How could a warm water Pacific typhoon that started near the Philippines travel 7,000 miles (12,000km) and drop temperatures to minus 27°F in Casper, Wyoming one week later?
Super Typhoon Nuri started on October 31, 2014, as a tropical depression in the warm waters of the Pacific east of the Philippine Islands. By November 2 it had blossomed into one of the most powerful typhoons of 2014 with sustained winds of 180 mph (300km/h). Fortunately, Nuri did not make landfall in either the Philippines or Japan as it traveled northeast, but did kick up high surf. Waves up to 16 ft (5m) hit Japan’s eastern shoreline.
Three days later, on November 5, 2014, Nuri had been downgraded to a tropical storm, phasing from a warm core tropical system to a cold core post tropical system. It had traveled north far enough to be picked up by the jet stream and regenerated into a powerful post tropical cyclone over the Bering Sea southwest of Alaska, with winds gusting to 100 mph (170kp/h), waves cresting at 50 ft (15m) and atmospheric pressure dropping to a record low 924 millibars.
When the storm was at its height on November 7 the jet stream weakened and super cold air from Siberia and the North Pole flooded into the remnants of Nuri. At the same time, high pressure set in over Alaska on one side and northwest Canada on the other, creating a direct pipeline for the newly formed Polar Express to sweep through Canada and down into the Midwestern section of the US, bringing freezing weather from the Rocky Mountains to the Ohio Valley.
Livingston, Montana dipped to minus 21°F and Denver to minus 14°F, the coldest November day since 1880. Texas and the Plains states saw daytime highs in the twenties (F), and in the Ohio Valley daytime highs dropped into the thirties. A new blast of polar air is expected in the same area the week of November 17.
Often we think of weather as a localized phenomenon. Will it rain or snow here? Will the sun shine tomorrow? But Typhoon Nuri’s journey demonstrates quite clearly that weather is a product of massive global forces that have no regard for manmade borders or schedules.