Thunderstorms developed during the evening hours of the 16th along a residual outflow boundary near the Red River, producing scattered reports of severe wind and hail, along with one tornado report. Storms continued into the early morning hours of the 17th.
Every event with a place to put it. Tap one for its entry below.
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 OUN wrote it up.
Thunderstorms developed during the evening hours of the 16th along a residual outflow boundary near the Red River, producing scattered reports of severe wind and hail, along with one tornado report. Storms continued into the early morning hours of the 17th.
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 Norman, OK wrote its last area forecast discussion before the first event at May 27, 10:34 AM CST, 1 hour 42 minutes earlier.
Area Forecast Discussion
National Weather Service Norman OK
1134 AM CDT Thu May 27 2021
...New AVIATION, UPPER AIR...
.SHORT TERM...
(Today and tonight)
Issued at 251 AM CDT Thu May 27 2021
The trend over the last day or so is for the air mass center over
southern Manitoba this morning to build south more quickly behind a
cold front and be centered over the central plains by Friday morning
with around a 1025mb MSLP. Additionally, the upper low over
southeastern MT this morning is expected to move into the upper
Mississippi Valley by late tonight. This would allow fairly strong
northwesterly mid-level flow which would assist in a faster frontal
passage. Given the increasing consensus of this trend in the
models, the front would move into northwestern OK around mid-day
today and cross the Red River Friday morning. Ahead of the front
entering northern Oklahoma today, there will be mesoscale
boundaries from thunderstorms there early this morning and
possibly new storms around sunrise in the OK/KS border area. There
may be scattered storm initiation in northern Oklahoma late this
morning that would drift into central Oklahoma early this
afternoon ahead of the synoptic front. Additionally, thunderstorms
are expected to form along this front as it moves through
northwestern Oklahoma early this afternoon. Sufficient shear and
instability will exist for some supercells and numerous severe
storms. By evening the front is expected to move into the southern
half of Oklahoma with numerous storms, possibly developing into
an MCS late evening and early Friday as it crosses the Red River.
&&
.LONG TERM...
(Friday through Wednesday)
Issued at 149 AM CDT Thu May 27 2021
Models continue to trend faster and farther south with the front
Thursday night into Friday. Rain chances Friday and Friday night
will echo this trend, being mostly confined to southern Oklahoma and
north Texas.
Upper level riding will start to move in this weekend, reducing rain
chances. Most areas on Saturday will see some sun with high
temperatures in the 70s.
A longwave trough will approach the area on Sunday and serve as a
driver for rain chances early through mid week, especially as a rich
flow of moisture returns.
Day
&&
.AVIATION...
(18Z TAFS)
Issued at 1127 AM CDT Thu May 27 2021
Two rounds of showers and thunderstorms will be possible
throughout the period. The first round of storms will start around
17Z and will initiate in western OK, and move towards the east
into central OK. The next round will be later this afternoon
associated with a cold front that will sweep through the area.
These storms will move from the north to the south. Otherwise,
some MVFR ceilings are possible through the period, along with a
wind shift associated with the cold front. Some sites could see
some IFR ceilings associated with the aforementioned
thunderstorms.
&&
.UPPER AIR...
Issued at 1127 AM CDT Thu May 27 2021
An Upper Air flight is planned for 18Z, and 00Z on May 28.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 60 73 54 73 / 90 20 10 10
Hobart OK 59 74 56 75 / 70 30 20 10
Wichita Falls TX 64 78 59 77 / 70 50 30 10
Gage OK 52 73 53 75 / 20 10 10 10
Ponca City OK 54 73 50 72 / 70 10 0 0
Durant OK 66 79 59 76 / 90 50 30 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch through late tonight for OKZ008-012-013-018>020-
024>031.
TX...None.
