Alert archive / Oklahoma / Mesoscale Discussions in 2023
Mesoscale Discussion 821
The Storm Prediction Center issued this mesoscale discussion at May 19, 2023, 12:49 PM CDT for 6 counties in Arkansas; 23 counties in Oklahoma; Red River County, Texas. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- May 19, 2023, 12:49 PM CDT (17:49 UTC)
- Expired
- May 19, 2023, 2:15 PM CDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...severe thunderstorm watch likely
- Chance of a watch
- 95%
All 30 counties
Howard County, AR, Little River County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, Atoka County, OK, Bryan County, OK, Choctaw County, OK, Coal County, OK, Garvin County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Marshall County, OK, McCurtain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Okfuskee County, OK, Okmulgee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Seminole County, OK, Sequoyah County, OK, Red River County, TX
The radar
The Western Arkansas radar (KSRX), 134 km from the middle of the area, began a volume at 17:50 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 12:00Z, 5.8 hours before the alert went out and 199 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
- 96 J/kg
- Mixed-layer CIN
- -49 J/kg
- Mixed-layer LCL
- 648 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 91 m²/s²
- 0-3 km storm-relative helicity
- 109 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.9
The text
As transmitted.
084
ACUS11 KWNS 191749
SWOMCD
SPC MCD 191749
ARZ000-TXZ000-OKZ000-191915-
Mesoscale Discussion 0821
NWS Storm Prediction Center Norman OK
1249 PM CDT Fri May 19 2023
Areas affected...portions of southeastern Oklahoma and the ArkLaTex
Concerning...Severe potential...Severe Thunderstorm Watch likely
Valid 191749Z - 191915Z
Probability of Watch Issuance...95 percent
SUMMARY...Scattered severe storms, including supercells, are
expected to develop this afternoon in the wake of an early morning
MCS. Large hail is expected to be the primary threat, though
isolated damaging gusts and a tornado cannot be ruled out. A Severe
Thunderstorm Watch is likely this afternoon.
DISCUSSION...In the wake of an early morning MCS and remnant MCV
across eastern OK and the ArkLaTex, clearing skies have aided in
rapid recovery of the air mass early this afternoon. Strong
insolation has allowed surface temperatures to warm into the 70s F
with dewpoints remaining in the low to mid 60s F. Continued
modification of the air mass is likely through the next couple of
hours, supporting the development of 1500-2000 J/kg of MLCAPE. As
instability develops and lingering inhibition is removed, the
development of severe storms is likely across a couple of areas this
afternoon.
Aided by the remnant MCV, area VAD/VWPs show moderate effective
shear (30-40 kt) sufficient for storm organization, including
supercells. Storms may first develop ahead of the remnant MCV across
eastern OK before spreading eastward into AR. A few storms may also
develop on the trailing outflow near the Red River and possibly as
far west as central OK. Despite the poor mid-level lapse rates, the
supercell storm mode will favor large hail potential with the
stronger sustained updrafts. The lack of stronger low-level flow
lends lower confidence in the potential for damaging winds and or
tornadoes. However, given the supercell mode, a strong gusts and a
brief tornado cannot be ruled out. With the potential for strong to
severe storms to develop early this afternoon, a new Severe
Thunderstorm Watch is likely.
..Lyons/Grams.. 05/19/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LZK...SHV...TSA...FWD...OUN...
LAT...LON 35019733 35619706 35759604 35429399 35169369 34729368
33779390 33639402 33569417 33549461 33579514 33789603
34009714 34369734 35019733SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 19, 1:09 PM CDT | Severe Thunderstorm Watch | SPC | Clark, Conway, Crawford, Franklin, Garland, Hempstead and 18 more | 9 hr |
| May 19, 3:30 PM CDT | Mesoscale Discussion | SPC | Clark, Garland, Hempstead, Howard, Lafayette, Little River and 11 more | 90 min |
| May 18, 9:52 PM CDT | Mesoscale Discussion | SPC | Armstrong, Carson, Hutchinson, Moore, Potter, Randall | 53 min |
| May 19, 1:43 PM CDT | Mesoscale Discussion | SPC | Bosque, Brown, Coke, Coleman, Collin, Comanche and 25 more | 62 min |
| May 19, 2:01 PM CDT | Severe Thunderstorm Watch | SPC | Bell, Bosque, Collin, Comanche, Coryell, Dallas and 20 more | 8 hr |
| May 19, 3:20 PM CDT | Severe Thunderstorm Watch | SPC | Andrews, Bandera, Blanco, Brown, Burnet, Callahan and 39 more | 9 hr |
| May 19, 5:33 PM CDT | Mesoscale Discussion | SPC | Brown, Coke, Coleman, Concho, Crane, Crockett and 32 more | 117 min |
| May 19, 5:49 PM CDT | Mesoscale Discussion | SPC | Bell, Bosque, Collin, Coryell, Dallas, Ellis and 12 more | 86 min |
Nearby
Mesoscale Discussions in Oklahoma, 2023Mesoscale Discussions in Arkansas, 2023Mesoscale Discussions in Texas, 2023Every mesoscale discussion in 2023
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.