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TROWAL Identification

Scott Lindstrom, Scott Bachmeier, Jon Martin


TROWAL stands for TROugh of Warm air ALoft


  1. Learn more about extratropical cyclone structure
  2. Learn how to use AWIPS to find TROWALs
  3. Can TROWAL identification help forecast accuracy?


  1. Review conceptual models of cyclone airflow
  2. Review vertical motion
  3. Historical review of TROWALs
  4. Characteristics of TROWALs
  5. How to find TROWALs
  6. Case study


This is a basic course. There are no prerequisites.

If you have not taken the VISIT Cyclogenesis session, it is recommended that you either signup for the Cyclogenesis teletraining OR go through the audio version before taking the TROWAL session.

Training Session Options

NOAA/NWS students - to begin the training, use the web-based video, YouTube video, or audio playback options below (if present for this session). Certificates of completion for NOAA/NWS employees can be obtained by accessing the session via the Commerce Learn Center

  1. Web-based video that can be taken at anytime (streamed, not recommended for low-bandwidth users). Be sure to have your speakers on and the volume loud enough to hear the presentation. Also be sure that you are using a flash enabled browser.
  2. Audio playback (recommended for low-bandwidth users) - This is an audio playback version in the form of a downloadable VISITview and can be taken at anytime.

    Create a directory to download the audio playback file (92 MB) from the following link:

    After extracting the files into that directory click on either the visitplay.bat or visitauto.bat file to start the lesson. If both files are present, use visitauto.bat

  3. Live VISIT teletraining (with an instructor leading the session). Check the VISIT Training Calendar to signup for teletraining. The session will last 75 minutes. This teletraining session uses the VISITview software, where a Windows PC with an Internet connection is needed.

    Please follow the teletraining installation instructions to install the session

References/Additional Links

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