Alert archive / Arkansas / Mesoscale Discussions in 2020
Mesoscale Discussion 252
The Storm Prediction Center issued this mesoscale discussion at Mar 28, 2020, 2:56 PM CDT for 40 counties in Arkansas; Dunklin County, Pemiscot County, Missouri. It was in force for 94 min.
The area
The outline as issued.
The facts
- Issued
- Mar 28, 2020, 2:56 PM CDT (19:56 UTC)
- Expired
- Mar 28, 2020, 4:30 PM CDT
- In force
- 94 min
- Issued by
- the Storm Prediction Center
All 42 counties
Arkansas County, AR, Bradley County, AR, Calhoun County, AR, Clay County, AR, Cleburne County, AR, Cleveland County, AR, Conway County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Faulkner County, AR, Grant County, AR, Greene County, AR, Hot Spring County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Jefferson County, AR, Lawrence County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Ouachita County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Sharp County, AR, St. Francis County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Dunklin County, MO, Pemiscot County, MO
The radar
The Little Rock radar (KLZK), 55 km from the middle of the area, began a volume at 19:58 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
Little Rock, AR (KLZK), launched 12:00Z, 7.9 hours before the alert went out and 162 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
- 172 J/kg
- Mixed-layer CIN
- -331 J/kg
- Mixed-layer LCL
- 810 m above ground
- 0-6 km bulk shear
- 74 kt
- 0-1 km storm-relative helicity
- 177 m²/s²
- 0-3 km storm-relative helicity
- 162 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
716
ACUS11 KWNS 281957
SWOMCD
SPC MCD 281956
TNZ000-MOZ000-ARZ000-MSZ000-282130-
Mesoscale Discussion 0252
NWS Storm Prediction Center Norman OK
0256 PM CDT Sat Mar 28 2020
Areas affected...Eastern Arkansas
Concerning...Tornado Watch 68...
Valid 281956Z - 282130Z
The severe weather threat for Tornado Watch 68 continues.
SUMMARY...The severe weather threat continues in tornado watch 68
with a main threat of damaging winds and a few tornadoes.
DISCUSSION...Storm coverage has increased along a cold front in
central Arkansas, but storm intensity has remained mostly limited.
The 19Z LZK sounding shows very weak mid-level lapse rates (~6 C/km)
and MLCAPE less than 1000 J/kg. In addition, winds below 1km are
less than 20 knots while effective shear is 80 knots beneath a 90 kt
500mb jet streak. This meager thermodynamic profile combined with a
highly sheared environment likely explains the lack of robust
updraft growth across central Arkansas despite adequate forcing for
pre-frontal development as parcel acceleration is not great enough
to balance the strong shear. Some brief QLCS tornadoes will be
possible, especially in northern Arkansas later this afternoon and
this evening as the low-level jet strengthens, but otherwise, wind
damage along the line will likely be the primary threat. Even the
wind damage will likely remain isolated, especially in the southern
half of the watch, given the weak low-level flow.
..Bentley.. 03/28/2020
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...MEG...JAN...LZK...SHV...
LAT...LON 33439335 34719289 35569273 36189238 36419157 36459054
36478990 36288951 34759042 33409138 33389247 33439335SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 28, 12:14 PM CDT | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Clark, Cleburne, Cleveland and 42 more | 2 hr |
| Mar 28, 1:17 PM CDT | Mesoscale Discussion | SPC | Clay, Randolph | 88 min |
| Mar 28, 2:10 PM CDT | Tornado Watch | SPC | Arkansas, Baxter, Bradley, Calhoun, Clark, Clay and 42 more | 5 hr |
| Mar 28, 4:59 PM CDT | Mesoscale Discussion | SPC | Crittenden, Lee, Mississippi, Phillips, St. Francis | 61 min |
| Mar 28, 6:34 PM CDT | Tornado Watch | SPC | Ashley, Chicot, Crittenden, Cross, Lee, Mississippi and 2 more | 7 hr |
| Mar 27, 8:02 PM CDT | Mesoscale Discussion | SPC | Bollinger, Cape Girardeau, Madison, Perry, Sainte Genevieve | 88 min |
| Mar 27, 8:33 PM CDT | Mesoscale Discussion | SPC | Audrain, Barton, Bates, Benton, Boone, Callaway and 30 more | 87 min |
| Mar 27, 10:16 PM CDT | Severe Thunderstorm Watch | SPC | Audrain, Boone, Callaway, Cole, Franklin, Gasconade and 11 more | 6 hr |
| Mar 27, 11:46 PM CDT | Mesoscale Discussion | SPC | Audrain, Boone, Callaway, Cole, Franklin, Gasconade and 9 more | 89 min |
| Mar 28, 1:34 AM CDT | Mesoscale Discussion | SPC | Atchison, Gentry, Harrison, Holt, Mercer, Nodaway and 1 more | 56 min |
| Mar 28, 7:05 AM CDT | Mesoscale Discussion | SPC | Barry, Barton, Bates, Benton, Boone, Camden and 27 more | 85 min |
| Mar 28, 1:33 PM CDT | Mesoscale Discussion | SPC | Adair, Audrain, Boone, Callaway, Chariton, Clark and 18 more | 117 min |
| Mar 28, 2:45 PM CDT | Tornado Watch | SPC | Adair, Audrain, Boone, Callaway, Chariton, Clark and 21 more | 6 hr |
| Mar 28, 3:53 PM CDT | Tornado Watch | SPC | Bollinger, Butler, Cape Girardeau, Carter, Crawford, Franklin and 20 more | 5 hr |
| Mar 28, 5:21 PM CDT | Mesoscale Discussion | SPC | Clark | 84 min |
Nearby
Mesoscale Discussions in Arkansas, 2020Mesoscale Discussions in Missouri, 2020Every mesoscale discussion in 2020
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.