Alert archive / Arkansas / Mesoscale Discussions in 2021
Mesoscale Discussion 211
The Storm Prediction Center issued this mesoscale discussion at Mar 17, 2021, 3:37 PM CDT for 11 counties in Arkansas; 11 counties in Missouri; 11 counties in Oklahoma. It was in force for 83 min.
The area
The outline as issued.
The facts
- Issued
- Mar 17, 2021, 3:37 PM CDT (20:37 UTC)
- Expired
- Mar 17, 2021, 5:00 PM CDT
- In force
- 83 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 34
All 33 counties
Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Crawford County, AR, Franklin County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Searcy County, AR, Washington County, AR, Barry County, MO, Christian County, MO, Douglas County, MO, Greene County, MO, Jasper County, MO, Lawrence County, MO, McDonald County, MO, Newton County, MO, Ozark County, MO, Stone County, MO, Taney County, MO, Adair County, OK, Cherokee County, OK, Craig County, OK, Delaware County, OK, Mayes County, OK, Nowata County, OK, Ottawa County, OK, Rogers County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK
The radar
The Western Arkansas radar (KSRX), 111 km from the middle of the area, began a volume at 20:40 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
Springfield, MO (KSGF), launched 12:00Z, 8.6 hours before the alert went out and 82 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
- 102 J/kg
- Mixed-layer CIN
- -235 J/kg
- Mixed-layer LCL
- 956 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- 220 m²/s²
- 0-3 km storm-relative helicity
- 236 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.9
The text
As transmitted.
923
ACUS11 KWNS 172037
SWOMCD
SPC MCD 172037
ARZ000-MOZ000-OKZ000-KSZ000-172200-
Mesoscale Discussion 0211
NWS Storm Prediction Center Norman OK
0337 PM CDT Wed Mar 17 2021
Areas affected...Northeast Oklahoma...southwest Missouri...and
northwest Arkansas.
Concerning...Tornado Watch 34...
Valid 172037Z - 172200Z
The severe weather threat for Tornado Watch 34 continues.
SUMMARY...The severe weather threat continues from northeast
Oklahoma to southwest Missouri and northwest Arkansas.
DISCUSSION...Storm activity has been mostly confined to the areas
with greatest low-level convergence near the surface low in
northeast Oklahoma. Current observations show decreasing convergence
along the boundary into west-central Arkansas which may limit
thunderstorm chances in this area. However, where storms do form
they may be strong to severe given MLCAPE around 500 to 750 J/kg and
effective shear in excess of 70 knots per SPC mesoanalysis. These
storms will pose a threat for large hail, damaging winds, and a few
tornadoes.
..Bentley.. 03/17/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LZK...SGF...TSA...ICT...
LAT...LON 36209646 36909585 37389381 37169252 36649212 35979234
35659319 35489398 35689493 35939583 36209646SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 17, 12:45 AM CDT | Mesoscale Discussion | SPC | Benton, Washington | 90 min |
| Mar 17, 1:32 AM CDT | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Clark, Cleveland, Columbia and 27 more | 118 min |
| Mar 17, 4:04 AM CDT | Mesoscale Discussion | SPC | Columbia, Hempstead, Lafayette, Little River, Miller, Sevier | 86 min |
| Mar 17, 4:37 AM CDT | Severe Thunderstorm Watch | SPC | Hempstead, Howard, Lafayette, Little River, Miller, Nevada and 1 more | 5 hr |
| Mar 17, 5:34 AM CDT | Mesoscale Discussion | SPC | Arkansas, Crittenden, Cross, Desha, Lee, Lincoln and 3 more | 86 min |
| Mar 17, 5:53 AM CDT | Tornado Watch | SPC | Arkansas, Bradley, Cleveland, Crittenden, Desha, Drew and 8 more | 7 hr |
| Mar 17, 6:40 AM CDT | Mesoscale Discussion | SPC | Calhoun, Clark, Columbia, Crawford, Dallas, Franklin and 19 more | 95 min |
| Mar 17, 7:38 AM CDT | Mesoscale Discussion | SPC | Crittenden, Lee, Monroe, Phillips, St. Francis | 67 min |
| Mar 17, 7:47 AM CDT | Tornado Watch | SPC | Calhoun, Clark, Conway, Dallas, Faulkner, Garland and 15 more | 5 hr |
| Mar 17, 8:43 AM CDT | Tornado Watch | SPC | Columbia, Union | 4 hr |
| Mar 17, 12:15 PM CDT | Mesoscale Discussion | SPC | Ashley, Chicot, Desha, Drew, Phillips | 90 min |
| Mar 17, 12:57 PM CDT | Tornado Watch | SPC | Ashley, Chicot, Lee, Phillips | 6 hr |
| Mar 17, 1:18 PM CDT | Mesoscale Discussion | SPC | Benton, Boone, Carroll, Clark, Crawford, Franklin and 22 more | 57 min |
| Mar 17, 2:00 PM CDT | Tornado Watch | SPC | Benton, Boone, Carroll, Crawford, Franklin, Johnson and 12 more | 7 hr |
| Mar 17, 2:56 PM CDT | Mesoscale Discussion | SPC | Ashley, Chicot, Desha, Drew | 94 min |
| Mar 17, 6:09 PM CDT | Mesoscale Discussion | SPC | Crittenden, Cross | 66 min |
| Mar 17, 1:54 AM CDT | Severe Thunderstorm Watch | SPC | Barry, Barton, Bates, Cedar, Dade, Jasper and 5 more | 6 hr |
| Mar 17, 5:18 AM CDT | Mesoscale Discussion | SPC | Barton, Bates, Vernon | 87 min |
| Mar 17, 8:51 AM CDT | Mesoscale Discussion | SPC | Audrain, Boone, Callaway, Camden, Christian, Cole and 35 more | 84 min |
| Mar 16, 7:49 PM CDT | Severe Thunderstorm Watch | SPC | Alfalfa, Beckham, Blaine, Caddo, Canadian, Custer and 19 more | 7 hr |
| Mar 17, 1:56 AM CDT | Mesoscale Discussion | SPC | Blaine, Custer, Garfield, Kay, Kingfisher, Logan and 3 more | 64 min |
| Mar 17, 4:38 AM CDT | Mesoscale Discussion | SPC | Beaver, Cimarron, Texas | 6 hr |
Nearby
Mesoscale Discussions in Arkansas, 2021Mesoscale Discussions in Missouri, 2021Mesoscale 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.