There is something strange going on .. I see the changes you made to the source, but that wouldn't change how it works (or doesn't work at present).
I ran my script with ?cache=refresh to force a cache reload and the view-source of the page showed the expected
<!-- atom-advisory.php - atom-advisory.php - V2.09 05-Nov-2011 -->
<!-- getting new file from http://alerts.weather.gov/cap/wwaatmget.php?x=NJZ013 -->
<!-- CURL GET /cap/wwaatmget.php?x=NJZ013 HTTP/1.1 Host: alerts.weather.gov -->
<!-- Time to fetch: 0.266 sec -->
<!-- cache saved to ./atom-advisory-NJZ013.txt -->
<p>There are no active watches, warnings or advisories for Western Monmouth (New Jersey).</p><!-- zone=NJZ013 -->
Doing the same with your script on your server returns just
If no warnings are listed, try selecting "Monmouth County" or "Ocean County".<p>Advisory Information Unavailable, error fetching or reading data from the <a href="http://alerts.weather.gov/cap/wwaatmget.php?x=NJZ013">NOAA advisories server.</a></p>
<!-- zone=NJZ013 -->
with none of the other debug stuff.
Trying your code on my server with ?cache=refresh shows
<!-- wxadvisory-johnn.php - atom-advisory.php - V2.09 05-Nov-2011 -->
<!-- getting new file from http://alerts.weather.gov/cap/wwaatmget.php?x=NJZ013 -->
<!-- CURL GET /cap/wwaatmget.php?x=NJZ013 HTTP/1.1 Host: alerts.weather.gov -->
<!-- Time to fetch: 0.276 sec -->
<!-- cache saved to ./atom-advisory-NJZ013.txt -->
<p>There are no active watches, warnings or advisories for Western Monmouth (New Jersey).</p><!-- zone=NJZ013 -->
So I'm suspecting that the problem is with cURL on your webserver (either not installed, or not configured to allow HTTP access).
You can change the line
if (!function_exists('curl_init')) {
to
if (true or !function_exists('curl_init')) {
to force the script to use the built-in function to retrieve the data (and not use cURL).
See if that works for you...
Best regards,
Ken