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Integrated Sensor Training (IST) Professional Development Series

Unit 9: AWIPS Multi-Source Data Displays

Instructional Component 9.1.12

TROWAL Identification

Scott Lindstrom, Scott Bachmeier, Jon Martin

1) Introduction

    TROWAL stands for TROugh of Warm air ALoft

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

    Outline:
    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


2) Prerequisites

    This is a basic course. 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. Follow the directions under section 4E on the Cyclogenesis student guide to go through the audio version on your own.

3) Teletraining Installation Instructions


4) Training Session Options:

    A.) The interactive VISITview training session. (To be used with a VISIT instructor leading the session ). Click here to signup for teletraining. The session will last 75 minutes. This teletraining session uses the VISITview software, where Windows PC (with 128 MB RAM or greater) with an Internet connection is needed.

    B.) Web-based training session - a "stand alone" version viewed via a Web browser, with embedded talking points included. This lesson version may be viewed at any time. These slides are ideal for printing from the web-browser, just print preview first to choose portrait or landscape mode. Best viewed with Internet Explorer or Netscape (prior to version 6).

    C.) Web-based Visitview session - This version uses the VISITview software within a Web browser, may be viewed at any time. It retains all the functionality of the VISITview software which you see in a "live" teletraining session. The talking points are not included in this lesson version, but can be viewed in a separate Web browser (or printed out beforehand).

    D.) Web-based video training session.

    E.) Audio playback - This VISITview file contains recorded audio and annotations and can be taken at anytime. Certificates of completion for NOAA employees can be obtained through your Science Operation Officer or training point of contact. For detailed information on how to view the recorded session click here.

    You may either request a DVD (with all VISIT audio playback files) OR download the file (see instructions below):

    Create a directory to download the audio playback file (it is about 92 MB in size) from one of the following sites:

    ftp://rammftp.cira.colostate.edu/bikos/audio/trowalaudio.zip
    or
    ftp://ftp.ssec.wisc.edu/visit/trowalaudio.zip

    After extracting the files into that directory click on the visitauto.bat file to start the lesson.


5) References/Additional Links

    Crocker, A. M., W. L. Godson, and C. M. Penner, 1947: Frontal Contour Charts. J. Meteor., Vol. 4, 95-99.

    Godson, W. L., 1951: Synoptic properties of frontal surfaces. Quart. J. Roy. Meteor. Soc., Vol. 77, 633-653.

    Penner, C. M., 1955: A three-front model for synoptic analyses. Quart. J. Roy. Meteor. Soc., Vol. 81, 89-91.

    Martin, J. E., 1998a: The structure and evolution of a continental winter cyclone. Part I: Frontal structure and the occlusion process. Mon. Wea. Rev., Vol. 126, 303-328.

    Martin, J. E., 1998b: The structure and evolution of a continental winter cyclone. Part II: Frontal forcing of an extreme snow event. Mon. Wea. Rev., Vol. 126, 329-348.

    Martin, J. E., 1999: Quasigeostrophic forcing of ascent in the occluded sector of cyclones and the TROWAL airstream. Mon. Wea. Rev., Vol. 127, 70-88.

6) Train the trainer

    Talking points - these may be used by local offices in tandem with the visitview training session (run in local mode - "visitlocal.bat"). The talking points may be printed out to easily review the session in detail at any time. The web page version contains talking points embedded in each slide (useful for printing).


7) Content developed/updated
    Developed: 2002
    Updated: 2005
7) Information contact