Nearcast, CI, and CTC over the SE U.S. and AR flight routes

It has been a rather quiet day weather-wise, and as such, one of our focus points has been the development of scattered convection in the SE U.S. Particularly the concern was around Jacksonville Center and the AR flight routes and whether air traffic in these areas would be impeded by convective development.

The simulated satellite imagery suggested the initiation of this convection would first occur near CHS by 1500 UTC, with further development of scattered convection south into Georgia by 1800 UTC. The Nearcast, shown in Figure 1, indicated some instability in southern Georgia, however noted mid-level stability over the coast of the South Carolina in the early afternoon, indicating any growth would quickly dissipate.

Figure 1. 20130819 1600 - 2000 UTC Nearcast Theta-E Difference

Shown in Figure 2 is the GOES-R Convective Initiation (CI) from 1302 -1845 UTC.

Figure 2. 20130819 1302 - 1845 UTC GOES-R Convective Initiation

Note the increasing probabilities along the coast of South Carolina around 1500 UTC along the outflow boundary of the pre-existing convection further NW. Subsequently, the Cloud Top Cooling (Figure 3) began to show cooling signals roughly 15 minutes later and some cloud growth occurred. However, shortly after that the CI probabilities quickly began to decrease and those clouds that had grown quickly dissipated. In this case, the behavior of the CI and CTC followed the Theta-E Nearcast, the mid-level stability stunting the convective growth.

Now take a look after 1500 UTC. By 1800 UTC the Nearcast showed some slight instability spreading north from the coast of Georgia to South Carolina, indicating some chance of convective development and growth. Around 1745 UTC, the CI began to show higher probabilities once more over both of these areas. Shortly after that the CTC began to show some cooling signals, though pre-existing cloud cover kept them from being widespread. By 1845 UTC some scattered convection had developed over these areas, though growth wasn't too impressive, once again correlating the Nearcast of theta-E over the area.

Figure 3. 20130819 1302 - 1845 UTC Cloud Top Cooling

In this case, having the CI and CTC as situational awareness tools for flight routing was beneficial. While the simulated imagery and many other models were indicating convective development over the AR routes and Jacksonville Center, the mid-level stability noted in the Nearcast theta-E kept any development to a minimum.