August 14th recap: convection over the Great Lakes

The last day of week 1 was spent watching the Great Lakes region for convection impacting the terminals at Chicago and Detroit, and ZOB's (Cleveland) airspace later in the afternoon. Comparing WRF and NAM simulated imagery (shown below in Figure 1) showed convection developing towards 2100 UTC north of Chicago and 2300 UTC north of Detroit. Meanwhile, an existing area of precipitation and embedded convection over Lake Erie and Ontario was forecast to proceed SE towards the New England area.

Figure 1. 20150814 1900 UTC WRF (left) and NAM Nest (right) simulated IR imagery over the Great Lakes, with forecasted lines at 1900 and 2100 UTC in dashed red

This information was relayed to CAWS participants. Keeping the tendency of the WRF to be slightly slow and the NAM to overdo convection, the final CAWS product indicated earlier and more scattered development shown below in Figure 2. 

Figure 2. 20150814 1700 UTC issued CAWS

By 1515 UTC, the GOES-R CI was beginning to show signals in northern MI and WI (Figure 3).

Figure 3. 20150814 1715 UTC GOES-R Convective Initiation

The Cloud Top Cooling also showed moderate signals by 1745 UTC (Figure 4). 

Figure 4. 20150814 1745 UTC Cloud Top Cooling

 As noted last week, products in the 0-2 hour range are not necessary useful for the issuance of the CAWS forecast. However, following a CAWS, the National Aviation Meteorologists at the ATSCC would be monitoring the area. Once activity was noted, they would then advise the TFMs and routers. This would be particularly useful if the TFMs had previously decided to go tactical, or reroute as needed. Having a little extra lead time would definitely be useful.

On a related side note, the GOES-R CI is actually utilized in the COSPA product as an additional input to future convective activity. COSPA is a 2-8 hour forecast tool similar to the OPC product (mentioned in an earlier post) that forecasts convection across the CONUS, and is used regularly by forecasters when issuing the CAWS. So, while not used directly, the CI does already play a valuable role.