It could be that the default version of PHP when run as ‘php -q /root/personal/public_html/nws-alerts.php > nws-alerts-status.txt 2>&1’ in cron is actually PHP 5.2 (or even PHP 4.x). Check your server for a link to PHP 5.3+ and include it in the path.
On my 1and1 shared server I had to use ‘/usr/bin/php5.5’ as the command in cron to get the correct PHP version running.