552 AXNT20 KNHC 141214 CCA TWDAT Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 805 AM EDT Sat Jul 14 2018 Corrected Atlantic Ocean Section 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 1145 UTC. ...SPECIAL FEATURES... ...Gale Warning off the coast of Colombia in the Caribbean Sea... NE gale-force winds that were occurring from 11N to 12N between 74W and 75W during the overnight hours are diminishing to near gale force this morning. Resultant seas with these winds are in the 10-13 ft range. The pressure gradient will tighten up again tonight on Sun night until daybreak on Mon to allow for NE gale force winds to once again develop within the same area, and pulse again from late on Tuesday night until sunrise on Wednesday 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 passing 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. The northern part of a tropical wave will move westward across the SW corner of the Gulf today. 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 south-central Caribbean. Refer to the Special Features section above for more information. 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...Corrected An area of low pressure, associated with the remnants of Beryl, is located about 250 miles north-northwest of Bermuda. This system has become better organized during the past several hours, and it is producing winds of near gale force east of the center. Some additional development is possible today and tonight, and a subtropical or tropical cyclone could form before the system moves over cold water north of the Gulf Stream on Sunday. The latest Tropical Weather Outlook gives this system a medium chance of tropical cyclone formation during the next 48 hours. A surface trough extends from the aforementioned weak low to the NW Bahamas. The trough will move little through Sun night while weakening. Scattered showers and isolated thunderstorms can be expected along and southeast of the trough. A recent scatterometer pass clearly indicates the wind shift associated with this trough. The remainder of the Atlantic forecast area is under the influence of the Bermuda-Azores High, with a center of 1034 mb located WNW of the Azores near 39N38W. The ridge extends SW into the NE 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. A surface trough passes through 31N69W to 28N72W, to the NW Bahamas. The trough will move little through Sun night while weakening. Scattered showers and thunderstorms can be expected along and SE of the trough to 25N. 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 period. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos/Aguirre