5 }7 a1 ?. v1 `! `. r8 CA very cold Arctic airmass and winds of 15 to 20 km/h will generate wind chill values below minus 40 across much of Alberta tonight. Conditions will improve somewhat by Sunday afternoon as temperatures rise. / G8 T) X7 B3 d |7 I( y$ Y# rAt these extreme wind chill values frostbite on exposed skin may occur in less than 10 minutes. ( F$ h8 C @) I# e- p7 L