Tag Archives: Severe Weather

Severe Weather 101 – Severe Weather Awareness Week wrap up

Supercell thunderstorms like this can be beautiful - but they can also be deadly. Do you know what to do when severe weather strikes? (Stormscape Photography / FLICKR)
Supercell thunderstorms like this can be beautiful – but they can also be deadly. Do you know what to do when severe weather strikes? (Stormscape Photography / FLICKR)

Over the past week we have highlighted some of the severe weather hazards that we face in Colorado every spring and summer in our Severe Weather 101 series.  The dangers these present are significant and not to be taken lightly.

Tornadoes grab most of the headlines and certainly are a danger however others like lightning and flooding are more common and actually claim more lives.  We ask all of our readers to please, take the time to review these important articles – they could save yours and your family’s lives!

The National Weather Service has published a nice wrap up of Severe Weather Awareness Week that covers all the basics – see it below.  For more in depth information, please use the links at the bottom to view each article on our Severe Weather 101 series.  Be safe and be weatherwise!

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
600 AM MDT SAT APR 16 2022

SEVERE WEATHER AWARENESS WEEK IN REVIEW

Severe Weather Awareness Week in review…

Severe Weather Awareness Week in Colorado concludes today. During the past week we have presented information and safety rules for tornadoes, lightning and wildfires, floods and flash floods, straight-line thunderstorm winds, hail, and our warning programs.

We will now review some of the most important safety rules in our effort to build a Weather-Ready Nation.

Be weather-wise by staying informed on expected weather in your area. The National Weather Service is typically aware of the potential for severe weather many hours or even days before any severe weather watches or warnings are issued, providing forecast products to heighten your awareness. A Weather Story product is posted each day on National Weather Service Internet pages and Facebook pages which includes a map and text on possible hazardous weather expected within the next seven days.

A Hazardous Weather Outlook is also issued daily with information on possible hazardous weather through the next seven days. A watch is issued when conditions for severe weather or flooding become possible. A warning is then issued when life threatening conditions are imminent or occurring.

Tornadoes

Tornadoes can even strike in mountain areas. In 2008 on August 23rd, this rope tornado struck Park County near Eleven Mile Reservoir. Image courtesy Jerry Bivens.
Tornadoes can even strike in mountain areas. In 2008 on August 23rd, this rope tornado struck Park County near Eleven Mile Reservoir. Image courtesy Jerry Bivens.

The best way to protect yourself from tornadoes is to have a plan of action. The safest place to be if a tornado approaches is in a basement or safe room within a well-built structure, or in an underground storm shelter. If none of these options are available, move to a hallway or a small interior room on the lowest floor, usually this is a closet or bathroom. Get under a heavy piece of furniture or in a bath tub and cover yourself with blankets. Remember, the greatest risk of injury from tornadoes is from flying debris.

Modular homes and mobile homes, even those tied down, offer little protection from tornadoes. If a tornado approaches, leave those locations and seek safety in a nearby sturdy building or storm shelter.

If you are driving in open country and see a tornado, if time permits, the best thing to do is simply drive away from the tornado path. Do not take shelter beneath a highway overpass. Wind speeds may actually be higher in these areas and often become collection points for debris.

If you are caught outside and cannot seek shelter inside a sturdy structure, crawl into a culvert or lie down in a narrow ditch or ravine and cover your head. But remember that the worst place to be when a tornado threatens is outside in the midst of flying debris.

Lightning

Lightning usually kills and injures more people in Colorado than any other thunderstorm hazard. Lightning also causes many wildfires.

The best defense to protect yourself against a lightning strike is to plan ahead and avoid being caught where you might be vulnerable. Check weather forecasts prior to venturing out, especially if you are heading into the mountains. Plan outdoor activities early in the day before storms develop.

If thunderstorms threaten, seek shelter in a building or in an enclosed metal-roof vehicle, making sure all windows and doors are closed. Never seek shelter under an isolated tree. During thunderstorms, stay off corded telephones, away from electrical devices, and away from plumbing. Also get out of shower stalls, bath tubs, swimming pools and lakes when lightning is nearby.

You should wait at least 30 minutes after the last sound of thunder before resuming outdoor activities. When thunder roars…go indoors.

