ZCZC MIATCPAT4 ALL TTAA00 KNHC DDHHMM BULLETIN Hurricane Harvey Intermediate Advisory Number 21A NWS National Hurricane Center Miami FL AL092017 100 PM CDT Fri Aug 25 2017 ...WEATHER CONDITIONS DETERIORATING AND WATER LEVELS RISING ALONG THE TEXAS COAST... SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...27.1N 96.3W ABOUT 85 MI...140 KM ESE OF CORPUS CHRISTI TEXAS ABOUT 90 MI...145 KM S OF PORT OCONNOR TEXAS MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H PRESENT MOVEMENT...NW OR 325 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...945 MB...27.91 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Port Mansfield to High Island Texas A Storm Surge Watch is in effect for... * South of Port Mansfield Texas to the Mouth of the Rio Grande A Hurricane Warning is in effect for... * Port Mansfield to Sargent Texas A Tropical Storm Warning is in effect for... * North of Sargent to High Island Texas * South of Port Mansfield Texas to the Mouth of the Rio Grande A Tropical Storm Watch is in effect for... * South of the Mouth of the Rio Grande to Boca de Catan Mexico A Storm Surge Warning means there is a danger of life-threatening inundation from rising water moving inland from the coastline in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area, in this case within the next 12 to 24 hours. Preparations to protect life and property should be rushed to completion. 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. Interests in southwestern Louisiana should continue to 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 100 PM CDT (1800 UTC), the eye of Hurricane Harvey was located by a NOAA Hurricane Hunter aircraft and NOAA Doppler radar near latitude 27.1 North, longitude 96.3 West. Harvey is moving toward the northwest near 10 mph (17 km/h), but its forward speed is expected to decrease significantly during the next couple of days. On the forecast track, Harvey will make landfall on the middle Texas coast tonight or early Saturday. Harvey is then likely to meander near or just inland of the middle Texas coast through the weekend. Maximum sustained winds are near 110 mph (175 km/h) with higher gusts. Some strengthening is possible, and Harvey is forecast to become a major hurricane before it reaches the middle Texas coast. Hurricane-force winds extend outward up to 35 miles (55 km) from the center, and tropical-storm-force winds extend outward up to 140 miles (220 km). A wind gust of 56 mph was recently reported at the Corpus Christi Naval Air Station. In addition, a wind gust of 53 mph was reported at Port Aransas, and a gust to 51 mph was measured at the Bob Hall Pier near Corpus Christi. A sustained wind of 56 mph and a gust to 69 mph were measured by NOAA buoy 42020. The minimum central pressure based on data from the NOAA plane is 945 mb (27.91 inches). HAZARDS AFFECTING LAND ---------------------- RAINFALL: Harvey is expected to produce total rain accumulations of 15 to 25 inches and isolated maximum amounts of 35 inches over the middle and upper Texas coast through next Wednesday. During the same time period Harvey is expected to produce total rain accumulations of 5 to 15 inches in far south Texas and the Texas Hill Country over through southwest and central Louisiana. Rainfall of this magnitude will cause catastrophic and life-threatening flooding. 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 is expected to reach the following heights above ground if the peak surge occurs at the time of high tide... N Entrance Padre Island Natl Seashore to Sargent...6 to 12 ft Sargent to Jamaica Beach...5 to 8 ft Port Mansfield to N Entrance Padre Island Natl Seashore...5 to 7 ft Jamaica Beach to High Island...2 to 4 ft Mouth of the Rio Grande to Port Mansfield...2 to 4 ft High Island to Morgan City...1 to 3 ft The deepest water will occur along the immediate coast near and to the northeast of the landfall location, where the surge will be accompanied by large and destructive 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: All last-minute preparations should be rushed to completion since tropical storm conditions are now occurring in portions of the hurricane and tropical storm warning areas. Hurricane conditions are likely to begin within the hurricane warning area later today or tonight. Tropical storm conditions are likely to persist along portions of the coast through at least Sunday. SURF: Swells generated by Harvey are affecting the Texas, Louisiana, and northeast Mexico coasts. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. TORNADOES: A few tornadoes are possible later today through Saturday near the middle and upper Texas coast. NEXT ADVISORY ------------- Next complete advisory at 400 PM CDT. $$ Forecaster Berg NNNN