The 2017 Texas Hurricane Season Recap
The 2017 Atlantic hurricane season was the seventh most active season on record since 1851 according to the ACE Index, which measures storm intensity and duration. For the National Hurricane Center, track accuracy continued to improve, with tracks for the three strongest hurricanes of the year being 25% more accurate than average. The landfall of Hurricane Harvey ended the 12 year drought of U.S. landfalling major (Category 3 or higher) hurricanes, dating back to Wilma in 2005. The season also included two additional landfalling major hurricanes after Harvey in Texas: Irma in Florida and Maria in Puerto Rico. The total counts for the year were 17 named storms (all named storms being at minimum a tropical storm), ten hurricanes, and six major hurricanes.
Texas was impacted by two storms during the 2017 hurricane season: Tropical Storm Cindy in mid-June and major Hurricane Harvey in late August. It had been two years since Tropical Storm Bill made landfall in the middle Texas coast (the last tropical storm to do so), but it had been since 2008 (Hurricane Ike) that the last hurricane made landfall in the state. That is a nine year drought for hurricanes (of any strength) making landfall in Texas and a 12 year drought since Rita made landfall for a major hurricane making landfall in the state. Below are the tracks and satellite images of Tropical Storm Cindy and Hurricane Harvey when they were at their strongest.
The main impacts from Tropical Storm Cindy were felt along the Gulf Coast from Louisiana to Florida in the form of significant rainfall totals. Parts of Louisiana, Mississippi, and Florida saw 10 inches of rainfall, with the highest total of 18.74 inches reported out of Mississippi. For the most part, Texas was spared impacts from Cindy as the storm made landfall on the Texas/Louisiana border with the drier side of the storm impacting Texas. However, three to six inch rainfall totals were reported out of the Galveston, Star Lake, and Mahaw Bayou areas across the southeast corner of the state.
Hurricane Harvey was the major story of the summer for the state of Texas. What follows is a general overview of the storm and how it impacted Texas. For more specific information, check out the references below as each impacted National Weather Service forecast office has created a webpage dedicated to the storm with more in-depth information.
Harvey began as a tropical wave off of Africa on August 13th, a full 12 days prior to its landfall in Texas. Between the 17th and 19th it was upgraded to a tropical storm before wind shear weakened the storm as it moved through the Yucatan Peninsula. Within the span of the 23rd and 24th Harvey not only regained tropical depression status but went through rapid intensification, strengthening into a major hurricane. Harvey made landfall on Friday evening, August 25th as a Category 4 storm near Rockport, TX with 130 mph sustained winds. According to NWS Corpus Christi, wind gusts to 140 and 150 mph were observed between San Jose Island and Rockport with storm surge values of 5 through 12 feet along the middle Texas Coast. As the storm moved inland it began to weaken and slow down, becoming stationary to the southeast of San Antonio. During this time the storm dumped buckets of rainfall from La Grange eastward to Houston, causing catastrophic main stem river flooding and flash flooding in these areas. The storm then moved eastward, entering the Gulf of Mexico again and making a second landfall in Louisiana on August 30th before being downgraded to a tropical depression and moving to the northeast into the Ohio Valley.
To the right is a rainfall summary graphic produced by the NOAA Weather Prediction Center. Multiple reports of over 50 inches of rain from Harvey were gathered from Harris and Galveston counties, with two 60+ inch rainfall reports from Jefferson County. For complete rainfall, wind, and damage reports refer to the "Post Tropical Cyclone Reports" from the various NWS offices in the reference section below.
By Aaron Treadway, National Weather Service Austin/San Antonio Meteorologist