Tropical Storm Imelda

Tropical Storm Imelda was the fifth-wettest tropical cyclone on record in the continental United States, 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.

This article is about the 2019 storm. For the 2013 cyclone, see Cyclone Imelda.

Tropical Storm Imelda
Tropical storm (SSHWS/NWS)
Tropical Storm Imelda just off the coast of Texas on September 17
FormedSeptember 17, 2019
DissipatedSeptember 21, 2019
(Remnant low after September 19)
Highest winds1-minute sustained: 45 mph (75 km/h)
Lowest pressure1003 mbar (hPa); 29.62 inHg
Fatalities6 direct, 1 indirect
Damage$5 billion (2019 USD)
Areas affectedTexas, Louisiana, Oklahoma, Arkansas
Part of the 2019 Atlantic hurricane season

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 43 inches (1,100 mm) of rain. Total damage is estimated in excess of $5 billion.[1]

Meteorological history
Map plotting the track and the intensity of the storm, according to the Saffir–Simpson scale

On September 14, the National Hurricane Center began monitoring an upper-level low off the west coast of Florida for possible tropical development.[2] During the next several days, the system moved westward across the Gulf of Mexico, though the NHC gave the disturbance only a low chance of development. By September 17, the system had reached the east coast of Texas.[3] 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.[4] 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.[5] 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 1,003 millibars (29.6 inHg).[6] 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).[7]

Imelda retained status as a tropical depression over land for the next 2 days, gradually weakening and slowing its motion, before degenerating to an remnant low on September 19, as it began passing over Louisiana; Imelda's remnants continued producing heavy rain and a few isolated tornadoes.[8] Imelda's remnants persisted for another couple of days, before dissipating early on September 21.[9]

Preparations and impact
Wettest tropical cyclones and their remnants in Texas
Highest-known totals
Precipitation Storm Location Ref.
Rank mm in
11538.760.58Harvey 2017Nederland[10]
21219.248.00Amelia 1978Medina[10]
31143.045.00Claudette 1979Alvin coop site[11]
4109643.15Imelda 2019Jefferson County[12]
51033.340.68Allison 2001Moore Road Detention Pond[10]
61008.639.71September Hurricane 1921Thrall[13]
7762.030.00September T.S. 1936Broome[13]
8755.929.76Unnamed 1960Port Lavaca #2[10]
9695.527.38Beulah 1967Pettus[10]
10688.327.10Alice 1954Pandale[13]

Imelda's slow movement over Southeast Texas and a continuous influx of tropical moisture led to copious amounts of rainfall over the region.[14] This moisture supported the formation of rainbands that repeatedly moved across the same areas of Southeast Texas between September 17–19.[15] Several counties spanning parts of the Greater Houston metropolitan area and Beaumont, Texas, recorded over 30 in (760 mm) of rain. A maximum rainfall total of 44.29 in (1,125 mm) was documented at a station 2 mi (3.2 km) 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.[14] The same station recorded 31 in (790 mm) of rain in 12 hours.[16] Rain fell at over 5 in (130 mm) per hour in several places.[17] Flood depths in some locations exceeded those recorded in Hurricane Harvey due to the high rainfall rates.[18] Where rainfall was heaviest, the rainfall total represented a 1-in-1000-year rainfall event.[16] 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.[14] Five deaths were directly attributed to the floods, of which three occurred in Jefferson, while two occurred in Harris County.[14][19][20][21] The National Centers for Environmental Information estimated Imelda inflicted $5 billion in damage.[14]

Aerial view of flooding in Roman Forest, Texas

Jefferson County, Texas, was the county most heavily impacted by Imelda.[14] An estimated 5,100 homes were flooded in the county, suffering $14 million in damage.[14][16] Major street flooding occurred in Beaumont where the Jefferson County flooding first began.[18] Over 38 inches (97 cm) of rain fell in the city.[22] Encroaching floodwaters prompted the evacuation of Riceland Medical Center in Chambers County, Texas.[14][23] Stream flooding persisted for days in Hardin County, Texas, where 10–40 in (250–1,020 mm) of rain was measured. Many buildings and roads were rendered impassable.[24][14] Sixty homes were flooded in the county, resulting in $2.3 million in damage. In Orange County, Texas, Imelda flooded 2,679 homes, resulting in $12 million in damage. Near Mauriceville, Cow Bayou reached its second-highest crest on record. In Jasper and Newton counties in Texas, an estimated $2.4 million in damage was incurred following the flooding of 15 homes.[16]

In Houston, Imelda's rainfall caused many of the local bayous to overtop their banks and flood residential areas. More than 1,000 people were rescued from floodwaters. All bus and rail services were temporarily shut down in the city. A roof of a United States Postal Service building collapsed, leaving three people with minor injuries. George Bush Intercontinental Airport closed for about 90 minutes due to flooding on the runways, canceling 655 flights.[25] Throughout Houston, hundreds of homes were affected by flooding and more than 1,600 vehicles were towed. In Harris County alone, 422 people required high-water rescue; the Texas National Guard rescued 130 people.[26] During the flood, nine barges escaped a shipyard, and at least two struck the Interstate 10 bridge over the San Jacinto River, causing visible damage to some of the columns supporting the highway.[27][28] The bridge was subsequently closed to traffic in both directions.[29]

The heaviest rains from Imelda, exceeding 40 in (1,000 mm), were concentrated in a small area in southeastern Texas while lighter rainfall extended to nearby states.

