Tropical Storm Erin was the fifth named storm of the 2007 Atlantic hurricane season. Erin formed in the Gulf of Mexico on August 15 north of the northwestern tip of the Yucatan Peninsula. In spite of initially being forecast to strengthen moderately, Erin only peaked at 40 mph, and indeed, had weakened to a tropical depression by the time of its Lamar, Texas landfall on August 16. After moving inland, Erin re-intensified over Oklahoma, as doppler radar imagery indicated an eye-like feature, along with well-defined banding features. Erin caused flooding across portions of Texas and Oklahoma, worsening an already dangerous flood situation in the state of Texas. Erin dissipated on August 17.
Erin killed 16 people and caused $25,000,000 (2007 USD) in damage.
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| Formation | August 15, 2007 |
|---|---|
| Dissipation | August 17, 2007 |
| Highest winds | 40 mph |
| Lowest pressure | 1003 mbar |
| Deaths | 16 direct |
| Damages | $25,000,000 (2007 USD) |
| Areas affected | Texas, Oklahoma, central United States |
| Part of the | 2007 Atlantic hurricane season |
Meteorological history[]
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Erin developed from a tropical wave that departed the western coast of Africa on August 3. Over the next week or so, the wave moved uneventfully westward across the Atlantic and Carribean Sea, until August 12, when a broad surface low developed in the western Carribean Sea in association with the wave. Development of the wave in the Carribean was hindered by an upper-level low centered north of the system, over the eastern Gulf of Mexico. On August 13 and 14, the aforementioned upper low moved westward away from the wave, which allowed vertical shear to decrease across the southeastern Gulf of Mexico, as the tropical wave headed in that general direction. As convective activity associated with the wave increased, the first Dvorak classifications were taken on the wave at 1800 UTC August 13. Subsequently, the wave gradually organized, becoming Tropical Depression Five at 0000 UTC August 15 while located about 375 miles east-southeast of Brownsville, Texas. By 1800 UTC August 15, the depression strengthened into a tropical storm as it moved northwestward to the south of a strong ridge of high pressure draped across the southern United States. When Erin became a tropical storm, it was located about 180 miles east of Brownsville. At about this time, Erin's outer rainbands began moving onshore the Texas coast. Erin remained disorganized over the Gulf of Mexico, with convection sputtering, and the overall storm structure remaining disorganized. Because of this, Erin's 40 mph intensity it attained when it became a tropical storm at 1800 UTC August 15 turned out to be its peak intensity. Early on August 16, Erin was barely hanging on as a tropical storm. Later that day, at around 1030 UTC, Erin made landfall at San Jose Island, Texas as a 35 mph tropical depression.
After landfall, the cyclone continued northwest, degenerating into a remnant low by 1200 UTC August 17 while located about 50 miles south of San Angelo, Texas. On August 18, Erin's remnants turned northward over extreme western Texas along the western periphery of a ridge centered across the southeastern United States. As Erin reached the northwestern extent of the ridge, it turned to the northeast, embedded within deep southwesterly flow, entering Oklahoma shortly after 0000 UTC August 19. Erin's remnants produced heavy rainfall across portions of Texas during the previous 36 hours, but the convection was not persistent and sufficiently organized to designate Erin a tropical cyclone during that period. As Erin moved generally east-northeast across Oklahoma early on August 19, convective activity sharply increased as it interacted with an eastward-moving shortwave trough. During a six-hour period that morning, surface wind speeds as high as 60 mph were observed at several locations in western and central Oklahoma, with isolated gusts being as strong as 80 mph. In addition to the intense convective activity the storm produced during this time, its organization also significantly improved, with an eye-like feature being observed on WSR-88D doppler radar between about 0800 UTC and 1300 UTC August 19 as the center of Erin's remnants passed just north of downtown Oklahoma City.
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Radar imagery of Erin, after its abrupt increase in organization occured over Oklahoma.
The organization of the storm was short-lived, however, with the eye-like feature disappearing after 1300 UTC. By this time, the maximum sustained winds within the storm had already begun decreasing as the shortwave trough responsible for the abrupt intensification moved off to the east, away from the storm.
Shortly after 1800 UTC that day, the surface circulation associated with Erin finally dissipated over northeastern Oklahoma, although remnant moisture associated with the system continued northeast into Missouri.
