HRRR Sub-hourly Surface Fields (CONUS)

Best (4-layer) lifted index uses parcels from the lowest four model layers to assess stability at 500 hPa. More negative values indicate greater instability.

• Units: K.
• Often used alongside CAPE and CIN in convective forecasting.

Accumulated precipitation represents the total water-equivalent amount of rain and snow during the output period. It is a primary field for hydrologic impacts and event totals.

• Units: kg/m^2.
• Use with the model time interval to interpret totals and compare to gauges.

Convective Available Potential Energy (CAPE) quantifies buoyant energy available to rising air parcels. Larger values generally imply stronger potential updrafts and greater convective intensity.

• Units: J/kg.
• Often used with CIN and lifting mechanisms to assess thunderstorm potential.

Convective cloud cover is the fraction of the grid cell covered by clouds produced by the convective parameterization. It is useful when you need to separate parameterized convective cloud from stratiform or total cloud amount.

• Units: %.
• Interpret it alongside total cloud cover and precipitation to see how much of the cloud field is tied to deep convection.

Categorical indicator of freezing rain occurrence at the surface during the output period.

• Units: flag.
• Useful as a mask for icing or glaze hazards.

Categorical indicator of ice pellet (sleet) occurrence at the surface during the output period.

• Units: flag.
• Use with precipitation fields to gauge intensity.

Convective Inhibition (CIN) measures the energy barrier that must be overcome to initiate convection. More negative values indicate a stronger cap that can suppress storms.

• Units: J/kg.
• When CIN is weak and CAPE is high, convection is more likely.

Percent frozen precipitation indicates the fraction of total precipitation that is falling in frozen form. It helps distinguish mixed-phase and winter precipitation impacts.

• Units: percent.
• Higher values indicate a larger frozen contribution to the total precipitation.

Categorical indicator of rain occurrence at the surface during the output period. Useful as a yes/no mask for rain.

• Units: flag.
• Use with accumulation or rate fields for intensity.

Categorical indicator of snow occurrence at the surface during the output period.

• Units: flag.
• Use alongside snowfall/snow-water-equivalent fields.

Downward longwave (thermal) flux represents incoming energy at the surface. It is a key driver of surface heating and cooling.

• Units: W/m^2.
• Shortwave affects surface heating; longwave affects radiative cooling.

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.

Downward radiative flux represents incoming energy at the surface. It is a key driver of surface heating and cooling.

• Units: W/m^2.
• Shortwave affects surface heating; longwave affects radiative cooling.

Freezing rain accumulation is the water-equivalent amount of freezing rain during the period. It relates directly to ice accretion risk.

• Units: kg/m^2.
• Accumulations represent water-equivalent depth over the output interval; rates describe intensity.

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

• Units: m/s.

High cloud cover is the fraction of the grid cell covered by clouds in the upper troposphere. It affects longwave radiation and aviation.

• Units: percent.
• Cloud fraction influences surface radiation and temperature.

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.

Storm-relative helicity measures the potential for streamwise vorticity to be ingested by a storm updraft. Higher values suggest a greater likelihood of rotating updrafts.

• Units: m^2/s^2.
• Commonly evaluated in the lowest 1 to 3 km layer.

Boundary layer height marks the depth of the turbulent surface-influenced layer. It affects mixing, dispersion, and surface fluxes.

• Units: m.

Ice cover is the proportion of the grid cell covered by ice. It is used as a surface-state mask for sea ice and related cryosphere diagnostics.

• Units: Proportion.

Land cover is a land/sea mask where 0 indicates sea and 1 indicates land. It is used to separate land and ocean surface processes.

• Units: Proportion.

Low cloud cover is the fraction of the grid cell covered by low clouds. It strongly affects visibility, fog potential, and surface temperatures.

• Units: percent.
• Cloud fraction influences surface radiation and temperature.

Lifted Index compares a lifted parcel's temperature to the environment at 500 hPa. More negative values indicate greater instability and thunderstorm potential.

• Units: K.
• Values near zero indicate neutral stability.

Lightning is a dimensionless model diagnostic in these NOAA mesoscale inventories. Higher values indicate greater modeled lightning or convective electrical activity.

• Units: non-dim.

Mid-level cloud cover is the fraction of the grid cell covered by clouds in the middle troposphere. It influences both shortwave and longwave radiation.

• Units: percent.
• Cloud fraction influences surface radiation and temperature.

Moisture availability represents how much moisture is available at the surface for evaporation. It is used in land-surface and fire-weather diagnostics.

• Units: percent.

