Derived Weather Parameters - General Weather State

Weather Symbol | Weather Code | Weather Text | Visibility | Runway Visual Range | Dew or Rime | Fog | Icing Potential | Slippery Road | Planetary Boundary Layer Height | Snow Line | Freezing Level | Stratospheric Polar Vortex | Power Line Oscillation Warning | Soaring Index | Leisure Indices | Cold Index | Probability for Snow Cover | Windshield Icing

General Weather State

Weather symbol

The weather symbol is the easiest way to query an overview of the weather state.

weather_symbol_<interval>:idx

Available intervals: 20min, 30min, 1h,3h, 6h, 12h, 24h

Examples

Symbol Id (Day) Symbol Id (Night) Description
0
0
A weather code could not be determined
1
101
Clear sky
2
102
Light clouds
3
103
Partly cloudy
4
104
Cloudy
5
105
Rain
6
106
Rain and snow / sleet
7
107
Snow
8
108
Rain shower
9
109
Snow shower
10
110
Sleet shower
11
111
Light Fog
12
112
Dense fog
13
113
Freezing rain
14
114
Thunderstorms
15
115
Drizzle
16
116
Sandstorm

 

Weather Code

Weather code according to the present weather code 4677 of the international WMO Standard (mean for 1h, 3h, 6h, 12h, 24h)

