Cloud and Hydrometeor Analysis Using Metar, Radar, and Satellite Data Within The Ruc/rapid Refresh Model

Abstract

Aviation users have a strong need for accurate short-range forecasts of sensible weather parameters including clouds, fog, ceiling and visibility and precipitation. Modelbased predictions of these parameters are the main source of guidance beyond a few hours and these predictions depend critically on the accurate initialization of cloud and hydrometeor fields. Thus, improving the initialization of these fields in mesoscale numerical models remains a key obstacle to better shore-range forecasts of surface sensible weather. These cloud and hydrometeor fields are not well sampled by conventional observing systems and no single observing platform fully captures the needed information. To address this, observations from a variety of observing systems (radar, satellite, and surface reports) must be combined to yield a more comprehensive depiction of existing clouds and hydrometeors suitable for initializing microphysical variables in numerical models. We describe herein a cloud analysis procedure developed for the Rapid Update Cycle (RUC) model and discuss ongoing and planned enhancements to it.