Adding Storm-Scale Forecasts over Nested Domains for High Impact Weather

Eli Dennis and Michael Colbert
Penn State
Noon June 7 in Room 2155

Two severe weather cases (28 April 2014 and 6 May 2015) are simulated using both the 1.33-km NAM fire-weather nest and the 4-km NAM. On 28 April 2014, convection initiates along and ahead of a cold front that traverses across Mississippi causing over 450 severe weather reports (153 of which were tornado reports). On 6 May 2015, convection initiation (CI) occurs in the vicinity of a dryline across Oklahoma resulting in nearly 200 severe weather reports (65 of which were tornado reports). Comparisons are made between the simulations and observations to explore the effects of model resolution on CI and storm evolution. The analysis focuses on seemingly unphysical artifacts in the simulated composite reflectivity field, the influence of cold pool strength on the strength and evolution of convection, and the effects of differences between observed and modeled soundings on storm mode and evolution. This research is a part of the Next Generation Global Prediction System (NGGPS) Project.