Miami FL 1157 AM EDT Sat Jul 14 2018 Updated Special Features section to include remnants of Beryl information 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 0600 UTC surface analysis and satellite imagery through 1530 UTC. ...SPECIAL FEATURES... An area of low pressure, associated with the remnants of Beryl, is located about 235 nm north-northwest of Bermuda. Satellite imagery indicates that the associated deep convection is becoming better organized, and if current trends continue advisories on a subtropical or tropical cyclone could be re- initiated later today. The convection consists of moderate isolated strong convection has increased during the morning within 180 nm north-northeast of the center. The low pressure now has a high chance of becoming a tropical cyclone during the next 48 hours. Refer to the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for more information. SW Caribbean gale warning off coast of Colombia: NE gale-force winds that occurred within 90 nm off the coast of Colombia during the overnight hours have diminished to strong to near gale force. Resultant seas with the recent gale force winds are in the 10-13 ft range from 11N-14N between 74W and 75W. The pressure gradient will tighten up again tonight into early Sun, and from Sun night into early Mon to allow for a repeat pulsing of the NE gale force winds to once again develop within the same area. Model guidance indicates that these winds will once again pulse to minimal gale force Tue night until early on Wed morning. Seas are expected to build to the range of about 10-14 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 far eastern Atlantic broad tropical wave as seen in early morning visible satellite imagery has its axis along 21W from 08N to 18N, moving westward at 10-15 kt. Scattered moderate convection associated with this wave is along its southern extent tied mainly to the monsoon trough, and it is noted from 08N-10N between 21W- 25W. Similar convection is behind the wave from 08N- 10N between 14W-16W and from 10N-12N between 17W-19W. A central Atlantic tropical wave has its axis extending from near 20N47W to 10N51W. This wave is observed as having a broad inverted-V shape cloud structure as seen in satellite imagery as it moves westward at 15-20 kt. The wave is moving through a rather dry and stable environment, and is void of deep convection. Only isolated showers and thunderstorms are seen behind the axis from 08N-12N between 41W-45W. An eastern Caribbean Sea tropical wave has its axis along 65W/66W S of 19N, moving westward at 15 kt. The northern portion is approaching the vicinity of Puerto Rico. Expect increasing moisture with scattered showers and isolated to affect some areas of the eastern Caribbean through tonight in the wake of the wave. This shower and thunderstorm may be further aided by an upper- level trough that extends from the Mona Passage to the far SW Caribbean. A central Caribbean Sea tropical wave has its axis along 75W, moving westward at 15 kt. The northern extent of this wave is passing across the Windward Passage. No significant deep convective precipitation is noted in latest satellite imagery, however isolated showers moving quickly westward are possible near the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal areas of Guinea Bissau near 11N15W, to 10N20W and 10N28W. The ITCZ continues from 10N28W to 09N32W 10N41W, 09N48W, 10N54W, and 08N60W. Aside from convection associated with the tropical wave along 21W, only scattered moderate convection is seen within 60 nm north of the ITCZ axis between 59W-60W, and west to just inland northeastern Venezuela. ...DISCUSSION... GULF OF MEXICO... A ridge continues to dominate the Gulf waters, with two weak high pressure centers of 1021 mb located across the northern Gulf. Under the influence of this system, mainly light to gentle anticyclonic flow will prevail across much of the Gulf region this upcoming weekend, with seas generally under 5 ft. Gentle to moderate SE-S winds are expected across the western Gulf on the western periphery on the ridge. According to the GOES-16 RGB Geocolor imagery, African dust has reached the SE Gulf, including the Yucatan Channel. Weak high pressure will prevail across the area through Wednesday. 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. CARIBBEAN SEA... Two tropical waves will continue to move across the basin. Refer to the Tropical Waves section above for details. A gale warning is in effect for the waters near the coast of Colombia. Refer to the Special Features section above for more information on this event. Saharan dust covers most of the Caribbean Sea, including the Greater Antilles, where partly cloudy and hazy conditions prevail. A tropical wave along 75W will move across the central Caribbean Sea through tonight, then across the western Caribbean Sea on Sun and Sun night. An eastern Caribbean Sea tropical wave will move through the rest of the eastern Caribbean Sea today, and into the central Caribbean Sea tonight. A central Atlantic tropical wave, with axis from 20N47W to 10N51W is forecast to reach the easternmost sections of the Caribbean Sea by late Sun into early Mon, move across the central Caribbean Sea late Mon into early Tues, and then into the western Caribbean Sea late Tues into early Wed. High pressure will build across the region behind each passing tropical wave, in order to freshen trade winds across the central Caribbean Sea. ATLANTIC OCEAN... A surface trough extends from the Special Features low pressure associated with the remnants of Beryl southwestward to 32N68W 28N72W and to the NW Bahamas. Scattered to numerous showers and thunderstorms are noted southeast and south of the trough north of 27N between a line from 32N62W to 27N65W and 73W. The trough will move little through Sun night while weakening. The remainder of the Atlantic forecast area is under the influence of the Bermuda-Azores High, with a center of 1033 mb located WNW of the Azores near 37N41W. Its associated ridge extends southwestward to the northeastern 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 this weekend. 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 the next few days. For additional information please visit http://www.hurricanes.gov/marine $$ Aguirre