A stationary front extended from a low near Amarillo east northeast to just south of Canadian, TX in the afternoon. The lower levels of the atmosphere were moistening from southeast surface winds into the stationary front and the edge of the southwest United States monsoon moisture plume was also present across the area.
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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 AMA wrote it up.
A stationary front extended from a low near Amarillo east northeast to just south of Canadian, TX in the afternoon. The lower levels of the atmosphere were moistening from southeast surface winds into the stationary front and the edge of the southwest United States monsoon moisture plume was also present across the area. Weak to moderate instability was found along and behind the front along with weak wind shear which was greatest in the far northern Panhandles and into Kansas. Thunderstorms initially developed near Amarillo around 2 pm as a weak upper level disturbance passed through the area. These storms were slow-moving and they were interacting with outflow boundaries. Some severe storms trained along and outflow boundary collision across the western side of Amarillo causing flooding. In addition, a couple of storms with large hail (up to 2 inches in diameter) moved northward across Lipscomb and Beaver Counties during the late afternoon/early evening where the better dynamics and wind shear were located.
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 Amarillo, TX wrote its last area forecast discussion before the first event at Aug 21, 12:10 PM CST, 2 hours 24 minutes earlier.
Area Forecast Discussion National Weather Service Amarillo TX 110 PM CDT Sat Aug 21 2021 .SHORT TERM... A surface low near Canyon TX had a stationary front extended northeast to the east central Texas Panhandle. This stationary front is expected to be the focus for initial thunderstorm development. Southwest flow aloft should carry the storms to the northeast. Some of the storms may become severe with large hail and damaging winds. Heavy rain may cause localized flooding. Thunderstorms will likely move out of our area or dissipate toward midnight. A thunderstorm will be possible across the northwest CWA on Sunday afternoon or evening. But will decide at the last minute on whether to insert this into the forecast. Not all models agree that there will be a thunderstorm in the northwest, so confidence is not very high at this time. Highs on Sunday will be close to a little above normal with readings in the upper 80's to the mid 90's. && .LONG TERM...Monday through Friday Upper high builds over the southern Plains states Monday through Thursday and should keep a dry pattern across the Panhandles. A shortwave trough over the southern Rockies late next week as the upper high breaks down will allow for the possibility of convection by late Friday and Friday night. The GFS hinting at the possibility for convection as early as Thursday afternoon and Thursday night mainly across the western or northwestern portions of the forecast area with the shortwave trough. Surface low over eastern Colorado and western Kansas Monday through Wednesday will deepen and allow for tightening of the surface pressure gradient resulting in gusty southerly to southwesterly winds. Surface low late next week across the central Plains states and central Rockies with surface trough extending south into New Mexico Thursday into Friday. Warmer and drier conditions expected next week with a few breezy to windy days. Schneider && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 68 92 69 96 70 / 30 5 0 0 0 Beaver OK 66 95 72 100 73 / 40 5 0 0 0 Boise City OK 62 93 66 96 66 / 10 5 0 5 0 Borger TX 71 96 73 100 74 / 30 5 0 0 0 Boys Ranch TX 68 93 70 97 71 / 20 5 0 0 0 Canyon TX 67 90 68 94 68 / 20 5 0 0 0 Clarendon TX 70 92 71 95 71 / 30 0 0 0 0 Dalhart TX 62 91 65 95 65 / 20 5 5 5 0 Guymon OK 65 95 70 99 71 / 20 5 0 5 0 Hereford TX 67 91 67 95 68 / 20 5 0 0 0 Lipscomb TX 67 93 71 97 72 / 40 5 0 0 0 Pampa TX 67 92 70 96 71 / 30 5 0 0 0 Shamrock TX 69 93 69 97 69 / 30 0 0 0 0 Wellington TX 70 95 69 98 70 / 20 0 0 0 0 && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && 15/11
Hazardous Weather Outlook National Weather Service Amarillo TX 114 PM CDT Sat Aug 21 2021 OKZ001>003-TXZ001>020-317-221100- Cimarron-Texas-Beaver-Dallam-Sherman-Hansford-Ochiltree-Lipscomb- Hartley-Moore-Hutchinson-Roberts-Hemphill-Oldham-Potter-Carson- Gray-Wheeler-Deaf Smith-Randall-Armstrong-Donley-Collingsworth- Palo Duro Canyon- 114 PM CDT Sat Aug 21 2021 This Hazardous Weather Outlook is for the Texas and Oklahoma Panhandles. .DAY ONE...This Afternoon and Tonight. Storms expected through tonight across much of the Texas and Oklahoma Panhandles. Storms may be severe with hail and damaging winds as the main threats. .DAYS TWO THROUGH SEVEN...Sunday through Friday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated at this time. Schneider
Special Weather Statement
National Weather Service Amarillo TX
238 PM CDT Sat Aug 21 2021
TXZ010-212045-
Hemphill TX-
238 PM CDT Sat Aug 21 2021
...A strong thunderstorm will impact portions of Hemphill County
through 345 PM CDT...
At 238 PM CDT, Doppler radar was tracking a strong thunderstorm 6
miles south of Canadian, moving north at 10 mph.
HAZARD...Wind gusts of 50 to 55 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Canadian, Glazier and Lake Marvin.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 3571 10006 3569 10052 3593 10054 3604 10054
3606 10025 3605 10002
TIME...MOT...LOC 1938Z 164DEG 8KT 3581 10040
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH
LGSpecial Weather Statement
National Weather Service Amarillo TX
243 PM CDT Sat Aug 21 2021
TXZ012-212045-
Potter TX-
243 PM CDT Sat Aug 21 2021
...A strong thunderstorm will impact portions of southwestern Potter
County through 345 PM CDT...
At 243 PM CDT, Doppler radar was tracking a strong thunderstorm over
Bushland, or 10 miles west of Amarillo, moving north at 10 mph.
HAZARD...Wind gusts of 50 to 55 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Amarillo and Bushland.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 3524 10217 3538 10217 3540 10183 3519 10189
3518 10213 3518 10216
TIME...MOT...LOC 1943Z 182DEG 7KT 3522 10204
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH
LGThe Amarillo radar (KAMA), 16 km away, was scanning. The volume nearest the first event began at 20:31 UTC.
5 hail, 2 flood, 1 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Trained spotter had reported street/road flooding, along with road closures and vehicles stranded.
A NWS employee reported 1.25 diameter hailstones at their house in southwest Amarillo.
Received report of widespread tree damage near Avondale Elementary and there was at least one large tree was completely uprooted.
Heavy flooding was reported under the bridge at I-40 and Bell, with traffic at a standstill in the west bound lane.
Road closed from 45th to Hillside on Coulter with 3 to 4 feet of water. Firefighters were helping motorist escape from flooding and stalled vehicles. An additional report was submitted by the public for water filling up West Hill Park with some roads around the park impassable.
A picture with the hail measurement was sent to the NWS office over social media. Numerous reports of golf ball size hail in an around Booker were also received.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2021Every state in 2021This day in weather historyWarnings in Texas, 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: 977677, 977679, 977680, 977681, 978370, 977686, 977678, 977676, 977682.