Flooding from Imelda in southwestern Louisiana was relatively minor. Freshwater flooding in Johnson Bayou inundated most secondary roads and was augmented by the elevated tide levels caused by the tropical storm.[14][30] The remnants of Imelda produced up to 7.6 in (190 mm) of rain in southeastern Oklahoma between September 6–7.[14] Heavy rainfall also occurred in portions of Arkansas.[31]

In addition to the rain, weather stations reported winds between 37–44 mph (59–70 km/h) as Imelda made landfall. At Baton Rouge Metropolitan Airport, an embedded thunderstorm within one of Imelda's rainbands produced a microburst that flipped four airplanes and damaged hangar doors on September 17; the airport registered a peak gust of 66 mph (106 km/h).[14][32] Storm surge also resulted in minor coastal flooding along the upper Texas and Louisiana coasts, inundating areas with 1–2 ft (0.30–0.61 m) of water. A National Ocean Service gauge at Eagle Point, Texas, measured a peak surge height of 2.35 ft (0.72 m) above normal tide levels. After September 17, freshwater runoff originating from inland flooding reached the coast and exacerbated the initial storm surge flooding. A gauge on Buffalo Bayou documented water levels 4.32 ft (1.32 m) above normal tide levels once runoff reached the coast. Imelda also produced two confirmed tornadoes, with an EF-1 tornado touching down on September 18 in Harris County, Texas, and an EF-0 tornado striking near Hackberry, Louisiana, in Cameron Parish on September 19. The EF-1 tornado unroofed a home and downed large tree limbs. The EF-0 tornado flipped a recreational vehicle and felled several trees.[14]

Records
See also: List of wettest tropical cyclones in the United States § Texas

Imelda has broken several rainfall records in the United States, producing over 42 inches (1,100 mm) of rain near Winnie, Texas. Imelda is currently the 7th wettest tropical cyclone to impact the United States, 5th wettest in the contiguous United States and the 4th wettest overall in the U.S state of Texas.

