Dangerous, prolonged heat is expected across portions of the Central and Southeast U.S. through July. Scattered severe thunderstorms are expected over parts of the northern Plains into the upper Mississippi Valley Tuesday, with damaging winds and large hail as the primary threats. Heavy rainfall could lead to areas of flooding across the northern Plains, Upper Midwest, Southeast and Southwest. Read More >
STATION PRESSURE: This is the pressure that is observed at a specific elevation and is the true barometric pressure of a location. It is the pressure exerted by the atmosphere at a point as a result of gravity acting upon the "column" of air that lies directly above the point. Consequently, higher elevations above sea level experience lower pressure since there is less atmosphere on which gravity can act. Put another way, the weight of the atmosphere decreases as one increases in elevation. Consequently then, in general, for every thousand feet of elevation gain, the pressure drops about 1 inch of mercury. For example, locations near 5000 feet (about 1500 meters) above mean sea level normally have pressures on the order of 24 inches of mercury. |