The Real-Time Mesoscale Analysis (RTMA) is a NOAA/NCEP high-spatial and temporal resolution analysis/assimilation system for near-surf ace weather conditions. Its main component is the NCEP/EMC Gridpoint Statistical Interpolation (GSI) system applied in two-dimensional variational mode to assimilate conventional and satellite-derived observations.

The RTMA was developed to support NDFD operations and provide field forecasters with high quality analyses for nowcasting, situational awareness, and forecast verification purposes. The system produces hourly analyses at 5 km and 2. 5 km resolution for the Conus NDFD grid, 6 km for the Alaska NDFD grid and 2.5 km for the Hawaii, Puerto-Rico and Guam NDFD grids.

Plans for the future include increasing the spatial resolution of the Alaska and Puerto Rico implementations to 3 km and 1.25 km, respectively.

RTMA fields for regions of the CONUS are displayed on the NCEP Model Analyses & Forecasts page.

In addition, NCEP/EMC displays its near-real-time parallels for evaluation e.g. 2.5 km CONUS and 2.5 km Guam.