Tropical Storm Allison

Tropical Storm Allison

Tropical storm (SSHWS/NWS)
Tropical Storm Allison on June 5, 2001
Formed	June 4, 2001
Dissipated	June 18, 2001
Highest winds	1-minute sustained: 60 mph (95 km/h)
Lowest pressure	1000 mbar (hPa); 29.53 inHg
Fatalities	41 direct, 14 indirect
Damage	$9 billion (2001 USD)
Areas affected	Texas (particularly around Houston), Louisiana, most of the Eastern United States
Part of the 2001 Atlantic hurricane season

Tropical Storm Allison was a tropical storm that devastated southeast Texas in June of the 2001 Atlantic hurricane season. An arguable example of the "brown ocean effect", Allison lasted unusually long for a June storm, remaining tropical or subtropical for 15 days, most of them over land dumping torrential rains. The storm developed from a tropical wave in the northern Gulf of Mexico on June 4, 2001, and struck the upper Texas coast shortly thereafter. It drifted northward through the state, turned back to the south, and re-entered the Gulf of Mexico. The storm continued to the east-northeast, made landfall on Louisiana, then moved across the southeast United States and Mid-Atlantic. Allison was the first storm since Tropical Storm Frances in 1998 to strike the northern Texas coastline.

The storm dropped heavy rainfall along its path, peaking at over 40 inches (1,000 mm) in Texas. The worst flooding occurred in Houston, where most of Allison's damage occurred: 30,000 became homeless after the storm flooded over 70,000 houses and destroyed 2,744 homes. Downtown Houston was inundated with flooding, causing severe damage to hospitals and businesses. Twenty-three people died in Texas. Along its entire path, Allison caused $9 billion (2001 USD) in damage and 41 deaths. Aside from Texas, the places worst hit were Louisiana and southeastern Pennsylvania.

Following the storm, President George W. Bush designated 75 counties along Allison's path as disaster areas, which enabled the citizens affected to apply for aid. Allison was the first Atlantic tropical storm to have its name retired without ever having reached hurricane strength.

A tropical wave moved off the coast of Africa on May 21, 2001. It moved westward across the Atlantic Ocean, retaining little convection on its way. After moving across South America and the southwestern Caribbean Sea, the wave entered the eastern North Pacific Ocean on June 1. A low-level circulation developed on June 2, while it was about 230 miles (370 km) south-southeast of Salina Cruz, Mexico. Southerly flow forced the system northward, and the wave moved inland on June 3. The low-level circulation dissipated, though the mid-level circulation persisted. It emerged into the Gulf of Mexico on June 4, and developed deep convection on its eastern side. Early on June 5, satellite imagery suggested that a tropical depression was forming in the northwest Gulf of Mexico, which was furthered by reports of wind gusts as high as 60 mph (95 km/h) just a few hundred feet above the surface, towards the east side of the system.