Alert archive / Arkansas / Mesoscale Discussions in 2021
Mesoscale Discussion 1896
The Storm Prediction Center issued this mesoscale discussion at Oct 24, 2021, 9:33 PM CDT for 29 counties in Arkansas; LeFlore County, Oklahoma. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- Oct 24, 2021, 9:33 PM CDT (02:33 UTC)
- Expired
- Oct 24, 2021, 11:00 PM CDT
- In force
- 87 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 532
All 30 counties
Baxter County, AR, Boone County, AR, Cleburne County, AR, Conway County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Garland County, AR, Hot Spring County, AR, Independence County, AR, Izard County, AR, Johnson County, AR, Logan County, AR, Marion County, AR, Montgomery County, AR, Newton County, AR, Perry County, AR, Polk County, AR, Pope County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Yell County, AR, LeFlore County, OK
The radar
The Western Arkansas radar (KSRX), 80 km from the middle of the area, began a volume at 02:36 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
Springfield, MO (KSGF), launched 00:00Z, 2.6 hours before the alert went out and 172 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
- 1534 J/kg
- Mixed-layer CIN
- -7 J/kg
- Mixed-layer LCL
- 846 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 296 m²/s²
- 0-3 km storm-relative helicity
- 317 m²/s²
- Significant tornado parameter
- 2.8
- Supercell composite
- 12.3
The text
As transmitted.
313
ACUS11 KWNS 250233
SWOMCD
SPC MCD 250233
ARZ000-OKZ000-250400-
Mesoscale Discussion 1896
NWS Storm Prediction Center Norman OK
0933 PM CDT Sun Oct 24 2021
Areas affected...Northern/West-Central AR...Southeast OK
Concerning...Tornado Watch 532...
Valid 250233Z - 250400Z
The severe weather threat for Tornado Watch 532 continues.
SUMMARY...Threat for damaging wind gusts and a tornado or two is
expected to continue for the next few hours. An additional watch
will likely be needed over portions of the region before Tornado
Watch 532 expires at 04Z.
DISCUSSION...A broken line of thunderstorms continues to progress
eastward from north-central AR southwestward into southeast OK. A
few storms did show some organization earlier, but now much of the
activity has transitioned back to a somewhat disorganized mode along
the front. The only exception is the cell in Johnson County AR which
has recently strengthened. Additionally, a few more discrete storms
have begun to develop within the warm sector ahead of the line.
The low-level kinematic environment throughout the warm sector is
quite impressive. Recent mesoanalysis estimates 0-1 km
storm-relative helicity is over 300 m2/s2 across
north-central/northeast AR. As a result, the threat for tornadoes
still exists with any more discrete storms that can maintain a
robust updraft. Strong wind gusts are the primary threat with any
storms along the front.
Given the current storm motion, expectation for the severe threat to
persist, and a watch expiration time of 04Z, an additional watch
will likely be needed over portions of the region to cover the
continuing threat.
..Mosier.. 10/25/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LZK...SHV...TSA...
LAT...LON 34749523 35599394 36039345 36419304 36469278 36389108
34849193 34259277 34339536 34749523SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 24, 10:34 PM CDT | Tornado Watch | SPC | Clay, Cleburne, Conway, Craighead, Cross, Faulkner and 20 more | 4 hr |
Nearby
Mesoscale Discussions in Arkansas, 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.