weather_code_<interval>:idx

Weather symbol mean for 1h, 3h, 6h, 12h, 24h

  • Meaning of Symbols: (click on a code group to expand/collapse)
    Code Meaning
    00 - 19 No precipitation, fog, ice fog (except for 11 and 12), duststorm, sandstorm, drifting or blowing snow
    00 Cloud development not observed or not observable Characteristic change of the state of sky during the past hour
    01 Clouds generally dissolving or becoming less developed
    02 State of sky on the whole unchanged
    03 Clouds generally forming or developing
    04 Visibility reduced by smoke, e.g. veldt or forest fires, industrial smoke or volcanic ashes
    05 Haze
    06 Widespread dust in suspension in the air, not raised by wind at or near the station at the time of observation
    07 Dust or sand raised by wind at or near the station at the time of observation, but no well developed dust whirl(s) or sand whirl(s), and no duststorm or sandstorm seen
    08 Well developed dust whirl(s) or sand whirl(s) seen at or near the station during the preceding hour or at the time ot observation, but no duststorm or sandstorm
    09 Duststorm or sandstorm within sight at the time of observation, or at the station during the preceding hour
    10 Mist
    11 Patches shallow fog or ice fog at the station, whether on land or sea, not deeper than about 2 metres on land or 10 metres at sea
    12 More or less continuous
    13 Lightning visible, no thunder heard
    14 Precipitation within sight, not reaching the ground or the surface of the sea
    15 Precipitation within sight, reaching the ground or the surface of the sea, but distant, i.e. estimated to be more than 5 km from the station
    16 Precipitation within sight, reaching the ground or the surface of the sea, near to, but not at the station
    17 Thunderstorm, but no precipitation at the time of observation
    18 Squalls at or within sight of the station during the preceding hour or at the time of observation
    19 Funnel cloud(s)**
    20 - 29 Precipitation, fog, ice fog or thunderstorm at the station during the preceding hour
    20 Drizzle (not freezing) or snow grains not falling as shower(s)
    21 Rain (not freezing)
    22 Snow
    23 Rain and snow or ice pellets
    24 Freezing drizzle or freezing rain
    25 Shower(s) of rain
    26 Shower(s) of snow, or of rain and snow
    27 Shower(s) of hail, or of rain and hail
    28 Fog or ice fog
    29 Thunderstorm (with or without precipitation)
    30 - 39 Duststorm, sandstorm, drifting or blowing snow
    30 Slight or moderate duststorm or sandstorm - has decreased during the preceding hour
    31 - no appreciable change during the preceding hour
    32 - has begun or has increased during the preceding hour
    33 Severe duststorm or sandstorm - has decreased during the preceding hour
    34 - no appreciable change during the preceding hour
    35 - has begun or has increased during the preceding hour
    36 Slight or moderate blowing snow generally low (below eye level)
    37 Heavy drifting snow
    38 Slight or moderate blowing snow generally high (above eye level)
    39 Heavy drifting snow
    40 - 49 Fog or ice fog at the time of observation
    40 Fog or ice fog at a distance at the time of observation, but not at the station during the preceding hour, the fog or ice fog extending to a level above that of the observer
    41 Fog or ice fog in patches
    42 Fog or ice fog, sky visible has become thinner during the preceding hour
    43 Fog or ice fog, sky invisible
    44 Fog or ice fog, sky visible no appreciable change during the preceding hour
    45 Fog or ice fog, sky invisible
    46 Fog or ice fog, sky visible has begun or has become thicker during the preceding hour
    47 Fog or ice fog, sky invisible
    48 Fog, depositing rime, sky visible
    49 Fog, depositing rime, sky invisible
    50 - 59 drizzle at the station at the time of observation
    50 Drizzle, not freezing, intermittent slight at time of observation
    51 Drizzle, not freezing, continuous
    52 Drizzle, not freezing, intermittent moderate at time of observation
    53 Drizzle, not freezing, continuous
    54 Drizzle, not freezing, intermittent heavy (dense) at time of observation
    55 Drizzle, not freezing, continuous
    56 Drizzle, freezing, slight
    57 Drizzle, freezing, moderate or heavy (dence)
    58 Drizzle and rain, slight
    59 Drizzle and rain, moderate or heavy
    60 - 69 rain at the station at the time of observation
    60 Rain, not freezing, intermittent slight at time of observation
    61 Rain, not freezing, continuous
    62 Rain, not freezing, intermittent moderate at time of observation
    63 Rain, not freezing, continuous
    64 Rain, not freezing, intermittent heavy at time of observation
    65 Rain, not freezing, continuous
    66 Rain, freezing, slight
    67 Rain, freezing, moderate or heavy (dence)
    68 Rain or drizzle and snow, slight
    69 Rain or drizzle and snow, moderate or heavy
    70 - 79 Solid precipitation not in showers at the station at the time of observation
    70 Intermittent fall of snowflakes slight at time of observation
    71 Continuous fall of snowflakes
    72 Intermittent fall of snowflakes moderate at time of observation
    73 Continuous fall of snowflakes
    74 Intermittent fall of snowflakes heavy at time of observation
    75 Continuous fall of snowflakes
    76 Diamond dust (with or without fog)
    77 Snow grains (with or without fog)
    78 Isolated star-like snow crystals (with or without fog)
    79 Ice pellets
    80 - 99 Showery precipitation, or precipitation with current or recent thunderstorm at the station at the time of observation
    80 Rain shower(s), slight
    81 Rain shower(s), moderate or heavy
    82 Rain shower(s), violent
    83 Shower(s) of rain and snow mixed, slight
    84 Shower(s) of rain and snow mixed, moderate or heavy
    85 Snow shower(s), slight
    86 Snow shower(s), moderate or heavy
    87 Shower(s) of snow pellets or small hail, with or without rain or rain and snow mixed - slight
    88 - moderate or heavy
    89 Shower(s) of hail, with or without rain or rain and snow mixed, not associated with thunder - slight
    90 - moderate or heavy
    91 Slight rain at time of observation Thunderstorm during the preceding hour but not at time of observation
    92 Moderate or heavy rain at time of observation
    93 Slight snow, or rain and snow mixed or hail at time of observation
    94 Moderate or heavy snow, or rain and snow mixed or hail at time of observation
    95 Thunderstorm, slight or moderate, without hail but with rain and/or snow at time of observation Thunderstorm at time of observation
    96 Thunderstorm, slight or moderate, with hail at time of observation
    97 Thunderstorm, heavy, without hail but with rain and/or snow at time of observation
    98 Thunderstorm combined with duststorm or sandstorm at time of observation
    99 Thunderstorm, heavy, with hail at time of observation
  • Corresponding symbols to weather codes:

Examples

Weather Text

This parameter provides an automated text snipped describing the general weather state of the queried day. It is currently available in English, German, French and Italian.

weather_text_de:str
weather_text_en:str
weather_text_fr:str
weather_text_it:str

Example

validdate;weather_text_en:str
2019-04-08T00:00:00Z;Today after sunrise the sky will be overcast.
In the afternoon it will be mostly sunny. About 4 hours of sunshine are predicted. 
It stays very balmy with temperatures between 9°C and 16°C. 
After daybreak there is a slight northeasterly wind which shifts afterwards to a slight southerly wind. 
In the late evening the sky is partly cloudy, in the second half of the night dense mist may appear.

