Forecasters: Arctic Mass to Stick Around for Most of January
As the new year has brought steep mercury drops in many areas of the U.S., Joe Bastardi, senior expert meteorologist for AccuWeather.com, said it is almost certain that for many people it's going to be the coldest 20-day period experienced since the winter of 1996.
"This is not unexpected," Bastardi told NGI. "It's the same kind of thing that Accuweather predicted in early December. We told people that in January the cold was going to come in big time. Worst case scenario, we are looking at some of the coldest weather in 10 years coming into the United States. It could rival 1994.
"Overall, we are probably looking at some of the coldest 10-day periods down the road here since the winter of 1996 for areas east of the Rockies," Bastardi continued. "Our forecasts stressed how erratic and how wild the swings would be in the weather this winter. The forecasted numbers that we came up with, which were a bit below normal in the East and a bit above normal in the Southwest, were by way of wider than average swings in the weather. It is something that we better get used to because this is the way the weather is going to run a lot of the time over the next 10-15 years because of the overall pattern in the Pacific and the Atlantic."
Bastardi, who had forecast that a sustained arctic sweep would hit last week, acknowledged that he was off by a week. He said that this is the same kind of pattern that hit at the start of December, but he noted that a January version is bigger, stronger and tends to last longer overall. The December cold spell was centered on the eastern seaboard, but the January chill will be centered further west around the Ohio Valley. "While the East may be as cold as it was [in December's chill], further west is going to be even colder this time.
"When you total things up from the period of Jan. 5 to Jan. 25 from the Rockies eastward, most people will be quite a bit below normal," Bastardi said. "By that, I mean on average 2-4 [degrees below normal], and there will probably be some people with 20-day means as much as 5-6 [degrees] below normal on the west slopes of the Appalachian, the Ohio Valley, the Lakes, all of the way down to Florida.
"Despite times when it gets milder, despite the fact that there can be three to four days where it goes above normal in Chicago, when the cold air comes back, it will come back every bit as strong and perhaps stronger than what we are seeing now," Bastardi said. "Also of concern to me is the possibility of citrus freezes in the deep South Texas and Florida before we can break out of this regime later in the month to early February."
Backing up the cold push forecast, Weather 2000 noted that "the intense post-New Year's wave of arctic air entering the U.S., commenced on cue this past Sunday with impressive results." The New York-based consulting and forecasting group noted that although the Houston area got struck again Tuesday morning with freezing temperatures and wind chills below 20, "this wave was never supposed to make headline news for the Deep South, nor will it."
The group added that temperatures will in fact be below normal for the South this week, but the coldest regions will be well north of the Gulf Coast States. "This wave is by far the most severe and widespread cold the contiguous U.S. has witnessed this season (both in terms of actual temperatures and anomalies)," Weather 2000 said in a Tuesday update. "An incredible 22 states had temperatures below 0°F this morning!"
While the West was walloped at the start of this cold air mass incursion, Weather 2000 forecasters expect "solid ridging" will soon establish itself once again across the western-third of the nation after another few waves of cold air this month.
Looking down the road in the 10+ day timeframe for the U.S., Weather 2000 said there is the potential for more cold bursts, noting that there "is still frigid air this year (largely locked up in Central Canada) which is cold enough to make this week's temperatures look like child's play."
While the second half of January is still too difficult to predict, Weather 2000 said that in the short-term the country can expect more of the same, with the chilliest air slowly progressing east this week, followed by some reinforcing shots and short-waves next week. While bitter cold temperatures never last long, the group warned that "warm-up" predictions for the upper-Midwest are may be overdone by models and other forecasters not incorporating snow-pack effects.
In WSI Corp.'s forecast, which was released Monday night, the company's January outlook called for cooler-than-normal temperatures in most of the eastern two-thirds of the U.S., with coolest temperatures, relative to normal, expected from the Central Plains to the Southeast (see Daily GPI, Jan. 6). The forecast calls for warmer-than-normal temperatures in California, Southwest, Pacific Northwest, and northern New England, with the largest positive temperature anomalies expected in the Southwest.