Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Definition of Term
    From: Jan Kalivoda
    Date: 2003 Jan 25, 11:17 +0100

    Dear Capt. Joe Kliment,
    I don't know, why you use the low travelling from S to N for your illustration 
    of the changing direction of wind in a low). Maybe it is motivated by your 
    personal or regional experience, but generally these lows are rather rare. In 
    textbooks, the low runing from W to E is invariantly used for this purpose, 
    with two observers to S (wind turning S ->SW->W->NW->N)  and N 
    (S->SE->E->NE->N, both cases for the northern hemisphere) of its path, as in 
    the most cases, the observers to the E and W of the low experience the wind 
    of a steady direction (cca N or S), only its strength is changing. Of course, 
    this is only an idealized case, but we all use such simplified patterns in 
    this discussion.
    As for the theme itself, I skimmed through my scarce texts on meteorology in 
    English and I suppose that they use "backing / veering" for northern regions, 
    but more general terms (e.g. "shifting / turning" with subsequent details) 
    when the southern hemisphere is explicitly meant, so as to avoid a 
    misunderstanding. U.S. Sailing directions for Australia (1931 and later) 
    provide a clear example.
    Jan Kalivoda
    ----- Original Message -----
    From: "kliment" 
    Sent: Saturday, January 25, 2003 5:08 AM
    Subject: Definition of Term
    > In the northern hemisphere high pressure systems are associated with
    > clockwise winds(anticyclonic) while low pressure systems are associated with
    > counterclockwise winds(cyclonic). This is opposite in the southern hemisphere
    > with counterclockwise highs and clockwise lows. Your location
    > with respect to a low will dictate whether the wind will "back" or "veer"
    > as the low passes. In the northern hemisphere if the low passes east of
    > your location the winds will "back" from NE ,N, NW,  to W and if the low passes
    > west of your location then winds will "veer" from NE, E, SE, to S.
    > By applying Buys Ballot's Law you can determine the location of the center
    > of the low and
    > predict it's path with either "backing" or "veering" winds.
    > Capt Joe Kliment
    > W3HZM
    > Middletown,De.

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site