Any dew formation on the cold side of this line will be in the form of frost. The magenta line is also an indicator of very dry air in warm desert regions. Wind Winds at a height of 10 meters above ground level are indicated by the streamlines. The streamlines show the instantaneous flow of air, and do not necessarily indicate the exact trajectory of air parcels, since the wind field fluctuates and evolves over time. Wind speed is indicated by the darkness of the streamline.
Temperatures are in degrees Fahrenheit.
Multiples of 10 have thicker contours and are labeled. Pressure is in millibars. Isobars are labeled as white numbers in black boxes. Units are millibars with only the last two digits shown. Mean sea-level pressure is about 1013 millibars.