Wednesday morning we talked about severe reports. Is “practically perfect” the way to go? How do we deal with people-sparse regions? Can or should we add an uncertainty to the location and time and veracity of each report?

With our current capability, we can’t reliably forecast whether a storm will be a wind or hail producer. I think that is what John Hart suggested.

Yesterday, the 0-4Z forecast ensemble was too eager to produce high updraft helicity severe weather for the first 20-0Z forecast period, but the 0-4 Z period was forecast almost perfectly. Ryan said UH is usually better than surface wind and hail (graupel).

The MODE area ratio is not as useful as area “bias”. Ratio is small-over-big and doesn’t tell you if the forecast is biased high or low.

I summarized bias, GSS, and MODE results for yesterday. For CSI, Radar assimilation jumped out to an early lead, but joined the control run at near-zero after 3 hours. MODE had some spotty matches, but no clear winner.

Dave Ahijevych

Tags: None