Weather Research and Forecasting model

Example output from the Weather Research and Forecasting model showing 48 hours of simulated rainfall for Typhoon Mawar from 22 August 2005 00Z to 24 August 2005 00Z. The model has 3.3 kilometres (2.1 mi) grid point spacing, and utilizes vortex following which is why the typhoon remains in the middle of the frame.

The Weather Research and Forecasting (WRF) model ( /ˈwɔrf/) is a specific computer program with a dual use for forecasting and research. It was created through a partnership that includes the National Oceanic and Atmospheric Administration (NOAA), the National Center for Atmospheric Research (NCAR), and more than 150 other organizations and universities in the United States and abroad.

WRF is the latest numerical program model to be adopted by NOAA's National Weather Service as well as the U.S. military and private meteorological services. It is also being adopted by meteorological services worldwide. It is based on the Eta model developed by Zaviša Janjić and Fedor Mesinger.

A specialized version of the program, the Hurricane Weather Research and Forecasting (HWRF) model became operational in 2007.

There are two distinct varieties of this model. NCAR's experimental, advanced research version, called ARW (Advanced Research WRF) features very high resolution and is being used to explore ways of improving the accuracy of hurricane track, intensity, and rainfall forecasts, among other meteorological questions.

The "Nonhydrostatic Mesoscale Model" or NMM is designed for forecasting operations. Versions of the NMM are run at various National Weather Service offices, colleges, and universities in the United States over relatively small regions, usually with the higher 4 km grid spacing.

External links

• WRF website
• WRF-NMM Online Tutorial
• NCAR News Release (August 25, 2006)