Using NUCAPS and GOES-16 Level 2 Stability products and LightningCast to anticipate lightning
LightningCast (available here) is a CIMSS-developed product (created at the request of OPC and WPC) designed to relate current ABI fields (Band 2 (0.64 µm), 5 (1.61 µm), 13 (10.3 µm) and 15 (12.3 µm)) to the likelihood of future lightning. (A short training video on this product is available here) In the animation above, probability contours are shown (blue: 10%; cyan: 25%; green: 50%; magenta: 75%) for the 45 minutes between 1731 and 1816 UTC, overlain on a sandwich-type RGB that includes visible imagery and enhanced Band 13 imagery for cold cloud tops. Of particular interest for this blog post is the region that develops east of Delmarva (as indicated in this image at 1751 UTC); probabilities increase there starting at 1741 and the first lightning is observed by GLM at 1756 UTC and it becomes more constant by 1806 UTC.
The GOES-16 Band 13 imagery at 1701 UTC — 45 minutes before the onset of the LightningCast — and derived Lifted Index shows convection approaching a ribbon of lower stability (show in yellow) to the east of North Carolina. That stability product is suggesting: this is where convection is most likely to strengthen because stability is lower here. Then 45 minutes later, the LightningCast probability increases and lightning is observed!
As noted in this blog post, some Level 2 products from GOES-R are clear sky only. The timing of this event was such that NUCAPS profiles could be used to fill in information where clouds obscure what is occurring (GOES level 2 stability product-wise). A challenge is that NUCAPS and GOES Stability products don’t match well (that is, it’s not easy to create a NUCAPS Lifted Index). The Total Totals Index derived from NUCAPS is shown below. (This figure shows the Retrieval Status of the profiles used). A corridor of instability is present where lightning-produced convection subsequently developed.
Use GOES-R Stability indices and NUCAPS stability indices to identify regions where LightningCast might be needed in the future to highlight where lightning might occur. The synthesis of the different products is very helpful to creating the best forecast. AWIPS imagery in this blog post was created using the NOAA/NESDIS TOWR-S AWIPS Cloud Instance. Thank you!