 

Visibility

This parameter returns the visibility in kilometers. You can expect foggy conditions if the visibility is less than about 1km.

visibility:

Available units: m, km, ft

Examples

Runway Visual Range

This parameter returns the distance over which a pilot is able to see the runway surface markings at the runway margin. This parameter is used for assessing the conditions for landing and takeoff.

runway_visual_range:m
runway_visual_range:ft

Examples

Dew or Rime

This index gives you an idea whether dew or rime will occur. Dew or rime forms if the surface cools down quicker than the surrounding air, which causes condensation onto the surface at high relative humidities. Dew and rime are very sensitive to solar radiation and disappear quickly as the surface warms. Rime is the frozen version of dew.

0: neither dew nor rime, 1: dew, -1: rime

dew_or_rime:idx

Example

Fog

Check if there was any fog within the last hour or 30 minutes.

0: no fog, 1: fog event

is_fog_:idx

Available intervals: 30min, 1h

Example

  • Show if there is any fog expected during the next four days. The visibility is also shown as the two parameters contain similar information:
    https://api.meteomatics.com/__replace__0T00:00:00ZP5D:PT1H/visibility:km,is_fog_1h:idx/47.412164,9.340652/html

  • Another example as a json output for fog expectation during the next six hours:
    https://api.meteomatics.com/__replace__0T00:00:00ZPT6H:PT1H/visibility:km,is_fog_1h:idx/47.412164,9.340652/json

    {"version":"3.0","user":"api-test","dateGenerated":"2018-02-07T16:10:49Z","status":"OK","data":
    [{"parameter":"visibility:km","coordinates":[{"lat":47.4122,"lon":9.34065,"dates":
    [{"date":"2017-02-07T00:00:00Z","value":20},{"date":"2017-02-07T01:00:00Z","value":20},
    {"date":"2017-02-07T02:00:00Z","value":20},{"date":"2017-02-07T03:00:00Z","value":20},
    {"date":"2017-02-07T04:00:00Z","value":20},{"date":"2017-02-07T05:00:00Z","value":20},
    {"date":"2017-02-07T06:00:00Z","value":20}]}]},
    {"parameter":"is_fog_1h:idx","coordinates":[{"lat":47.4122,"lon":9.34065,"dates":
    [{"date":"2017-02-07T00:00:00Z","value":0},{"date":"2017-02-07T01:00:00Z","value":0},
    {"date":"2017-02-07T02:00:00Z","value":0},{"date":"2017-02-07T03:00:00Z","value":0},
    {"date":"2017-02-07T04:00:00Z","value":0},{"date":"2017-02-07T05:00:00Z","value":0},
    {"date":"2017-02-07T06:00:00Z","value":0}]}]}]}

Icing Potential

Icing is absolutely critical in aviation and in-flight icing on planes are the cause of multiple near-accidents or even crashes. Consequently, it is crucial for aviation to have reliable icing forecasts predicting the expected occurrence of icing on different altitudes and allowing for early circumnavigation.

icing_potential_:idx

Available levels: 1000hPa, 975hPa, 950hPa, 925hPa, 900hPa, 875hPa, 850hPa, 825hPa, 800hPa, 775hPa, 750hPa, 700hPa, 650hPa, 600hPa, 550hPa, 500hPa, 450hPa, 400hPa, 350hPa, 300hPa

Index Description
0.0-0.2 No Icing
0.2-0.4 Traces
0.4-0.6 Light
0.6-0.8 Moderate
0.8-1.0 Heavy

Examples

    • Below showing an example screenshot of the icing potential at 500hPa displayed via the powerful Meteomatics WMS interface. Very well visible the icing potential along the cold front associated with the strong low pressure system West of Ireland.

