Email me when it's more than 30% likely to rain soon... Pop it into cron once daily and forget. A simple and practical example of working with NOAA/weather.com DWML feeds in PHP

gistfile1.php

<?php

$email = "me@example.com";

// To find your weather feed....
// * Go here: http://forecast.weather.gov/MapClick.php?lat=37.7749295&lon=-122.41941550000001#.UdpHAj7714E
// * Search for your location (upper left side of the page as of 7/7/2013)
// * Click the orange "XML" button/link (on the right hand side, beneath the first map as of the same date)
$feed = 'http://forecast.weather.gov/MapClick.php?lat=39.01000&lon=-96.28&unit=0&lg=english&FcstType=dwml';

// Times are relative so it doesn't matter what you put here...
// this is mainly in case you get warnings about TZ settings
date_default_timezone_set("UTC");

// Ugly hack to give me a more or less simple native data structure to work with. Because I wanted something
// now more than something perfect... For this kind of toy one hour project...
$data = json_decode( json_encode( simplexml_load_file( $feed ) ) );

$time_layouts = array();

foreach( $data->data[0]->{"time-layout"} as &$layout )
  $time_layouts[$layout->{"layout-key"}] = $layout;

$pop = $data->data[0]->{"parameters"}->{"probability-of-precipitation"};
$pop_time_layout = $pop->{"@attributes"}->{"time-layout"};
$likely = 0;
$report = "";
foreach( $pop->{"value"} as $idx => $val ) {
  $ts = strtotime( $time_layouts[$pop_time_layout]->{"start-valid-time"}[$idx] );
	if ( ( intval( date( "H", $ts ) ) - 12 ) < 0 )
		$tod = "AM";
	else
		$tod = "PM";
	if ( !is_string( $val ) )
		$this_pop = 0;
	else
		$this_pop = intval( $val );
	if ( $this_pop > 30 )
		$likely++;
	$report .= sprintf(
		"%10s %s, %s %2d %3d%%\n",
		date( "l", $ts ),
		$tod,
		date( "M", $ts ),
		date( "j", $ts ),
		$this_pop
	);
}
if ( $likely ) {
	mail(
		$email,
		'Looks like rain...',
		sprintf(
			"<a href='%s'>Details</a><br/><pre>%s</pre>",
			sprintf(
				"http://forecast.weather.gov/MapClick.php?lat=%s&lon=%s",
				$data->{"data"}[0]->location->point->{"@attributes"}->latitude,
				$data->{"data"}[0]->location->point->{"@attributes"}->longitude
			),
			$report
		),
		"Content-type: text/html; charset=utf8"
	);
}