Tropical Storm Imelda was a tropical cyclone which was the fourth-wettest storm on record in the U.S. state of Texas, causing devastating and record-breaking floods in southeast Texas. The eleventh tropical cyclone and ninth named storm of the 2019 Atlantic hurricane season, Imelda formed out of an upper-level low that developed in the Gulf of Mexico and moved westward. Little development occurred until the system was near the Texas coastline, where it rapidly developed into a tropical storm before moving ashore shortly afterward on September 17. Imelda weakened after landfall, but continued bringing large amounts of flooding rain to Texas and Louisiana, before dissipating on September 21.
Impacts began when Imelda made landfall as a weak tropical storm. The system brought heavy rain and dangerous flooding to parts of southeastern Texas (especially the cities of Galveston and Beaumont) as its motion gradually slowed over land. Dozens of water rescues were needed by September 19 as areas became overwhelmed by the rainfall, with some areas experiencing over of rain. Total damage is estimated in excess of $5 billion (2019 USD). Despite the storm causing substantial damage, the name Imelda was not retired following the season, making Imelda the second-costliest Atlantic tropical cyclone name on record to not be retired, with the costliest being Hurricane Sally the following year.
Meteorological history
Imelda originated from a mid-to-upper level trough located over the Eastern United States. Between September 10–12, the low moved to the southwest towards the eastern Gulf of Mexico. Once over the Gulf, associated convection began to increase, as a weak surface trough formed within the upper—level low on September 14, traversing to the west—northwest. That same day, the National Hurricane Center began to monitor the low for possible tropical cyclogenesis. Although, the NHC only gave the disturbance a low chance of formation. By September 17, the system had reached the east coast of Texas. Soon afterward, organization in the system rapidly increased, and at 17:00 UTC that day, the system organized into Tropical Depression Eleven, just off the coast of Texas. At 17:45 UTC, an observation deck at Freeport, Texas recorded sustained winds of 40 mph (65 km/h) with gusts of 47 mph (76 km/h), indicating that the depression had strengthened to Tropical Storm Imelda.
Shortly thereafter, at 18:30 UTC, Imelda made landfall near Freeport, Texas at peak intensity, with maximum 1-minute sustained winds of 45 mph (65 km/h) and a minimum central pressure of . Imelda weakened after landfall, becoming a tropical depression at 03:00 UTC on the next day. At that time, the NHC passed on the responsibility for issuing advisories to the Weather Prediction Center (WPC). Imelda retained status as a tropical depression over land for the next 2 days, gradually weakening and slowing its motion, before degenerating into a trough on September 19, as it began passing over Louisiana; Imelda's remnants continued producing heavy rain and a few isolated tornadoes. Imelda's remnants persisted for another couple of days, before dissipating early on September 21.
Preparations and impact
Texas
Imelda's slow movement over Southeast Texas and a continuous influx of tropical moisture led to copious amounts of rainfall over the region. This moisture supported the formation of rainbands that repeatedly moved across the same areas of Southeast Texas between September 17–19. Several counties spanning parts of the Greater Houston metropolitan area and Beaumont, Texas, recorded over of rain. A maximum rainfall total of was documented at a station south-southwest of Fannett, Texas; this made Imelda the seventh-wettest tropical cyclone in U.S. history, fifth-wettest in the contiguous U.S., and fourth-wettest in Texas history. The same station recorded of rain in 12 hours. Rain fell at over per hour in several places. Flood depths in some locations exceeded those recorded in Hurricane Harvey due to the high rainfall rates. Where rainfall was heaviest, the rainfall total represented a 1-in-1000-year rainfall event. Destructive flooding occurred along Interstate 10 between Winnie and Orange, Texas, marooning vehicles for 2.5 days; over a thousand vehicles were caught in these floods. Many homes and businesses were also flooded, resulting in numerous high-water rescues. Approximately 8,200 homes were flooded in Harris, Jefferson, Liberty, and Montgomery counties in Texas. Five deaths were directly attributed to the floods, of which three occurred in Jefferson, while two occurred in Harris County. The National Centers for Environmental Information estimated Imelda inflicted $5 billion in damage.