ERCOT Severe Weather Drill Hurricane Gayle May 2014

Storm Warnings (8:30 a.m. Drill Day 1) Hurricane Gayle is entering the Gulf of Mexico. Gayle is located just off the Yucatan peninsula at 21.7 N, 86.3 W moving NW @ 15 MPH. Gayle is a Category 3 storm with 125 mph winds and is expected to strengthen to a Category 4 hurricane over the next few hours. Computer models predict the probability of landfall anywhere from Corpus Christi, TX to Port Arthur, TX. (10:30 a.m. Drill Day 1) Hurricane Gayle is located at 23.1 N, 88.3 W moving NW @ 15 MPH. Gayle is now a minimal Category 5 hurricane with winds measured at 156 mph. Hurricane models have landfall probabilities to the Mid-Texas coastline. A Hurricane Watch has been issued for the Texas coast from Corpus Christi to Port Arthur. Predictions indicate a 10% probability of landfall within the next 72 hours at Freeport, a 20% probability at Port Lavaca and a 10% probability at Corpus Christi. (1:30 p.m. Drill Day 1) Hurricane Gayle is located at 24.9 N, 91.8 W moving NW @ 15 MPH. Hurricane Gayle has become a dangerous Category 5 hurricane with winds clocked at 162 mph. A Hurricane Watch remains in effect for the Texas coast from Corpus Christi to Port Arthur. A Hurricane Warning has been issued for the Texas coast from Corpus Christi to Galveston. Predictions now indicate a 20% probability of landfall at Freeport, a 40% probability at Port Lavaca and a 20% probability at Corpus Christi within the next 48 hours. (3:30 p.m. Drill Day 1) Hurricane Gayle is located at 26.7 N, 94.5 W moving NW @ 15 MPH. Gayle has weakened to a Category 4 hurricane with 153 mph winds. The highest probability of landfall is now 75% at Port Lavaca by tomorrow morning. Hurricane force winds are expected to extend out 100 miles either side of the storm creating 15-20 foot storm surges as far north as Galveston and southward towards Port Aransas. A Hurricane Warning continues from Corpus Christi to Galveston. Once Gayle makes landfall it is expected to weaken rapidly as it moves inland and then make a northerly turn as it collides with high pressure in West Texas. (08:00 a.m. Drill Day 2) Hurricane Gayle is located at 29.5 N, 97.2 W moving NNW @ 15 MPH. Gayle is moving ashore near Port Lavaca, Texas as a Category 4 storm with 135 mph winds. Gayle is expected to turn to a more Northerly path and rapidly lose strength. (10:30 a.m. Drill Day 2) Hurricane Gayle is located at 32.8 N, 97.4 W moving N @ 10 MPH placing it on a course toward Dallas. Gayle has weakened to a Category 1 Hurricane with winds of 81 mph and is expected to weaken to Tropical Storm strength within several hours. (1:00 p.m. Drill Day 2) Tropical Storm Gayle is located at 33.5 N, 97.0 W moving NNE @ 4 MPH. Gayle has been downgraded to a Tropical Storm with winds of 56 mph. Gayle is expected to remain almost stationery and dump up to 15 inches of rain per hour throughout the evening.

Wind Facts Highest wind gust = 175mph at Port Lavaca. Hurricane force winds (min 74mph)in a diameter of 300 miles. Tropical Storm force winds (min 39mph) extended to a diameter of 500 miles. Tornados reported in the following cities: Galveston had 2 (one was an F4) Bay City Channelview Hardin Jacksonville Additional wind reports: Austin = 40-50mph sustained Houston = 52mph  sustained Dallas  35mph sustained

Rain Totals Bay City – 17.48 inches Galveston – 13-15 inches Liberty – 12.55 inches Dickinson – 12.47 inches Columbus – 10.59 inches Smithville – 8.9 inches Corpus Christi – 4.73 inches Victoria – 6.25 inches Austin – 3.5 inches Waco – 2.2 inches

Storm Surge Storm surge at 10ft above sea level between Sabine Pass and Port Aransas. Highest tide reported was 18.5ft at Port Lavaca (another source states a 22ft storm surge at Port Lavaca, which is the highest surge in Texas history) Wave heights reached 10ft at Galveston 1.7 million acres were inundated with water from the storm surge.

100 95 90 85 80 75 70 65 45 40 36.2 N 94.0 W 35 32.8 N 97.2 W 30 29.5 N 97.2 W 26.1 N 93.3 W 25 24.9 N 91.8 W 20.9 N 86.0 W 20

34.0 N 96.0 W 32.8 N 97.2 W 29.5 N 97.2 W Storm Track Wind Swath

Compressed Drill Time Line All drill activities to occur during normal business hours (0700-1700 CPT) Emergency Communications Simulation Day 1 Day 2 06 00 12 00 18 00 24 00 06 00 12 00 18 00 23.7 N 89.8 W Advisory 27.0 N 95.0 W Watch 32.8 N 97.2 W 19.1 N 85.6 W OCN 26.1 N 93.3 W 29.5 N 97.2 W Landfall Emergency Notice 34.0 N 96.0 W