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: Joe Kliment
    Date: 2003 Jan 25, 11:01 -0500

    You are correct, my example is motivated by regional experience. Generally,
    low pressure
    systems follow a southwest to northeast track across the eastern portion of
    the US.
    This ,of course, is dictated by the meaderings of the jet stream for we are
    in the prevailing
    westerlies as part of the Temperate Zone. Regardless, your location
    relative to the low dictates
    whether the wind will back or veer. For reasons of simplicity, I always
    refer to an idealized
    south to north path of the low when teaching weather.
    Joe Kliment
    At 11:17 AM 1/25/03 +0100, you wrote:
    >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