Thornton, Colorado, USA
UpdatedSun, 04-Dec-2016 1:10am MST 


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Thornton’s Thursday continues the heat, brings better chance of storms

Thursday, July 28th, 2016 5:24am MST

Temperatures a bit above normal will continue the recent trend today. We do however see a chance for thunderstorms, our best chance for them in recent days.

We start out the day under mostly sunny skies and those will be with us for most of the day. The afternoon will bring an increase in coverage. In terms of temperatures, look for a high today in the low to mid-90s again.

As for the thunderstorm chances, things a bit unsettled in the forecast on that front. We do see a good bit of instability but the winds and moisture are the wildcards. The SPC does put us within an area of ‘marginal’ risk for severe storms and we do see the potential as being there.

Strong winds, brief, heavy rain and hail will be a possibility. The question is though whether it will come to us or remain further east. As for timing, from mid-afternoon forward the potential for storms is there with the best opportunity looking to come starting at around 6:00pm.

Our Severe Weather Briefing Page has all the latest.

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July 24 to July 30: This week in Denver weather history

Wednesday, July 27th, 2016 4:09pm MST
This Week In Denver Weather History

July 24 to July 30: This week in Denver weather history

As we near the end of July the weather in Denver tends to be a bit more stable. That doesn’t mean the severe weather threat disappears as can be seen at our look back at this week in Denver weather history. Particularly notable are lightning injuries and deaths, flash flood events and even tornadoes.

From the National Weather Service:


In 1934…a streak of 15 consecutive days of 90 degrees ranked 5th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.


In 2008…a streak of 24 consecutive days of 90 degrees shattered the previous record of 18 consecutive days established in 1901 and 1874. Ironically…no new single day record high temperatures were set in the month of July. In August however…a record of 104 degrees was set on the 1st…and another record of 103 degrees was set on the 2nd. In addition…a record low min of 70 degrees was set on August 2nd.


In 1987…a streak of 16 consecutive days of 90 degrees ranked 4th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.


In 1965…heavy showers and thunderstorms doused metro Denver with significant rain each day. Rainfall for the six days totaled 5.16 inches at Stapleton International Airport. Massive rainfall occurred on the 20th…21st…and 25th… Flooding streets and basements and causing streams to overflow. The heaviest rainfall…2.05 inches…at Stapleton International Airport occurred on the 25th.


In 1896…heavy cloudbursts in the foothills west of Denver caused flash flooding on Bear Creek…Clear Creek…Golden Gate Gulch…and Mount Vernon Creek…resulting in a total of 27 deaths. The downpour dislodged large Boulders…one of which crushed a house. The heavy rain also caused a dam on cub creek to wash out…adding even more water to the flood. A wall of water as high as 10 feet flooded Evergreen and passed down bear creek…washing away many structures along the way. The flood crest produced 3 feet of water in downtown Morrison during the early evening. Flash flooding on Mount Vernon Creek added to the flooding in Morrison. In Golden…the flooding washed out bridges on clear creek and on Cresman and Tucker gulches and forced the closure of the power plant. In Denver…a thunderstorm produced hail of unknown size during the afternoon and rainfall of 1.23 inches overnight.

In 1958…a thunderstorm wind gust to 52 mph was recorded at Stapleton Airport.

In 1965…heavy rain caused flooding on clear creek and tucker gulch in Golden and west Denver. Damage in Golden was estimated at 80 thousand dollars. Heavy rain south of Denver washed out temporary earthen bridges constructed following the June floods in Castle Rock…Littleton… Englewood…and Denver. Bear creek in south Denver reached flood stage. A cloudburst on cub creek in Evergreen washed out bridges and roads. Heavy rain fell over all the Denver and Aurora areas…causing some flooding of roads…streets… And bridges. A man drowned in a flooded irrigation canal near Hudson. Heavy rain caused flooding of streets and roads in Blackhawk and central city. Hail caused minor damage in Idaho Springs.

In 1967…seven bridges were washed out along a normally dry creek bed south of State Highway 7 west of Brighton. One car was washed into the creek when a bridge gave way.

In 1970…hail stones to 1 1/4 inches in diameter fell in the foothills of Jefferson County southwest of Denver.

In 1971…golf ball size hail was reported in foothill areas of Jefferson County west of Denver. A funnel cloud was sighted in Aurora. Wind gusts estimated at 60 mph…hail… And heavy rain up to an inch in 15 minutes caused local flooding and some other damage in several areas of metro Denver. Hailstones to 3/4 inch in diameter fell 7 miles southeast of Denver.

In 1973…a thunderstorm wind gust to 52 mph was recorded at Stapleton International Airport where one inch diameter hail was measured.

