WHAT IS A SOUNDING?

Sounding plots give information about the vertical structure of the atmosphere at a particular location. You can think of a sounding as a description of the air in a long cylinder stretching upward from the ground at one location to the high reaches of the atmosphere. Soundings traditionally are made from real observations taken from radiosondes that measure atmospheric variables. Computer weather models are also able to predict these same variables and produce forecasts of soundings hours into the future. These soundings are from the numerical weather simulations the department run; they are model forecasts NOT observational profiles. Along with soundings each location has a complementary suite of products that include a forecasted meteogram and time-height product.

BACKGROUND GRAPH:

Labeled on the left are solid horizontal black lines representing different atmospheric pressure levels measured in millibars (mb). Solid green lines are lines of constant potential temperature defined as dry adiabats. Dashed red lines are known under a few different names such as wet adiabats, saturated adiabats or pseudoadiabats. Dashed purple lines represent the saturation mixing ratio of the air.

DATA:

Drawn on the background graph are two lines, one red and one blue. The blue line represents the dew point of the atmosphere at different levels at the selected location. The red line represents the environmental air temperature at different levels at the selected station.

WIND BARBS

Evenly spaced to the right of the graph are wind barbs that indicate the strength and direction of the wind. They are stacked vertically to represent the wind at different levels in the atmosphere at the station location. The height level is determined by pressure levels labeled on the far left of the graph.

1 kt ~ 1.15 mph ~ 1.85 km/hr

WHY IS THIS IMPORTANT?

Soundings give forecasters a snapshot of the vertical structure of the atmosphere. Dry and moist regions of the vertical atmosphere can easily be determined along with the stability of the air. Soundings are critical in determining the air quality as they can help predict the height of the boundary layer and the location and strength of an inversion. For a more detailed explanation please click here.