000 WTNT33 KNHC 281459 TCPAT3 BULLETIN Tropical Depression Eighteen Advisory Number 4 NWS National Hurricane Center Miami FL AL182017 1100 AM EDT Sat Oct 28 2017 ...AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT FINDS A TROPICAL DEPRESSION HAS FORMED OVER THE NORTHWESTERN CARIBBEAN SEA... ...TROPICAL STORM WATCH ISSUED FOR THE UPPER FLORIDA KEYS AND SOUTHEAST FLORIDA... SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...20.8N 82.9W ABOUT 55 MI...90 KM S OF THE ISLE OF YOUTH ABOUT 170 MI...270 KM S OF HAVANA CUBA MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...NNE OR 20 DEGREES AT 22 MPH...35 KM/H MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Tropical Storm Watch has been issued for portions of southeastern Florida and the upper Florida Keys from Craig Key to Golden Beach. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Cuban provinces of Isla de la Juventud, La Habana, Ciudad de la Habana, Matanzas, Cienfuegos, and Villa Clara * Northwestern Bahamas A Tropical Storm Watch is in effect for... * Craig Key to Golden Beach * Central Bahamas A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within the next 12-24 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, in this case within 24 hours. Interests in the Cayman Islands should monitor the progress of this system. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside the United States, please monitor products issued by your national meteorological service. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ At 1100 AM EDT (1500 UTC), the center of Tropical Depression Eighteen was located by reconnaissance aircraft and radars from Cuba and Grand Cayman near latitude 20.8 North, longitude 82.9 West. The depression is moving toward the north-northeast near 22 mph (35 km/h) and this motion is expected to continue today. A motion toward the northeast with an increase in forward speed is expected to begin tonight and continue through Sunday. On the forecast track, the center will move across west-central Cuba this afternoon, across the Straits of Florida tonight, and across the northwestern Bahamas Sunday morning. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Strengthening is forecast during the next 48 hours, and the depression is expected to become a tropical storm by tonight. The estimated minimum central pressure based on reconnaissance data is 1005 mb (29.68 inches). HAZARDS AFFECTING LAND ---------------------- RAINFALL: The depression is expected to produce the following rainfall totals: The Cayman Islands, western and central Cuba, northern Bahamas: 4 to 8 inches with isolated maximum totals of 10 inches through Sunday. These rainfall amounts may produce life threatening flash floods and mudslides. South Florida, including the Keys: 2 to 4 inches with isolated maximum totals of 6 inches through Sunday. These rainfall totals may produce flash flooding, especially in urbanized areas. WIND: Tropical storm conditions are expected to first reach the warning area in Cuba later today and the northwestern Bahamas tonight. Tropical storm conditions are possible in the central Bahamas tonight or early Sunday. TORNADOES: A couple of brief tornadoes are possible across far South Florida and the Florida Keys this afternoon and evening. NEXT ADVISORY ------------- Next intermediate advisory at 200 PM EDT. Next complete advisory at 500 PM EDT. $$ Forecaster Stewart