Point Forecast Variables
The Point Forecast API data is made up of meteorological and oceanographic variables. We have split the variables into three groups: atmospheric, waves, and hydrodynamic.
Atmospheric
Atmospheric variables describe properties of the atmosphere and land within it.
air.humidity.at-2m
Relative humidity 2 meters above ground level.
Standard Name: relative_humidity_at_2m_above_ground_level
Units: %, percent
air.pressure.at-sea-level
Air pressure at sea level is the quantity often abbreviated as MSLP or PMSL. Air pressure is the force per unit area which would be exerted when the moving gas molecules of which the air is composed strike a theoretical surface of any orientation. "Mean sea level" means the time mean of sea surface elevation at a given location over an arbitrary period sufficient to eliminate the tidal signals.
Standard Name: air_pressure_at_sea_level
Units: Pa, pascal
air.temperature.at-2m
Air temperature is the bulk temperature of the air, not the surface (skin) temperature.
Standard Name: air_temperature_at_2m_above_ground_level
Units: K, Degrees Kelvin
air.visibility
The visibility is the distance at which something can be seen.
Standard Name: visibility_in_air
Units: m, meter
atmosphere.convective.potential.energy
Integrated amount of work that the upward (positive) buoyancy force would perform on a given mass of air (called an air parcel) if it rose vertically through the entire atmosphere. Positive CAPE will cause the air parcel to rise, while negative CAPE will cause the air parcel to sink. Nonzero CAPE is an indicator of atmospheric instability in any given atmospheric sounding, a necessary condition for the development of cumulus and cumulonimbus clouds with attendant severe weather hazards.
Standard Name: atmosphere_convective_available_potential_energy
Units: J/kg, joules per kilogram
cloud.base.height
A cloud base (or the base of the cloud) is the lowest altitude of the visible portion of a cloud. Cloud base refers to the base of the lowest cloud. Height is the vertical distance above the surface.
Standard Name: cloud_base_height
Units: m, meter
cloud.cover
Total cloud cover in the atmosphere column. "Area fraction" is the fraction of a grid cell's horizontal area that has some characteristic of interest. It is evaluated as the area of interest divided by the grid cell area. It may be expressed as a fraction, a percentage, or any other dimensionless representation of a fraction. The cloud area fraction is for the whole atmosphere column, as seen from the surface or the top of the atmosphere.
Standard Name: cloud_area_fraction
Units: %, percent
precipitation.rate
'Precipitation' in the earth's atmosphere means precipitation of water in all phases. The abbreviation 'lwe' means liquid water equivalent. 'Precipitation rate' means the depth or thickness of the layer formed by precipitation per unit time.
Standard Name: lwe_precipitation_rate
Units: mm/hr, millimeters per hour
radiation.flux.downward.longwave
The surface called 'surface' means the lower boundary of the atmosphere. 'longwave' means longwave radiation. 'Downward' indicates a vector component which is positive when directed downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, 'flux' implies per unit area, called 'flux density' in physics.
Standard Name: surface_net_downward_longwave_flux
Units: W/m^2, irradiance, or radiant flux density
radiation.flux.downward.shortwave
The surface called 'surface' means the lower boundary of the atmosphere. 'shortwave' means shortwave radiation. 'Downward' indicates a vector component which is positive when directed downward (negative upward). Net downward radiation is the difference between radiation from above (downwelling) and radiation from below (upwelling). In accordance with common usage in geophysical disciplines, 'flux' implies per unit area, called 'flux density' in physics.
Standard Name: surface_net_downward_shortwave_flux
Units: W/m^2, irradiance, or radiant flux density
wind.direction.at-10m
The direction from which it is blowing at 10 meters above ground. North = 360, east = 90 and 0 means no wind / clam
Standard Name: wind_from_direction_at_10m_above_ground_level
Units: °, degree
wind.direction.at-100m
The direction from which it is blowing at 100 meters above ground. North = 360, east = 90 and 0 means no wind / clam
Standard Name: wind_from_direction_at_100m_above_ground_level
Units: °, degree
wind.speed.at-10m
Wind speed at 10m above ground level
Standard Name: wind_speed_at_10m_above_ground_level
Units: m/s, meters per second
wind.speed.at-100m
Wind speed at 10m above ground level
Standard Name: wind_speed_at_100m_above_ground_level
Units: m/s, meters per second
wind.speed.eastward.at-100m
Eastward wind speed vector component which is positive when directed eastward (negative westward). At 10 meters (or 100 meters) above ground level.
Standard Name: eastward_wind_at_100m_above_ground_level
Units: m/s, meters per second
wind.speed.eastward.at-10m
Eastward wind speed vector component which is positive when directed eastward (negative westward). At 10 meters (or 100 meters) above ground level.