Floods and Flash Floods

The Big Thompson Flood in 1976 claimed the lives of 144 Coloradoans and serves to remind us of the dangers of floods. (USGS)
The Big Thompson Flood in 1976 claimed the lives of 144 Coloradoans and serves to remind us of the dangers of floods. (USGS)

When flooding or flash flooding is possible, you should remain alert and be ready to quickly evacuate to higher ground or climb to safety. Flash floods often occur suddenly and without warning. You need to follow some basic flood safety rules:

  • Do not camp or park your vehicle along streams and washes, particularly during threatening conditions.
  • If you are near a river, be aware of water levels and be prepared to move to higher ground if river levels rise.
  • Do not enter areas that are already flooded.
  • If walking or fishing along a river, be aware that erosion from swift running water can cause river banks to collapse.
  • Never let your children play around high water, storm drains, viaducts or arroyos.

At least half of all flash flood fatalities are vehicle related. While driving your automobile, look out for flooding at highway dips, bridges and low areas. Two feet of moving water will carry away most vehicles. Never attempt to drive across a flooded road. And be especially cautious at night when it is difficult to see flood dangers.

Strong Straight-Line Winds

Straight-line winds from thunderstorms, including microbursts, can become quite strong, even reaching speeds in excess of 100 mph in extreme cases. When thunderstorms approach, high winds can suddenly develop, causing things on the ground to become swift moving airborne missiles with a potential force to injure or kill. As with any thunderstorm, seek shelter before the storm arrives.

Hail

This is one of the largest recorded hail stones which is more than 7 inches in diameter and fell in Nebraska in 2003. (NOAA)
This is one of the largest recorded hail stones which is more than 7 inches in diameter and fell in Nebraska in 2003. (NOAA)

Large hail can pose a danger to animals and people. Hail also produces considerable damage to crops and personal property each year in Colorado. Again, get indoors before thunderstorms arrive. A fall of small hail can suddenly change to a fall of very large ice missiles which can injure or kill. Make efforts to protect personal property before storms threaten.

Warning Notification

When thunderstorms threaten, tune to NOAA All-Hazards Weather Radio, The Weather Channel, or your local radio or television stations. Also check the Internet web site from the National Weather Service office serving your area. And if you have a relatively new cell phone you should receive Tornado and Flash Flood Warnings on your phone if you are in the area of the warning.

During threatening weather days, plan the actions you will need to take so that you will be prepared if dangerous weather conditions actually develop.

NOAA’s National Weather Service wishes you a safe severe weather season.

Severe Weather Awareness Week in Colorado concludes today. During the past week we have presented information and safety rules for tornadoes, lightning and wildfires, floods and flash floods, straight-line thunderstorm winds, hail, and our warning programs.

 

Severe Weather 101 – Hail and Wind

Straight line winds can be as damaging as a tornado. This image is from a park in Tennessee. (NWS)
Straight line winds can be as damaging as a tornado. This image is from a park in Tennessee. (NWS)

During the spring and summer months in Colorado, a wide array of severe weather can strike. Tornadoes may grab all the headlines, but straight line winds and hail can do a great amount of damage in their own right – and they are more common.

Straight line winds are winds out of a thunderstorm and are classified as severe when they hit 58 mph. These winds can reach tornado and hurricane force and as a result, cause property damage and can injure and even kill animals and humans.

These winds are usually the result of air cooling rapidly due to precipitation or evaporation. As the cooler air is heavier than the surrounding warmer air, it rushes downward, accelerating toward the ground and spreads out as it hits, much like pancake batter being poured onto a griddle.

Continue reading Severe Weather 101 – Hail and Wind

Severe Weather 101 – Floods and Flash Floods

The Big Thompson Flood in 1976 claimed the lives of 144 Coloradoans and serves to remind us of the dangers of floods.
The Big Thompson Flood in 1976 claimed the lives of 144 Coloradoans and serves to remind us of the dangers of floods.

For much of Colorado, floods and flash floods present a grave danger to life and property. These usually are the result of one of two things – spring snow melt occurring rapidly or a severe thunderstorm. Colorado is very susceptible to flash flooding and these occur somewhere every year in the state.

The waters from flash floods can move with extraordinary speed and strike with little or not warning.  Their force can be extremely destructive and when coupled with trees, dirt, rocks and other debris they carry downstream, they are deadly.

