AllSkyLAP Layer Showalter Index: First Impressions

A first look at the AllSkyLAP Showalter Index (SI) product and comparison with the SPC Mesoscale Analysis SI product yields a few observations/thoughts.

1. The color scale seems inverted to me. The negative SI values should grab one's attention, so perhaps they should be in the brighter (yellow/orange/red) colors?

2. Until GOES-17/GOES West comes online, I would use this product (and all AllSkyLAP products) with a lot of caution over the west due to parallax and lack of data. We can see some of this in the NW corner of the first image below.

3. The AllSkyLAP SI again has areas across the central and northern Plains (NE-SD-S MN) that are significantly different (greater negative values) than what is displayed on SPC's SI product at approximately the same time, especially across SD/S MN. However, it actually captured gradients across IA and MO pretty well...and values there were similar to what are shown on SPC's SI product.

4. Certainly be aware of where there are clouds/precip, as SI values will not match SPC's SI product values. This is the case in the image below across northeast MT/northwest SD and northern/cntrl MN.

- Thomas Bell