ZCZC MIATCPAT4 ALL TTAA00 KNHC DDHHMM BULLETIN Tropical Storm Harvey Advisory Number 15 NWS National Hurricane Center Miami FL AL092017 400 AM CDT Thu Aug 24 2017 ...HARVEY FORECAST TO STRENGTHEN IN THE GULF OF MEXICO... ...HURRICANE WARNING ISSUED FROM PORT MANSFIELD TO MATAGORDA... SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...23.2N 92.8W ABOUT 425 MI...680 KM SSE OF PORT OCONNOR TEXAS ABOUT 370 MI...600 KM SE OF PORT MANSFIELD TEXAS MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...995 MB...29.39 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Storm Surge Warning has been issued for the Texas coast from Port Mansfield to San Luis Pass. A Storm Surge Watch has been issued from Port Mansfield south to the Mouth of the Rio Grande. A Hurricane Warning has been issued for the Texas coast from Port Mansfield to Matagorda. A Tropical Storm Warning has been issued from north of Matagorda to High Island Texas A Tropical Storm Warning and a Hurricane Watch has been issued from south of Port Mansfield to the Mouth of the Rio Grande. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Port Mansfield to San Luis Pass A Storm Surge Watch is in effect for... * South of Port Mansfield to the Mouth of the Rio Grande * North of San Luis Pass to High Island A Hurricane Warning is in effect for... * Port Mansfield to Matagorda A Tropical Storm Warning is in effect for... * North of Matagorda to High Island * South of Port Mansfield to the Mouth of the Rio Grande A Hurricane Watch is in effect for... * South of Port Mansfield to the Mouth of the Rio Grande A Tropical Storm Watch is effect for... * South of the Mouth of the Rio Grande, Texas to Boca de Catan Mexico. 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 Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours 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 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 Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. In addition, 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 400 AM CDT (0900 UTC), the center of Tropical Storm Harvey was located by reconaissance planes near latitude 23.2 North, longitude 92.8 West. Harvey is moving toward the north near 10 mph (17 km/h). A track toward the northwest or north-northwest at a faster forward speed is expected for the next 48 hours. On the forecast track, Harvey will approach the southern Texas coast on Friday. Air Force Reserve and NOAA Hurricane Hunter aircraft report that the maximum sustained winds have increased to near 45 mph (75 km/h) with higher gusts. Some additional strengthening is forecast during the next 48 hours and Harvey is expected to become a hurricane by Friday. Tropical-storm-force winds extend outward up to 115 miles (185 km) from the center. The estimated minimum central pressure based on data from NOAA and Air Force Hurricane Hunter aircraft is 995 mb (29.39 inches). HAZARDS AFFECTING LAND ---------------------- RAINFALL: Harvey is expected to produce total rain accumulations of 10 to 15 inches and isolated maximum amounts of 25 inches over the Texas coast through next Wednesday. During the same time period Harvey is expected to produce total rain accumulations of 3 to 9 inches along its outer radius including parts of south, central, and eastern Texas and the lower Mississippi Valley. Rainfall from Harvey may cause 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... Port Mansfield to San Luis Pass...5 to 7 ft San Luis Pass to High Island...2 to 4 ft Mouth of the Rio Grande to Port Mansfield...2 to 4 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: Hurricane conditions are likely within the hurricane warning area late Friday or Friday night, with tropical storm conditions possible by Friday. SURF: Swells generated by Harvey are likely to affect the Texas, Louisiana, and northeast Mexico coasts by Friday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 700 AM CDT. Next complete advisory at 1000 AM CDT. $$ Forecaster Avila/Zelinsky NNNN