The use of the UW-CIMSS Cloud Top Cooling (CTC) product in the Storm Prediction Center (SPC) has been highlighted in a several previous posts on this blog. Please view previous posts for a brief description of this product, along with its utility in operational environments. This post demonstrates yet another example of this product being utilized in the decision-making process of SPC forecasters.
On May 10, SPC highlighted a slight risk for severe weather across eastern Kansas into much of Nebraska. The threat included significant hail, damaging winds, and even a few tornadoes. One of the biggest challenges facing SPC forecasters is not only being able to identify where convective initiation is going to occur (or is concurring) in the near future, but also which of the developing storms will be the strongest and most likely ones to produce severe weather (information beyond just CI). The CTC product can be used for this purpose, as it tells the forecaster where you have convection developing, but also quantifies that vertical growth.
Looking at the animation below, convection began initiating in south-central Kansas on the 10th shortly after 1800 UTC along a dryline/warm front (Fig 1). At 1830 UTC, the CTC product indicated weak cooling, and by 1915 UTC very strong cooling (<-20K/15 min) was detected, indicating that convection was beginning to develop rapidly. The first severe weather with this storm was reported at 2021 UTC (1″ hail), over one hour after the first very strong CTC detection. Storms continued to exhibit rapid cooling over the next several hours as they initiated to the southwest and northeast along the boundary. These storms produced widespread severe hail, wind and even a couple of tornadoes across Kansas and into Missouri (Fig 2).
Figure 1: GOES-East Visible Imagery, Cloud Top Cooling rates (K/15 min)
Figure 2: SPC severe storm reports across Kansas and Missouri
The SPC forecaster on shift at the mesoscale desk was monitoring the CTC product during this event (FIg 3). In a Mesoscale Discussion (MD) issued at about 0100 UTC, the forecaster mentions the CTC product: “…WITH THE GOES-R CLOUD TOP COOLING PRODUCT INDICATING THE GREATEST COOLING ATTENDANT TO THE STORMS IN THESE THREE KS COUNTIES.” This is an example of how the CTC product gave the forecaster additional confidence to where the strongest storms were developing within the watch box. Full MD can be found at: http://www.spc.noaa.gov/products/md/md0555.html
– Bill Line, SPC/HWT Satellite Liaison
Satellite Liaison Blog 