A mesoscale prediction system for high latitudes that assimilates Direct Broadcast MODIS

The Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin has developed a version of the CIMSS Regional Assimilation System (CRAS) that assimilates products from the Moderate Resolution Infrared Spectroradiometer (MODIS) instrument onboard the NASA Aqua and Terra satellites. The Direct Broadcast CRAS (DBCRAS) package is now being distributed with the International MODIS/AIRS Processing Package (IMAPP), a software package used to retrieve meteorological products from the MODIS instrument in real-time. DBCRAS is a highly efficient prediction model that runs on a standard Linux workstation. A 12-hour DBCRAS spin-up forecast is used to define the initial conditions for a 72-hour forecast. During the spin-up, DBCRAS checks for locally processed total precipitable water and cloud retrievals and assimilates them. The resulting water vapor and cloud fields are merged with winds and temperatures from a global forecast model to complete the set of initial conditions for a DBCRAS forecast. DBCRAS can be installed anywhere on the globe. It provides a numerical weather prediction tool with satellite assimilation capability at remote satellite receiving stations where internet bandwidth may not support large data transfers. DBCRAS has successfully generated forecasts for Anchorage, Alaska, the South Pole, Tromso, Norway, and the North Pole. A DBCRAS forecast for Anchorage, Alaska is currently running in real-time using MODIS retrievals from NASA (see http://cimss.ssec.wisc.edu/model/realtime/cras45_AK/daily.html). We will demonstrate how DBCRAS guidance can assist aviation and marine forecasters at remote, high latitude locations.