The Official Colorado Front Range Weather Thread (Denver, Colorado Springs: neighborhood, getaway)

[jazzlover]

I've studied Colorado climate for a hobby for about 30 years. According to Weather Service data, Denver has approximately 41 thunderstorm days per year (a "thunderstorm day" is counted on any day that there is audible thunder at the weather site). The number of thunderstorm days tends to decrease north of Denver until one gets near Cheyenne, Wyoming, where the higher elevation makes it increase again. Thunderstorm frequency increases south of Denver as one climbs the Palmer Divide. Colorado Springs is the most thunderstorm-prone major city in Colorado, with around 51 thunderstorm days per year.

The thunderstorm "hot spot" in Colorado is generally considered to be around Palmer Lake. Just south of Colorado, the area on the eastern slope of the Sangre de Cristo Mountains in northern New Mexico is considered the thunderstorm "hot spot" in the Rockies, with some data indicating over 100 thunderstorm days per year--though many climatologists question that figure.

Colorado thunderstorms generally occur from mid-afternoon to early evening, unlike the Midwest, where the greater frequency is at night. The storms are generally less severe and shorter-lived than the Midwest storms, and form tornadoes relatively infrequently. They can and do, however, frequently produce damaging hail. The Front Range is part of "Hail Alley," and numerous damaging hailstorms have occurred. One hailstorm, in 1990, that pounded Denver held the record for several years as the second most damaging storm in terms of dollars of damage in the US. Cheyenne, Wyoming is considered the hail capital of the US, with an average of 10 hailstorms per year.

This page ( NWS Pueblo Lightning Page ) from the Pueblo office of the National Weather Service has a lot of good lightning information.

[rgb123]

very interesting factoids! hmmm I could live with less hail and more thunder/rain but I guess no place is perfect.... I guess I never realized either that our thunderstorms happened more at night....in summer we get the afternoon ones the most too I thought, seems a pretty common occurence after a hot day. thanks!

[Joslyn]

My husband and I moved to the Denver area 10 years ago. We have lived in NY, Ill, TX, CA. We would never live anywhere other than here. It is just heavenly.

Usually when it snows, the sun comes out, people go out and shovel the light dry snow in tee shirts. The sun melts most of it anyway. The big snow that you hear about is in the mountains.

We live in Parker, a new subdivision called Idyllwilde. Absolutely LOVE our new house and this community.

Joslyn

[SheridanL]

The most beautiful sight, IMO is, when it snows with the sun out. It looks like millions of diamonds falling from the sky!!

I do on occasion, like the dark & cloudy in the middle of the day with snow...just doesn't happen very often.
Still in all......one can't beat Colorado's sleeping weather!! It always cools down just enough, even in the heat of summer! Miss That!! 12 more days until I leave the humid jungle of Florida!! YAY!!

I also can't wait to see the mountains again! They are good for things besides skiing....for instance, one always knows where "west" is!!!

[blacksmith76]

Originally Posted by Joslyn

Usually when it snows, the sun comes out, people go out and shovel the light dry snow in tee shirts. The sun melts most of it anyway. The big snow that you hear about is in the mountains.

Yeah, I just came in from shoveling in the 28 degree blowing snow. All my neighbors and me were wearing flip flops and hawaiian shirts, and there was a calypso band on the street corner playing the steel drums and selling jerk chicken because of the mild winter weather.

For those of us who didn't grow up with snow and don't like it, it still sucks!

[LBear]

Originally Posted by jazzlover

I've studied Colorado climate for a hobby for about 30 years. According to Weather Service data, Denver has approximately 41 thunderstorm days per year (a "thunderstorm day" is counted on any day that there is audible thunder at the weather site). The number of thunderstorm days tends to decrease north of Denver until one gets near Cheyenne, Wyoming, where the higher elevation makes it increase again. Thunderstorm frequency increases south of Denver as one climbs the Palmer Divide. Colorado Springs is the most thunderstorm-prone major city in Colorado, with around 51 thunderstorm days per year.

The storms are generally less severe and shorter-lived than the Midwest storms, and form tornadoes relatively infrequently. They can and do, however, frequently produce damaging hail. The Front Range is part of "Hail Alley," and numerous damaging hailstorms have occurred.

