Replace “Howdy” in Admin Bar

Use this function to replace “Howdy, $username” with “Welcome, $username”:

    function howdy_message($translated_text, $text, $domain) {  
        $new_message = str_replace('Howdy', 'Welcome', $text);  
        return $new_message;  
    }  
    add_filter('gettext', 'howdy_message', 10, 3);

Thanks to Thoriq Firdaus! Replayed from: http://www.hongkiat.com/blog/wordpress-howdy-customized/, where you’ll also find a clever function to customize the message for special occasions.