'It will feel more like early fall': December heat wave to send temps soaring

Tens of millions of Americans are set to spend the final days of fall basking in a December heat wave that will send temperatures soaring as high as 30 or even 40 degrees Fahrenheit above normal in the days ahead.

Even though Old Man Winter was alive and well in the western United States and parts of the northern Plains on Friday, where significant snow fell to close out last week, his visit to most of those places will end abruptly, and unseasonably warm weather will envelop much of the eastern two-thirds of the nation in the days leading up to Christmas, AccuWeather meteorologists say.

"It will feel more like early fall across the Central states this week," Accuweather Meteorologist Nicole LoBiondo said.

Temperatures more typical of October and September are expected to flourish over much of the nation's midsection this week. Even in many areas that were buried by snow over the northern Plains and Upper Midwest, that snow will rapidly melt away this week as temperatures surge into the 50s, 60s, 70s and even the 80s F, or 20-40 degrees above average for the middle of December.

Skiing enthusiasts may want to hit the slopes before the snow melts away in the central Appalachians and Upper Midwest or before ideal snow-making conditions slip away in the coming days. Some resorts may find it a challenge to stay ahead of rising temperatures during the day and mild air at night.

The warmup this week may even surpass unusually warm levels last Thursday and Friday over the Central states and on Saturday in the East, making for an all-out December heat wave, which the National Weather Service (NWS) defines as a period of abnormally hot weather generally lasting more than two days. In addition, the unusual December heat might give some a break on the need for indoor heating in what is typically a chilly, if not downright cold, time of year.

Temperatures in northern Nebraska, southern Minnesota and central Wisconsin, all of which received significant snow to close out last week, are forecast to climb into the 50s and 60s this week.

Both Des Moines, Iowa, and Omaha, Nebraska, will have a warming trend into early this week, and temperatures are forecast to peak during the middle of this week at levels never recorded before in December.

High temperatures in both Des Moines and Omaha are forecast to climb into the mid-70s this week. Other metro areas over the Central states, such as St. Louis and Kansas City, Missouri, will make a run at all-time December highs should temperatures reach the mid-70s, as AccuWeather forecasters anticipate.

On Dec. 3, that St. Louis matched its all-time high mark for the month with a 76-degree reading, a temperature first recorded on Dec. 15, 1948. The unseasonably warm weather could help the city make another run at that record.

Farther north, forecasters are calling for a high temperature in the upper 60s for Chicago on Wednesday, which would be enough to break the daily record of 64 for Dec. 15. If cool breezes coming off Lake Michigan do not intervene, temperatures could make a run at the all-time monthly high of 71 last reached on Dec. 2, 1981.

The heat wave will stretch farther south as well. Dallas is forecast to see temperatures at least 10 degrees above normal for about a week, with the height of the heat arriving on Wednesday, when the temperature could top out near 80 degrees, bringing it within striking distance of 83, the all-time high for Dec. 15 in the Big D. The all-time high December temperature in Dallas, however, appears to be safe. That record is a whopping 90 degrees reached on Dec. 30, 1951.

Even in the Eastern U.S., temperatures could even feel like late summer at times through the third week of December, the last full week of fall.

"The core of the warmth, or rounds of warmth, will be focused over the Central states, but some strong warmups will still occur east of the Appalachians as well over the next couple of weeks," AccuWeather Senior Meteorologist Brett Anderson said.

Atlantic water temperatures are above average but are still cooler than the air trying to come in from the Midwest and South. Water temperatures generally range from the 40s off New England to the 50s off the mid-Atlantic coast.

"It generally takes a stiff southwest wind to really warm things up along Eastern Seaboard, especially in the Northeast at this time of the year, but there will be some days, like Saturday, where that can happen moving forward this month," Anderson said.

High temperatures climbed well into the 50s, 60s and 70s in the Northeast on Saturday. In New York City's Central Park, the record of 64 set in 1874 was toppled when the mercury hit 66. In many other cities in the Northeast, record highs last reached several decades ago or longer were topped, including Philadelphia and Washington, D.C.

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Later this week, temperatures are again forecast to spike to well-above-average levels in the East with highs forecast to again climb well into the 50s, 60s and perhaps even the 70s. But, even the air preceding the next warm surge will bring above-average temperatures much of the time through the first part of this week with highs well into the 40s and 50s.

"The main reason for the persistent or repeating warmth is that the jet stream has retreated and will generally remain well to the north over the Central and Eastern states through at least the third week of December it seems," AccuWeather Meteorologist Brandon Buckingham said. He added that the pattern also does not bode well for those hoping for a white Christmas.

There is still some hope (for snow-lovers) that the jet stream may retreat enough to the south over the Midwest and Northeast to allow some cold air to sink southward and linger when a storm tries to come calling within a few days of Christmas.

"We are leaving the window open still for a storm to extend far enough south into the Midwest and interior Northeast in the Dec. 23-25 period from some snow or wintry mix," Buckingham said.

Still, persistent moderate weather may prevail in the Central and Eastern states much of this month.

"The indicators for significant cold air and snow for the Midwest and Northeast have backed off over the past couple of days," Buckingham explained.

"The best chances east of the Rockies may be across the northern Plains and Upper Midwest for any storm to leave an inch of snow by Christmas morning and the trend seems to be lowering odds for snow across the rest of the Midwest most of the Northeast for a white Christmas," he added.

The warm pattern and strong northerly storm track will raise some serious severe weather threats, however.

A round of severe weather could erupt near the peak of this week's warmth, and AccuWeather forecasters will be monitoring closely for that potential in the days ahead.

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