(RUC-2 analysis at Jackson, Tennessee, 05 UTC 11/27/01, updated by 05 UTC surface ob at MKL):
OHX base refl. 0528 UTC 11/27/01
Tornadic profile with shallow inversion near the ground
The following type of environment is not uncommon in the southern states during cool season severe weather episodes.
Example 2. The shallow inversion in the bottom 50 mb with this example masks an environment capable of supporting significant tornadoes. Using a surface parcel on the left, 0-3 km CAPE appears small and CIN quite large, suggesting an "elevated" environment with little or no support for tornadoes. However, on the right, a lifted parcel from not far above the surface (about 400 m or 40-50 mb AGL) generates significant low-level CAPE and only small CIN from the same profile. The inversion is shallow enough that this environment is not truly elevated. Large SRH and vertical wind shear is present (wind profile not shown).
When the more unstable parcel is used, shear-CAPE combinations are
strong with good vertical shear, and low-level thermodynamic parameters are strong as
well, suggesting good support for significant tornadoes.
(RUC-2 analysis at Jackson, Tennessee, 05 UTC 11/27/01, updated by 05 UTC surface ob at
MKL):
OHX base refl. 0528 UTC 11/27/01
Observed: F3 tornado, 1 dead and 12 injured |
total ML CAPE 1692 J/kg 0-1 km SRH 450 m2/s2 |
| parameter value | support for supercell tornadoes? | why? | comments | |
| 0-1k EHI | 4.8 | strong | > 3.0 | |
| BL-6k shear | 38 kts | ok | >= 38 kts | |
| LCL height | 590 m | strong | < 1000 m | |
| all parameters "strong" or "ok" | ||||
| CIN | 35 J/kg | strong | < 50 J/kg | |
| LFC height | 1550 m | ok/strong | near 1500 m | |
| 0-3k CAPE | 94 J/kg | strong | > 90 J/kg |
description and key for examples
operational low-level thermodynamic parameter guidelines