2. Parameters

Temperature/Levels » Thickness Strengths and Limitations

Thickness values are widely used to forecast surface high and low temperatures, since these values are proportional to mean temperatures in layers of the atmosphere, and since operational numerical models often have difficulty with surface temperature forecasts. At a given location, depending on the season and cloud cover, typical values of thicknesses derived from empirical studies are utilized to get an estimate of daily maximum or minimum temperatures.

Thickness values are also used to forecast precipitation type. For example, the critical rain/snow threshold corresponds to a 1000-500 thickness of 5400 m (540 dm) or a 1000-850 thickness of 1300 m (130 dm)—with adjustments made for higher elevation locations and maritime regions.

Caution: Threshold thickness values are just one diagnostic tool and need to be considered with other important factors such as latent cooling, precipitation rate, cold advection, cloud depth, etc.

For more information on using thickness values to forecast precipitation type, see:
Topics in Precipitation Type Forecasting / Partial Thickness Analysis