$(document).ready(function() {
    var selCity = $("select[id$='_ddlCities'] :selected").val();

    $("select[id$='_ddlCities']").change(function() {
        selCity = $("select[id$='_ddlCities'] :selected").val();

        $("#weatherFlashHolder").find(".weatherFlash").each(function() {
            if (jQuery(this).attr('id') == selCity) {
                $(this).show();
            }
            else {
                $(this).hide();
            }
        });
    });

   

});