Surface weather analysis United States, temperature and dewpoint are plotted in degrees Celsius. The wind barb points in the direction from which the wind is coming. Each full flag on the wind barb represents of wind, each half flag represents . When winds reach , a filled in triangle is used for each of wind. In the United States, rainfall plotted in the corner of the station model are in inches. The international standard rainfall measurement unit is the millimeter. Once a map has a field of station models plotted, the analyzing isobars (lines of equal pressure), isallobars (lines of equal pressure change),
Isochrone map Isochrone map An isochrone map (or chart/diagram) in geography and urban planning is a map showing areas related to isochrones between different points. An isochrone is defined as "a line drawn on a map connecting points at which something occurs or arrives at the same time". Such a map is sometimes termed simply an isochrone (iso = equal, chrone = time). In hydrology and transportation planning isochrone maps are commonly used to depict areas of equal travel time. The term is also used in cardiology as a tool to visually detect abnormalities using body surface distribution. Isochrone maps have been