rtma
RTMA (Real-Time Mesoscale Analysis) is NOAA/NCEP's near-real-time, hourly surface analysis designed to provide the best estimate of current weather conditions within about 30-45 minutes of valid time. It uses a two-dimensional variational (2D-Var) assimilation system to combine a short-range model background with surface, mesonet, buoy, ship, and radar-derived observations.
The analysis is generated on the National Digital Forecast Database (NDFD) grids, including the 2.5 km CONUS Lambert Conformal grid, as well as Alaska (~3 km), Hawaii, Puerto Rico, and Guam. Standard RTMA parameters include 2 m temperature, dewpoint, 10 m wind speed, direction, gust, surface pressure, visibility, cloud ceiling, and precipitation fields. RTMA provides high-resolution situational awareness in regions with sparse observations, including offshore waters and complex terrain.
Because RTMA prioritizes timeliness, it does not incorporate late-arriving observations. Instead, its role is to provide provisional “actuals now,” supporting operational dashboards, bias correction, and rapid verification of short-term forecasts. For finalized, higher-quality analyses, see URMA, which reruns RTMA about six hours later with expanded datasets.
Name | Level | Info | Description | Introduced | Min Horizon | Max Horizon |
---|---|---|---|---|---|---|
CEIL | cloud ceiling | Ceiling Height (m) | 2018-01-01T00:00:00Z | 0 | 0 | |
DPT | 2 m above ground | Dew Point Temperature (K) | 2018-01-01T00:00:00Z | 0 | 0 | |
GUST | 10 m above ground | Wind Gust Speed (m/s) | 2018-01-01T00:00:00Z | 0 | 0 | |
HGT | surface | Geopotential Height (gpm) | 2018-01-01T00:00:00Z | 0 | 0 | |
PRES | surface | Pressure (Pa) | 2018-01-01T00:00:00Z | 0 | 0 | |
SPFH | 2 m above ground | Specific Humidity (kg/kg) | 2018-01-01T00:00:00Z | 0 | 0 | |
TCDC | entire atmosphere (considered as a single layer) | Total Cloud Cover (%) | 2018-01-01T00:00:00Z | 0 | 0 | |
TMP | 2 m above ground | Temperature (K) | 2018-01-01T00:00:00Z | 0 | 0 | |
UGRD | 10 m above ground | U-Component of Wind (m/s) | 2018-01-01T00:00:00Z | 0 | 0 | |
VGRD | 10 m above ground | V-Component of Wind (m/s) | 2018-01-01T00:00:00Z | 0 | 0 | |
VIS | surface | Visibility (km) | 2018-01-01T00:00:00Z | 0 | 0 | |
WDIR | 10 m above ground | Wind Direction (degrees) | 2018-01-01T00:00:00Z | 0 | 0 | |
WIND | 10 m above ground | Wind Speed (m/s) | 2018-01-01T00:00:00Z | 0 | 0 |