Also, TORNADO ALLEY charts from NOAA have TWO charts, each showing different locations. The first chart shows Colorado to be COMPLETELY OUT of Tornado Alley. The second shows EASTERN COLORADO to be in Tornado Alley, around the Wiggins, Limon & Fort Morgan area, and east of there.

CHART #1
CHART #2

Being in the Brighton area. I always notice that the stronger storms can be seen to the SOUTH and to the NORTHEAST of me. I would assume that would be Colorado Springs and then the Wyoming and Eastern Colorado areas.

Like today, we got maybe 1" of snow while Castle Rock got 12" of snow and Eastern Colorado got 12" of snow. They had to shut I-70 down near Limon towards the Kansas border, as they got blizzard like conditions. We did get hit with 50MPH winds.

[jazzlover]

Originally Posted by Pettrix

Also, TORNADO ALLEY charts from NOAA have TWO charts, each showing different locations. The first chart shows Colorado to be COMPLETELY OUT of Tornado Alley. The second shows EASTERN COLORADO to be in Tornado Alley, around the Wiggins, Limon & Fort Morgan area, and east of there.

CHART #1
CHART #2

Being in the Brighton area. I always notice that the stronger storms can be seen to the SOUTH and to the NORTHEAST of me. I would assume that would be Colorado Springs and then the Wyoming and Eastern Colorado areas.

Like today, we got maybe 1" of snow while Castle Rock got 12" of snow and Eastern Colorado got 12" of snow. They had to shut I-70 down near Limon toward the Kansas border, as they got blizzard like conditions. We did get hit with 50MPH winds.

If one looks at long-term data, there is a clearly identifiable "slot" north of Denver where severe summer storms are somewhat less frequent (though they certainly can and do occur there). It basically encompasses the area for about 5 to 15 miles on either side of I-25, from roughly Denver north to Fort Collins. East of there, storm frequency and intensity increases as one heads east on the plains, because more abundant moisture is frequently available. Thus, a common pattern is for storms to develop over the higher elevations of the Front Range, move eastward, soaking the foothills, then diminish in precipitation and intensity until they get a ways out onto the plains where they can draw more moisture, whereupon they re-intensify. Of course, if easterly winds are sufficient in strength to blow moisture up against the foothills and they are moist enough, the storms can hammer the areas immediately east of the the foothills and on eastward. These are typically the severe storms that pummel places like Denver, Longmont, Fort Collins, etc. If the easterly wind component is exceptionally strong, it may push moisture clear up into the foothills, and may overcome the prevailing westerly wind component that blows storms out of the mountains eastward over the plains. In this scenario, a storm may become near stationary over the mountains or foothills, with an ample supply of moisture for extremely heavy rain. That can cause huge rainfalls over a concentrated area in a short period of time, leading to flash flooding. That is exactly what happened in the Big Thompson flood in 1976, which killed many.

[LBear]

Jazzlover -

I also read and noticed that in the PALMER DIVIDE area the storm intensity and frequency does increase. Remember the LAMAR/ELLICOTT tornado in 2001, was located in the Palmer Divide area, it was an F3. If you go to NOAA - National Oceanic and Atmospheric Administration you can enter in the area and it will list all storms since 1952.

[jazzlover]

Originally Posted by Pettrix

Jazzlover -

I also read and noticed that in the PALMER DIVIDE area the storm intensity and frequency does increase. Remember the LAMAR/ELLICOTT tornado in 2001, was located in the Palmer Divide area, it was an F3. If you go to NOAA - National Oceanic and Atmospheric Administration you can enter in the area and it will list all storms since 1952.

My reference is not only from reading--I've personally observed the storm behavior on the Palmer Divide. One of the most intense thunder and lightning events I ever experienced was in Palmer Lake many years ago. It was my "personal record" until last summer, when a severe thunderstorm at my then home in Cheyenne, Wyoming precipitated a 45 minute lightning show that left even the Weather Service people just about speechless (it was after dark, to boot). At one point, I was counting a distinct, separate visible lightning flash every 2 to 3 seconds. I should have taken video, but I was afraid the hail was going to break the windows in my house. Some storm.

[LBear]

I-80 between Cheyenne and Rawlins has got to be one of the most TREACHEROUS spots in winter. The winds are notorious and that highway closes down on a weekly basis during winter. The winds rip through there, especially near Rawlins, at 75MPH+ during winter.

It is like a wind tunnel up there.