Elevation, dewpoints and storms

[Ed Mahmoud]

OK, I know it is probably more complex than this, and has something to do with the dreaded cap that blows off the plateau of Mexico towards Houston, but is difference in elevation why it seems dewpoints in the 50s are plenty high enough for strong storms, it seems, in the Plains (Texas P-handle to the Dakotas), but usually insufficient for strong storms here around Houston?

[wall_cloud]

The culprit isn't necessarily the dewpoints themselves since I'm sure you are aware that dewpoints in Houston are usually higher than in the Plains (especially in the TX Panhandle where we rarely see 70s). The problem is in that Houston has a more tropical environment, meaning your lapse rates are usually low compared to the locations you mentioned in the Plains. The elevated mixed layer (EML) does have some effect, but that is usually strong as you had southwest (toward Corpus Christi). Granted, higher dewpoints would result in more available energy, but you already have dewpoints that are quite high relative to others. Also, with the tropical environment, you get deeper moisture that will reduce the ability of the lapse rates to steepen as a system approaches. Hope this makes sense.