&&
SHORT TERM...09
LONG TERM....14
AVIATION...13Hazardous Weather Outlook National Weather Service Norman OK 1141 AM CDT Thu May 27 2021 OKZ004>048-050>052-TXZ083>090-281645- Harper-Woods-Alfalfa-Grant-Kay-Ellis-Woodward-Major-Garfield- Noble-Roger Mills-Dewey-Custer-Blaine-Kingfisher-Logan-Payne- Beckham-Washita-Caddo-Canadian-Oklahoma-Lincoln-Grady-McClain- Cleveland-Pottawatomie-Seminole-Hughes-Harmon-Greer-Kiowa-Jackson- Tillman-Comanche-Stephens-Garvin-Murray-Pontotoc-Coal-Cotton- Jefferson-Carter-Johnston-Atoka-Love-Marshall-Bryan-Hardeman- Foard-Wilbarger-Wichita-Knox-Baylor-Archer-Clay- 1141 AM CDT Thu May 27 2021 This hazardous weather outlook is for portions of northern... western...central...and southern Oklahoma...and western north Texas. .DAY ONE...Today and Tonight... .Thunderstorms... There is an enhanced risk for severe thunderstorms Thursday afternoon and evening across most of Oklahoma into parts of western north Texas. Two rounds of storms are possible this afternoon. The first round is likely to start around the early afternoon and move from western OK into central OK. Later in the afternoon, storms will fire along a cold front in northern OK and move south across the area. Large hail up to the size of baseballs and damaging winds up to 80 mph will be the main threats, though during the early evening there will also be a low tornado risk. .Heavy Rainfall... Localized heavy rainfall and flooding will be possible late on Thursday, mainly across central and southern Oklahoma and north Texas. .SPOTTER AND EMERGENCY MANAGEMENT STATEMENT... Storm spotter groups and emergency management personnel across Oklahoma and western north Texas should prepare for severe weather operations this afternoon and evening. .DAYS TWO THROUGH SEVEN...Friday through Wednesday... .Thunderstorms... Friday and Saturday will see thunderstorm chances across mainly southern Oklahoma and north Texas. More widespread chances for showers and storms will return Sunday through Wednesday of next week. Get graphics and more details at weather.gov/norman...and follow our weather forecast office on Twitter and Facebook.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE Norman OK 1156 AM CDT Thu May 27 2021 OKZ012-018-019-271730- Garfield OK-Kingfisher OK-Logan OK- 1156 AM CDT Thu May 27 2021 ...SIGNIFICANT WEATHER ADVISORY FOR south central Garfield... northeastern Kingfisher and northwestern Logan Counties Until 1230 PM CDT... AT 1153 AM CDT, a strong thunderstorm was located near Hennessey, moving northeast at 25 MPH. HAZARDS INCLUDE... Hail up to the size of nickels... Wind gusts to 50 MPH... LAT...LON 3593 9796 3616 9805 3631 9765 3605 9750 TIME...MOT...LOC 1653Z 245DEG 24KT 3605 9790 JT
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
1200 PM CDT Thu May 27 2021
OKZ011-012-017-018-271730-
Major OK-Garfield OK-Kingfisher OK-Blaine OK-
1200 PM CDT Thu May 27 2021
...SIGNIFICANT WEATHER ADVISORY FOR southeastern Major...southwestern
Garfield...northwestern Kingfisher and northern Blaine Counties Until
1230 PM CDT...
AT 1157 AM CDT, a strong thunderstorm was located near Hitchcock,
moving northeast at 35 MPH.
HAZARDS INCLUDE...
Hail up to the size of nickels...
Wind gusts to 50 MPH...
LAT...LON 3580 9863 3603 9863 3629 9808 3608 9793
3584 9848
TIME...MOT...LOC 1657Z 238DEG 31KT 3600 9837
JTSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE Norman OK 1211 PM CDT Thu May 27 2021 OKZ015>017-271745- Dewey OK-Custer OK-Blaine OK- 1211 PM CDT Thu May 27 2021 ...SIGNIFICANT WEATHER ADVISORY FOR eastern Dewey...northeastern Custer and west central Blaine Counties Until 1245 PM CDT... AT 1209 PM CDT, a strong thunderstorm was located near Putnam, moving northeast at 35 MPH. HAZARDS INCLUDE... Hail up to the size of nickels... Wind gusts to 50 MPH... LAT...LON 3573 9898 3588 9909 3615 9869 3582 9846 TIME...MOT...LOC 1709Z 241DEG 28KT 3586 9892 JT
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
1235 PM CDT Thu May 27 2021
OKZ008-013-271800-
Kay OK-Noble OK-
1235 PM CDT Thu May 27 2021
...SIGNIFICANT WEATHER ADVISORY FOR southeastern Kay and northeastern
Noble Counties Until 100 PM CDT...
