The National Hurricane Center (NHC) classified a low pressure system over the western Gulf of Mexico as Tropical Storm Bill.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Bill was located at latitude 27.1°N and longitude 94.2°W which put it about 160 miles (260 km) east-southeast of Port OConnor, Texas and about 155 miles (250 km) south-southeast of Galveston, Texas.  Bill was moving toward the northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 50 m.p.h. (85 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1005 mb.  A Tropical Storm Warning has been issued for the portion of the coast from Baffin Bay to High Island, Texas.

Bill formed as a result of the interaction between a broad surface low pressure system and an upper level low over the Gulf of Mexico.  Thunderstorms began to form near the center of circulation on Monday afternoon and the structure of the system changed to a more tropical cyclone like pattern.  The thunderstorms near the center began to warm the middle and upper troposphere and create a warm core.  The thunderstorms became substantial enough to generate upper level divergence from the core of the circulation and NHC classified it as Tropical Storm Bill.  Bill is moving over water where the Sea Surface Temperature (SST) is near 29°C.  The vertical wind shear over the system decreased on Monday and Bill has a few hours during which it could intensify before it makes landfall in Texas.

An upper level ridge over the southeastern U.S. is steering Bill northwestward toward the coast of Texas and that motion is expected to continue.  Bill is expected to make landfall in Texas on Tuesday.  Although Bill will bring some wind when it makes landfall, heavy rainfall will be the biggest hazard.  Heavy rain on top of wet soils will create the potential for new flooding in some locations, especially in Texas and Oklahoma.  Winds blowing toward the coast will also create some water level rises and Coastal Flood Warnings and Advisories have been issued for portions of the coast of Texas and Louisiana.