May 2021 South Central United States flooding
{{Short description|none}}
{{Use American English|date=May 2025}}
{{Use mdy dates|date=February 2025}}
{{Infobox flood
| name = May 2021 South Central United States flooding
| image = May 2021 South Central United States Weather System.jpg
| caption = The weather system partially responsible for the May 2021 South Central United States flooding, entering the Gulf of Mexico on May 19
| duration = {{start date|2021|05|16|}}–late May 2021{{Cite news|url=https://www.washingtonpost.com/weather/2021/05/19/texas-louisiana-flood-threat/|title=Serious flood threat continues in Texas, Louisiana as more heavy rain brews|author=Matthew Cappucci|newspaper=The Washington Post|date=May 19, 2021|access-date=May 22, 2021}}
| date =
| damages = $1.1 billion[http://thoughtleadership.aon.com/Documents/20211006_analytics-if-may-global-recap.pdf Global Catastrophe Recap - May 2021], Aon, June 2021
| affected = Most of the South Central United States
}}
In May 2021, prolonged rainfall from a series of weather disturbances affected the South Central United States, namely Texas and Louisiana.{{Cite web|url=https://mercurynews.com/2021/05/18/south-inundated-after-torrential-rain-sparks-flooding/|title=South inundated after torrential rain sparks flooding|publisher=CNN.Com Wire Service|website=The Mercury News|date=May 18, 2021|access-date=May 22, 2021}} As a result of rainfall totals, which peaked at {{cvt|17.16|in|cm}} in Fannett, Texas, widespread flash flooding occurred. Outside those states, Kansas saw up to {{convert|8.16|in|cm}} of rain, and {{convert|70|mph|kph}} wind gusts, while New Mexico recorded a {{convert|69|mph|kph}} wind gust.{{cite news |last1=Travis |first1=Courtney |title=Texas, Louisiana at risk for major flooding |url=https://www.accuweather.com/en/severe-weather/texas-louisiana-at-risk-for-major-flooding/947491 |access-date=May 8, 2022 |date=May 16, 2021}}
Meteorological history
At around 18:00 UTC on May 16, 2021, an outflow boundary developed over Northeastern Texas and moved generally southward.{{Cite web|url=https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=05/16/2021&selmap=2021051618&maptype=namussfc|title=WPC Surface Analysis Archive|website=Weather Prediction Center|date=May 16, 2021|access-date=May 22, 2021}}{{Cite web|url=https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=05/16/2021&selmap=2021051621&maptype=namussfc|title=WPC Surface Analysis Archive|website=Weather Prediction Center|date=May 16, 2021|access-date=May 22, 2021}} The outflow boundary then dissipated just 12 hours later and was quickly followed by an outbreak of severe thunderstorms over Texas while torrential rainfall began to affect portions Louisiana and Southeastern Texas. As a result of this rainfall, flash flooding began to occur over southeastern Texas and southwestern Louisiana.{{Cite web|url=https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=05/17/2021&selmap=2021051700&maptype=namussfc|title=WPC Surface Analysis Archive|website=Weather Prediction Center|date=May 17, 2021|access-date=May 22, 2021}}{{Cite web|url=https://cnn.com/2021/05/17/weather/texas-hail-severe-storms-tornado-forecast/index.html|title=Baseball-sized hail threatens again as flood risk increases|author=Jackson Dill, Jennifer Gray|website=CNN|date=May 17, 2021|access-date=May 22, 2021}} Throughout the day, several areas of low pressure and outflow boundaries developed over the Texas Hill Country.{{Cite web|url=https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=05/17/2021&selmap=2021051712&maptype=namussfc|title=WPC Surface Analysis Archive|website=Weather Prediction Center|date=May 17, 2021|access-date=May 22, 2021}}{{Cite web|url=https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=05/17/2021&selmap=2021051715&maptype=namussfc|title=WPC Surface Analysis Archive|website=Weather Prediction Center|date=May 17, 2021|access-date=May 22, 2021}} This caused severe thunderstorms to form over the region, which brought gusty winds, rainfall, and even some reports of hail.{{Cite web|url=https://kxan.com/weather/live-blog-storms-move-into-hill-country/|title=GALLERY: Severe storms move across Central Texas Monday afternoon|author=Russell Falcon, Wes Wilson|website=KXAN|date=May 17, 2021|access-date=May 22, 2021}} The next day, showers and thunderstorms began to develop over South Texas, which brought further rainfall to the area.{{Cite web|url=https://kristv.com/flash-flood-watch-issued-for-south-texas|title=Flash Flood Watch issued for South Texas|author=Juan Acuña|website=KRIS|date=May 18, 2021|access-date=May 22, 2021}} On May 19, another round of severe thunderstorms moved through both Texas and Louisiana, worsening flooding across both states, and even causing impacts as far away as Oklahoma, Arkansas, and Mississippi.{{Cite web|url=https://cnn.com/2021/05/19/weather/texas-extreme-weather/index.html|title=Millions in Texas and Louisiana are under flash flood watches due to torrential rain|author=Aya Elamroussi|website=CNN|date=May 19, 2021|access-date=May 22, 2021}}
