Alert archive / Arkansas / Mesoscale Discussions in 2021
Mesoscale Discussion 68
The Storm Prediction Center issued this mesoscale discussion at Feb 10, 2021, 10:36 PM CST for 21 counties in Arkansas; DeSoto County, Tunica County, Mississippi; 8 counties in Tennessee. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 10, 2021, 10:36 PM CST (04:36 UTC)
- Expired
- Feb 11, 2021, 3:30 AM CST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Freezing rain
All 31 counties
Arkansas County, AR, Cleveland County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, Woodruff County, AR, DeSoto County, MS, Tunica County, MS, Crockett County, TN, Fayette County, TN, Gibson County, TN, Haywood County, TN, Lauderdale County, TN, Madison County, TN, Shelby County, TN, Tipton County, TN
The radar
The Little Rock radar (KLZK), 110 km from the middle of the area, began a volume at 04:37 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 00:00Z, 4.6 hours before the alert went out and 101 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
- 13 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 403 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 174 m²/s²
- 0-3 km storm-relative helicity
- 206 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
105
ACUS11 KWNS 110436
SWOMCD
SPC MCD 110436
TNZ000-MSZ000-ARZ000-110930-
Mesoscale Discussion 0068
NWS Storm Prediction Center Norman OK
1036 PM CST Wed Feb 10 2021
Areas affected...Southern Arkansas to Western Tennessee/Northwest
Mississippi
Concerning...Freezing rain
Valid 110436Z - 110930Z
SUMMARY...Freezing rain threat will increase from southern Arkansas,
spreading into western Tennessee and far northwest Mississippi over
the next 2-4 hours. Rain rates will exceed 0.05 inches per hour in
the heaviest convection.
DISCUSSION...Weak low-level warm advection appears to be primarily
responsible for gradual increase in convection across northeast
TX/northern LA into southeast AR. A fair amount of lightning is
noted with this elevated convection and forecast soundings exhibit
appreciable MUCAPE if lifting a parcel near 850mb. Much of this
activity should spread northeast atop sub-freezing surface
temperatures over the next few hours.
Latest surface analysis suggests the freezing line extends from
Madison County TN - DeSoto County MS - Jefferson County AR.
Low-level cold advection across AR should allow the freezing line to
sag a bit south across AR over the next few hours, while little
movement is expected over MS through 09z. For this reason, a primary
short-term corridor for freezing rain w/thunder should be noted from
south-central AR into western TN. Some sleet may mix in later
tonight near the MO Bootheel but the primary concern is freezing
rain.
..Darrow.. 02/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MEG...JAN...LZK...
LAT...LON 34629282 35739088 36088857 35508861 34749015 33479158
33709306 34629282SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 11, 4:02 AM CST | Mesoscale Discussion | SPC | Arkansas, Cleveland, Craighead, Crittenden, Cross, Grant and 14 more | 5 hr |
Nearby
Mesoscale Discussions in Arkansas, 2021Mesoscale Discussions in Tennessee, 2021Mesoscale Discussions in Mississippi, 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.