AT 1233 PM CDT, a strong thunderstorm was located 5 miles east of
Marland, moving northeast at 20 MPH.
HAZARDS INCLUDE...
Hail up to the size of nickels...
Wind gusts to 50 MPH...
LAT...LON 3675 9684 3675 9689 3668 9694 3656 9689
3653 9699 3651 9701 3651 9703 3646 9703
3645 9709 3652 9718 3663 9705 3660 9704
3659 9706 3659 9697 3660 9691 3667 9694
3669 9698 3678 9687
TIME...MOT...LOC 1733Z 238DEG 19KT 3653 9706
JTSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE Norman OK 1240 PM CDT Thu May 27 2021 OKZ011-012-271815- Major OK-Garfield OK- 1240 PM CDT Thu May 27 2021 ...SIGNIFICANT WEATHER ADVISORY FOR southeastern Major and southwestern Garfield Counties Until 115 PM CDT... AT 1238 PM CDT, a strong thunderstorm was located 4 miles northeast of Isabella, moving east at 55 MPH. HAZARDS INCLUDE... Hail up to the size of nickels... Wind gusts to 50 MPH... LAT...LON 3617 9840 3633 9850 3650 9786 3623 9774 TIME...MOT...LOC 1738Z 256DEG 50KT 3627 9828 JT
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
108 PM CDT Thu May 27 2021
OKZ006-007-012-271845-
Garfield OK-Alfalfa OK-Grant OK-
108 PM CDT Thu May 27 2021
...SIGNIFICANT WEATHER ADVISORY FOR northwestern Garfield...southern
Alfalfa and Grant Counties Until 145 PM CDT...
AT 107 PM CDT, a strong thunderstorm was located 4 miles northeast of
Nash, moving northeast at 40 MPH.
HAZARDS INCLUDE...
Hail up to the size of nickels...
Wind gusts to 50 MPH...
LAT...LON 3674 9750 3651 9818 3653 9842 3660 9852
3669 9844 3700 9774 3700 9768
TIME...MOT...LOC 1807Z 236DEG 33KT 3671 9800
JTThe Vance AFB radar (KVNX), 86 km away, was scanning. The volume nearest the first event began at 18:15 UTC.
12 flash flood, 5 thunderstorm wind, 5 hail, 4 flood, 1 tornado. Local standard time, as filed.
Storm chasers observed a brief tornado 3.2 miles east of Loyal that occurred in a field about 50 yards north of County Road EW720. No damage was observed.
Damage to mobile home.
Large tree limbs down over roadway.
About a foot of water over roadways in Kingfisher.
Time radar estimated.
Car stranded in one to two feet of water near center of town.
Tree and sign damage, along with power outages in Tryon.
Overflowing creek.
Northbound lanes on highway 177 underwater.
Water nearly into houses, flooded yards and streets.
Stalled vehicles in deep water.
Two cars stalled out and road closed at 33rd and Kelly.
Video of streets flooded and cars stalled in the road.
Estimated severe wind gust.
Stalled cars in the roadway.
Multiple cars stalled out.
Cherry Creek out of its banks and up to police SUV vehicle doors.
Street flooding reported across town.
Flooding reported in several spots around the city.
At least 3 cars stalled at Lindsey/Elm street intersection. Water up to 2 feet.
Main and Peters streets flooded with manhole covers dislodged.
Benedict street is flooded, 1 vehicle stalled, to be closed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oklahoma in 2021Every state in 2021This day in weather historyThe tornado archive for Oklahoma, 2021Warnings in Oklahoma, May 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: 961144, 961412, 961413, 961414, 961416, 961442, 961443, 961444, 961447, 961448, 961449, 961450, 961451, 961452, 961456, 961459, 961460, 961805, 961806, 961811, 961826, 961829, 961830, 961832, 961834, 961839, 961840.