Alert archive / Oklahoma / Severe Thunderstorm Watches in 2020
Severe Thunderstorm Watch 151
The Storm Prediction Center issued this severe thunderstorm watch at Apr 28, 2020, 3:30 PM CDT for 32 counties in Oklahoma; Archer County, Clay County, Wichita County, Texas. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2020, 3:30 PM CDT (20:30 UTC)
- Expired
- Apr 28, 2020, 11:00 PM CDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 3 in
- Strongest gust expected
- 70 kt
All 35 counties
Atoka County, OK, Bryan County, OK, Caddo County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Kay County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Noble County, OK, Oklahoma County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Tillman County, OK, Archer County, TX, Clay County, TX, Wichita County, TX
The radar
The Norman radar (KTLX), 21 km from the middle of the area, began a volume at 20:29 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 80%
- One or more gusts of 65 knots or more
- 70%
- Ten or more severe hail reports
- 70%
- One or more hailstones of 2 inches or more
- 70%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
40 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 4:02 PM CDT | Severe Thunderstorm Warning | OUN | Noble | 43 min |
| Apr 28, 4:18 PM CDT | Severe Thunderstorm Warning | OUN | Garfield, Logan, Noble, Payne | 42 min |
| Apr 28, 4:37 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Kingfisher, Logan, Oklahoma | 53 min |
| Apr 28, 4:44 PM CDT | Severe Thunderstorm Warning | OUN | Noble, Payne | 31 min |
| Apr 28, 4:45 PM CDT | Severe Thunderstorm Warning | OUN | Logan, Payne | 30 min |
| Apr 28, 5:15 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Logan, Oklahoma | 45 min |
| Apr 28, 5:15 PM CDT | Severe Thunderstorm Warning | OUN | Noble, Payne | 45 min |
| Apr 28, 5:18 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Oklahoma | 27 min |
| Apr 28, 5:27 PM CDT | Severe Thunderstorm Warning | OUN | Noble, Payne | 33 min |
| Apr 28, 5:43 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Cleveland, Oklahoma | 25 min |
| Apr 28, 5:46 PM CDT | Severe Thunderstorm Warning | OUN | Noble, Payne | 44 min |
| Apr 28, 5:49 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Cleveland, Grady, McClain, Oklahoma | 26 min |
| Apr 28, 5:52 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Logan, Oklahoma | 25 min |
| Apr 28, 6:03 PM CDT | Severe Thunderstorm Warning | OUN | Logan, Oklahoma | 27 min |
| Apr 28, 6:06 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Grady | 24 min |
| Apr 28, 6:12 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Cleveland, Grady, McClain, Oklahoma | 48 min |
| Apr 28, 6:17 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Payne | 43 min |
| Apr 28, 6:22 PM CDT | Severe Thunderstorm Warning | OUN | Grady | 53 min |
| Apr 28, 6:54 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Oklahoma, Pottawatomie | 36 min |
| Apr 28, 6:58 PM CDT | Severe Thunderstorm Warning | OUN | McClain | 32 min |
| Apr 28, 7:06 PM CDT | Severe Thunderstorm Warning | OUN | Grady, Stephens | 39 min |
| Apr 28, 7:19 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Pottawatomie, Seminole | 41 min |
| Apr 28, 7:30 PM CDT | Severe Thunderstorm Warning | OUN | Garvin, McClain | 30 min |
| Apr 28, 7:31 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Pottawatomie, Seminole | 44 min |
| Apr 28, 7:43 PM CDT | Severe Thunderstorm Warning | OUN | Grady, Stephens | 47 min |
| Apr 28, 7:47 PM CDT | Severe Thunderstorm Warning | OUN | Cleveland, Pottawatomie, Seminole | 43 min |
| Apr 28, 7:52 PM CDT | Severe Thunderstorm Warning | OUN | Cotton, Jefferson, Stephens | 38 min |
| Apr 28, 7:57 PM CDT | Severe Thunderstorm Warning | OUN | Hughes, Seminole | 33 min |
| Apr 28, 8:11 PM CDT | Severe Thunderstorm Warning | OUN | Hughes, Pontotoc, Seminole | 34 min |
| Apr 28, 8:25 PM CDT | Severe Thunderstorm Warning | OUN | Carter, Cotton, Jefferson, Stephens | 50 min |
| Apr 28, 8:29 PM CDT | Severe Thunderstorm Warning | OUN | Coal, Hughes, Pontotoc, Seminole | 46 min |
| Apr 28, 8:45 PM CDT | Severe Thunderstorm Warning | OUN | Clay | 45 min |
| Apr 28, 8:47 PM CDT | Severe Thunderstorm Warning | OUN | Carter, Love, Murray | 43 min |
| Apr 28, 8:50 PM CDT | Severe Thunderstorm Warning | OUN | Carter, Jefferson, Love, Stephens | 55 min |
| Apr 28, 9:03 PM CDT | Severe Thunderstorm Warning | OUN | Clay | 27 min |
| Apr 28, 9:04 PM CDT | Severe Thunderstorm Warning | OUN | Atoka, Coal, Hughes, Johnston, Pontotoc | 41 min |
| Apr 28, 9:06 PM CDT | Severe Thunderstorm Warning | OUN | Johnston, Murray | 39 min |
| Apr 28, 9:27 PM CDT | Severe Thunderstorm Warning | OUN | Archer, Clay | 48 min |
| Apr 28, 9:29 PM CDT | Severe Thunderstorm Warning | OUN | Carter, Love, Marshall | 46 min |
| Apr 28, 9:43 PM CDT | Severe Thunderstorm Warning | OUN | Atoka, Bryan, Coal, Johnston, Marshall | 62 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Norman, OK (KOUN), launched 12:00Z, 8.5 hours before the alert went out and 11 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1292 J/kg
- Mixed-layer CIN
- -331 J/kg
- Mixed-layer LCL
- 1080 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 213 m²/s²
- 0-3 km storm-relative helicity
- 244 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -1.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 1:55 PM CDT | Mesoscale Discussion | SPC | Adair, Blaine, Canadian, Cherokee, Cleveland, Craig and 34 more | 3 hr |
| Apr 28, 3:18 PM CDT | Tornado Watch | SPC | Adair, Cherokee, Choctaw, Craig, Creek, Delaware and 19 more | 8 hr |
| Apr 28, 6:15 PM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Delaware, Haskell, McIntosh, Mayes and 6 more | 2 hr |
| Apr 28, 10:09 AM CDT | Mesoscale Discussion | SPC | Angelina, Jasper, Nacogdoches, Newton, Sabine, San Augustine and 2 more | 3 hr |
| Apr 28, 12:47 PM CDT | Mesoscale Discussion | SPC | Austin, Brazoria, Brazos, Burleson, Chambers, Colorado and 24 more | 118 min |
Nearby
Severe Thunderstorm Watches in Oklahoma, 2020Severe Thunderstorm Watches in Texas, 2020Every severe thunderstorm watch in 2020
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.