UK air traffic control organisation Nats has issued an aviation warning for a "sleigh powered by eight reindeer" transiting across the skies.
Nats warned pilots to also be alert for a possible ninth reindeer “with a special red air navigation light in the case of heavy snow fall”.
Craft should be particularly "vigilant" when transiting areas with high concentration of chimneys, it said in the "Christmas present delivery" alert issued to pilots and airlines. Aeroplanes flying later in the night should be aware there may be erratic movements as "festive drink is undertaken by the pilot of the sleigh", it said. Read the note at nats.aero It has published a video showing radar footage of the path taken by Santa Claus last year.
Conditions for Santa's arrival in Ireland at about 8pm tonight are forecast to be good. Met Éireann has forecast a cold, dry night with fresh westerly winds and lowest temperatures of -1 degrees. However there is a sharp frost and icy stretches forecast, so the reindeer should take care.
Santa Claus has already begun his long journey around the world with every move being tracked by the North American Aerospace Defense Command (Norad) Santa tracker.
By 4pm Irish Time the bearded one and his team of reindeer had delivered parcels to children in much of Asia including Cambodia and North Korea. Rudolph's red nose was spotted somewhere over the Great Wall of China at about 2pm Irish Time
Norad has been following St Nicholas’s annual pilgrimage from the North Pole for more than 50 years.
According to Norad, its tradition began in 1955 after an advertisement misprinted the phone number to call Santa and put them through to Norad instead. Children who called were given updates on his location, it said.
In recent years Norad's advanced technology has been relied upon by parents, children and members of the media to track the journey around the world. See Noradsanta.org.