| Track: http://www.nhc.noaa.gov/refresh/graphics_at2+shtml/205017.shtml?cone#contents Satellite Floater: http://www.ssd.noaa.gov/PS/TROP/floaters/02L/02L_floater.html Radar: http://barbadosweather.org/Composite/kidbuuComposite_displayer.php?Product=Reflectivity&Sector=EC_centralAtlantic&Composite=Sabre Tropical Storm Bret Discussion Number 5 NWS National Hurricane Center Miami FL AL022017 500 PM AST Mon Jun 19 2017 An Air Force WC-130 invest mission this afternoon into the disturbance was able - after much effort - to find a well-defined closed circulation. The location of the center was substantially farther west than anticipated, as the system is now moving toward the west-northwest at a very quick 26 kt. Because the system has developed a well-defined center, it is now considered a tropical storm and has been named Bret. Convection continues to display robust bands on the northwestern and southeastern quadrants of the disturbance, as seen in the geostationary satellite and Trinidad radar imagery. The Hurricane Hunter mission also found maximum surface winds of about 35 kt, which agrees with the Dvorak 2.5 CI number from TAFB. These winds are only occurring in the northern semicircle due to the very quick translational velocity of the system. While the convective structure has been impressive today, it appears that the window of opportunity for the system to further develop is closing. Between interaction with the landmass of Venezuela and increasing vertical shear beginning in about a day, the intensity model guidance does not show any significant intensification. The official intensity forecast is steady state for about a day, followed by gradual weakening until dissipation in about three days. An alternative scenario - given that the disturbance has tracked left, or equatorward, of the guidance thus far - is that it could remain south of the forecast track and dissipate over Venezuela and never reach the Caribbean Sea. The system is anticipated to slow somewhat, but still move at a rapid rate toward the west-northwest until dissipation, steered by strong trade winds south of the Bermuda high. The official track forecast is based upon the HCCA corrected consensus technique and is faster compared with the previous advisory, due to the farther west initial position. FORECAST POSITIONS AND MAX WINDS INIT 19/2100Z 9.4N 59.8W 35 KT 40 MPH 12H 20/0600Z 10.1N 62.1W 35 KT 40 MPH 24H 20/1800Z 11.3N 65.3W 35 KT 40 MPH 36H 21/0600Z 12.2N 68.5W 30 KT 35 MPH 48H 21/1800Z 13.0N 73.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 22/1800Z...DISSIPATED $$ Forecaster Landsea Tropical Storm Bret Advisory Number 5 NWS National Hurricane Center Miami FL AL022017 500 PM AST Mon Jun 19 2017 ...HURRICANE HUNTER AIRCRAFT FIND THE DISTURBANCE HAS BECOME A TROPICAL STORM... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...9.4N 59.8W ABOUT 125 MI...200 KM SE OF TRINIDAD ABOUT 225 MI...365 KM SE OF GRENADA MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...WNW OR 290 DEGREES AT 30 MPH...48 KM/H MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Trinidad * Tobago * Grenada * Venezuela from Pedernales to Cumana including Isla de Margarita A Tropical Storm Watch is in effect for... * Bonaire * Curacao * Aruba A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within 24 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ At 500 PM AST (2100 UTC), the center of Tropical Storm Bret was located by an Air Force Hurricane Hunter aircraft to be near latitude 9.4 North, longitude 59.8 West. Bret is moving toward the west-northwest near 30 mph (48 km/h) and is expected to continue at a slightly slower speed over the next 48 hours. On the forecast track, the tropical storm is expected to move near or over Trinidad and the eastern coast of Venezuela tonight and early Tuesday. Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Little change in strength is forecast during the next 48 hours. Tropical-storm-force winds extend outward up to 80 miles (130 km) from the center, mainly north of the center. The estimated minimum central pressure is 1007 mb (29.74 inches). HAZARDS AFFECTING LAND ---------------------- WIND: Tropical storm conditions are expected to first reach portions of the warning area tonight, making outside preparations difficult or dangerous. RAINFALL: The disturbance is expected to produce total rain accumulations of 2 to 4 inches over the Windward Islands and the eastern coast of Venezuela tonight and Tuesday. NEXT ADVISORY ------------- Next intermediate advisory at 800 PM AST. Next complete advisory at 1100 PM AST. $$ Forecaster Landsea |