In this particular case, you don't need to work this way. I entered your data and ended up with this URL:
http://vortex.plymouth.edu/cgi-bin/gen_uacalplt-u.cgi?id=KMIA&pl=none&yy=05&mm=08&dd=24&hh=00&pt=parcel&size=640x480
This produces something that looks like a text file in the browser, as well as in source, but contains 2 lines of extra HTML tags, ending in a "PRE" tag, upfront.

Just download this file, for example with LWP, and you're ready to start parsing. 

use LWP::Simple;
getstore('http://vortex.plymouth.edu/cgi-bin/gen_uacalplt-u.cgi?id=KMI
+A&pl=none&yy=05&mm=08&dd=24&hh=00&pt=parcel&size=640x480', 'preKatrin
+aData.txt');

[download]

In reply to Re: Screen scraper by bart
in thread Screen scraper by MKevin

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.