4/18/02 late night "elevated" nontornadic supercell in north central Kansas

On the night of 4/18/02, thunderstorms reformed in north central Kansas north and east of a wave on a stationary front, after supercells earlier in the evening had dissipated in central Kansas.  After midnight in the early morning hours on the 19th, one of the storms became a supercell with strong rotation on radar in Lincoln and Ottawa counties of north central Kansas, prompting a couple tornado warnings.  No tornadoes occurred, but 1.75" hail was reported.
< surface map 07 UTC       < ICT radar base refl. 0618 UTC and 0708 UTC

This storm was in a "very elevated" environment north of the surface front, as can be seen by the RUC-2 profile for Salina at 07 UTC, which shows no CAPE for parcels in the lowest 100 mb. Parcels that yielded CAPE for this profile were around 750-700 mb, well above the boundary layer.  With more than 50 kts of deep layer shear interacting with the updraft, this storm was able to produce large hail.   But with such a stable profile in low-levels, the tornado potential with this strongly elevated storm was very low:
<Salina KS RUC-2 analysis sounding 07 UTC

Using SPC graphics around 07 UTC, the elevated CAPE not far to the south can be seen, along with notable 0-1 km EHI in southern Kansas within a capped environment where no storms occurred.  But the large CIN (> 200 J/kg) in central Kansas to south of the front with high LFC heights (around 3000 m and higher) confirmed the elevated environment across Kansas on both sides of the front:
< 07 UTC most unstable CAPE  < 07 UTC 0-1 km EHI
< 07 UTC LFC height  < 07 UTC CIN & Sig Tor Parameter  < 07 UTC LFC height

When there is no CAPE to be found using any parcels from the lowest 100 mb of a profile, this suggests that the environment is very "elevated", with storm buoyancy and primary inflow coming from well above the boundary layer.  In such cases, experience suggests that tornado potential is very low.

- Jon Davies 7/1/20

back to 2002 cases page