In 1981…strong winds downed a power line in northeast Denver. Wind gusts to 50 mph were recorded at Chatfield Reservoir.

In 1987…3/4 inch diameter hail fell 5 miles northeast of Commerce City.

In 1996…hail…up to 1 3/4 inches in diameter…fell at Chatfield Reservoir. Hail to 3/4 inch in diameter was measured near Bennett.

In 2000…lightning struck near two golfers at ute creek golf course near Longmont…knocking them to the ground. The men received only minor injuries.

In 2001…lightning from a thunderstorm knocked out electrical power to about 1500 residents in the city of Denver.

In 2004…a chilly day with fog and thunderstorms resulted in two temperature records. The low temperature of 49 degrees was a record minimum for the date. The high temperature of only 58 degrees was a record low maximum for the date.


In 2003…maximum temperature of 100 degrees on the 24th was a record high for the date. Low temperature of 73 degrees on the 25th was a record high minimum for the date.


In 1875…brief heavy rain and hail lasted only 5 minutes… But the 1/4 inch diameter hail covered the ground to a depth of 1/2 inch and made the streets look like there had been snowfall. There was much crop damage…especially to corn…and some sheep were killed. Precipitation totaled 0.51 inch in the city.

In 1896…a heavy thunderstorm produced sustained northwest winds to 45 mph with gusts to 50 mph and 1.02 inches of rain.

In 1965…a cloudburst dumped 1.99 inches of rain in 30 minutes at Stapleton International Airport. The storm was accompanied by strong winds gusting to 70 mph. The heavy rain flooded numerous streets in east Denver and Aurora. One inch diameter hail accompanied a cloudburst…9 miles southwest of Denver. A funnel cloud was sighted 25 miles northwest of Denver. In Aurora…there were unofficial reports of 2.30 inches of rain in 40 minutes and 3.30 inches of rain in 30 to 40 minutes. Rainfall totaled 2.05 inches at Stapleton International Airport. Rainfall of 2.42 inches for 24 hours on the 24th and 25th was the second greatest on record for July.

In 1977…a tornado touched down briefly in Aurora southeast of Cheery Creek Reservoir. No damage was reported. A funnel cloud was sighted for 4 minutes by national weather service personnel 10 miles north of Stapleton International Airport near Henderson.

In 1991…heavy rain…up to half an inch in 10 minutes…caused flooding in Westminster…Northglenn…and north Denver where a section of railroad track was washed away. At Stapleton International Airport…heavy thunderstorm rain totaled 1.85 inches and briefly reduced the visibility to 1/4 mile. Hail to 1/8 inch in diameter was also measured. A tornado touched down briefly near Fort Lupton. No damage was reported.

In 1998…heavy monsoonal thunderstorm rains caused flooding and flash flooding in eastern and southern sections of metro Denver…including Englewood and Aurora…when about 2 to 3 inches of rain inundated the area. Both I-25 and I-70 were closed for 2 to 3 hours as several low lying areas became impassable due to the high waters. The water was estimated to be 15 feet deep in one flooded underpass along I-25. As a result…the freeway was closed from south of 6th Avenue to University Blvd. Standing water forced the closure of I-70 at gun club road east of Denver. In Englewood…U.S. Highway 285 was closed…when high water made it impassable. Several cars were reportedly floating down the roadway near Sheridan Blvd. In Aurora…the intersection at Yale Ave. And chambers rd. Was flooded by high water up to 4 feet deep when a spillway on the high line canal was breached. Lightning also knocked out 11 transformers across metro Denver…causing several small fires and scattered power outages. Flood and flash flooding also occurred north of Strasburg when as much as 2.51 inches of rain fell in an hour. The deluge resulted in considerable flooding of local streets and County roads. Torrential rainfall of 2 to 3 inches in less than an hour triggered a flash flood in Virginia Canyon. County road 279 between Idaho Springs and Central City was closed for two days to clear debris from mudslides. Several cars in Idaho Springs were washed off the road…and numerous basements were flooded in town. Thunderstorm rainfall totaled 2.69 inches at Denver International Airport.

In 2001…lightning struck two homes in Lafayette…damaging the roof and attic of one and shorting out the electrical system in another. Hail to 1 3/4 inch in diameter was measured 7 miles north of Castle Rock with 3/4 inch hail 7 miles north of Sedalia.

In 2005…heavy thunderstorm rain in the vicinity of the overland wildfire burn scar triggered a mudslide in Jamestown. Rocks the size of bowling balls…along with silt and mud slid down the mountain into the town. No one was injured. One parked car was buried by the debris.

