Currently monitoring OCTANE data in the vicinity of the Missouri border at about 1850Z on Tuesday, May 24.

North of the border (far southwest Iowa) there is mature convection, with a clear signal for changes in direction and speed on the anvil (top two panes). The mature convection shows cloud top divergence, with new convection on the southern flank showing a sharp signal for cloud top cooling (bottom left).

There is an area of banded cirrus moving through the region just south of this. This cirrus shows up on day cloud phase imagery (bottom right) but also in the OCTANE speed product. Looking at satellite data qualitatively, it’s clear the cumulus field is much less impressive in this area. Convection is not yet initiating here. Surface observations don’t show a clear signal for a less favorable air mass, so it’s possible the mid-level conditions are not as favorable.

South of all of this, we are looking at a new area of updraft initiation occurring just on the Kansas side of the border. On conventional satellite imagery we can see updrafts reaching upper levels and shearing off (orphaned anvils) indicating true convective initiation is still a little ways off, but we are getting very close. There is a consistent signal on OCTANE cloud top cooling for some of these spotty updrafts. Comparing with conventional imagery, the OCTANE cloud top cooling signals provided 5-10 minutes of lead time on the orphaned anvils. This is useful information, as once these storms begin maturing, they may provide a little more lead time on the initiation of lightning in addition to just the initiation of mature updrafts.