Since the advent of rawinsonde observations, thermodynamic diagrams have been used by meteorologists to analyze sounding data in the course of preparing their weather forecasts. This module comprehensively examines the use of the tephigram, widely used for over 60 years by meteorologists in the United Kingdom, Canada, and other countries throughout the world particularly in Europe and Africa. It explores thermodynamic properties, convective parameters, stability assessment, and several forecast applications. The module is designed for both instruction and reference. It also comes with an interactive Web-based tephigram that calculates several common forecast parameters.
Module Goal: Teach novice forecasters to effectively use the tephigram. After completing the module, they should be able to read and interpret a sounding plotted on a tephigram and apply that information to aid in the weather forecasting process.
Performance Objectives:
Given a tephigram, identify and describe the various lines.
Given a sounding plotted on a tephigram:
Read or calculate the thermodynamic properties at various levels.
Determine the convective levels, including the LCL, CCL, LFC, MCL, EL, and MPL.
Determine stability indices such as LI, SSI, KI, TT, and SWEAT and use them to assess the potential for severe weather.
Describe how CAPE and CIN are determined.
List and describe the different types of stability and identify them in a sounding plotted on a tephigram.
List and describe the different types of lapse rates and relate them to stability.
List and describe processes that alter stability and give examples of common cases where those processes occur.
Given a suitable synoptic environment and a sounding plotted on a tephiram, interpret the sounding with regard to common forecast problems.
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