Tuesday, September 28, 2010

Welcome to Kansas

The weather has always nudged and poked and prodded me. So when I packed my stuff into a truck and drove 28 hours over 2 days to Salina, Kansas I was hoping for some big displays of thunder and lightning and rain. Instead I awoke to see the front about an hour north and I was heading south.

I stopped to gas up, collect my thoughts, and look up. Indeed my welcome into the Great Plains was some kind of gravity wave and/or bore. I joked with myself about it prior to leaving the hotel saying how funny it would be to see a wave or bore. And there they were.

below are the velocity images to prove what my awful cell phone pictures are trying to depict.

The shades of blue within the gold colors are the waves and there appear to be two specific areas. The gravity wave was behind the bores, of which there were two cloud lines. The two areas were spaced roughly ten minutes apart while I was driving 70 mph straight south. The leading edge of the bore was interesting because the roll cloud feature was elevated and their were diffuse cumulus clouds underneath it, almost water fall like.

The structures within the clouds were fishbone like, indicative of a spectrum of wave activity present on a scale of meters rather than kilometers.

the gravity wave was only recognizable since I had seen the IEMs web cam animation of a similar wave/bore here:

This wave has been written about recently in the AMS journals.

My wave appeared stagnant but then again I was not standing still taking 6 second images so I could animate them.

Times: 7:08, 7:22, 7:28

The first picture showed what appeared to be an arc shape with clouds in the ridge, while the middle shows the southern most portion of the bore front. The last pic is of the bore front looking east to see the fishbone structure and a bit of the cumulus that was vertically below the "smoother" wave clouds.

Without a doubt its nice to see the radar had something that resembled the bore I thought I was seeing.

UPDATE: I don't know why I didn't include a satellite image. Thanks Adam Clark for the suggestion:
This was the clearest image after sunrise showing the wave clouds over Kansas. The 1 minute ASOS data might be able to capture the pressure perturbations associated with these waves...more on that once the data for September are published.