1989 жылғы Атлант мұхитының тропикалық дауілі "Эллисон"

Atlantic tropical storm in 1989

Tropical Storm Allison was a tropical cyclone that produced severe flooding in the southern United States. The second tropical cyclone and the first named storm of the 1989 Atlantic hurricane season, Allison formed on June 24 in the northwestern Gulf of Mexico. Development of Allison was a result of the interaction of a tropical wave and the remnants of Pacific hurricane Hurricane Cosme. It moved south and became a tropical storm on June 26. By June 27, Allison made landfall near Freeport, Texas. Allison quickly weakened to a tropical depression later that day, and transitioned into an extratropical cyclone on the following day. However, the storm's remnants persisted for another 10 days and meandered across the area, triggering flooding across the region, before dissipating on July 7. The storm caused heavy rainfall, amounting to in some places. In total, 11 fatalities resulted from the storm, as well as $560 million (1989 USD, $  USD) in damage.

Three meteorological phenomena combined to produce Tropical Storm Allison. First, Hurricane Cosme moved northward through Mexico in response to a strong mid to upper level ridge. Its remnants entered the Gulf of Mexico on June 22, when a westward moving tropical wave reached the area. Finally, a strong anticyclone over the Gulf allowed for the disturbed area to organize into Tropical Depression Two in the western Gulf of Mexico on June 24. The depression continued to organize as it drifted to the north, and became Tropical Storm Allison on June 26 off the Texas coast. The frontal trough outran the system, and the building ridge to Allison's north forced the extratropical depression turned to the south and southwest. After executing a cyclonic loop over Texas, the ridge to the north began to erode, allowing Allison to track northeast and out of the state. Its circulation dissipated on July 1, but the remnants retained some organization, and continued to the northeast. On July 3 and July 4, the shortwave that influenced the remnants of Allison accelerated ahead of the storm, causing Allison to become stationary over the borders of Kentucky, Illinois, and Indiana. A second shortwave trough brought the remnants of Allison southward into Alabama. It turned to the northwest, and the remnants of Allison became unidentifiable over Arkansas on July 7.

The slow movement of Allison and its remnants resulted in heavy rainfall over East Texas, with some areas receiving more than Severe flooding occurred, with more than 6,200 homes suffering water damage, which forced hundreds of residents to evacuate and stranding thousands of other people. Losses in Texas were estimated between $200 million and $400 million. Additionally, there were three deaths in the state, all of which due to drowning. In Brazoria County, rainfall amounts were generally between , causing flooding in the West Columbia area. Precipitation up to in Chambers County inundated many streets and caused water intrusion into several homes. Along the Trinity Bay, tides reached almost 7 feet (2 m) above normal at Anahuac. Low lying areas around the mouth of the Trinity River were completely submerged for several days. Local flooding was reported in Galveston County due to rainfall amounts of , particularly in Clear Lake, Galveston Island, Kemah, and Texas City. The highest storm surge in the area was 3.9 feet (1 m) above mean sea level, causing some beach erosion. An estimated of sand was washed away, while Texas State Highway 87 was closed due to sand and debris spewed onto the roadway from the storm surge. Wind gusts up to downed some trees limbs and power lines. Additionally, a tornado was spawned in Gilchrist and caused minor damage and one injury. In Hardin County, rains of fell. The Pine Island Bayou overflowed, flooding homes in Pinewood Estates and Silsbee. Rainfall from the storm extended eastward into the Mid Atlantic States, producing flooding. In Delaware, the rainfall led to record breaking discharge rates at three gauging stations, while one third of the state's gauging stations reported significant discharges. of rain fell at a site in Arkansas, the highest rainfall total from a tropical cyclone in the state. Eleven people were reported killed from the storm. Three deaths occurred in Texas, five in Mississippi and three in Louisiana. Two teenage boys were killed when their raft got sucked into a drainage pipe from the runoff of Allison in Beaumont, Texas. An eighteen year old was killed in Harris County, Texas from drowning during a swim. The eight final deaths in Louisiana and Mississippi were by drowning. The extreme flooding in turn led to heavy damage, amounting to around $560 million (1989 USD).