In late January of last year, a warm weather system travelled from the coast across western Canada. On January 25th, the city of Calgary, Alberta experienced its warmest January day since records began, with the temperature topping 17 °C! That same day, Cranbook, B.C. was also unusually warm, but temperatures only reach 10 °C.

Name and briefly explain weather phenomenon might explain the difference in high temperatures reached in Cranbrook and Calgary. To answer the question, you may wish to consult a map and do some external research.