Alert archive / Tennessee / Mesoscale Discussions in 2021
Mesoscale Discussion 549
The Storm Prediction Center issued this mesoscale discussion at May 6, 2021, 10:05 AM CDT for 5 states. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- May 6, 2021, 10:05 AM CDT (15:05 UTC)
- Expired
- May 6, 2021, 11:30 AM CDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
- Concerning
- Outlook upgrade
All 60 counties
Clay County, AR, Crittenden County, AR, Mississippi County, AR, Alexander County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Cape Girardeau County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Stoddard County, MO, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, Obion County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Weakley County, TN
The radar
The Paducah radar (KPAH), 33 km from the middle of the area, began a volume at 15:08 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
Nashville Metro, TN (KBNA), launched 12:00Z, 3.1 hours before the alert went out and 234 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1719 m above ground
- 0-6 km bulk shear
- 65 kt
- 0-1 km storm-relative helicity
- -90 m²/s²
- 0-3 km storm-relative helicity
- -71 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
679
ACUS11 KWNS 061505
SWOMCD
SPC MCD 061505
TNZ000-KYZ000-INZ000-ILZ000-MOZ000-ARZ000-061630-
Mesoscale Discussion 0549
NWS Storm Prediction Center Norman OK
1005 AM CDT Thu May 06 2021
Areas affected...Portions of the Mid-South
Concerning...Outlook upgrade
Valid 061505Z - 061630Z
SUMMARY...A Slight Risk will be added in the forthcoming 1630Z D1
Convective Outlook.
DISCUSSION...Potential for multiple lower-topped supercells capable
of large hail appears to have increased across a portion of the
Mid-South region this afternoon. These may linearly organize with an
increased threat for damaging winds as well. Please see the 1630Z D1
Convective Outlook update for further details.
..Grams.. 05/06/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OHX...PAH...MEG...
LAT...LON 38388898 38508825 37598761 36538760 35048873 35109029
35849061 36499043 38388898SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 6, 12:02 PM CDT | Mesoscale Discussion | SPC | Clay, Craighead, Greene, Lawrence, Mississippi, Randolph | 118 min |
| May 6, 12:38 PM CDT | Severe Thunderstorm Watch | SPC | Clay, Craighead, Crittenden, Cross, Greene, Jackson and 4 more | 5 hr |
| May 6, 2:45 PM CDT | Mesoscale Discussion | SPC | Clay, Craighead, Crittenden, Cross, Greene, Mississippi and 1 more | 90 min |
| May 6, 9:52 AM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Clinton, Greene, Jersey, Macoupin and 7 more | 83 min |
| May 6, 1:10 PM CDT | Mesoscale Discussion | SPC | Champaign, Christian, Coles, Cumberland, DeWitt, Douglas and 10 more | 2 hr |
| May 6, 5:11 PM CDT | Mesoscale Discussion | SPC | Bedford, Cannon, Cheatham, Coffee, Davidson, Franklin and 18 more | 94 min |
Nearby
Mesoscale Discussions in Tennessee, 2021Mesoscale Discussions in Illinois, 2021Mesoscale Discussions in Kentucky, 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.