See also

References
  1. "2010-2019: A landmark decade of U.S. billion-dollar weather and climate disasters". National Oceanic and Atmospheric Administration. Retrieved January 8, 2020.
  2. Jack Beven (September 14, 2019). "Two-Day Graphical Tropical Weather Outlook". www.nhc.noaa.gov. Miami, Florida: National Hurricane Center. Retrieved September 19, 2019.
  3. Stacy R. Stewart (September 17, 2019). "Two=Day Graphical Tropical Weather Outlook". www.nhc.noaa.gov. Miami, Florida: National Hurricane Center. Retrieved September 17, 2019.
  4. Daniel Brown (September 17, 2019). "Tropical Depression Eleven Special Discussion Number 1". www.nhc.noaa.gov. Miami, Florida: National Hurricane Center. Retrieved September 17, 2019.
  5. Michael Brennan; Daniel Brown (September 17, 2019). "Tropical Storm Imelda Tropical Cyclone Update". www.nhc.noaa.gov. Miami, Florida: National Hurricane Center. Retrieved September 19, 2019.
  6. David Zelinsky; Daniel Brown (September 17, 2019). "Tropical Storm Imelda Tropical Cyclone Update". www.nhc.noaa.gov. Miami, Florida: National Hurricane Center. Retrieved September 19, 2019.
  7. Richard Pasch (September 18, 2019). "Tropical Depression Imelda Discussion Number 3". www.nhc.noaa.gov. Miami, Florida: National Hurricane Center. Retrieved September 19, 2019.
  8. Gregg Gallina; Frank Pereira (September 19, 2019). "Remnants Of Imelda Advisory Number 10". wpc.ncep.noaa.gov. Weather Prediction Center. Retrieved September 22, 2019.
  9. Peter Mullinax (September 20, 2019). "Storm Summary Number 11 for Heavy Rainfall Associated With Imelda". wpc.ncep.noaa.gov. Weather Prediction Center. Retrieved September 22, 2019.
  10. Roth, David M. (October 18, 2017). "Tropical Cyclone Point Maxima". Tropical Cyclone Rainfall Data. United States Weather Prediction Center. Retrieved November 26, 2017.
  11. Roth, David M; Hydrometeorological Prediction Center. "Tropical Storm Claudette". Tropical Cyclone Point Maxima. United States National Oceanic and Atmospheric Administration's National Weather Service. Retrieved June 4, 2012.
  12. Meg Wagner, Paul P. Murphy, Mike Hayes and Fernando Alfonso III (September 19, 2019). "Serious flooding in Texas". cnn.com. CNN. Retrieved September 19, 2019.CS1 maint: multiple names: authors list (link)
  13. Schoner, Robert W; Molansky, Sydney; National Hurricane Research Project (1956). Rainfall associated with Hurricanes and other Tropical Disturbances (PDF) (Report). United States National Oceanic and Atmospheric Administration's National Weather Service. Retrieved June 14, 2012.
  14. Latto, Andy; Berg, Robbie (February 7, 2020). Tropical Storm Imelda (PDF) (Tropical Cyclone Report). Miami, Florida: National Hurricane Center. Retrieved February 1, 2021.
  15. "Upper Texas Coast Tropical Cyclones in the 2010s". National Weather Service Houston/Galveston, TX. Dickinson, Texas: National Weather Service. Retrieved February 1, 2021.
  16. "Tropical Storm Imelda". National Weather Service Lake Charles, LA. Lake Charles, Louisiana: National Weather Service. Retrieved February 1, 2021.
  17. Brian Kahn (September 19, 2019). "Tropical Depression Imelda Has Dumped More Than 40 Inches of Rain on the Texas Gulf Coast". Gizmodo. G/O Media Inc. Retrieved September 19, 2019.
  18. "Event Report for Flash Flood in Jefferson County, Texas, on September 18, 2019". Storm Events. National Centers for Environmental Information. Retrieved February 1, 2021.
  19. Ron Brackett; Jan Wesner Childs. "Barges Hit Bridge on Interstate 10 in Texas; Portions of Roadway Remain Flooded". The Weather Channel. Web. Retrieved September 20, 2019. Hunter Morrison was electrocuted by a downed power line in nearby floodwaters while he and his father were trying to save one of their horses on their property in Beaumont, Jefferson County Emergency Management confirmed to The Weather Channel.
  20. Ed Gonzalez [@SheriffEd_HCSO] (September 19, 2019). "We're sad to report that an adult occupant, extracted from the submerged van, has been pronounced deceased at the hospital. It remains unknown if the male was the only occupant in the van. #HouNews" (Tweet) – via Twitter.
  21. Iracheta, Michelle (September 19, 2019). "2 deaths linked to Imelda as hundreds flooded throughout Southeast Texas". Houston Chronicle. Retrieved September 21, 2019.
  22. David K. Li; Annie Rose Ramos (September 19, 2019). "Imelda slams southeast Texas, bringing flash floods and mandatory evacuations". NBC News. Retrieved September 19, 2019.
  23. Juan A. Lozano (September 20, 2019). "Houston area sees relief, rescues after Imelda leaves 4 dead". apnews.com. Associated Press. Retrieved January 14, 2021.
  24. "Event Report for Flash Flood in Hardin County, Texas, on September 18, 2019". Storm Events. National Centers for Environmental Information. Retrieved February 1, 2021.
  25. Deerwester, Jayme (September 19, 2019). "Houston Bush Intercontinental Airport reopens: Rains prompt 650+ canceled flights". USA Today. Retrieved September 19, 2019.
  26. James Leggate (September 21, 2019). "Imelda's death toll in Houston rises to 5 as damage assessments begin". Fox Business. Retrieved September 21, 2019.
  27. Brackett, Ron; Childs, Jan Wesner (September 20, 2019). "Barges Hit Bridge on Interstate 10 in Texas; Portions of Roadway Remain Flooded". The Weather Channel. Retrieved September 21, 2019.
  28. FOX 26 Houston staff (September 20, 2019). "Barges strike bridge over San Jacinto River; I-10 shutdown in both directions". KRIV. Retrieved September 21, 2019.
  29. "Interstate 10 bridge near Houston closed after being hit by barges during Imelda". NOLA.com. The Associated Press. September 20, 2019. Retrieved September 21, 2019.
  30. "Event Report for Flash Flooding in Cameron Parish, Louisiana, on September 19, 2019". Storm Events. National Centers for Environmental Information. Retrieved February 1, 2021.
  31. Elisha Fieldstadt, Alex Johnson, Annie Rose Ramos (September 19, 2019). "Imelda swamps parts of Texas with more than 3 feet of rain, leaves 3 dead". nbcnews.com. NBC News. Retrieved January 14, 2021.CS1 maint: multiple names: authors list (link)
  32. "Event Report for Thunderstorm Wind in East Baton Rouge on September 17, 2019". Storm Events. National Centers for Environmental Information. Retrieved February 1, 2021.
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