CI and CTC just west of San Francisco Center

An interesting case occurred this afternoon just south of San Francisco Center. While it hasn't caused any delays, there has been some convective development off the coast just south of the airport, rare for this side of the country.

Shown below in Figure 1 is the 20130819 1852 - 1957 UTC GOES-R CI. Note the higher probabilities just south of the airport by 1911 UTC, indicating the likelihood of convective growth off the coast.

Figure 1. 20130819 1852- 1957 UTC GOES-R CI

Now take a look at the Cloud Top Cooling from 1830 - 2000 UTC shown here in Figure 2.

Figure 2. 20130819 1830 - 2000 UTC Cloud Top Cooling

The first cooling signal was detected at 1845 UTC. Thereafter, signals increased in intensity, reaching -30K/15 mins by 1915 UTC! This type of significant cooling not often seen along the West Coast. Cooling signals continue to be detected along this line as it drifts offshore.

Again, this did not cause any issues in San Francisco Center as they've got a lot of airspace to work with and fewer flights than on the East Coast. However, it's doubtful they see this type of convective activity often so it was an interesting case to explore.