Flooding is the number one weather killer in the United States.

Continue reading Severe Weather 101 – Floods and Flash Floods

Severe Weather 101 – Tornadoes and tornado safety

Last year's Windsor Tornado highlights the very real danger twisters present in Colorado. Do you know when to do when one strikes?
The 2008 Windsor Tornado highlights the very real danger twisters present in Colorado. Do you know when to do when one strikes?

One fact that may surprise those new to Colorado is that we are actually on the western edge of the infamous Tornado Alley. This large swath of land comprises much of the nation’s midsection and is a unique place as the United States sees more tornadoes than any other place on earth. In fact, tornadoes have been recorded in all 50 states including Alaska and Hawaii.

Closer to home, Colorado sees our share of these storms. In fact, one metro area county – Weld County – holds the distinction of being the “tornado capital of the world.” With 252 tornados from 1950-2011, no single county in the nation has had more tornadoes! Adams County is number two in the state and isn’t far behind with 156 over that same period.  Granted these numbers are skewed a bit simply due to the sheer size of those counties, but it does serve to highlight the real danger that tornadoes present.

Even here in the metro area tornadoes are a real danger. The Thornton area was struck in 1981, one of the worst tornadoes to strike the Denver area in history. At 2:30 p.m. this tornado touched down and by 2:45 p.m., the tornado had hit Thornton City Hall. The tornado’s destruction sent 53 injured people to hospitals, 25 homes were destroyed and 239 structures were damaged.

One common myth is that tornadoes don't strike metropolitan areas. This has been disproved many times including here in Colorado in 1982 when an F2 tornado struck Thornton. Image courtesy the City of Thornton archives.
One common myth is that tornadoes don’t strike metropolitan areas. This has been disproved many times including here in Colorado in 1981 when an F2 tornado struck Thornton. Image courtesy the City of Thornton archives.

The most well known tornado outbreak in the metro area occurred on June 15, 1988. Five tornadoes resulted in seven injuries and damage in excess of $15 million.

We all of course also remember in 2008 when the town of Windsor, not far from Denver, was struck with an EF-3 tornado that claimed one life and destroyed and damaged hundreds of buildings.

The greatest threat for tornadoes occurs during late spring and early summer when you have a combination of heat and moisture in the lower atmosphere. Here in Colorado, tornadoes are frequent from May through August with June being the most active month.

However, there is no hard and fast rule for when tornadoes strike, as Colorado witnessed on March 29, 2007 when Holly, Colorado was struck by an EF-3 tornado with winds of 165 mph. Two women lost their lives as a result of that event and 160 homes were damaged.

Colorado ranks 10th in terms of the number of tornadoes with 1,911 events from 1950-2011. One good thing is that our high altitude and drier air do make it harder for the monster supercells that spawn the biggest tornadoes to form. Most of our tornadoes are small and short lived. Further, thanks to the wide open spaces of the eastern half of our state, many strike sparsely populated areas. This is reflected in the fact that we rank 38th for tornado related deaths.

Continue reading Severe Weather 101 – Tornadoes and tornado safety

Severe Weather 101 – Watches, Warnings and More

Last year's Windsor tornado highlighted just how dangerous weather in Colorado can be. Are you and your family prepared? Do you know what the watches and warnings all mean?
The 2008 Windsor tornado highlighted just how dangerous weather in Colorado can be. Are you and your family prepared? Do you know what the watches and warnings all mean?

We’ve all seen TV or Internet news of a weather related watch or warning being issued. But, how many really know what they mean? There is a pretty big difference between the two and it is important to be aware just what it means to you so you can take the appropriate precautions.

Dozens of weather related fatalities occur every year in Colorado, many simply out of ignorance. Taking the time to be aware of the conditions around you and taking appropriate action will keep you from becoming a statistic.

Naturally you can get information on current advisories from television as local stations usually do a good job of “crawling” them on the screen when they are issued. This works well if you have a TV available but if not, the radio would be a secondary source. The Internet and the National Weather Service’s website are a great one when at a computer.

The problem with relying on news media or the Internet is that their ability to warn you of a developing weather situation is dependent on your monitoring them.  Severe weather can strike without little warning.  How will you know if severe weather is about to strike if you don’t have the TV or radio on?

