Verifying Numerical Weather Prediction Forecasts of Temperature Levels Critical for the 45th Weather Squadron's Lightning Launch Commit Criteria

The potential for naturally occurring or rocket-triggered lightning strikes is an important consideration for determining whether a planned launch can proceed at Cape Canaveral Space Force Station (CCSFS) and Kennedy Space Center (KSC). The 45th Weather Squadron evaluates the Lightning Launch Commit Criteria (LLCC) for every launch from CCSFS and KSC. The LLCC are the complex set of weather rules designed to avoid natural and rocket-triggered lightning strikes to inflight space launch vehicles. Evaluating the LLCC requires knowledge of the heights of the 0°C, -10°C, and -20°C temperature levels. Currently, these values are determined from rawinsonde data from Cape Canaveral (XMR) during launch countdowns. However, with the increased frequency of launches from CCSFS, it is desirable to assess if alternate, more cost-effective methods can be used to determine the critical temperature levels for evaluating the LLCC. Prior studies have explored the variability of these critical temperature levels in consecutive rawinsonde launches that occurred less than 6 hours apart. The current study verifies forecasts of the critical temperature levels from numerical weather prediction (NWP) output against the XMR rawinsonde data. Rapidly updating forecast systems will be evaluated first. The period of study for each forecast product will be provided, along with the multiple verification strategies to analyze the results diurnally and seasonally. Results will show standard verification statistics from the NWP forecasts and discuss whether numerical weather prediction forecasts have the potential to reduce the number of rawinsonde launches required to evaluate the LLCC.