Using simulated IR imagery to estimated cloud tops over the Southeast

It was a relatively quiet day around the NAS, so the GOES-R desk looked at some scattered convection over the Southeast U.S. The image below in Figure 1 shows simulated IR imagery for 1800 UTC, and is using a color table designed to highlight convective tops. From this table it is possible to provide a rough estimate of cloud tops.

Figure 1. 20140813 1800 UTC simulated IR forecast

Several areas of interest were examined more closely, as indicated by the dashed yellow and red lines. Off the Atlantic Coast, it was estimated that tops would reach to FL450+, while over Florida and the Gulf, tops were forecast to remain at FL400 or below.

Figure 2 shows the actual IR imagery at 1815 UTC.

Figure 2. 20140813 1815 UTC IR imagery

The simulated IR imagery appears to have done a fairly good job with the convection over Florida and off the Atlantic Coast, but was more widely scattered in the Gulf. Additionally, the tops appeared to be a bit lower than forecast.

To further examine tops, the GOES-R cloud altitudes were examined.

In this image, the color bar for the GOES-R cloud altitudes was adjusted to highlight tops above FL300 at 2000 foot intervals. The maroon colored tops over the Atlantic and over Florida indicated tops to FL460+ feet. Radar echo tops in the area at the same time corroborated fairly well. So, the cloud top forecast from the simulated imagery did fairly well.

So why are cloud top tools like this important? Traffic flow managers, when looking at convection, want to know what the prerocity and tops will be. In other words, can they send planes through the gap or overtop of cells to avoid diverts and delays? A product like the cloud altitudes provides additional information towards this end by giving a view, not only of the heights of tops but if there are holes in convective coverage.