Thunderstorms developed across portions of southeastern Oklahoma during the early morning hours of the 19th. A very moist air mass across the region and weak wind flow aloft resulted in slow-moving thunderstorms that produced very heavy rainfall, some of which resulted in flash flooding.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS TSA wrote it up.
Thunderstorms developed across portions of southeastern Oklahoma during the early morning hours of the 19th. A very moist air mass across the region and weak wind flow aloft resulted in slow-moving thunderstorms that produced very heavy rainfall, some of which resulted in flash flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Tulsa, OK wrote its last area forecast discussion before the first event at Aug 19, 5:35 AM CST, 1 hour 25 minutes earlier.
Area Forecast Discussion National Weather Service Tulsa OK 635 AM CDT Thu Aug 19 2021 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. Lower MVFR ceilings are expected to spread into northeast Oklahoma shortly after 12Z. Thunderstorms with heavy rainfall will likely move into the KMLC/KFSM areas by mid morning with IFR conditions. The stronger storms this afternoon may be more scattered in nature further north with activity decreasing in coverage this evening with loss of diurnal heating. && .PREV DISCUSSION... /Issued 302 AM CDT Thu Aug 19 2021/ DISCUSSION... Scattered showers and storms are on tap for eastern Oklahoma and western Arkansas again today. Activity is expected to start picking up across southeast Oklahoma over the next few hours with an increase in isentropic lift. The showers and storms will continue to spread to the north as the day wears on as a subtle upper level shortwave moves into the area. With precipitable water values in excess of 2 inches, locally heavy rainfall will again be a concern today with the potential for flooding of lying areas in some spots. This activity is expected to diminish with the loss daytime heating. The potential for isolated to scattered showers and storms will increase again late tonight and into Friday with the greatest coverage across far eastern Oklahoma into western Arkansas. Again locally heavy rains will be a concern with the moisture laden airmass in place across the region. A cold front is set to stall out near the Kansas/Oklahoma border Friday night into Saturday as a mid-level shortwave works across the Plains. The boundary will close enough to trigger some showers and storms across the area Friday night into Sunday morning before the boundary surges back to the north. Hot and humid conditions are set to be the norm across the region over the weekend and into next week as an upper level ridge builds over the area. Heat headlines will be possible as early as Friday with the potential continuing into next week. Have to stayed fairly close to the NBM guidance through the period. && .PRELIMINARY POINT TEMPS/POPS... TUL 89 76 94 77 / 50 40 20 20 FSM 88 75 92 76 / 60 40 40 10 MLC 86 75 91 75 / 60 20 20 10 BVO 88 73 92 74 / 50 40 20 20 FYV 86 71 89 73 / 70 50 50 10 BYV 88 72 89 74 / 70 50 50 10 MKO 86 73 91 75 / 50 40 30 10 MIO 89 73 90 74 / 60 50 40 20 F10 88 74 94 75 / 50 30 20 10 HHW 84 75 89 75 / 70 20 10 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && AVIATION.....12
Hazardous Weather Outlook National Weather Service Tulsa OK 454 AM CDT Thu Aug 19 2021 ARZ001-002-010-011-019-020-029-OKZ049-053>076-201000- Adair OK-Benton AR-Carroll AR-Cherokee OK-Choctaw OK-Craig OK- Crawford AR-Creek OK-Delaware OK-Franklin AR-Haskell OK-Latimer OK- Le Flore OK-Madison AR-Mayes OK-McIntosh OK-Muskogee OK-Nowata OK- Okfuskee OK-Okmulgee OK-Osage OK-Ottawa OK-Pawnee OK-Pittsburg OK- Pushmataha OK-Rogers OK-Sebastian AR-Sequoyah OK-Tulsa OK-Wagoner OK- Washington OK-Washington AR- 454 AM CDT Thu Aug 19 2021 This Outlook is for Northwest and West Central Arkansas as well as much of Eastern Oklahoma. .DAY ONE...Today and Tonight. FLASH FLOOD. RISK...Limited. AREA...Mainly southeast Oklahoma. ONSET...This morning. HEAVY RAIN. RISK...Limited. AREA...Mainly southeast Oklahoma. ONSET...Ongoing. THUNDERSTORMS WITH DANGEROUS LIGHTNING. RISK...Elevated. AREA...Eastern Oklahoma and western Arkansas. ONSET...Ongoing. DISCUSSION... Scattered showers and thunderstorms are expected across eastern Oklahoma and western Arkansas today as an upper level disturbance affects the region. Locally heavy rain will be possible with the strongest storms which could lead to flooding of low lying areas. SPOTTER AND EMERGENCY MANAGEMENT ACTION STATEMENT... Spotter Activation Not Expected. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. FRIDAY...Thunderstorm Potential... High Wind Potential...Dangerous Heat Potential. SATURDAY...Thunderstorm Potential...Dangerous Heat Potential. SUNDAY THROUGH TUESDAY...Dangerous Heat Potential. WEDNESDAY...Thunderstorm Potential... Dangerous Heat Potential...Heavy Rain Potential. EXTENDED DISCUSSION... Scattered showers and storms will continue to be possible on Friday and into Saturday as a cold front stalls out near the Kansas/Oklahoma border Friday night into Saturday. Hot and humid conditions are set to return this weekend and continue into next week. Showers and thunderstorms return to the forecast Wednesday night with the approach of a cold front. weather.gov/tulsa contains additional information.
The Western Arkansas radar (KSRX), 168 km away, was scanning. The volume nearest the first event began at 12:59 UTC.
2 flash flood. Local standard time, as filed.
Portions of several roads were flooded and closed, including both lanes of Highway 93 near the Choctaw/Pushmataha County line.
Several sections of Highway 3 were flooded between Rattan and Ringold.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oklahoma in 2021Every state in 2021This day in weather historyWarnings in Oklahoma, August 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 973225, 979376.