February 22, 2009

What are the causes of mid-winter warm-ups?

Warm temperatures in the middle of winter are certainly not unheard-of in Colorado. There are many causes for an increase in temperature, even during the cold season. For this week in particular, there are a couple of factors contributing to our upcoming bout of spring-like weather.

To figure out exactly what is going on, meteorologists usually start by looking at mid-level wind patterns. The air flow around 18,000 feet can tell us quite a bit about the overall weather conditions to be expected. Right now, the mid-level wind flow over Colorado is generally from a west-northwest direction. If you notice our weather maps, there is quite a bit of moisture in the air to our west. So why isn't this moisture making it down to Denver? In a westerly mid-level flow, the air must rise over the Continental Divide. When air rises, the moisture condenses out of it because air cools as it rises due to a decrease in pressure. So, the moisture is being wrung out. Then the drier air descends down the eastern slope. Descending air increases in temperature due to higher pressures at lower elevations. Now the air is not only dry, it's warm too.

Another factor to look at is the pressure field over Colorado. We are under the influence of a high-pressure ridge. High pressure simply means that the air is sinking, causing the pressure to increase. It's very difficlut for clouds to form under such conditions. Again, this is because air warms as it sinks. Warmer air holds more moisture, so we don't usually get clouds or precipitation while under high pressure. We did have some clouds over the Denver area today, but these were mainly due to the strong mid-level winds, blowing cloud material off the mountains and over the Front Range.

Most of our Front Range heavy snow events come when the wind flow is from the east or southeast. Until the general west-to-east pattern changes, we can expect dry and above-average temperatures. Even though we're below-average in precipitation, we don't hear too many people complaining about the warmer weather! Enjoy a "taste of spring" this week!

February 16, 2009

February has been quiet and dry month so far in the Denver area and that trend does not look to change much in the near future. The Front Range has had only a trace of precipitation on three seperate days this month, amounting to just a trace for the month at DIA. Some areas along the I-25 Corridor have had better luck, with a few spots getting about 6 inches of snow so far. The average amount of snow fall is 6.3 inches for Denver in February. On average February is one of the driest months of the year in Denver and across the eastern plains.

The mountains have been better off as recent storms have continued to deposit a nice mantle of snow over most of the high country. The average snowpack is currently about 110% of normal in our mountains. That is great news for skiers, but also for our spring and summer water supply.

As the month of February transitions into March, we should see more precipitation that eastern Colorado desperately needs. As we move toward the spring time months weather patterns become more active for our area. In 2003, eastern Colorado was in a very similar type pattern and Mother Nature delivered that big blizzard that virtually filled the reservoirs that spring and summer.

Over the next 4 weeks, the Pacific Northwest looks to be cooler than average with above average precipitation. Across the southern states and the Southwest, temperatures are suppose to be above normal with below average precipitation. Colorado is expecting average temperatures and precipitation from now through the middle of March.

February 13, 2009

Snow and cold greeted Coloradans on this Friday the 13th. A fast moving storm system raced over the state last night and brought a quick burst of snow to the region. Snow fell heavily in the mountains, adding another 4-8 inches of powder to the slopes for the Presidents Day Weekend.

On the plains, the snow has been lighter over the I-25 Corridor, but still enough to slow traffic. The northeast corner of the state has had the brunt of this storm, with four to six inches of snow. Travel will be slick over the I-76 route and then east across Nebraska on I-80.

This storm will be long gone by this evening as it zips east into the Mississippi Valley. Behind the storm, another fast moving system will sweep into the state on Saturday. This storm will be weaker and will bring a few inches of snow to the mountains and some flurries to the eastern plains for Saturday.

There will be a stronger storm spinning off the West Coast late this weekend and early in the next week. The storm will probably stay off the coast, but it will push plenty of moisture into California. We will be watching this system carefully for next week. If it breaks free from the eastern Pacific and heads our way, it could pack a pretty good punch.

February 12, 2009

As an early out break of servere weather ripped across Oklahoma on Tuesday it reminds us that the annual National Storm Chaser Convention is coming to town this weekend!

The National Storm Chaser convention is a great experince for weather enthusiast to get together of all different forms. The worlds best storms chasers will be there sharing their experiences along with videos and pictures.

This event is for everyone. Chasing one of natures most beautiful and devastating wonders is very dangerous if you are unfamiliar with storms tendencies. This convention will give you the chance to get up close and personal and see what it is like to chase a storm from the eyes of some of the greatest chasers in the world.

The convention runs from the 13-15th, at the Red Lion Hotel at I-225 and Parker Road . The festivities kick off Friday night with the ice-breaker, then the conference talks and video presentations get rolling Saturday morning.

For more information, including registration information, check out the convention website! All the information, speaker bios, and agenda can be found there!

This is a must attend event for anyone with an intrest in server storms. Here are a few websites related to storm chasing with our very best local chasers.

Tony Laubach

Roger Hill

Tim Samaras

Verne Carlson

February 10, 2009

As the snow showers came to end across the Front Range Tuesday evening, the severe weather roared across Texas, Oklahoma, and Kansas. The severe outbreak that affected eastern New Mexico and western Texas Sunday into Monday shifted to the east on Tuesday. There were several tornadoes confirmed near Oklahoma City with damage near Edmond and at least eight fatalities in the town of Lone Grove.

Stormchasers were on the Oklahoma storms, getting up close video of the twisters. These same chasers will make a stop in Denver this weekend for the National Storm Chasers Convention.

Tornado chasing can be an awesome experience, but you had better know what you are doing. If you have ever wanted to know what it is like to get "up close and personal" with one of Nature's most extreme forces, here is your chance!

The National Storm Chasers Convention is in Denver this weekend and it offers you a chance to learn from the best. This is the premiere storm chasing event in the nation and it is one that you do not want to miss.

Chasing tornadoes can be dangerous, especially if you do not know what part of the storm is the most severe. You can also waste plenty of time and gasoline and never see a twister if you do not know where to go when the severe weather is developing.

Storm chasers from all over the world will be bringing their best videos, close encounters and amazing stories of tornado and hurricane chases. You can attend and meet some of the people who travel all over the globe in pursuit of the meanest and most dangerous weather!

The National Storm Chasers Convention will be held on February 13-15th, at the Red Lion Hotel at I-225 and Parker Road . The festivities kick off Friday night with the ice-breaker, then the conference talks and video presentations get rolling Saturday morning.

Last year was one of the biggest years on record for twisters in the United States, with over 1,600 tornadoes reported. Get up close and personal with these awesome storms and learn from the experts how to successfully chase these storms - and live to tell about it!

The speakers include some of the biggest names in storm chasing, as well as some of the brightest severe weather minds! Definitely worth-while for anyone who enjoys a good storm! This is a once-a-year event and your chance to meet the severe weather experts featured in shows like "Storm Chasers" on the Discovery Channel and in articles in National Geographic.

For more information, including registration information, check out the convention website! All the information, speaker bios, and agenda can be found there!

If storm chasing and tornadoes are of interest to you, this is an event you do NOT want to miss! In the meantime, you can check out the websites of several local storm chasers that will be at the convention!

Tony Laubach

Roger Hill

Tim Samaras

Verne Carlson