BULLETIN Hurricane Delta Intermediate Advisory Number 13A NWS National Hurricane Center Miami FL AL262020 700 PM CDT Wed Oct 07 2020 ...DELTA STRENGTHENING WHILE MOVING OVER THE SOUTH-CENTRAL GULF OF MEXICO... ...LIFE-THREATENING STORM SURGE AND DAMAGING WINDS INCREASINGLY LIKELY ALONG PORTIONS OF THE NORTHERN GULF COAST BEGINNING FRIDAY... SUMMARY OF 700 PM CDT...0000 UTC...INFORMATION ---------------------------------------------- LOCATION...22.3N 90.2W ABOUT 550 MI...890 KM SSE OF CAMERON LOUISIANA MAXIMUM SUSTAINED WINDS...90 MPH...150 KM/H PRESENT MOVEMENT...NW OR 305 DEGREES AT 17 MPH...28 KM/H MINIMUM CENTRAL PRESSURE...973 MB...28.73 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has changed the Hurricane Warning from Rio Lagartos to Dzilam, Mexico to a Tropical Storm Warning, and discontinued all warnings for the remainder of the Yucatan Peninsula. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Watch is in effect for... * High Island Texas to the Alabama/Florida border including Calcasieu Lake, Vermilion Bay, Lake Pontchartrain, Lake Maurepas, Lake Borgne and Mobile Bay A Hurricane Watch is in effect for... * High Island Texas to Grand Isle Louisiana A Tropical Storm Warning is in effect for... * Rio Lagartos to Dzilam Mexico A Tropical Storm Watch is in effect for... * San Luis Pass to west of High Island Texas * East of Grand Isle Louisiana to Bay St. Louis Mississippi, including New Orleans * 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 Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. 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 OUTLOOK ---------------------- At 700 PM CDT (0000 UTC), the center of Hurricane Delta was located by an Air Force Hurricane Hunter aircraft near latitude 22.3 North, longitude 90.2 West. Delta is moving toward the northwest near 17 mph (28 km/h). A northwestward motion with a reduction in forward speed is expected through early Thursday. A north-northwestward motion is expected by late Thursday, and a faster northward to north-northeastward motion is forecast on Friday and Friday night. On the forecast track, the center of Delta will move over the southern and central Gulf of Mexico through Thursday, and approach the northern Gulf coast within the hurricane watch area on Friday. Delta is forecast to move inland within the hurricane watch area by late Friday or Friday night. Maximum sustained winds have increased to near 90 mph (150 km/h) with higher gusts. Further strengthening is forecast while the hurricane moves over the southern and central Gulf of Mexico through Thursday, and Delta is expected to become a major hurricane again. Some weakening is forecast as Delta approaches the northern Gulf coast on Friday. Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). During the past few hours, a Mexican weather station on Isla Perez, off the north coast of the Yucatan Peninsula, measured a sustained wind of 65 mph (105 km/h) and a gust to 90 mph (145 km/h). The estimated minimum central pressure is 973 mb (28.73 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Delta can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT1, WMO header WTNT41 KNHC, and on the web at www.hurricanes.gov/text/MIATCDAT1.shtml. STORM SURGE: The combination of a dangerous 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... Pecan Island, LA to Port Fourchon, LA including Vermilion Bay...7-11 ft Cameron, LA to Pecan Island, LA...4-7 ft Port Fourchon, LA to Ocean Springs, MS including Lake Borgne...4-6 ft Lake Pontchartrain and Lake Maurepas...3-5 ft Ocean Springs, MS to AL/FL border including Mobile Bay...2-4 ft High Island, TX to Cameron, LA including Calcasieu Lake...2-4 ft Sabine Lake...1-3 ft Port O'Connor, TX to High Island, TX including Galveston Bay...1-3 ft The deepest water will occur along the immediate coast near and to the east of the landfall location, where the surge will be accompanied by large and dangerous waves. 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. WIND: Tropical storm conditions are possible within the watch areas along the Gulf coast by late Thursday night or early Friday with hurricane conditions possible within the hurricane watch area by Friday. RAINFALL: Through early Thursday, Delta is expected to produce 4 to 6 inches of rain, with isolated maximum totals of 10 inches, across portions of the northern Yucatan Peninsula. This rainfall may result in areas of significant flash flooding. Friday through Saturday, Delta is expected to produce 4 to 8 inches of rain, with isolated maximum totals of 12 inches across portions of the central Gulf Coast north into portions of the Lower to Middle Mississippi Valley. These rainfall amounts will lead to flash, urban, small stream and minor to isolated moderate river flooding. As Delta moves farther inland, 1 to 3 inches of rain, with locally higher amounts, is expected in the Ohio Valley and Mid Atlantic this weekend. TORNADOES: The risk of a few tornadoes will increase late Thursday night into Friday over portions of southern Louisiana, southern Mississippi, and southwest Alabama. SURF: Swells from Delta will begin to affect portions of the northern and western Gulf coast on Thursday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.