(RUC-2 analysis profile at Tekamah, Nebraska, 00 UTC 6/19/01, updated by 00 UTC surface obs at TQE-OMA):
OAX base refl. 0047 UTC 6/19/01"Non-elevated" profile (no deep inversion) that suggests little potential for supercell tornadoes
Example 4a. This environment has marginal
shear-CAPE combinations and poor vertical wind shear with a high LCL, and therefore
appears unlikely to support much in the way of supercell tornadoes. While some might
call this an "elevated" profile due to the high LCL (resulting a high cloud
base) and elongated area of CIN, it doesn't have the deep inversion that other strongly
elevated examples have (see "elevated"
supercell examples). Profiles like this are common in late spring and summer,
particularly in the plains.
(RUC-2 analysis profile at Tekamah, Nebraska, 00 UTC 6/19/01, updated by 00 UTC surface
obs at TQE-OMA):
OAX base refl. 0047 UTC 6/19/01
Observed: Brief F0 tornado (no damage), supercell otherwise nontornadic (1.75" hail) |
total ML CAPE 3886 J/kg 0-1 km SRH 63 m2/s2 |
| parameter value | support for supercell tornadoes? | why? | comments | |
| 0-1k EHI | 1.5 | marginal | < 2.0 | |
| BL-6k shear | 24 kts | poor | < 30 kts | |
| LCL height | 1509 m | poor | > 1500 m | |
| parameters "poor" to "marginal" | ||||
| CIN | 81 J/kg | ok | < 100 J/kg | |
| LFC height | 2106 | marginal | > 2000 m | |
| 0-3k CAPE | 29 J/kg | poor/marginal | near 30 J/kg |
description and key for examples
operational low-level thermodynamic parameter guidelines
Example 4b. Even though low-level thermodynamic
parameters here are favorable, the wind fields are weak, resulting in poor
shear-CAPE combinations and generally poor vertical shear. Even though there is good
turning with height on the wind profile, winds below 500 mb are only around 10 kts or
less. The weak wind fields suggest little potential for significant supercell
tornadoes.
(RUC-2 analysis profile at Newton, Kansas, 23 UTC 9/17/01, updated by 23 UTC surface ob at
EWK):
ICT base refl. 9/17/01 2300 UTC
Observed: Nontornadic supercell with 1.75" hail |
total ML CAPE 2615 J/kg 0-1 km SRH 28 m2/s2 |
| parameter value | support for supercell tornadoes? | why? | comments | |
| 0-1k EHI | 0.5 | poor | > 3.0 | shear-CAPE combinations are |
| BL-6k shear | 30 kts | marginal/poor | = 30 kts | "poor" and wind fields are weak, |
| LCL height | 366 m | strong | < 1000 m | even though low-level |
| thermodynamic factors are | ||||
| CIN | 54 J/kg | ok | < 100 J/kg | favorable |
| LFC height | 1185 m | strong | < 1500 m | |
| 0-3k CAPE | 151 J/kg | strong | > 90 J/kg |
description and key for examples
operational low-level thermodynamic parameter guidelines