Assessing GREMLIN skills

 Around 2000Z, a squall line was observed over Oklahoma and Kansas. GREMLIN successfully reproduces the overall reflectivity distribution seen by the KVNX radar, though it slightly underestimates the reflectivity of the convective cores (Fig. 1).

Fig 1: GREMLIN synthetic radar reflectivity (left) and KVNX NEXRAD actual radar reflectivity (right)

By 2016Z, convection intensifies, with convective cores covering larger areas. GREMLIN reproduces most of these features (Fig. 2), though some are heavily underestimated (black marks). The isolated convection—likely poorly resolved by satellite observations—appears to be particularly challenging for GREMLIN to accurately simulate.

Fig 2: GREMLIN synthetic radar reflectivity (left) and KVNX NEXRAD actual radar reflectivity (right). Black marks represent areas where GREMLIN did not reproduce correctly the intensity of the radar reflectivity field.

- Iceman