GribStream

Real-Time Mesoscale Analysis (RTMA)

Code GribStream: rtma

Description

RTMA (Real-Time Mesoscale Analysis) est l'analyse horaire de surface quasi temps réel de la NOAA/NCEP. Elle est conçue pour fournir la meilleure estimation disponible des conditions actuelles environ 30 à 45 minutes après l'heure valide.

Elle utilise un système d'assimilation variationnelle bidimensionnelle (2D-Var) qui combine un champ de fond de modèle court terme avec observations de surface, mesonet, bouées, navires et données dérivées du radar.

L'analyse est générée sur des grilles NDFD, dont la grille Lambert CONUS de 2.5 km, ainsi que Alaska, Hawaii, Puerto Rico et Guam. Les paramètres typiques incluent température à 2 m, point de rosée, vent à 10 m, direction et rafales, pression de surface, visibilité, plafond nuageux et précipitation.

RTMA aide à maintenir une veille opérationnelle haute résolution là où les observations sont rares, par exemple eaux côtières, terrain complexe ou zones avec changements locaux rapides.

RTMA privilégie la rapidité et n'intègre donc pas les observations tardives. Pour une analyse finalisée de meilleure qualité, utilisez URMA, qui relance RTMA environ six heures plus tard avec des données élargies.

Détails

Datasets liés

Paramètres

Rechercher des paramètres
0 paramètres

Cliquez sur un paramètre pour voir ses variantes dans une table compacte avec des sélecteurs JSON prêts à copier. Les codes, niveaux et valeurs de sélecteur restent exactement tels que l'API les expose.

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 Speed (Gust) (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 (percent)
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 (m)
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":""}

Aucun paramètre ne correspond à la recherche.