EWP forecasters are in the act of warning on storms across KS and OK. One of the more notable storms this evening formed west of Wichita, KS and began moving east towards the northern part of the city. The storm had a very nice hook echo and many reports of funnel clouds and large hail. The forecasters were asked to examine the overshooting-top / thermal couplet products while they were making their warnings. Unfortunately no overshooting-tops were detected... which means there was no chance of detecting a thermal couplet because it requires an overshooting-top detection. Starting from top left and moving clockwise the image above shows the standard IR window, visible, overshooting-top magnitude and NLDN lightning detections within the 4-panel AWIPS D2D display. While it is fairly clear in the IR window and visible imagery at 2345 UTC that there is an overshooting-top, as well as a nice wake signature in the visible, no overshooting-top was detected. At the time of this blog post the storm still has not had an overshooting-top detection.
It was hypothesized that initially the minimum IR brightness temperature requirement for the overshooting-top product was not reached early on. Then once the storm continued to grow, the spatial tests to identify isolated areas of relatively cold cloud tops associated with an overshooting-top failed because cold cloud top temperatures were too close together. These problems are likely due to the relatively poor spatial resolution of the GOES-13 imager and the product would be much improved if resolutions were similar to what will be available on ABI.
It is tough to tell if the OT was significantly colder than the surrounding anvil. I'm surprised to see that this one was not detected, it looks like it should be very easy to detect. There were definitely no thermal couplets present with this storm, so I am glad that none were detected
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