Wednesday, May 19, 2010

post storm analysis

Well my gut telling me that south central OK would be the best play wasn't quite correct.

The second initiation of convection to the south near Lawton just took forever to congeal into a supercell after many many mergers of smaller storms. The hint is that the cap was too strong, or the shear was too strong for the minimal instability being released. This would suggest that the stronger dynamical forcing to the north was a key factor in the rapid transition from small cells into bigger supercells.

The shear though was also questionable at FWD , despite 200 SRH, only the lowest km had significant hodograph curvature. aloft the hodograph was a straight line. At OUN, within some sort of convection, the hodograph was much larger and curvature much more pronounced.

The observed 500 hPa frontal zone was pretty much in contact with the main supercell of the day and had a pretty good connection to the initiation in southern OK. V2 soundings might shed light on this .

Overall I am not sure what to think of an event like this. The soundings to the north in OK appeared to be uncapped and the shear great. Tornado production was similar to the day before ... apparently present but most short lived. Moisture was present, SRH was high, BRNSHR was in the 10-80 range, and the hodographs all had good curvature.

To the south, there was a cap, perhaps weaker forcing until much later, hodographs were curved by trended to be more straightline (window of opportunity was shorter to the south perhaps), but the instability was greater. I did notice that the southern supercells, had outflow attached to them. So perhaps the mid level dryness enhanced cold pool strength. This case has lots of interesting questions.