Alert archive / Oklahoma / Mesoscale Discussions in 2021
Mesoscale Discussion 1907
The Storm Prediction Center issued this mesoscale discussion at Oct 26, 2021, 10:09 PM CDT for 13 counties in Kansas; 37 counties in Oklahoma. It was in force for 66 min.
The area
The outline as issued.
The facts
- Issued
- Oct 26, 2021, 10:09 PM CDT (03:09 UTC)
- Expired
- Oct 26, 2021, 11:15 PM CDT
- In force
- 66 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch likely
- Chance of a watch
- 80%
All 50 counties
Butler County, KS, Chase County, KS, Chautauqua County, KS, Cowley County, KS, Elk County, KS, Greenwood County, KS, Harvey County, KS, Marion County, KS, Montgomery County, KS, Sedgwick County, KS, Sumner County, KS, Wilson County, KS, Woodson County, KS, Atoka County, OK, Bryan County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Creek County, OK, Garfield County, OK, Garvin County, OK, Grant County, OK, Hughes County, OK, Johnston County, OK, Kay County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Marshall County, OK, Mayes County, OK, McClain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Noble County, OK, Nowata County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Rogers County, OK, Seminole County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK
The radar
The Tulsa radar (KINX), 83 km from the middle of the area, began a volume at 03:07 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Norman, OK (KOUN), launched 00:00Z, 3.2 hours before the alert went out and 132 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
- 791 J/kg
- Mixed-layer CIN
- -225 J/kg
- Mixed-layer LCL
- 916 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 277 m²/s²
- 0-3 km storm-relative helicity
- 380 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.5
The text
As transmitted.
524
ACUS11 KWNS 270310
SWOMCD
SPC MCD 270309
OKZ000-KSZ000-TXZ000-270415-
Mesoscale Discussion 1907
NWS Storm Prediction Center Norman OK
1009 PM CDT Tue Oct 26 2021
Areas affected...portions of southeast Kansas into central and
eastern Oklahoma
Concerning...Severe potential...Watch likely
Valid 270309Z - 270415Z
Probability of Watch Issuance...80 percent
SUMMARY...The severe threat is increasing for portions of
southeastern Kansas into central and eastern Oklahoma as severe wind
producing line segments approach from the west. A WW will be issued
shortly to address the severe threat.
DISCUSSION...Multiple line segments have organized over the past
couple of hours and are approaching the I-35 corridor. These line
segments are progressing within a modestly unstable (1000 J/kg
MLCAPE) but highly sheared airmass. Latest ICT and OKC VWPS depict
60+ kt flow below 1-km AGL, which can efficiently be transported to
the surface in any vigorous cell/line segment. As such, damaging
gusts are anticipated to continue overnight despite the presence of
increasing convective inhibition. In addition, given modest
surface-1 km veering contributing to 400+ m2/s2 0-1 km SRH, embedded
circulations and perhaps a couple brief tornadoes are also possible.
A WW will be issued shortly to account for this scenario.
..Squitieri/Hart.. 10/27/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TSA...TOP...ICT...FWD...OUN...
LAT...LON 33819736 36409792 37819777 38419758 38599717 38499654
37969575 37319534 36319523 35179534 34429549 33939582
33699619 33819736SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 26, 8:59 PM CDT | Mesoscale Discussion | SPC | Barber, Barton, Clark, Comanche, Edwards, Ellis and 23 more | 91 min |
| Oct 26, 10:26 PM CDT | Severe Thunderstorm Watch | SPC | Butler, Chautauqua, Cowley, Harvey, McPherson, Marion and 3 more | 7 hr |
| Oct 26, 7:23 PM CDT | Severe Thunderstorm Watch | SPC | Caddo, Comanche, Cotton, Grady, Greer, Harmon and 5 more | 8 hr |
| Oct 26, 9:37 PM CDT | Mesoscale Discussion | SPC | Beckham, Caddo, Comanche, Cotton, Grady, Greer and 5 more | 83 min |
| Oct 27, 1:13 AM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Coal, Creek, Hughes, Johnston and 15 more | 2 hr |
Nearby
Mesoscale Discussions in Oklahoma, 2021Mesoscale Discussions in Kansas, 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.