Twice a day, the NWS directly samples temperature, wind, pressure, and humidity of the troposphere by launching weather balloons. These instruments take observations at mandatory pressure levels (as well as others) to allow for map analyses to be made using all available balloon launches. One of these mandatory levels is at 850 hPa (millibar), which is a handful of thousands of feet above the ground here in the plains. The featured chart presents the time series of 850 hPa temperature (given in Centigrade) from the Omaha sounding site for the evening launch. The red line represents the time series of observations this year with the shaded areas showing the climatology based on long term data from the area. It stands to reason that with record warm temperatures at the surface, that the air aloft is also very warm for this time of year. Indeed, recent reports are shown at the top of the historical range. Since the 850 hPa level is relatively close to the surface, it correlates well with the air temperatures we humans feel. As you go higher in the atmosphere, record warmth near the surface often leads to record cold temperatures aloft at a given pressure level due to the increased thicknesses pushing a pressure level to higher altitudes and thus colder temperatures.

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