Pressure of the level from which the parcel was lifted indicates the parcel source level used for stability indices. It helps interpret lifted index and CAPE products.

• Units: Pa.

Precipitation rate is the total intensity of precipitation over the period. It combines convective and stratiform contributions.

• Units: kg/(m^2 s).
• Accumulations represent water-equivalent depth over the output interval; rates describe intensity.

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

• Units: Pa.

Pressure reduced to mean sea level is MSLP computed from surface pressure and temperature. It is used to locate highs and lows.

• Units: Pa.

Precipitable water is the total column water vapor from the surface to the top of the atmosphere. It is a key moisture indicator.

• Units: kg/m^2.

Composite reflectivity is the maximum reflectivity in the column. It is a standard radar‑style field for identifying convective cores and precipitation intensity.

• Units: dBZ.

Reflectivity is a radar‑style measure of hydrometeor concentration at a given level. Higher values generally correspond to heavier precipitation.

• Units: dBZ.

Echo top height is the altitude of the highest reflectivity in the column. It is a proxy for storm depth and convective vigor.

• Units: m.

Simulated brightness temperature for GOES-11 channel 3 represents modeled radiance converted to an equivalent blackbody temperature. It supports satellite comparison and cloud diagnostics.

• Units: K.

Simulated brightness temperature for GOES-11 channel 4 represents modeled radiance converted to an equivalent blackbody temperature. It supports satellite comparison and cloud diagnostics.

• Units: K.

Simulated brightness temperature for GOES-12 channel 3 represents modeled radiance converted to an equivalent blackbody temperature. It supports satellite comparison and cloud diagnostics.

• Units: K.

Simulated brightness temperature for GOES-12 channel 4 represents modeled radiance converted to an equivalent blackbody temperature. It supports satellite comparison and cloud diagnostics.

• Units: K.

Snow depth is the physical thickness of the snowpack. It is distinct from snow water equivalent, which measures water content.

• Units: m.

Snow cover is the fraction of the grid cell covered by snow. It helps interpret albedo, runoff timing, and surface energy balance.

• Units: percent.

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.

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.

Total column integrated cloud ice is the vertically integrated mass of suspended cloud ice. It is used in cloud microphysics, radiation, and satellite forward calculations, especially when separating ice cloud from liquid cloud contributions.

• Units: kg/m^2.
• Use it with TCOLW or TCOLC to understand whether the column condensate is dominated by ice or liquid water.

Total Column Integrated Cloud Ice.

• Values retain the source encoding and units; no conversion is applied.

Total column integrated cloud water is the vertically integrated mass of suspended liquid cloud water. It is distinct from rainwater and is used in cloud, radiation, fog, and satellite forward-model diagnostics.

• Units: kg/m^2.
• Compare it with TCOLI or TCOLC to separate liquid cloud from ice cloud and total condensate.

Total Column Integrated Cloud Water.

• Values retain the source encoding and units; no conversion is applied.

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

• Units: K.

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.

Upward longwave (thermal) flux represents outgoing energy at the surface. It is a key driver of surface heating and cooling.

• Units: W/m^2.
• Shortwave affects surface heating; longwave affects radiative cooling.

Updraft helicity is the vertical integral of rotating updraft strength. It is used to identify supercell potential.

• Units: m2/s2.

U‑component of storm motion is the east‑west component of the storm translation vector.

• Units: m/s.

Upward radiative flux represents outgoing energy at the surface. It is a key driver of surface heating and cooling.

• Units: W/m^2.
• Shortwave affects surface heating; longwave affects radiative cooling.

Visible beam downward solar flux is the direct visible sunlight at the surface. It is important for illumination and solar energy.

• Units: W m-2.

Visible diffuse downward solar flux is the scattered visible light at the surface. It increases under clouds or aerosol loading.

• Units: W m-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.

Categorical land-use/vegetation class. It is used to set roughness, albedo, canopy properties, and other surface-exchange parameters.

• Units: code.

Vertically‑integrated liquid water is the total column liquid water content. It is used as a proxy for precipitation intensity and hail potential.

• Units: kg/m^2.

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

• Units: m.

V-component storm motion represents the north-south component of storm motion. Positive values indicate motion toward the north.

• Units: m/s.

Vertical u-component shear describes how the east-west wind component changes with height.

• Units: 1/s.

Vertical v-component shear describes how the north-south wind component changes with height.

• Units: 1/s.

Snow water equivalent (SWE) is the total liquid water stored in the snowpack. It integrates depth and density of existing snow.

• Units: kg/m^2.
• Accumulations represent water-equivalent depth over the output interval; rates describe intensity.

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

• Units: m/s.