By Tom Skilling
The smoke of distant wildfires, many ignited by lightning and feeding on bettle-kill trees across British Columbia, the Yukon and sections of Interior Alaska, are playing a role in generating the spectacular sunrises and sunsets visible in recent days across the Chicago area. Sunlight is composed of a mix of colors. Smoke and particulates have the effect of screening out the blue end of the color spectrum allowing just the orange and yellow colored rays to pass through.
A satellite analysis generated Thursday by NOAA's National Environmental Satellite, Data and Information Service (NESDIS), revealed a swath of wildfire smoke extending southeastward nearly 3,200 miles from the Canada/Alaska border into northern Indiana and east to western Quebec Canada. Estimates put the number of wildfires contributing to the plume at 300 in western Canada's British Columbia, a handful in the Yukon and 36 in Interior Alaska.
2010's first air quality advisories were issued for the Vancouver metro area on the country's southwest coast as smoke from the Canadian fires rode northeast winds into that area, extending into the Seattle area of the Pacific Northwest as well.
Temperatures in recent days have flirted with 90-degrees in the Yukon Territory and well into the 80s in Interior Alaska. The arrival of clouds and rains in Alaska Thursday dropped temperatures.
It's not uncommon for thunderstorms to bubble up across Alaska and northwest Canada in the nearly continuous sunlight which showers down on North America's arctic regions in summer. All the sun destabilizes the atmosphere there quickly because of the impressive daytime heating which results. The lightning which follows is often responsible for igniting wildfires there.
Sunrise over DeKalb courtesy of Chuck Hagen: Here's a shot looking northeast as the sun came up over DeKalb this
morning, but to the southwest, the sky took on a much angrier look.
Wildfires in Russia turn deadly and even more numerous as record heat and drought continue
Smoke from wildfires hangs even more heavily over Russia---particularly western sections of the country. The region has been mired in extreme and deadly heat for over a month which has included many 90 and even some 100-degree days since the early part of July. A NASA satellite analysis indicated Thursday the smoke from nearly 520 fires across western Russia extended nearly 6 miles into the atmosphere and covered an area roughly 1,860 miles from west to east---roughly the distance from San Francisco to Chicago. A cross-polar branch of the jet stream, extending from northwest Russia across the North Pole and into Canada, may be mixing some of the Russian wildfire smoke with that originating from the wildfires burning on this continent.
Strengthening equatorial Pacific La Nina likely to impact Chicago's winter; heavier than average snowfalls have occurred in 56 percent of past El Nino seasons since 1950.
NOAA climate scientists confirmed Thursday what seasonal computer forecast models have been indicating. La Nina---the cooling of equatorial Pacific between South America and Australia---is continuing. It's a trend expected to persist with global weather implications through the coming winter.
An in-house analysis of nine previous La Nina cool seasons since 1950 in Chicago suggests temperatures over the coming winter could be volatile, with odds favoring near normal December through February temperatures overall, but hinting at increased odds of above normal precipitation. Five of 9 La Nina cold seasons here over the period---56 percent of the them---have produced above average snowfall.
It's more comfortable; Chicago dew points crash to the 50s Thursday from Wednesday's 8 year high of 77-degrees!
northwest steering winds which have led to the demise---at least
temporarily---of the stormy "ring of fire" pattern, which dominated the
past week, have also transported markedly drier, less humid air into
the Chicago area. The moisture content here Thursday was just shy of
half what it had been only a day earlier: 1.08 inches Thursday versus.
1.87 Wednesday. Dew points, which gauge the atmosphere's water content,
plummeted 20-degrees off Wednesday's Amazon River Valley-level
77-degrees---the highest dew point reading here in 8 years.