Standard Name: eastward_wind_at_10m_above_ground_level
Units: m/s, meters per second
wind.speed.gust.at-10m
The speed of wind gusts.
Standard Name: wind_speed_of_gust_at_10m_above_ground_level
Units: m/s, meters per second
wind.speed.northward.at-100m
Northward wind speed vector component which is positive when directed northward (negative southward). At 10 meters (or 100 meters) above ground level.
Standard Name: northward_wind_at_100m_above_ground_level
Units: m/s, meters per second
wind.speed.northward.at-10m
Northward wind speed vector component which is positive when directed northward (negative southward). At 10 meters (or 100 meters) above ground level.
Standard Name: northward_wind_at_10m_above_ground_level
Units: m/s, meters per second
Wave
Waves variables describe swells in the ocean.
wave.height
Significant wave height, which is the average height of the highest one third of the waves for the location. The height is defined as the vertical distance from a wave trough to the following wave crest.
Standard Name: sea_surface_wave_significant_height
Units: m, meter
wave.height.max
Maximum wave height, which is the height of the largest single wave at the location.
Standard Name: sea_surface_wave_maximum_height
Units: m, meter
wave.direction.peak
Spectral peak direction of the total sea state. The direction from which the most energetic waves are coming. The spectral peak is the most energetic wave in the total wave spectrum.
Standard Name: sea_surface_wave_from_direction_at_variance_spectral_density_maximum
Units: °, degree
wave.period.peak
A period is an interval of time, or the time-period of an oscillation. Also called peak wave period, is the period of the most energetic waves in the total wave spectrum at a specific location.
Standard Name: sea_surface_wave_period_at_variance_spectral_density_maximum
Units: s, second
wave.height.above-8s
Swell waves are waves on the ocean surface and are the low frequency portion of a bimodal wave frequency spectrum. Significant wave height is a statistic computed from wave measurements and corresponds to the average height of the highest one third of the waves, where the height is defined as the vertical distance from a wave trough to the following wave crest.
Standard Name: sea_surface_above_8s_period_wave_significant_height
Units: m, meter
wave.height.below-8s
Significant wave height of wind seas. It is computed from the portion of a wave frequency spectrum where periods are below 8s. Wind waves are waves on the ocean surface and are the high frequency portion of a bimodal wave frequency spectrum. Significant wave height is a statistic computed from wave measurements and corresponds to the average height of the highest one third of the waves, where the height is defined as the vertical distance from a wave trough to the following wave crest.
Standard Name: sea_surface_below_8s_period_wave_significant_height
Units: m, meter
wave.period.above-8s.peak
Period of the most energetic waves within the swell wave component of a sea. Swell waves are waves on the ocean surface and are the low frequency portion of a bimodal wave frequency spectrum. A period is an interval of time, or the time-period of an oscillation. Wave period is the interval of time between repeated features on the waveform such as crests, troughs or upward passes through the mean level.
Standard Name: sea_surface_above_8s_period_wave_period_at_variance_spectral_density_maximum
Units: s, second
wave.period.below-8s.peak
Period of the most energetic waves within the wind wave component of a sea. Wind waves are waves on the ocean surface and are the high frequency portion of a bimodal wave frequency spectrum. A period is an interval of time, or the time-period of an oscillation. Wave period is the interval of time between repeated features on the waveform such as crests, troughs or upward passes through the mean level.
Standard Name: sea_surface_below_8s_period_wave_period_at_variance_spectral_density_maximum
Units: s, second
wave.direction.above-8s.peak
Spectral peak direction of the portion of a wave frequency spectrum where periods are above 8s. Direction from which the most energetic waves are coming in the swell wave component of a sea. Swell waves are waves on the ocean surface and are the low frequency portion of a bimodal wave frequency spectrum. The spectral peak is the most energetic wave in the wave spectrum partition.
Standard Name: sea_surface_above_8s_period_wave_from_direction_at_variance_spectral_density_maximum
Units: °, degree
wave.direction.below-8s.peak
Spectral peak direction of the portion of a wave frequency spectrum where periods are below 8s. Direction from which the most energetic waves are coming in the wind wave component of a sea. Wind waves are waves on the ocean surface and are the high frequency portion of a bimodal wave frequency spectrum. The spectral peak is the most energetic wave in the wave spectrum partition.
Standard Name: sea_surface_below_8s_period_wave_from_direction_at_variance_spectral_density_maximum
Units: °, degree
wave.direction.mean
Mean wave direction of where the waves are coming from
Standard Name: sea_surface_wave_mean_from_direction
Units: °, degree
wave.directional-spread
Directional spread is the (one-sided) directional width within a given sub-domain of the wave directional spectrum, S(t,x,y,f,theta) where t is time, x and y are horizontal coordinates (such as longitude and latitude), f is frequency and theta is direction. For a given mean wave (beam) direction the quantity approximates half the root mean square width about the beam axis, as derived either directly from circular moments or via the Fourier components of the wave directional spectrum. The primary swell is the most energetic swell partition identified using the watershed partioning method.