 

Slippery Road

Check if there is any chance for slippery roads within the given interval.

Probability:

prob_slippery_road_:p

Provides the probability for slippery roads from 0-100 %.

Binary Index:

is_slippery_road_:idx

0: no slippery road conditions, 1: slippery roads possible

Available intervals: 1h, 3h, 6h, 12h, 24h

Examples

Planetary Boundary Layer Height

The planetary boundary layer (PBL) height is determined by identifying the height, where big wind direction changes, local minima of wind speed, local maxima of temperature, high temperature increases (inversion) or high potential temperature increases occur.

pbl_height:m

Examples

Snow Line

The snow line parameter provides the height above which precipitation occurs in the form of snow. Should it be undeterminable, for example if it is below ground level, it returns -666.

snow_line:m

Examples

Freezing Level

The freezing level parameter provides the altitude where the temperature equals 0 °C. If the freezing level is below ground, the return value is -666. In case of strong convection, the height of the freezing level correlates with the size of hail observed at the surface, since it determines the melting area for falling hail.

freezing_level:m

Examples

Stratospheric Polar Vortex (SPV): Wind speed

This index provides the average wind speed at 10, 50 or 200 hPa between 60°N and 90°N and thus indicates the strength of the stratospheric polar vortex during the polar winter.
The SPV index provides a measure of the circumpolar vortex strength and indirectly relates to a risk of cooling temperatures near the surface in the northern hemisphere, if decreasing below zero.
If the index becomes negative, the vortex disruption is such that a “split" or strong “displacement" is under way, possibly weakening the jet stream in the troposphere.

polar_vortex_:ms

Available levels: 200hPa, 50hPa, 10hPa

Example

Power line oscillation warning

Precipitation in the form of freezing rain or wet snow can freeze onto overland power lines. With the increase in diameter and mass come a bigger air resistance and a lower resonance frequency. Strong wind over a sufficient amount of time could then excite the conductors to oscillate near their resonance frequency (sometimes referred to as gallop) and thereby damage the lines and masts.

A power line oscillation warning for the past 24 hours can be queried with the following parameter:

power_line_oscillation_24h:idx

The warning is binary with 1 corresponding to a warning and 0 to an all clear. Not taken into account are things like constructional details of the power lines or the Joule heat emitted by active power lines.

Example

Soaring Index

The soaring-index is used for an estimation of the thermal situation. It is useful for paraglider and other sport pilots. A higher soaring-index also shows a greater chance of showers and thunderstorms, as it is a measure of the lift caused by convective clouds. The soaring index is independent of altitude, as it is computed with variables in different altitudes.

soaring conditions soaring index range
poor <-10
moderate -10 to 5
good 5 to 20
excellent >20 
soaring_index:idx

Example

Leisure Indices

The leisure index combines different weather parameters and assesses if weather conditions are favorable for certain outdoor activities or not. The index ranges from 0 to 1, where 1 means that conditions are perfect for the queried activity at the queried point in time (i.e. the parameter is instantaneous).
The indices are based on a combination of precipitation, temperature, wind speed, wind gusts, humidity, sunshine duration, snow cover, visibility and fog.

leisure_:idx
Available activities: ballooning, bbq, beach, biking, climbing, fishing, gardening, gliding, hiking, hunting, sailing, skiing, tv

 

Cold Index

This index combines several weather parameters like temperature, wind speed, humidity and precipitation and assesses how favorable these weather conditions are for catching a cold. The index takes values from 1 to 100, where higher values indicate higher risks.

cold_index:idx

Examples

Probability for Snow Cover

Gives the probability for a location/region being covered by snow. The probability is determined by combining information about temperatures at different altitudes and precipitation predictions.

prob_snow_cover:p

Examples

Index for Windshield Icing

Gives the probability for the occurrence of windshield icing for cars. This index combines information about temperature, humidity, wind speed and other parameters and yields a probability in the range of 0-100 %. In addition, it is possible to specify an inclination between 0° (flat) and 90° (vertical) of the windshield - the default value is 50°.

prob_car_windshield_frost_<inclination>d:p

Examples