Warmest Christmas Week in Living Memory Possible as 'Blowtorch' Weather Pattern Likely in the East, Midwest

December 18,2015
There is growing confidence that the widespread warmth we've seen so far this December will also dominate much of Christmas week in the eastern half of the United States. Depending on how long the mild weather pattern holds on, next Friday could be the warmest Christmas Day of your lifetime, particularly if you live in one of the East Coast states.
This mild forecast means the prospect for a white Christmas is highly unlikely for many of those states.
(MORE: White Christmas Forecast)
Meteorologists sometimes jokingly refer to the type of warm weather pattern we have seen recently, and the one coming next week, as a "blowtorch" in social media. The term may be a reference to weather maps showing temperatures compared to normal; these patterns tend to resemble a large red or white scorch mark surrounded by shades of orange and yellow, as if a giant blowtorch had been pointed at the Earth.
Of course, the actual cause is not a blowtorch but a weather pattern that keeps typical winter chill at bay and holds air from the Pacific or the tropics over the mainland United States.
The current warm weather pattern in the East has come to an end as a cooldown has arrived in time for the weekend. However, computer model forecast guidance is giving us a strong signal that widespread unseasonable warmth will return for much of Christmas week in most areas east of the Rockies. This could add to the more than 2,400 daily record high temperatures that have been tied or broken across the Lower 48 in the first 16 days of the month.

Atmospheric Pattern Christmas Week

Below we have a look at the forecast, followed by perspective on how warm this December has been so far.

Forecast: A Brief Cooldown First

There will be a brief interruption in the December warm spell over the central and eastern U.S. that will continue into this weekend as chillier air dives south and east in the wake of Winter Storm Echo.
(MORE: Forecast Temperature Maps)
Temperatures will remain near average through the weekend in the eastern third of the nation, with even some snow possible in the interior Northeast, including some of the Great Lakes snowbelts, and central Appalachians.
However, the return of abnormal warmth will start to build in the nation's midsection Saturday. This leads us back into the "blowtorch" weather pattern that will return for Christmas week.

Next Week: Warm Weather Pattern Returns

The warmer than average temperatures will initially start to build back into parts of the Plains and Midwest Saturday into Sunday. Highs Sunday could be 10 to 20 degrees above average from Texas to parts of Minnesota, Wisconsin and Michigan.
This mild air will continue to build east, with most areas from the southern Plains to the East Coast 10 to 20 degrees above average by Tuesday.
(Forecast: Chicago | Boston | New York)
Though the intensity of the above-average warmth may fluctuate each day, most locations in the central and eastern states will see temperatures stay above average right through Christmas Eve or Christmas Day.

Forecast Highs Compared to Average

Confidence in this weather pattern is extremely high. NOAA's Climate Prediction Center assigned a 90 percent or greater chance of above-normal temperatures over the five-day period from Dec. 24 through Dec. 28 for the eastern third of the U.S.

6 to 10 Day Temperature Outlook

But this won't be a sunny, clear-sky type of mild weather pattern in many areas. A procession of low-pressure systems and a southerly flow of moisture from the Gulf of Mexico will bring cloud cover and periods of rain next week, potentially leading to some travel hassles at airports and on the roads.
(FORECAST: Atlanta | Dallas | Nashville)

Forecast Highs Christmas Week

However, the cloud cover will also result in unbelievably balmy nighttime temperatures for Christmas carolers, partygoers and last-minute shoppers. Low temperatures could stay more than 30 degrees above average in some areas Christmas Eve morning.
Depending on how this mild weather pattern evolves, some cities could flirt with their highest temperatures on record for Christmas Eve. Here are a few of the daily record highs that are within reach on Christmas Eve (Dec. 24) for select cities based on the current forecast:

• New York City (63 degrees in 1996)
• Washington, D.C. (69 degrees in 1933)
• Burlington, Vermont: (51 degrees in 1957)
• Raleigh (75 degrees in 1931)

We're still a week from Christmas Day and it's still somewhat unclear to what extent a brief shot of colder air in the northern tier of states may interrupt the warm spell on Christmas Day.
That said, there is the potential for Christmas morning to be incredibly mild over the eastern half of the country. By the time children tear open their gifts, temperatures may already be above normal daytime highs in many areas east of the Mississippi River.

Christmas Morning Forecast

For the rest of Christmas Day, it's not out of the question that some cities could see record high temperatures. The map below shows our current forecast high temperatures, along with the record Christmas Day highs, for selected cities.

Christmas Day Forecast Highs Compared to the Daily Record

Even if your city doesn't set a record, it could still be one of the warmest Christmas Days in your lifetime. Several cities set their Christmas record highs before the oldest human still alive had been born in 1899. A few examples:

• Pittsburgh: Christmas record high is 67 in 1895; warmest in living memory is 66 in 1982.
• Cincinnati: Christmas record high is 66 in 1893; warmest in living memory is 65 in 1932, followed by 64 in 1982.
• St. Louis: Christmas record high is 71 in 1889; warmest in living memory is 67 in 1936, followed by 66 in 1982.
• Nashville: Christmas record high is 73 in 1889; warmest in living memory is 72 last set in 1982.

You'll notice 1982 pops up on the map and list above quite often. It's probably not pure coincidence that Christmas 1982, like this Christmas, happened during a strong El Niño.
In fact, Christmas Day highs in parts of the Mid-Atlantic states and South may more closely resemble average highs around Halloween, than Christmas.
(MAPS: Monthly Average Highs & Lows)

December Record Warmth So Far

According to preliminary data from NOAA's National Centers for Environmental Information (NCEI), at least 2,475 record daily highs were tied or broken across the U.S. during the first 16 days of December, representing just over 6 percent of the roughly 40,000 daily high-temperature reports received from more than 3,000 locations. More than 3,427 additional record-warm daily low temperatures have been set during the same time period.
By comparison, just 102 daily record lows were set in the same time frame, most of which were on or before Dec. 5.

Record Temperature Tracker

Incredibly, record daily high temperatures were set during the morning hours in several Midwest and Northeast cities during the four-day period spanning Dec. 12-15.

Temperature departures from average Dec. 1-14 across the United States. Dark brown shaded locations have seen temperatures eight or more degrees above average.
(NOAA/CPC)

The overall average temperatures (highs and lows averaged together) during the first 14 days of December were 8 to 14 degrees above average for a large swath of the country, stretching from the Midwest into parts of New England and the mid-South, according to an analysis by NOAA's Climate Prediction Center. This is incredible considering the upper limit of the legend used on the graphic is eight degrees.

Why Will it Be So Warm Christmas Week?

After a southward dip in the jet stream accompanied by cooler air moves through the East into Saturday, it will quickly build back north across the eastern half of the nation and allow the widespread mild air to return. This lifting of the jet stream back to the north will be in response to a southward dip in the jet stream sweeping into the West.
Meanwhile, the clockwise flow around high pressure in the western Atlantic will allow southerly surface winds to dominate the East next week, pumping warm air from the tropics northward. Southerly winds ahead of a couple of low-pressure systems moving across the country next week will also help pump in the mild, moist air from the south.
Computer forecast models are still resolving the details regarding a shot of slightly cooler air Wednesday into Thursday in the nation's northern tier, specifically, how far south it reaches and how quickly it retreats by Christmas Day.
Either way, temperatures are unlikely to get much below freezing in most areas outside of the Upper Midwest east of the Mississippi River on Christmas Day, even in the morning and late evening.

MORE: Christmas Destinations