Rapid marine cyclogenesis forecast sensitivity to high resolution sea surface temperatures during ERICA IOP-5

Abstract

The influence of high resolutions sea surface temperatures (SST) on Nested Grid Model (NGM) predictions of rapid marine cyclogenesis is examined. Satellite data provides a gridded SST analysis with a resolution of 50 km. Forecasts using the operational "blended" SST analysis with a neutral stratification assumed in the calculation of surface exchange coefficient over the ocean are compared to forecasts using the high resolution SST analysis with a stability dependent surface exchange coefficient. Further comparison is made to NGM forecasts with no surface fluxes. This study covers the Intensive Observation Period (IOP) 5 of the Experiment on Rapidly Intensifying Cyclones over the Atlantic (ERICA). Results show little sensitivity of central pressure and storm position to the high resolution SSTs. However, differences in mesoscale features are present, primarily surface fluxes, precipitation, and frontal circulations.