General Information
Forecasting cloud elements will undoubtedly take up a substantial portion of your students' forecast routine. Time must be spent determining cloud characteristics such as height,type, and amount, as well as formation and dissipation times. An understanding of the physical processes involved in cloud formation is required to correctly forecast cloud events.
Cloud Formation Ingredients
Three ingredients are required before clouds can form: condensation nuclei, moisture, and a cooling process.
Condensation Nuclei
Although the atmosphere is chiefly composed of gases and water vapor, the atmosphere also contains significant quantities of particles called condensation nuclei. Condensation nuclei are suspended particles of sea salt, dust, organic matter and smoke. The presence of condensation nuclei is necessary before condensation will occur.
Moisture
Obviously, moisture is needed or clouds would not form regardless of how much condensation nuclei is present or how much cooling was applied to the atmosphere. Moisture is supplied to the atmosphere by the process of evaporation. The moisture is then spread horizontally and vertically around the globe by wind currents.
Cooling Process
Finally, cloud formation requires a cooling process. The three cooling processes we will discuss in this QTP are radiational cooling, convective cooling, and mechanical cooling.
Summary
Incorrect cloud forecasts can cause aircraft diversions, delays in take-off, and mission aborts. It not only can cost valuable time and money, but in extreme cases, can cost lives. Accurate forecasting of clouds depends on the proper evaluation of atmospheric motion, temperature, moisture fields, stability, modification of air masses, distance from moisture source and topographical influence. Difficulty lies in quantifying the results of interactions between these elements and account for local effects.
The picture below show just how difficult cloud forecasting can be. This area, though, is vital to ensuring proper resource protection. You must emphasize this with your students. They must know the dyamics of cloud formation and not just what the weather models depict.
Now let's use the SmartNotebook to get your views on clouds and how they form near frontal systems. Please begin with the file below.