Your first line of defense – NOAA All Hazards Radio

NOAA Weather RadioFor just about anywhere, a special radio that picks up the NOAA’s All Hazard Radio broadcasts is the way to go and provides information from the source. Oftentimes simply called a weather radio, we highly recommend every household have one of these.

These radios are relatively inexpensive and allow you to be immediately notified of official National Weather Service warnings, watches, and forecasts as well as other hazard information like earthquakes, avalanches, chemical spills, and even AMBER alerts.  In fact, with these radios, you will be notified at the exact same time the news media is made aware giving you a head start on preparing for a developing situation.

To learn more about these devices and what you should look for when buying one, click here.

A high-tech alternative – Cell phone weather apps

Many people now have smartphones that allow for downloadable apps and weather-related ones are among the most popular.

All of these applications have a number of weather related features in common.  All provide current conditions for either the location the user is in now or for saved locations and all provide some sort of radar.

Most can be configured to sound an alert when the National Weather Service issues a watch or warning.  While they are no substitue for a weather radio, these apps provide you with immediate notification no matter where you are at.

For a look at some of these weather apps and their features, click here.

Continue reading Severe Weather 101 – Watches, Warnings and More

Severe Weather Awareness Week in Colorado gets started

In 1981 a tornado ripped through Thornton and caused major damage. Last year, funnel clouds were spotted across much of the area. Image courtesy City of Thornton archives.

As is customary as we get further into spring, this coming week has been proclaimed Severe Weather Awareness Week.  This is an opportunity for the public to get reacquainted with the dangers severe weather presents in Colorado.

Tornadoes, lightning, hail, severe wind and flooding are very real hazards that Coloradans face every year during severe weather season.  It is important that you know what to do to protect you and your family.

Just 12 years ago in what was Denver’s weather story of the year, we suffered through a period of unusually severe weather including a tornado that ripped through the Southlands Mall.

Thirteen years ago on May 22nd an EF3 tornado raced north through Weld and Larimer counties resulting in one fatality near Windsor and causing several injuries and destroyed or heavily damaged hundreds of homes.

And of course in 1981 Thornton was the site of the worst tornado to ever strike the Denver metro area.

Tornadoes may get all the press but other severe weather can be damaging and deadly.

Just eight years ago, late summer flooding caused millions of dollars of damage across northeastern Colorado.  It was 45 years ago that thunderstorms brought a raging torrent of water down the Big Thompson and caused one of Colorado’s worst natural disasters.  Eleven years ago hail struck the Thornton area causing damage to homes and vehicles.

In conjunction with the National Weather Service’s statements on Severe Weather Awareness Week, ThorntonWeather.com will be publishing our Severe Weather 101 series.  Each day this week a weather hazard will be discussed in depth and we will outline protective measures you can take to keep yourself and your family safe.  Please be sure to check back every day to read these important message.

Continue reading Severe Weather Awareness Week in Colorado gets started

Death Toll Climbs As Unusual Weather Hits Florida, Georgia, Mississippi, Carolinas

Severe thunderstorms and tornados threatened Florida, Georgia and North Carolina Sunday night as heavy winds, large hail and rains hit the Southeast coast and killed at least 16 people. Residents were urged to seek safe shelter and listen to their radios for any emergency warnings. “There is a significant risk for large, long-tracked and extremely destructive… Continue reading Death Toll Climbs As Unusual Weather Hits Florida, Georgia, Mississippi, Carolinas

A look back at the most destructive tornado in Denver metro history: June 3, 1981 Thornton, Colorado

June 3, 1981 - An F2 tornado rips through the heart of Thornton, Colorado. (NCAR)
June 3, 1981 – An F2 tornado rips through the heart of Thornton, Colorado. See more images in the slideshow below.(NCAR)

June 3, 1981 appeared to be a pretty typical late spring day in the Denver metro area.  Afternoon thunderstorms though would become a ‘perfect storm’ and soon the city of Thornton would find itself witness to a tornado that would go down in the Denver weather history books.

Five tornadoes would strike that day but one would become the most infamous.  The Thornton tornado would tear through what was then the heart of the city damaging homes and businesses and sending many residents to the hospital.

