GribStream

Real-Time Mesoscale Analysis (RTMA)

GribStream Code: rtma

Description

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.

Parameters

Search parameters
0 parameters

Click a parameter to reveal variants in a compact table with ready-to-copy JSON selectors.

CEIL –Ceiling Height (m)
1 variant
NOAA GRIB2 Table 4.2-0-3

Ceiling height is the altitude of the lowest cloud base that covers a significant portion of the sky. It is a key aviation and surface-visibility metric.

  • Units: m.
Level Info Horizon Introduced Selector
cloud ceiling 0h 2018-01-01
{"name":"CEIL","level":"cloud ceiling","info":""}
DPT –Dew Point Temperature (K)
1 variant
NOAA GRIB2 Table 4.2-0-0

Dew point temperature is the temperature at which the air becomes saturated. It is a direct measure of moisture content.

  • Units: K.
  • When dew point is close to air temperature, fog or low cloud potential increases.
Level Info Horizon Introduced Selector
2 m above ground 0h 2018-01-01
{"name":"DPT","level":"2 m above ground","info":""}
GUST –Wind Gust Speed (m/s)
1 variant
NOAA GRIB2 Table 4.2-0-2

Wind gust is the peak short-duration wind speed. It captures brief, hazardous bursts that can exceed sustained winds.

  • Units: m/s.
Level Info Horizon Introduced Selector
10 m above ground 0h 2018-01-01
{"name":"GUST","level":"10 m above ground","info":""}
HGT –Geopotential Height (gpm)
1 variant
NOAA GRIB2 Table 4.2-0-3

Geopotential height is the altitude of a pressure surface in the atmosphere. It is the primary field for identifying ridges, troughs, and large‑scale flow patterns.

  • Units: gpm.
Level Info Horizon Introduced Selector
surface 0h 2018-01-01
{"name":"HGT","level":"surface","info":""}
PRES –Pressure (Pa)
1 variant
NOAA GRIB2 Table 4.2-0-3

Pressure is the atmospheric pressure at the specified level. It is a fundamental mass-field variable for dynamics and thermodynamics.

  • Units: Pa.
Level Info Horizon Introduced Selector
surface 0h 2018-01-01
{"name":"PRES","level":"surface","info":""}
SPFH –Specific Humidity (kg/kg)
1 variant
NOAA GRIB2 Table 4.2-0-1

Specific humidity is the mass of water vapor per mass of air at the specified level. It is central to moisture transport.

  • Units: kg/kg.
  • Higher values indicate more atmospheric moisture and greater cloud or precip potential.
Level Info Horizon Introduced Selector
2 m above ground 0h 2018-01-01
{"name":"SPFH","level":"2 m above ground","info":""}
TCDC –Total Cloud Cover (%)
1 variant
NOAA GRIB2 Table 4.2-0-6

Total cloud cover is the fraction of the grid cell covered by clouds at any level. It influences radiation, temperature, and visibility.

  • Units: percent.
  • Cloud fraction influences surface radiation and temperature.
Level Info Horizon Introduced Selector
entire atmosphere (considered as a single layer) 0h 2018-01-01
{"name":"TCDC","level":"entire atmosphere (considered as a single layer)","info":""}
TMP –Temperature (K)
1 variant
NOAA GRIB2 Table 4.2-0-0

Air temperature is the thermal state of the atmosphere at the specified level. It influences density, stability, and energy exchange.

  • Units: K.
Level Info Horizon Introduced Selector
2 m above ground 0h 2018-01-01
{"name":"TMP","level":"2 m above ground","info":""}
UGRD –U-Component of Wind (m/s)
1 variant
NOAA GRIB2 Table 4.2-0-2

U‑component of wind is the east‑west component of the horizontal wind. Combine with v for speed and direction.

  • Units: m/s.
  • Combine u and v components to compute speed and direction.
Level Info Horizon Introduced Selector
10 m above ground 0h 2018-01-01
{"name":"UGRD","level":"10 m above ground","info":""}
VGRD –V-Component of Wind (m/s)
1 variant
NOAA GRIB2 Table 4.2-0-2

V‑component of wind is the north‑south component of the horizontal wind. Combine with u for speed and direction.

  • Units: m/s.
  • Combine u and v components to compute speed and direction.
Level Info Horizon Introduced Selector
10 m above ground 0h 2018-01-01
{"name":"VGRD","level":"10 m above ground","info":""}
VIS –Visibility (km)
1 variant
NOAA GRIB2 Table 4.2-0-7

Horizontal visibility at the surface. Lower values indicate reduced visibility due to fog, precipitation, or aerosols.

  • Units: m.
Level Info Horizon Introduced Selector
surface 0h 2018-01-01
{"name":"VIS","level":"surface","info":""}
WDIR –Wind Direction (degrees)
1 variant
NOAA GRIB2 Table 4.2-0-2

Wind direction indicates the direction from which the wind is blowing at the specified level.

  • Units: degrees.
Level Info Horizon Introduced Selector
10 m above ground 0h 2018-01-01
{"name":"WDIR","level":"10 m above ground","info":""}
WIND –Wind Speed (m/s)
1 variant
NOAA GRIB2 Table 4.2-0-2

Wind speed is the magnitude of the horizontal wind at the specified level. It is used for transport, mixing, and hazards.

  • Units: m/s.
Level Info Horizon Introduced Selector
10 m above ground 0h 2018-01-01
{"name":"WIND","level":"10 m above ground","info":""}

No parameters match your search.