Alert archive / Oklahoma / Mesoscale Discussions in 2021
Mesoscale Discussion 933
The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2021, 11:37 PM CDT for 10 counties in Oklahoma. It was in force for 113 min.
The area
The outline as issued.
The facts
- Issued
- Jun 11, 2021, 11:37 PM CDT (04:37 UTC)
- Expired
- Jun 12, 2021, 1:30 AM CDT
- In force
- 113 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 261
Counties Alfalfa County, OK, Garfield County, OK, Grant County, OK, Kay County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, Noble County, OK, Pawnee County, OK, Payne County, OK
The radar
The Vance AFB radar (KVNX), 59 km from the middle of the area, began a volume at 04:38 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.
The nearest sounding before it
Norman, OK (KOUN), launched 00:00Z, 4.6 hours before the alert went out and 136 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
- 3394 J/kg
- Mixed-layer CIN
- -216 J/kg
- Mixed-layer LCL
- 1175 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 55 m²/s²
- 0-3 km storm-relative helicity
- 225 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
The text
As transmitted.
476 ACUS11 KWNS 120437 SWOMCD SPC MCD 120437 OKZ000-KSZ000-120630- Mesoscale Discussion 0933 NWS Storm Prediction Center Norman OK 1137 PM CDT Fri Jun 11 2021 Areas affected...Northern/Central Oklahoma Concerning...Severe Thunderstorm Watch 261... Valid 120437Z - 120630Z The severe weather threat for Severe Thunderstorm Watch 261 continues. SUMMARY...Damaging wind gusts are possible with a thunderstorm cluster as it propagates from north-central into central Oklahoma into the early-morning hours. DISCUSSION...A small MCS has evolved over the last few hours along the KS/OK border. This activity initially struggled to grow upscale due to very warm 2-3km temperatures. However, an expanding precip shield/cold pool appears to have developed such that the MCS is now surging a bit quicker along the I-35 corridor. The leading edge of this activity is moving at roughly 25kt suggesting it could approach the northern Oklahoma City metro by 06z. Winds have recently gusted to 78 mph in northeast Kay County and damaging winds are the primary severe threat as this activity propagates south. There is some concern that propagation may spread a bit west of the initial watch, continuing south through the metro. Given the 700mb temperature observed at OUN this evening was 19C, if the cold pool weakens the MCS will likely become even more elevated in nature and weaken. ..Darrow.. 06/12/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TSA...ICT...OUN... LAT...LON 37039799 36759655 35689668 35529785 36609848 37039799
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 11, 9:20 PM CDT | Mesoscale Discussion | SPC | Garfield, Grant, Kay, Noble, Osage, Pawnee and 1 more | 115 min |
| Jun 12, 2:58 AM CDT | Mesoscale Discussion | SPC | Caddo, Cleveland, Comanche, Cotton, Garvin, Grady and 6 more | 92 min |
Nearby
Mesoscale Discussions in Oklahoma, 2021Every mesoscale discussion in 2021
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.