Preparations[]
Upon becoming a tropical cyclone, a Tropical Storm Watch was issued from Freeport, Texas to the U.S./Mexico border; at the same time, the government of Mexico issued a Tropical Storm Watch southward to Rio San Fernando. Shortly before the system became a tropical storm, the aforementioned watch in Texas was upgraded to a warning. Late on August 15, the warning was extended to San Luis Pass, while the watch in Mexico was discontinued, as the storm moved away from that country. As Erin was making landfall, the Tropical Storm Warning along the Texas coast was discontinued, as the storm was a depression. During this time, several Flood Watches and warnings were issued for various counties across southeastern Texas. Texas Governor Rick Perry activated the National Guard and dispatched emergency personnel to the location that was expected to be in the path of the storm. Erin was forecast to bring flooding to the state, which had already been declared a disaster area on August 7.
As Erin moved into Oklahoma, Flood Warnings as well as Flash Flood Warnings were issued for several counties.
On August 15, oil futures rose to $74.01 in fear of the storm disrupting oil supplies produced along the Texas coast, combined with low oil reserves. Because of the threat from Erin, the Shell Oil Company evacuated 188 of its workers on the oil platforms along the northwestern Gulf of Mexico.
Impact[]
Texas[]
By midday on August 15, the outer rainbands of Erin began affecting the Texas coast. As Erin made landfall, it produced heavy rainfall near and to the northeast of its path, reaching 11.02 inches at Lockwood. Erin caused several bayous in the Houston area to reach or exceed flood levels. Erin also spawned several funnel clouds across portions of southeastern Texas, and it also spawned an EF0 Tornado near Iah. Erin produced only minor wind gusts across the state, reaching 35 mph at Palacios, an unofficially reaching 39 mph at Jamaica Beach. As Erin made landfall, it produced a storm surge of 3.22 feet at Pleasure Pier, which caused minor beach erosion. At Clear Lake City, a portion of the roof of a grocery store collapsed due to heavy rainfall, which killed two workers. Heavy rains caused moderate flooding across eastern portions of Harris County, with over 400 homes and 40 businesses flooded. Flooding across the Greater Houston area briefly halted the METRORail, and also caused several road closures. One person drowned after driving into a retention pond. Also, several people needed rescue, and a car accident in Comal County associated with Erin killed three people.
Erin left around 20,000 residents without electricity, although most power outages were quickly restored. In San Antonio, one body was recovered from a creek and another person died after driving onto a flooded roadway and being swept into a drainage ditch, in which four other people survived. In the town of Sisterdale, two people were killed when they were swept away, stalled over Sister Creek. In Taylor County, near the city of Abilene, one person died from the flooding, which also forced the evacuation of 2,000 residents.
Oklahoma[]
Because of the unexpected re-intensification of Erin over Oklahoma, the state was significantly affected, with several communities in central Oklahoma being flooded due to heavy rainfall. The towns of Watonga, Kingfisher, and Geary were the hardest-hit locations in the state, where many homes and buildings were inundated by floodwaters. In addition, wind gusts as high as 82 mph were reported in Watonga, which caused tree and power line damage, and also extensively damaged mobile homes. The entire town lost electricity as a result of the hurricane force winds experienced there, and a total of 15,000 customers in the Oklahoma City metropolitan area lost electricity because of Erin. In addition, a section if Interstate 40 was closed for awhile. In Fort Cobb, a person drowned in a cellar, with another drowning in Kingfisher. Erin also took one life in Seminole. In addition, three other people were found dead after an automobile accident related to Erin occured near Carnegie. Another automobile accident fatality occured in Okmulgee County, although it is unclear if it was related to Erin. Total damage in Oklahoma from Erin reached $2,000,000 (2007 USD).
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A stranded became car atop a lone piece of ground due to the road below it washing away.
Missouri[]
Even though Erin's surface circulation had dissipated by the time it reached the state, its mid- to upper-level circulation remained intact, which led to heavy rainfall across Missouri on August 20, with 11.94 inches of rain falling at Miller. This rainfall total became the wettest Missouri rainfall total associated with a tropical cyclone since at least 1972. Also, one person was killed in the town of Sleeper when he drove into floodwaters which swept away a bridge he was trying to get on. A total of 9 water rescures occured along the Interstate 44 corridor, with most of them being associated with Erin's heavy rainfall. Total damage in Missouri reached $19.8 million (2007 USD), mainly in Polk County.
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Rainfall totals from Tropical Storm Erin.
Lack of Retirement[]
Because it did not cause extensive damage, the name Erin was not retired in the Spring of 2008 by the World Meteorological Organization. It will be used again during the 2013 Atlantic hurricane season.
See Also[]
References[]
http://www.nhc.noaa.gov/pdf/TCR-AL052007_Erin.pdf
http://en.wikipedia.org/wiki/Tropical_Storm_Erin_(2007)