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Spire Weather Data Bundles

Bundles

We have organized our Weather variables in bundles, each one grouping variables for a specific domain. The bundles currently available are:

Basic Bundle (basic)

Field Name

Vertical Level

Description

Units

Temperature

2 meters AGL

Air temperature at standard observation height (2 meters above the surface)

K

Relative humidity

2 meters AGL

The fractional ratio of the partial pressure of water vapor to the equilibrium vapor pressure at a given temperature, expressed as a percentage


%

Dewpoint temperature

2 meters AGL

Temperature at which a parcel of air cooled at constant pressure and specific humidity reaches saturation

K

u-wind component

10 meters AGL

The eastward component of the horizontal wind

m/s

v-wind component

10 meters AGL

The northward component of the horizontal wind

m/s

Mean sea-level pressure

Sea level

Air pressure adjusted to mean sea level


Pa

Accumulated precipitation

Surface

The total accumulated (liquid) precipitation occurring since the beginning of the forecast

Read more about working with accumulated fields.

kg/m2

Wind gust speed

10 meters

AGL

Instantaneous wind gust (speed)

m/s

Maximum temperature

2 meters AGL

Maximum air temperature in the previous six hours

K

Minimum temperature

2 meters AGL

Minimum air temperature in the previous six hours

K

Cloud cover

Whole atmosphere

The percentage of the sky covered by clouds

%

Visibility

Surface

The horizontal visibility

m

This bundle is available at the file, point, and WMS API endpoints.

Maritime Bundle (maritime)

Field Name

Vertical Level

Description

Units

Sea Surface Temperature

Sea level

The temperature of the ocean surface

K

Ocean Currents (eastward component)

Sea level

The eastward component of the ocean current vector


m/s

Ocean Currents (northward component)

Sea level

The northward component of the ocean current vector


m/s

Significant Wave Height

Sea level

Wave heights of combined swell and wind waves

m

Mean Wave Direction

Sea level

Mean wave direction of combined swell and wind waves

Degrees

Mean Wave Period

Sea level

Mean wave period of combined swell and wind waves

Seconds

This bundle is available at the file, point, and WMS API endpoints.

 

Maritime Atmospheric Bundle (maritime-atmos)

Field Name

Vertical Level

Description

Units

u-wind component

50 meters AGL

The eastward component of the horizontal wind

Download a sample of how to convert from u/v components to speed and direction.

m/s

v-wind component

50 meters AGL

The northward component of the horizontal wind

m/s

This bundle is available at the file, point, and WMS API endpoints.

Maritime Waves Bundle (maritime-wave)

Field Name

Vertical Level

Description

Units

Significant Wind Wave Height

Sea level

Wave heights of waves generated by local winds

m

Mean Wind Wave Direction

Sea level

Mean wave direction of waves generated by local winds

Degrees

Mean Wind Wave Period

Sea level

Mean wave period of waves generated by local winds 

Seconds

Significant Total Swell Wave Height

Sea level

Wave heights of combined swell waves


m

Mean Total Swell Wave Direction

Sea level

Mean wave direction of combined swell waves

Degrees

Mean Total Swell Wave Period

Sea level

Mean wave period of combined swell waves

Seconds

This bundle is available at the file, point, and WMS API endpoints.

 

Thunderstorm Bundle (thunderstorm)

Field Name

Vertical Level

Description

Units

CAPE

Whole atmosphere

Convective Available Potential Energy

J/kg

CIN

Whole atmosphere

Convective Inhibition

J/kg

Lifted Index

Whole atmosphere

The temperature difference between the air lifted from the surface to 500 hPa and the environmental temperature at that level


K

Storm-relative helicity

0-3 km

A measure of the transfer of vorticity from the environment to an air parcel in convective motion from a frame of reference moving with a thunderstorm


m2/s2

Storm motion (eastward component)

0-6 km

The eastward component of the storm-motion vector


m/s

Storm motion (northward component)

0-6 km

The northward component of the storm-motion vector


m/s

0-6 km shear vector (eastward component)

0-6 km

The eastward component of the deep-layer shear vector


s−1

0-6 km shear vector (northward component)

0-6 km

The northward component of the deep-layer shear vector


s−1

Precipitable Water

Whole atmosphere

The depth of water in a column of the atmosphere, if all the water in that column were precipitated as rain

kg/m2

This bundle is available at the file API endpoint.

