From sizzle to snow
September 8, 2012
EAGLE COUNTY – Congratulations, you just lived through one of the hottest summers in at least six decades.
That’s pretty much over because we’re in for chilly fall temperatures and some early snow, says AccuWeather, the national weather tracking service.
While cold air may be slow in coming to areas farther east in the nation, cold shots will have no problem reaching the Rockies, said meteorologist Paul Pastelok.
“I think there will be some early cold outbreaks over the central and northern Rockies, especially. I think that where the winter season is going to start much quicker,” Pastelok said.
It could mean an early kick start to the ski season in the Rockies, Pastelok said.
Temperatures are expected to average 1-2 degrees below normal for the northern Rockies this fall.
As the jet stream shifts, the Four Corners region could get snow before anyone, as soon as early to mid-October, Pastelok said.
The central and southern Rockies may be a hot spot for snow by the middle of the season.
Steven Root is a meteorologist and president and CEO of WeatherBank, Inc., and keeps track of things like weather patterns. He has been examining hourly and daily temperatures in 59 hub cities dating back to Jan. 1, 1950.
Root chose 1950 as his starting point because so many reporting stations in the U.S. and southern Canada began recording hourly temperature data that year.
This is where Root starts computing cooling degree days for each of those 59 cities during air conditioning season, May 15-Sept. 15. Cooling degree days are the number of degrees that a day’s average temperature is above 65 degrees.
Root estimates that by the middle of this month, we’ll have 59,484 cooling degree days. That makes it the third hottest summer since 1950, Root said.
Last year was the hottest summer when those 59 cities had 60,402 cooling degree days, Root said. The second hottest was 1951 with 60,078 cooling degree days.
The coolest summer was 1965 with 43,337 cooling degree days.
The National Oceanic and Atmospheric Administration’s 30-year average is 53,933 cooling degree days.
In the U.S., seven out of the last 10 summers have been hotter than the 62-year average. In the 1960s and 1970s, seven of 10 summers were cooler than NOAA’s 30-year average.
The 1980s and 1990s were a 50/50 split, half warmer and half cooler.
Pastelok says while it’ll likely be cooler in the Rockies in autumn, the rest of the nation could be warmer than normal.
Since the soil is still warm from summer, another heat wave would push 2012 to No. 1 in the heat parade, Pastelok said.
“While cooler and potentially wetter conditions are projected to expand in the West, the most extreme warmth, relative to normal, could be forced out of the Plains and take root in the Great Lakes and Northeast, during September and October,” Pastelok said.