These storms exited into the Gulf of Mexico, and began to be monitored by the National Hurricane Center (NHC) on May 21 for potential tropical cyclogenesis. Initially only given a low chance to develop, the NHC did note that conditions were slightly favorable for a short-lived tropical depression or storm to form in the western Gulf of Mexico, before the disturbance moved ashore back into Texas.{{Cite web|url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202105202315&basin=atlc&fdays=2|title=Two-Day Graphical Tropical Weather Outlook|author=Daniel Brown, Andrew Latto|website=National Hurricane Center|date=May 21, 2021|access-date=May 22, 2021}} By 12:00 UTC that day, a low-level circulation formed in association with the disturbance, however, the system lacked convection needed to designated as a tropical cyclone.{{Cite web|url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202105211145&basin=atl&fdays=2|title=Two-Day Graphical Tropical Weather Outlook|author=Jack Beven, Philippe Papin|website=National Hurricane Center|date=May 21, 2021}} Winds near the center reached up to {{cvt|35|mph}}, with the NHC stating that any increase in thunderstorm activity would warrant the upgrade to a tropical depression, with the chance of doing so being raised to about 60%.{{Cite web|url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202105211753&basin=atl&fdays=2|title=Two-Day Graphical Tropical Weather Outlook|author=Jack Beven, Philippe Papin|website=National Hurricane Center|date=May 21, 2021|access-date=May 22, 2021}} Although at 0:00 UTC on May 22 while the disturbance was located roughly {{cvt|150|mile}} east-southeast of Corpus Christi, Texas, the probability of tropical cyclogenesis was lowered to around 50%.{{Cite web|url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=latest&basin=atl&fdays=2|title=Two-Day Graphical Tropical Weather Outlook|author=Daniel Brown, Andrew Latto|website=National Hurricane Center|date=May 22, 2021|access-date=May 22, 2021}} Had the system developed into a tropical storm, it would have either received the name Ana or Bill, if the former had not been taken by another more-organized disturbance near Bermuda.{{Cite web|url=https://www.tampabay.com/hurricane/2021/05/21/hurricane-season-could-get-an-early-start-if-ana-and-bill-strengthen/|title=Hurricane season could get an early start if Ana and Bill strengthen|website=Tampa Bay Times|access-date=May 22, 2021}}
Effects
=Texas=
File:NWS Corpus Christi Snapped Tree Branch.jpg Office in Corpus Christi following a severe thunderstorm on May 19]]
Ahead of the severe weather outbreaks in Texas, flash flood alerts were put in place across Texas, which affected millions of residents.{{Cite web|url=https://www.crossroadstoday.com/millions-across-southeat-texas-and-part-of-louisiana-remain-under-flash-flood-watches-into-thursday/|title=Millions across southeast Texas and part of Louisiana remain under flash flood watches into Thursday|website=Crossroads Today|agency=CNN|access-date=May 22, 2021}}
In Portland, the Green Lake Dam collapsed following heavy rains at the Northshore Country Club.{{Cite web|url=https://www.msn.com/en-us/travel/tripideas/green-lake-dam-collapses-in-portland-following-severe-weather/vp-AAKb39Z|title=Green Lake Dam collapses in Portland following severe weather|website=Microsoft News|agency=KRIS|date=May 19, 2021|access-date=May 22, 2021}} Oer 100,000 residents of Texas lost power.{{cite news |last1=Elamroussi |first1=Aya |title=Millions in Texas and Louisiana are under flash flood watches due to torrential rain |url=https://www.cnn.com/2021/05/19/weather/texas-extreme-weather/index.html |access-date=May 8, 2022 |publisher=CNN |date=May 19, 2021}} Wind gusts soared up to {{convert|71|mph|kph}} in Dimmitt, Texas, while hail in Snyder, Texas reached {{convert|4.25|in|cm}} of rain. Several cities in Texas broke rainfall records May 19 with {{convert|2-3|in|cm}} of rain.[https://www.valleycentral.com/news/local-news/record-rainfall-for-the-mid-valley/ Record Rainfall for the Mid Valley], Valley Central, May 19, 2021 Parts of Jefferson County, Texas were put under a flash flood emergency, which also extended into Louisiana.[https://weather.com/news/news/2021-05-17-louisiana-texas-flooding-emergency-lake-charles Flooding Emergencies Declared in Louisiana, Texas; Widespread Flooding Reported in Baton Rouge], The Weather Channel, May 18, 2021
= Louisiana =
All five deaths occurred in Louisiana, four due to driving in flooded waters, according to John Bel Edwards.{{cite web |title=Heavy rain may bring more floods to Louisiana, Texas; 5 dead |url=https://www.reuters.com/world/us/heavy-rain-may-bring-more-floods-louisiana-texas-5-dead-2021-05-21/ |website=Reuturs |access-date=May 8, 2022}} In Lake Charles, Louisiana, a 24-hour period saw {{convert|11.8|in|cm}} of rain, a daily record.{{cite news |title=Severe storms lash Texas and Louisiana, flood emergency declared |url=https://watchers.news/2021/05/18/severe-storms-texas-louisiana-flood-emergency-declared-may-2021/ |access-date=May 8, 2022 |publisher=The Watchers |date=May 18, 2021}}
References
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{{Authority control}}{{2021 floods}}
Category:2021 floods in the United States