Alert archive / Tennessee / Mesoscale Discussions in 2021
Mesoscale Discussion 551
The Storm Prediction Center issued this mesoscale discussion at May 6, 2021, 12:02 PM CDT for 5 states. It was in force for 118 min.
The area
The outline as issued.
The facts
- Issued
- May 6, 2021, 12:02 PM CDT (17:02 UTC)
- Expired
- May 6, 2021, 2:00 PM CDT
- In force
- 118 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 60%
All 55 counties
Clay County, AR, Craighead County, AR, Greene County, AR, Lawrence County, AR, Mississippi County, AR, Randolph County, AR, Alexander County, IL, Hardin County, IL, Jackson County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, Williamson County, IL, Ballard 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, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Dunklin County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Perry County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Benton County, TN, Carroll County, TN, Crockett County, TN, Dyer County, TN, Gibson County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, Obion County, TN, Tipton County, TN, Weakley County, TN
The radar
The Paducah radar (KPAH), 89 km from the middle of the area, began a volume at 17:03 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, 5.0 hours before the alert went out and 201 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
- 1745 m above ground
- 0-6 km bulk shear
- 76 kt
- 0-1 km storm-relative helicity
- 47 m²/s²
- 0-3 km storm-relative helicity
- 88 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
276
ACUS11 KWNS 061703
SWOMCD
SPC MCD 061702
TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-061900-
Mesoscale Discussion 0551
NWS Storm Prediction Center Norman OK
1202 PM CDT Thu May 06 2021
Areas affected...Southeast MO/MO Bootheel...Southern IL...Far
Western KY...Western TN...Northeast AR
Concerning...Severe potential...Watch possible
Valid 061702Z - 061900Z
Probability of Watch Issuance...60 percent
SUMMARY...Large hail and damaging wind gusts are possible across the
region this afternoon as strong to severe thunderstorms develop
along and ahead of the cold front.
DISCUSSION...Updrafts continue to deepen within the convective
cluster along and ahead of the cold front moving southeastward into
southeast MO and adjacent southern IL. Expectation is for these
storms to continued to strengthen as they move into the slightly
warmer and more moist air mass downstream.
Cold mid-level temperatures and resulting steep lapse rates will
support moderate buoyancy, despite the relatively modest low-level
moisture. Strong unidirectional deep-layer flow will result in fast
storm motion as well as the potential for a strong, convectively
augmented wind gusts. Additionally, given the cold mid-level
temperatures and moderate mid-level flow, hail is also possible with
the stronger updrafts. Anticipated strong to severe nature of the
storms merits possible watch issuance and convective trends are
being monitored closely.
..Mosier/Grams.. 05/06/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OHX...PAH...MEG...LSX...LZK...
LAT...LON 37339077 38128968 37758824 36678775 35638830 35248919
35329036 36129123 37339077SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 6, 10:05 AM CDT | Mesoscale Discussion | SPC | Clay, Crittenden, Mississippi | 85 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 Missouri, 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.