Standard Name: sea_surface_wave_directional_spread
Units: °, degree
wave.period.tm01.mean
Tm01 is mean wave period using the zeroth- and first-order moments = m0/m1. Tm01 is less dependent on the high-frequency part of the spectrum, it is usually a more reliable parameter to be compared against observations since it is less dependent on high-frequency noise. It represents the inverse of the mean frequency of the spectrum. The spectral models used to provide the wave forecast are based on the wave energy spectrum (distribution of wave energy in frequency and direction). The mean wave periods Tm01 and Tm02 provided by the our forecast models are expressed in terms of the moments of the spectrum.
Standard Name: sea_surface_wave_mean_period_from_variance_spectral_density_first_frequency_moment
Units: s, second
wave.period.tm02.mean
Tm02 is mean wave period using the zeroth- and second-order moments = sqrt(m0/m2). Tm02 gives the closest result to the mean period obtained with the Zero-crossing method (usually referred as TM or TZ) in the time domain. The spectral models used to provide the wave forecast are based on the wave energy spectrum (distribution of wave energy in frequency and direction). The mean wave periods Tm01 and Tm02 provided by the our forecast models are expressed in terms of the moments of the spectrum.
Standard Name: sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment
Units: s, second
Hydrodynamic
Hydrodynamic variables describe the motion of water within the Earth's oceans.
current.speed.eastward.at-sea-surface
“Surface" means the lower boundary of the atmosphere. A velocity is a vector quantity. "Eastward" indicates a vector component which is positive when directed eastward (negative westward).
Standard Name: surface_eastward_sea_water_velocity
Units: m/s, meters per second
current.speed.eastward.at-sea-surface-no-tide
The surface called 'surface' means the lower boundary of the atmosphere. 'Water' means water in all phases, including frozen i.e. ice and snow. A velocity is a vector quantity. 'Eastward' indicates a vector component which is positive when directed eastward (negative westward).
Standard Name: surface_eastward_sea_water_velocity_assuming_no_tide
Units: m/s, meters per second
current.speed.eastward.barotropic
Average current over the full water column / to the bottom of the sea. A velocity is a vector quantity. "Eastward" indicates a vector component which is positive when directed eastward (negative westward).
Standard Name: barotropic_eastward_sea_water_velocity
Units: m/s, meters per second
current.speed.eastward.barotropic-no-tide
A velocity is a vector quantity. 'Eastward' indicates a vector component which is positive when directed eastward (negative westward).
Standard Name: barotropic_eastward_sea_water_velocity_assuming_no_tide
Units: m/s, meters per second
current.speed.northward.at-sea-surface
"Surface" means the lower boundary of the atmosphere. A velocity is a vector quantity. "Northward" indicates a vector component which is positive when directed northward (negative southward).
Standard Name: surface_northward_sea_water_velocity
Units: m/s, meters per second
current.speed.northward.at-sea-surface-no-tide
The surface called 'surface' means the lower boundary of the atmosphere. 'Water' means water in all phases, including frozen i.e. ice and snow. A velocity is a vector quantity. 'Northward' indicates a vector component which is positive when directed northward (negative southward).
Standard Name: surface_northward_sea_water_velocity_assuming_no_tide
Units: m/s, meters per second
current.speed.northward.barotropic
Average current over the full water column / to the bottom of the sea. A velocity is a vector quantity. "Northward" indicates a vector component which is positive when directed northward (negative southward).
Standard Name: barotropic_northward_sea_water_velocity
Units: m/s, meters per second
current.speed.northward.barotropic-no-tide
A velocity is a vector quantity. 'Northward' indicates a vector component which is positive when directed northward (negative southward).
Standard Name: barotropic_northward_sea_water_velocity_assuming_no_tide
Units: m/s, meters per second
sea.temperature.at-surface
Sea surface temperature is usually abbreviated as "SST". It is the temperature of sea water near the surface (including the part under sea-ice, if any).
Standard Name: sea_surface_temperature
Units: K, Degrees Kelvin
sea.temperature.at-surface-anomaly
The term 'anomaly' means difference from climatology. Sea surface temperature is usually abbreviated as 'SST'. It is the temperature of sea water near the surface (including the part under sea-ice, if any). More specific terms, namely sea_surface_skin_temperature, sea_surface_subskin_temperature, and surface_temperature are available for the skin, subskin, and interface temperature. respectively. For the temperature of sea water at a particular depth or layer, a data variable of sea_water_temperature with a vertical coordinate axis should be used.
Standard Name: sea_surface_temperature_anomaly
Units: K, Degrees Kelvin