Tropical Storm Bill Moving Ashore Over Texas

Tropical Storm Bill is pushing ashore over the Central Texas coast, bringing torrential rains and sustained winds near 60 mph. At 7:45 am CDT, the Brazos 538 oil rig off the Central Texas coast recorded sustained winds of 41 mph gusting to 64 mph. While heavy flooding rains are the main threat from Bill, a few weak tornadoes will also be be possible today, particularly in the Houston metropolitan area. NOAA's Storm Prediction Center is giving a 40% chance that they will issue a tornado watch for the area today. Radar out of Corpus Christi and satellite images showed that Bill's heavy thunderstorms increased markedly in areal coverage and intensity on Tuesday morning, and its a good thing the storm did not have another twelve hours over water, or it would have become a hurricane. Bill's landfall in Texas makes the U.S. two-for-two so far for landfalls this hurricane season: Tropical Storm Ana, the first named storm of the season, hit South Carolina back on May 10. The last time the first two named storms of the season both made landfall in the U.S. was in 2001, when Tropical Storm Allison hit Texas and Tropical Storm Barry hit the Florida Panhandle. Bill is the fourteenth named storm to form in the Gulf of Mexico in the month of June since 1950 (thanks to Phil Klotzbach for this stat.)


Figure 1. Tropical Storm Bill near landfall in Texas as seen from the Corpus Christi radar at 8:29 am CDT June 16, 2015.


Figure 2. Tropical Storm Bill as seen from the International Space Station on Monday afternoon, June 15, 2015. Bill had not yet been named at this time, but was generating sustained winds of 45 mph over the Gulf of Mexico. Image credit: Scott Kelly.

Bill a major flood threat
A huge area of flash flood watches stretches from Central Texas to Illinois in anticipation of the arrival of tropical moisture from Bill. Bill poses its most serious flood threat along a swath from eastern Texas into eastern Oklahoma, where up to 8" of rain is possible through Wednesday. Both states just experienced the wettest single month in their history during May, and soils remain near saturation. Houston lies at the edge of the predicted heaviest swath of rain, and Dallas is squarely in the bulls-eye. Steering currents will be weak as the system rotates clockwise around a strong, hot dome of high pressure over the Southeast late in the week, and Bill's remnants are expected to dump as much as five inches of rain over portions of Missouri and Illinois on Thursday and Friday.


Figure 3. Projected five-day precipitation totals from the NOAA Weather Prediction Center, for the period from 8:00 am June 16 to June 21, show the expected track of Bill around the high-pressure center in the southeast U.S. Image credit: NWS/WPC.

We'll have an update on Bill this afternoon.

Jeff Masters