The twister initially touched down at 2:43 p.m. and ripped across 2 miles of the city.  The tornado was rated an F2 on the Fujita Scale packing winds up to 157mph.

Following is a description of the event from the National Weather Service and below that is a slideshow of some photos of the event we have accumulated.

In 1981…severe thunderstorms produced tornadoes over metro Denver.  The first tornado touched down at the intersection of Alameda Ave. And Sheridan Blvd.  The twister moved north along Sheridan Blvd….damaging businesses…apartment buildings…homes…and vehicles.  Over ten homes were unroofed.  The roof of one landed in the middle of a neighborhood park.  At least 10 mobile homes were wrecked.

The tornado curved to the northeast into northwest Denver… Hopping up and down in several places.  Very strong winds outside the actual funnel caused 20 to 30 thousand dollars in damage in downtown Denver.  The third floor of one old building was demolished.  No major injuries were reported from the tornado…although several people were hurt slightly in traffic accidents on Sheridan Blvd. in the confusion caused by the storm.  Damage in Lakewood alone was estimated at 200 thousand dollars. 

At the same time… The worst tornado to ever hit metro Denver struck Thornton. Coming from the same thunderstorm that spawned the Denver twister…the Thornton tornado tore a swath through the heart of the city.  87 homes were destroyed…110 others damaged at least moderately.  In all…600 homes in a 100 block area sustained some damage.  The twister also hit shopping centers…several restaurants…and other buildings. Seven of the 42 injured were considered serious.  The storm was strong enough to snap lamp posts in half and drive a 6- inch slab of wood 2 feet into the ground.  Damage was estimated at up to 50 million dollars. 

The same storm that struck Thornton produced another damaging tornado that touched down in the northwest section of Fort Lupton.  This twister damaged 16 homes and numerous cars and campers. Two children were slightly injured when the car they were in was knocked about and its windows shattered by the storm.  The twister also damaged two commercial buildings.  Damage was very spotty…and observers said the storm hopped up and down at least 3 times.  Dollar damage was estimated at 500 thousand dollars. 

The thunderstorm complex that produced 3 damaging tornadoes also dropped large hail which damaged many cars over northwest Denver.  One to 2 inches of rain fell in less than an hour…flooding a mobile home park with 3 to 4 feet of water on the northwest edge of Denver.  The high water damaged about half of the 392 homes in the park.  Local flooding was also reported in other areas across metro Denver.  A tornado was also sighted near Franktown…but caused no damage.  A thunderstorm wind gust to 52 mph was recorded at Stapleton International Airport.

Also see:

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Second day of storms miss Thornton so ThorntonWeather.com goes on the chase

A massive storm churns near Simla, Colorado on Thursday, July 7, 2012. See more photos in the slideshow below.
A massive storm churns near Simla, Colorado on Thursday, July 7, 2012. See more photos in the slideshow below.

Mother Nature brought severe weather to northeastern Colorado again yesterday but for the second day in a row Thornton missed out on the action.  Since the storms wouldn’t come to us, ThorntonWeather.com went to the storms.

Thornton seems to be in a bit of a ‘storm drought’ of late with most thunderstorms passing us by and yielding little more than a few rain drops.  Elsewhere along the Colorado Front Range the story has been much different over the last two days.

The setup was near perfect thanks to the formation of a Denver cyclone with moist air pulling in from the south meeting dry air from the north.

ThorntonWeather.com took off in mid-afternoon and headed east to Bennett, then on to Byers and east on Highway 36.  The initial storm cell that was beginning to take shape broke in to three and decisions had to be made on which one to follow.

The southernmost cell seemed to hold the most promise so we headed south, through Limon and tracked the storm near Simla.

The storm would drop tennis ball size hail and push out wind gusts measured at 80mph.  As many as four tornadoes were reported to have been caused by the storm, a number which will be confirmed and finalized later today.

In Elbert County, emergency agencies are conducting damage assessments from at least one of the twisters that tore through the central part of the county.  Extensive damage to as many as seven homes west of Simla was seen.  One person received minor injuries.

Thursday’s storms were the second day in a row for severe weather in the area.  On Wednesday thunderstorms brought massive amounts of hail to the southern Denver metro area and Colorado Springs.  Tornadoes were also spawned although there was no damage from the twisters.

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