Mike's Weather Blog Archive: November 2009

Two decent storms have hit Denver and left behind quite a bit of snow over the past six weeks, and if trends are any indication of what's to hold, we may see a smiliar pattern set up again in late winter/early Spring. These early storms are typical for an El Niño pattern which we are seeing right now.

El Niño, a warming event of the tropical Pacific Ocean that affects weather patterns in the United States and elsewhere, has strengthened in recent months and already appears to have influenced Colorado’s fall weather, says Klaus Wolter, an atmospheric scientist with the University of Colorado at Boulder and the National Oceanic and Atmospheric Administration.

“Four of the last five El Niños have had a snowy October here on the Front Range of Colorado,” said Wolter. “In general, it tends to be wetter than average in the fall season -- September through November -- from Arizona through New Mexico and Colorado into the high plains.”

"The La Niña event of 2007-09 was replaced by weak-to-moderate El Niño conditions by last June, only to stagnate at this level through September. A secondary growth spurt in October elevated this event to borderline strong conditions. Given its present size, El Niño conditions will continue right through the winter season, and potentially into next spring", according to Wolter.

Wolter also added, "the last month has brought above-average moisture to the eastern plains of Colorado, including the anticipated significant snow storm to the northern Front Range in late October. The rest of the interior southwestern U.S. has remained mostly dry this fall season, in particular over Arizona. After a mild and dry Thanksgiving, this weekend should see a return of cold and somewhat unsettled weather for much of the interior southwestern U.S., especially over Colorado and New Mexico."

The middle part of the winter season may turn quite a bit drier. Wolter states, "my experimental forecast guidance for the late winter season (January-March) continues dry for Arizona, in stark contrast to typical El Niño outcomes. Colorado and Utah are also covered by a generally dry forecast well beyond the El Niño-typical winter dryness for higher elevations of northern and central Colorado. On the other hand, the forecast for eastern New Mexico remains wet, consistent with El Niño expectations."

When the fall turns into the middle of winter, the storm track shifts and usually leads to fewer storms across the region. While this doesn't sound like great news, it doesn't mean the ski areas will not see snow at all. It just means the storms will be fewer. Not happy news if you're a snow person, especially in the mountains. Ski resorts at the higher elevations typically have drier winters during El Niño. The storms that do hit will be hard hitters, but they won't be frequent enough to give out as many powder days.

But there is a silver lining to this, said Wolter. While chances are that the state will have fewer snowstorms, temperatures will tend to hover closer to normal and there should be fewer windstorms, especially along the Front Range.

“An El Niño doesn’t mean you can’t get a windstorm, it just means you don’t get high wind speeds like 60 miles per hour for days on end,” he said.

As winter comes to a close, the storm track moves back into a favorable area to bring hard hitting snows back to the region, including the front range. The resorts east of the divide will tend to have a much wetter Spring as well. In fact, the big storms of 1997 and 2003 both occured during El Niño years, along with the Christmas blizzards of 1982 and 2006 which were rare given the normally dry mid-winter setting. And of course, this year's El Niño gave us the two-footer back in October.

According to Wolter, "the bottomline - the fledgling El Niño of 2009 has gained noticeable strength since early October, entering the upcoming winter season with at least moderate strength. My outlook for the winter season has remained surprisingly pessimistic for Arizona and southern Colorado in particular, where many previous El Niño seasons have brought wetter-than-average winters. Since forecasts for both states have shown marginal skill in the last decade, the more typical El Niño-related wetness is still in the cards."

If you would like to read more about Klaus Wolter's research, you can go to this website:Web site for CIRES Climate Diagnostics Center NOAA-ESRL

"Storm Chasers" on the Discovery Channel continues this Sunday with the fifth episode of season 3 and once again will feature Denver-based storm chasers Tim Samaras and Tony Laubach. Tim heads up the research team, TWISTEX, and will continue to be featured every Sunday through November on "Storm Chasers"

This week's episodes will feature one of TWISTEX's shining moments in southwest Kansas. The show will also have Colorado ties and should feature clips from the Southlands Mall tornado earlier this year as the Denver-based group was out chasing in Missouri. 7News Meteorologist Chris Spears may also get a cameo in the episode as well, so its definitely worth watching this Sunday!

The episode will air this Sunday on the Discovery Channel at 8pm MT. This is the fifth of eight episodes in this series that will air through the first weekend in December.

DO NOT MISS THE COLORADO ENVIRONMENTAL FILM FESTIVAL!

If you're passionate about the environment and love watching films, check out the fourth Annual Colorado Environmental Film Festival, running from Nov. 5 to 7 at the American Mountaineering Center in Golden.

The festival will also include a mix of films showing audiences where oil comes from and explaining where old televisions, computers or cell phones end up. TAPPED, a noteworthy film, will show the future of our precious water resources for Colorado's landscape and the livelihoods of landowners.

In all, two dozen films will be shown during the four-day event.

On Saturday filmmakers will answer audience questions about their films and explain what it takes to produce an environmental film. There will also be a silent auction during the festival, where patrons can bid on some of the DVD versions of the films and other environmentally friendly items.

Over the weekend, many organizations will be at the festival with information on the environment, including Project Learning Tree, the International Center for Appropriate and Sustainable Technology, Colorado Mountain Club, the U.S. Forest Service and Colorado State Forest Service.

There is also fun for the kids on Saturday from 11 a.m. to 1 p.m. There will be activities available to teach kids about renewable and nonrenewable energy sources.

The festival will also hold a free recycling event of electronics, such as PCs, cell phones, fax machines, printers, microwaves and anything with a circuit board. Monitors can be recycled for an $8 fee, televisions for $10 to $25. The recycling event will be held Saturday, Nov. 7 from 11 a.m. to 2 p.m. at the Mountaineering Center.

If you would like to purchase tickets and download a schedule with brief synopsis of each film, go to: the Web site for Colorado Environmental Film Festival 2009.