Hurricane Harvey: SE Texas Impacts 10 PM CDT UPDATE Friday, August 25, 2017 Prepared by: Lance Wood
Latest Observations Hurricane Harvey making landfall this evening near Rockport as a category 4 hurricane. Winds are still coming up along the upper southeast coast, will peak overnight. From Weatherflow A TCOON station at Aransas Pass recently reported sustained winds of 111 mph and a wind gust of 131 mph.
Situation Overview Hurricane Harvey a category 4 hurricane (max winds 130 mph sustained) and is making landfall this evening near Rockport. Latest models continue to show a slow movement after landfall. Could see impacts through at least Wednesday Life threatening Storm Surge inundation of: Port O'Connor to Sargent...6 to 9 ft Sargent to Jamaica Beach...4 to 6 ft Jamaica Beach to High Island...2 to 4 ft Catastrophic flooding likely from rainfall especially around and south of the I-10 corridor. Tornado threat continues with rainbands coming onshore tonight and tomorrow.
Watches and Warnings (no changes) Hurricane Warning in effect from Port Mansfield to Sargent, TX Tropical Storm Warning in effect from Matagorda to High Island Storm Surge Warning is in effect from Port Mansfield to High Island Storm Surge Watch is in effect around Galveston Bay
Watches and Warnings (continued) Flash Flood Watch in effect for all of our forecast area Flash flood threat in effect until further notice, possibly into middle of next week Watch means potential for life threatening flooding; stay alert for any later warnings
Tornado Watch Tonight Tornadoes in rainbands spin up quickly and are usually short lived. Most are EF0s but can be stronger.
Forecast Cone Next 5 days Forecast to make landfall on the Texas coast (most likely mid-coast) Friday night then stall Track of center within cone 2/3 of the time based on past errors. Note the considerable uncertainty once inland (large hatched cone after landfall) Track shape
Rainfall, Potentially Devastating Flood Threat Landfall then a slow track over the area will mean periods of heavy rain from today into at least Wednesday, possibly longer. Impacts: Widespread flooding with numerous road closures as rainfall amounts grow through the weekend. Major bayou and river flooding is expected. Structure flooding is possible. 15 to 30 inches likely with local amounts 40 inches possible across southern portions, much less well inland. There may be a tight gradient on northern edge of the rainfall pattern. Flash Flood Watches are in effect for most of the area (excluding far NE). 15+ Today Saturday Sunday
Forecast Rainfall (Through Wednesday) 2 to 4 4 to 10 10 to 15 15 to 30 inches, isolated 40 possible
River Concerns West Gulf River Forecast Center PQPF Contingency Forecasts Harvey Catastrophic Flooding Expected 7 Day Model River Forecast In Banks Action Minor Moderate Major 7 Day Model River Forecast In Banks Action Minor Moderate Major Record Catastrophic flooding expected! Record Contingency forecasts with 7 day rainfall show Major to Record flooding for a large portion of the Texas Coast and South Central Texas. Rainfall amounts will exceed 20 inches in many places. Isolated pockets will receive more than 35 inches of rainfall! Official forecasts with 72 hours of forecast rainfall available on webpage. 8/25/2017 10:44 PM www.weather.gov/wgrfc
Potential Storm Surge Flooding
Potential Storm Surge Flooding
Potential Storm Surge Flooding In most places water levels should peak at our next high tide cycle now through 130 AM Water levels wont change much through Saturday midday and should slowly recede some late Saturday night and Sunday, but will remain above normal through midweek.
Summary of Marine Impacts Tropical Storm and Hurricane conditions tonight affecting the Texas coastline into Saturday. Increasing Winds and Winds/Seas Large surf & strong rip currents Coastal Flooding TS force winds are and 12-20 foot seas are ongoing tonight. Large surf. Strong rip currents. Beach erosion. Coastal flood risk imminent. 6-12 feet inundation near landfall. 2-4 feet inundation extreme north/south Precipitation Periods of rain/storms. Tornadoes and waterspouts possible in spiral bands mainly on the right side of the track Prolonged heavy/flooding rain a good possibility. Spans several days. Potential river flooding and elevated water levels into early next week. Expect unsettled conditions along the upper Texas coast into midweek!