Alert archive / Arkansas / Mesoscale Discussions in 2021
Mesoscale Discussion 1859
The Storm Prediction Center issued this mesoscale discussion at Oct 14, 2021, 3:46 PM CDT for 4 states. It was in force for 119 min.
The area
The outline as issued.
The facts
- Issued
- Oct 14, 2021, 3:46 PM CDT (20:46 UTC)
- Expired
- Oct 14, 2021, 5:45 PM CDT
- In force
- 119 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
All 34 counties
Baxter County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Lawrence County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, Alexander County, IL, Pulaski County, IL, Ballard County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Dunklin County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Oregon County, MO, Pemiscot County, MO, Perry County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO
The radar
The Memphis radar (KNQA), 152 km from the middle of the area, began a volume at 20:46 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
Little Rock, AR (KLZK), launched 12:00Z, 8.8 hours before the alert went out and 198 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
- 167 J/kg
- Mixed-layer CIN
- -17 J/kg
- Mixed-layer LCL
- 677 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 62 m²/s²
- 0-3 km storm-relative helicity
- 105 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.8
The text
As transmitted.
335
ACUS11 KWNS 142046
SWOMCD
SPC MCD 142046
TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-142245-
Mesoscale Discussion 1859
NWS Storm Prediction Center Norman OK
0346 PM CDT Thu Oct 14 2021
Areas affected...northern Arkansas into southeast Missouri and
southern Illinois
Concerning...Severe potential...Watch unlikely
Valid 142046Z - 142245Z
Probability of Watch Issuance...5 percent
SUMMARY...A few strong storms are possible from northern Arkansas
into southeast Missouri/southern Illinois with gusty winds the most
likely threat.
DISCUSSION...Storms have slowly increased over northern AR near a
diffuse front, with modest instability along the ahead of the
boundary. This front is situated roughly parallel to the winds
aloft, suggesting storms may track along it over the next several
hours.
Effective SRH is generally weak, but deep-layer shear is favorable
at 35-40 kt to sustain a few longer-lived storms given the moist
environment. Weak cyclonic shear has been noted recently on the AR
activity, and while tornadoes are not expected, could aid gusty wind
potential.
..Jewell/Dial.. 10/14/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...MEG...LSX...LZK...SGF...
LAT...LON 37128895 36558922 36058990 35849049 35499135 35279210
35249284 35399301 35569304 35829296 36189263 37399082
37679023 37738988 37658945 37398915 37128895Nearby
Mesoscale Discussions in Arkansas, 2021Mesoscale Discussions in Missouri, 2021Mesoscale Discussions in Illinois, 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.