Upper Air Bundle (upper-air)

Field Name

Vertical Level

Description

Units

Geopotential height

Isobaric levels

The approximate height of a given point in the atmosphere above the surface of the earth accounting for variations in gravity


gpm

Temperature

Isobaric levels

Air temperature

K

u-wind component

Isobaric levels

The eastward component of the horizontal wind

m/s

v-wind component

Isobaric levels

The northward component of the horizontal wind

m/s

Relative humidity

Isobaric levels

The fractional ratio of the partial pressure of water vapor to the equilibrium vapor pressure at a given temperature expressed as a percentage


%

Vertical velocity

Isobaric levels

The component of the full velocity vector in the vertical direction

m/s

Absolute vorticity

Isobaric levels

The vertical component of the absolute vorticity vector measuring the local rotation of the atmosphere

s−1

Cloud water mixing ratio

Isobaric levels

The ratio of the mass of non-precipitating liquid water to the mass of dry air in a unit volume of air

kg/kg

Cloud ice mixing ratio

Isobaric levels

The ratio of the mass of non-precipitating frozen water to the mass of dry air in a unit volume of air

kg/kg

This bundle is available at the file API endpoint. The following isobaric levels are available: 1000, 950, 925, 900, 850, 800, 700, 600, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30, 20 hPa.



Aviation Bundle (aviation)

Field Name

Vertical Level

Description

Units

Temperature

Flight levels

Air temperature

K

Relative humidity

Flight levels

The fractional ratio of the partial pressure of water vapor to the equilibrium vapor pressure at a given temperature, expressed as a percentage


%

u-wind component

Flight levels

The eastward-component of the horizontal wind

m/s

v-wind component

Flight levels

The northward-component of the horizontal wind

m/s

Visibility

Surface

The horizontal visibility

m

Height

Level of max. winds

The height (above sea level) where the maximum wind speed is found

gpm

u-wind component

Level of max. winds

The eastward component of the horizontal wind

m/s

v-wind component

Level of max. winds

The northward component of the horizontal wind

m/s

Clear-air turbulence

Flight levels

Potential severity of turbulence associated with wind shear (not due to mountain waves or convection), using the EDR (Eddy Dissipation Rate).


%

Icing severity

Flight levels

Potential for aircraft icing (0-1)

0 - 1

This bundle is available at the file API endpoint.

The flight levels currently available range from FL100 to FL450 (10,000 feet to 45,000 feet mean sea level), in 1000ft increments.

The altitudes in the files are shown in meters and correspond to the following values:

  • 3048, 3352, 3657, 3962, 4267, 4572, 4876, 5181, 5486, 5791, 6096, 6400, 6705, 7010, 7315, 7620, 7924, 8229, 8534, 8839, 9144, 9448, 9753, 10058, 10363, 10668, 10972, 11277, 11582, 11887, 12192, 12496, 12801, 13106, 13411, 13716.

 

Agricultural Bundle (agricultural)

Field Name

Vertical Level

Description

Units

Skin (surface) temperature

Surface

Temperature at the interface between the air and the ground

K

Specific humidity

2 meters AGL

The ratio of the mass of water vapor to the total mass of an air parcel in a moist atmosphere taken at screen level

kg/kg

Soil moisture

0-10 cm,

10-40 cm,

40-100 cm, 

100-200 cm

Volumetric soil moisture content, expressed as a fraction, for a given depth below the surface


Fraction

Soil temperature

0-10 cm,

10-40 cm,

40-100 cm, 

100-200 cm

The temperature of the soil for a given depth below the surface


K

Latent heat flux

Surface

The exchange of heat between the surface and the air owing to evaporation (and sublimation)

W/m2

Sensible heat flux

Surface

The exchange of heat between the surface and the air due to the turbulent motion of air

W/m2

This bundle is available at the file and point API endpoints.

 

Solar Energy Bundle (solar-energy)

Field Name

Vertical Level

Description

Units

Incoming shortwave radiation (acc.)

Surface

Accumulated shortwave radiation directed at the surface from above, including direct and diffuse components

Read more about working with accumulated fields.


J/m2

Incoming longwave radiation (acc.)

Surface

Accumulated longwave radiation directed at the surface from above


J/m2

Outgoing longwave radiation (acc.)

Surface

Accumulated longwave radiation directed (upwards) away from the surface


J/m2

Outgoing shortwave radiation (acc.)

Surface

Accumulated shortwave radiation directed (upwards) away from the surface


J/m2

Outgoing longwave radiation (acc.)

Top of atmosphere

Accumulated longwave radiation directed (upwards) away from the top of the atmosphere


J/m2

This bundle is available at the file and point API endpoints.

Precipitation Bundle (precipitation)

Field Name

Vertical Level

Description

Units

Precipitation Type

Surface

The predominant precipitation type. Values are "no_precipitation", "rain", "snow", "freezing_rain", "mixed/ice"

Note: At the file API, available as categorical masks for areas of each of the precipitation types

-

Snowfall Amount

Surface

The total accumulated snowfall occurring since the beginning of the forecast.

Read more about working with accumulated fields.

m

This bundle is available at the file, point, and WMS API endpoints.

