After 22 months of testing, NOAA started using a sophisticated new short term weather forecast model. The Rapid Refresh Model (RAP) for short, will improve predictions of quickly developing severe weather situations such as thunderstorms, winter storms, and aviation hazards like turbulence. It replaces an older model called Rapid Update Cycle (RUC).
RAP was developed by NOAA’s Earth System Research Lab in Boulder, CO and the National Centers for Environmental Predicton in Camp Springs, MD. It updates every hour producing a fresh forecasting extending 18 hours over most of North America. The U.S. is the only country in the world to routinely update a weather forecast model every 1 hour with the latest observations from ground and satellite based sensors, along with radar, ships, and aircraft.
Forecast skill has improved using the RAP model for most variables including wind and precipitation. For example the RAP did a better job of showing where a large area of extreme rainfall would occur last June over the middle of the country. Aviation interests in Alaska are seeing improvement to flying safety using this model. This is especially important to that state because there are numerous sections of Alaska only accessible by airplane.
You can learn more about the RAP model and other forecasting issues from the following link. http://www.noaanews.noaa.gov/stories2012/20120501_rapmodel.html