000 WTNT31 KNHC 261146 TCPAT1 BULLETIN Subtropical Storm Alberto Intermediate Advisory Number 4A NWS National Hurricane Center Miami FL AL012018 700 AM CDT Sat May 26 2018 ...ALBERTO MOVING NORTHWARD TOWARD THE SOUTHEASTERN GULF OF MEXICO... ...HEAVY RAINFALL EXPECTED TO AFFECT WESTERN CUBA...FLORIDA...AND THE NORTHEASTERN GULF COAST THROUGH THE WEEKEND... SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...20.9N 85.1W ABOUT 120 MI...195 KM ENE OF COZUMEL MEXICO ABOUT 70 MI...115 KM S OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...N OR 10 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has discontinued the Tropical Storm Watch for the Yucatan Peninsula. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Watch is in effect for... * Horseshoe Beach Florida to the Mouth of the Mississippi River A Tropical Storm Watch is in effect for... * Cuban province of Pinar del Rio * Indian Pass Florida to Grand Isle Louisiana * Lake Pontchartrain and Lake Maurepas A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. A Tropical Storm Watch means that tropical storm conditions are possible in the watch area in Cuba, in this case within the next 24 hours. A Tropical Storm Watch means that tropical storm conditions are possible in the United States portion of that watch area within 48 hours. 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 OUTLOOK ---------------------- At 700 AM CDT (1200 UTC), the center of Subtropical Storm Alberto was located near latitude 20.9 North, longitude 85.1 West. The storm is moving toward the north near 9 mph (15 km/h). A northward or north-northeastward motion is expected today, followed by a turn to the northwest on Sunday. On the forecast track, the center of Alberto is expected to move near the western tip of Cuba today, track across the eastern Gulf of Mexico Saturday night through Monday, and approach the northern Gulf Coast in the watch area Monday night. Maximum sustained winds remain near 40 mph (65 km/h) with higher gusts. Gradual strengthening is forecast until the system reaches the northern Gulf Coast by Monday night. Winds of 40 mph extend outward up to 140 miles (220 km) mainly to the east of the center. The estimated minimum central pressure based on data from a NOAA buoy is 1005 mb (29.68 inches). HAZARDS AFFECTING LAND ---------------------- RAINFALL: Alberto is expected to produce total rain accumulations of 10 to 15 inches with isolated totals of 25 inches across the western Cuba. These rains could produce life-threatening flash floods and mudslides. Rainfall accmumulations of 3 to 7 inches with maximum amounts of 10 inches are possible across the Florida Keys and southern and southwestern Florida. Heavy rain will likely begin to affect the central Gulf Coast region and the southeastern United States later this weekend and continue into early next week. Flooding potential will increase across this region early next week as Alberto is forecast to slow down after it moves inland. WIND: Tropical storm conditions are possible within the watch area in Cuba today. Tropical storm conditions are possible within the United States watch area beginning on Sunday. STORM SURGE: The combination of storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Horseshoe Beach to the Mouth of the Mississippi River...2 to 4 ft The deepest water will occur along the immediate coast. Surge- related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office. TORNADOES: A tornado or two may occur over the Florida Keys and parts of southwestern Florida this evening and tonight. SURF: Swells generated by Alberto are affecting portions of the coast of eastern Yucatan Peninsula and western Cuba. These swells are likely to cause life-threatening surf and rip current conditions. Hazardous surf conditions are likely to develop along much of the central and eastern U.S. Gulf Coast through the weekend. For more information, consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 1000 AM CDT. $$ Forecaster Brown