if you wanted to do an automated msg with the cat name you would do something like this.
Code:
<?php if (is_category() && !is_paged()) { ?>
<?php $catid = get_query_var('cat'); ?>
<?php $catname = get_cat_name($catid);?>
<div class="message">
welcome to the archives for <?php echo $catname;?>
</div>
<?php } ?>