 

Wind Energy Bundle (wind-energy)

Field Name

Vertical Level

Description

Units

u-wind component

80 meters AGL

The eastward component of the horizontal wind

Download a sample of how to convert from u/v components to speed and direction.

m/s

v-wind component

80 meters AGL

The northward component of the horizontal wind

m/s

u-wind component

100 meters AGL

The eastward component of the horizontal wind

m/s

v-wind component

100 meters AGL

The northward component of the horizontal wind

m/s

u-wind component

120 meters AGL

The eastward component of the horizontal wind

m/s

v-wind component

120 meters AGL

The northward component of the horizontal wind

m/s

Air Density

80 meters AGL

The air density at 80 m above ground level. Air density is the density of the atmosphere. It is a function of atmospheric pressure, temperature and humidity and decreases with increasing altitude.


kg/m³

Air Density

100 meters AGL

The air density at 100 m above ground level. Air density is the density of the atmosphere. It is a function of atmospheric pressure, temperature and humidity and decreases with increasing altitude.


kg/m³

Air Density

120 meters AGL

The air density at 120 m above ground level. Air density is the density of the atmosphere. It is a function of atmospheric pressure, temperature and humidity and decreases with increasing altitude.


kg/m³

This bundle is available at the file and point API endpoints.

Point-optimized forecast variables

For the point-optimized forecasts, we offer the following list of weather variables:

Field Name

Vertical Level

Description

Units

Temperature

2 meters AGL

Air temperature at standard observation height (2 m above the surface)

K

Dewpoint temperature

2 meters AGL

Temperature at which a parcel of air cooled at constant pressure and specific humidity reaches saturation

K

Relative humidity

2 meters AGL

The fractional ratio of the partial pressure of water vapor to the equilibrium vapor pressure at a given temperature, expressed as a percentage


%

24-h Maximum temperature UTC

2 meters AGL

Maximum air temperature for the remainder of the current calendar day (day in UTC time - same across all stations)

For example, at 18 UTC, the Maximum Temperature is predicted for the period between 19:00 and 23:59.

K

24-h Minimum temperature UTC

2 meters AGL

Minimum air temperature for the remainder of the current calendar day (day in UTC time - same across all stations)

K

24-h Maximum temperature local

2 meters AGL

Maximum air temperature for the remainder of the current calendar day (day in the station local time zone)

K

24-h Minimum temperature local

2 meters AGL

Minimum air temperature for the remainder of the current calendar day (day in the station local time zone)

K

Mean sea-level pressure

Sea level

Air pressure adjusted to mean sea level


Pa

Cloud ceiling

Surface

The height above the Earth's surface of the base of the lowest layer of cloud with a coverage of more than 50%. Data is provided in ranges

For example, “0 to 800 m” or “No Ceiling”

m (range)

Total cloud cover

Surface

The percentage of the sky around the location covered by clouds

%

Visibility

Surface

The horizontal visibility

m

Probability of fog

Surface

The probability of fog

%

Probability of thunderstorm

Surface

The probability of thunderstorm

%

Wind speed

10 meters AGL

The wind speed at standard observation height (10 m above the surface)

m/s

Wind direction

10 meters AGL

The meteorological wind direction (90° corresponds to wind from east)

degrees

Eastward wind velocity

10 meters AGL

The eastward component of the horizontal wind. It is the horizontal speed of air moving towards the east

m/s

Northward wind velocity

10 meters AGL

The northward component of the horizontal wind.  It is the horizontal speed of air moving towards the north

m/s

1-h Probability of precipitation

Surface

The probability of (liquid) precipitation in the next one hour

%

1-h Accumulated precipitation

Surface

The total accumulated (liquid) precipitation occurring in the next one hour

mm

3-h Probability of precipitation

Surface

The probability of (liquid) precipitation in the next three hours

%

3-h Accumulated precipitation

Surface

The total accumulated (liquid) precipitation occurring in the next three hours

mm

6-h Probability of precipitation

Surface

The probability of (liquid) precipitation in the next six hours

%

6-h Accumulated precipitation

Surface

The total accumulated (liquid) precipitation occurring in the next six hours

mm

24-h Probability of precipitation

Surface

The probability of (liquid) precipitation in the next 24 hours

%

Conditional probability of rain

Surface

Conditional probability of rain. Likelihood of receiving rain if precipitation were actually to occur.

%

Conditional probability of snow

Surface

Conditional probability of snow. Likelihood of receiving snow if precipitation were actually to occur.

%

Conditional probability of ice

Surface

Conditional probability of ice (freezing rain or sleet). Likelihood of receiving ice if precipitation were actually to occur.

%

Cloud Ceiling Notes

There are 2 variable fields which are relevant for the cloud ceiling:
  • The first is total_cloud_cover which is a percentage between 0 and 100.
  • The second is ceiling which is an altitude range, with values like 944-1676 m
It is also possible for ceiling to have a value of none when clouds are either too high or the coverage is insufficient for there to be a ceiling.

Cloud ceiling has two components: there must be a certain amount of clouds (broken or overcast coverage) and they must be below a certain level (typically 12,000 ft).

100% coverage of high, thin clouds (like you'd see outside an airplane window) won't give you a ceiling value but would be considered for the total_cloud_cover value.