Added on: January 27, 2015
Thermodynamic charts such as the Skew-T log (p) diagram are one of the best kept secrets in aviation. It represents one of the most versatile power tools in the pilot's preflight planning toolbox. Specifically, the Skew-T log (p) diagram allows the pilot to "drill down" over a particular location to identify or describe adverse weather better in time and space than any other single chart or diagram. Icing potential, cloud bases, cloud tops, cloud layers, turbulence, non-convective low level wind shear, haze, instability, thunderstorm potential, precipitation type, cloud type, fog and visibility are just some of the adverse weather elements that can be inferred by this diagram.
The Skew-T log (p) diagram depicts the actual environmental temperature, dewpoint temperature and wind (speed and direction) as a function of pressure or altitude captured by weather balloons, also known as radiosondes, that are launched twice daily from approximately 87 NWS launch sites throughout the U.S. and its territories. More importantly, a Skew-T log (p) diagram can be generated from the output of a numerical weather prediction forecast model such as the Rapid Update Cycle (RUC) to depict a forecast for temperature, dewpoint and wind as a function of pressure for many reporting stations (airports) throughout the U.S. Having a forecast of these three basic environmental weather elements can tell us a tremendous amount about the adverse weather we might face before, during and after our scheduled flight. As a result, this premium workshop offers an introduction to the Skew-T log (p) diagram.
Using many real world examples in this online presentation you will learn:
- The origin and use of each and every line on the Skew-T log (p) base diagram.
- Lapse rates and parcel theory and how they are used to assess atmospheric (in)stability.
- How to determine the bases of stratus and cumulus clouds at an airport.
- How to use the dewpoint depression to identify stratus cloud tops.
- How to use a lifted parcel to identify the tops of cumuliform clouds and thunderstorms.
- How to derive the Lifted Index (LI), Convective Available Potential Energy (CAPE) and Convective Inhibition (CINH).
- How to assess convective potential or thunderstorm potential.
- How to identify the freezing level to recognize the potential for icing, freezing rain, freezing drizzle and supercooled liquid water.
- How to recognize the potential for radiation fog and other phenomenon related to temperature inversions.
- What causes non-convective low level wind shear (LLWS).
- The signature for mountain wave turbulence and how to find the altitude that will give you the smoothest ride.
- How to use the ESRL/GSD (formerly FSL) forecast sounding tool found at http://rucsoundings.noaa.gov/.
- ...and much more.
In this premium workshop, a short quiz is included at the end of each training module to test your comprehension.
*Please note that this program is no longer available on CD-ROM. It can only be purchased for online viewing which requires an Elite member account. If you are not an Elite member of AvWxWorkshops.com and would like to purchase this workshop, you will get a free 7-Day Elite membership to view the program. An Elite membership also provides you with access to 80+ basic workshops and seamless access to the Internet Weather Brief Roadmap, a suite of weather briefing guidance unlike any other available online. If you choose not to renew your Elite membership to retain these other benefits, you will be able to login and retain access to this workshop to view as often as you'd like.