It’s looking to be an El Niño-dominated winter across much of the U.S., as the truly impressive event this year makes forecasters more confident that the climate phenomenon’s impacts will show up this coming season. In its monthly update of the seasonal outlook, National Oceanic and Atmospheric Administration forecasters on Thursday held steadyMore
Forget a white fir or Norway spruce for your Christmas tree. A palm tree might be a more apt as warm weather is forecast for a large part of the U.S. to start December.
Every state will see increased odds for warmer-than-normal temperatures over the first two weeks of December, according to the National Weather Service. And yes, Canada will be getting in on the action, too, according to Environment Canada. In the Northeast and Upper Midwest, there’s an 80 percent chance conditions will be warmer than normal during the second week of December.
The trend is likely to continue throughout the month for much of the northern half of the U.S. and parts of Canada, though the southern tier of the U.S. is likely to see temperatures closer to normal to wrap the month. WSI meteorologist Michael Ventrice said in a blog post that there could be “historic warmth” in some areas, with temperatures running 4-5°F above normal. That won’t make it beach weather in Minneapolis, but it’s certainly mild enough to cut down on heating bills.
Canada is likely to be even toastier. Temperatures could be 10-15°F above normal in Ontario, Quebec and Manitoba (still not warm enough to lounge on the shores of Hudson Bay, though). That doesn't mean there won't be a few cold spells or a snowstorm, just that mild temperatures are likely to be the prevailing pattern.
The warmth is yet another sign of El Niño’s growing influence on weather. The pool of warm water in the eastern and central tropical Pacific has downstream impacts on weather in the U.S. and Canada, particularly during the winter.
El Niño increases the chances of a ridge of high pressure forming over northern U.S. and southern Canada. That in turn can help drive up temperatures. This year’s El Niño is shaping up to be one of the strongest on record — and the strongest by one measure — so these types of impacts aren’t necessarily a surprise, though the potential for record-setting heat is certainly notable.
Global warming has also raised background temperatures, making record-setting heat more common. The average winter temperature in the U.S. has risen 2.5°F since 1970. Northern states have warmed faster than that, with Minnesota leading the pack as the fastest warming state. Winter temperatures have risen 4.5°F since 1970, nearly double the national average.
The hot end to the year in North America comes at the tail end of what is the hottest year on record globally. This year’s record heat is almost entirely the product of manmade greenhouse gases, according to a Climate Central analysis.