Weather in Europe
Temperature
The key below the image shows the corresponding temperature value for each color.
Heat Index
Heat index is the apparent temperature considering both the temperature and relative humidity. The key below the image shows the corresponding heat index for each color.
Wind Chill
Wind chill is the apparent temperature considering both the temperature and the wind speed. The key below the image shows the corresponding wind chill for each color.
Humidity
Relative humidity is the ratio of water vapor contained in the air to the maximum amount of water vapor that can be contained in the air at the current temperature. The key below the image shows the corresponding relative humidity for each color.
Dew Point
Dew point is the temperature to which the air needs to be cooled in order for the relative humidity to reach 100 % (when a cloud would form). The key below the image shows the corresponding dew points for each color.
Wind
Wind vector arrows are also displayed to show the wind direction. The key below the image shows the corresponding wind speed for each color.
Visibility
Visibility is the maximum horizontal distance that can be seen. The key below the image shows the corresponding visibility for each color.
Visible Satellite Map
Visible Satellite images shows the location of the clouds.
Infrared Satellite Map
Infrared satellite images indicate the temperature of cloud tops. The cooler the clouds, the brighter the color on the map. Since air temperature generally decreases with increasing altitude, the cooler (brighter) the clouds, the higher the clouds. Unlike the visible satellite image, infrared satellites work at night.
Jet Stream
Jet stream is the wind where the atmospheric pressure is 300 hPa. Arrows showing the direction the wind is blowing at that level are overlaid. A pressure of 300 hPa corresponds to an altitude of approximately 8000 - 10000 meters above ground--the altitude where the jet stream is typically found. The data shown is the 6-hour forecast from the AVN computer model, which is run twice daily at 00 and 12 GMT by the National Center for Environmental Prediction (NCEP). The jet stream images are updated twice per day, at approximately noon and midnight EST.
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