In 2006…heavy thunderstorm rainfall caused flash flooding 1 mile north of the town of Westcreek in southwestern Douglas County. Several maintenance roads were washed out by the floodwaters.


In 1891…a thunderstorm produced sustained northeast winds to 44 mph with gusts to 60 mph and 0.16 inch of rain.

In 1894…a thunderstorm produced sustained southwest winds to 36 mph with gusts to 58 mph…but only 0.04 inch of rain.

In 1910…the high temperature reached 100 degrees in downtown Denver.

In 1959…a Denver man was stunned while standing by a car that was struck by lightning. He was treated for burns and shock at a local hospital. Thunderstorm winds gusted to 55 mph at Stapleton Airport.

In 1983…two heavy thunderstorms hit the northern and western suburbs. The first drenched Northglenn with an inch of rain in 30 minutes. The second storm dumped an inch or more of rain in Idaho Springs and Evergreen. The heaviest rainfall… 2.90 inches in an hour…caused minor street flooding in Golden.

In 1984…heavy early morning thunderstorms drenched the foothills southwest of Denver. Rainfall to 1 1/2 inches in just 30 minutes occurred between Evergreen and Conifer. In nearby Turkey Creek Canyon…1.80 inches of rain was recorded in 35 minutes.

In 1985…a long rope-like white tornado touched down 5 miles east of Erie and stayed on the ground…mainly over an open field…for 18 minutes. However…the twister damaged a few cars on I-25 and injured 3 people from broken glass. The storm flipped over a van…blew out car windows…and ripped a highway sign. It also blew an outbuilding off its foundation. A tornado also touched down briefly 8 miles north of Bennett. No damage was reported from this storm.

In 1988…a 9-year-old girl was slightly injured by lightning in Parker.

In 2003…a severe thunderstorm in and south of Franktown produced hail as large as 1.75 inches in diameter.

» Click here to read the rest of July 24 to July 30: This week in Denver weather history

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More above normal temps for Wednesday, little chance for precipitation

Wednesday, July 27th, 2016 5:24am MST

These forecasts lately are sounding like a broken record. The same basic pattern of above average temperatures and slight chances for storms keeps repeating, just as it will today.

We start out the day with mostly sunny skies and will see clouds slowly increasing as the day progresses but never becoming overly thick. Temperatures will be climbing to a high in the low to mid-90s.

As for storms, activity today unfortunately looks to be focused to our east. We have just a slight chance and that will come a bit later than usual, closer to 6:00pm.

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Thornton’s Tuesday brings hot temps, slight chance for storms

Tuesday, July 26th, 2016 4:58am MST

With a high pressure ridge firmly entrenched over us, we will continue to see warmer than normal temperatures today. There is once again, just a slight chance for storms.

We start out the day with mostly sunny skies then will see a few clouds arrive by mid-morning or so. They will do little to inhibit temperatures though as we head for a high in the mid-90s.

Some scattered thunderstorm activity may be possible but activity is expected to be minimal along the Front Range.

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Very warm temperatures, slight chance for storms start Thornton’s workweek

Monday, July 25th, 2016 5:05am MST

High pressure is building over the area and that is going to help lead to yet another day of above normal temperatures. The late afternoon brings only a slight chance for thunderstorms.

We start today with mostly sunny skies and those will be with us for most of the day. Temperatures start out a bit cooler that in days past but we will be warming up this afternoon to a high of around 94 degrees.

A few thunderstorms are possible after 2:00pm into this evening although activity is not expected to be very widespread and may miss us entirely.

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Weekend to start hot with a few storms, some cooling later in the period

Friday, July 22nd, 2016 5:36am MST

While the three-day period will start out quite toasty in Thornton, we do expect to see some cooling later in the weekend and into the first part of the week. As is typical this time of year, there will be daily chances for thunderstorms.

Friday looks to be the hottest day of the period and it also brings the best chances for storms. Temperatures will be climbing to a high of around 96 degrees. We’ll start out clear but then see increasing clouds with chances for thunderstorms later, particularly in the late afternoon and early evening.

For Saturday, we see a day similar to today but with more sun and less of a chance for storms. Look for highs in the mid-90s with slight chances for PM storms.

A cold front will be moving through Sunday morning and while its effects won’t be huge, they will allow temperatures to drop closer to normal. Look for a high right near the average for the date of 90 degrees. As you would expect, there will be a slight chance for PM thunderstorms.

Have a great weekend!

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Rinse and repeat: Thursday’s forecast a virtual clone of recent days’

Thursday, July 21st, 2016 5:05am MST

Little change in Thornton’s weather forecast for today as we expect to see similar conditions to what the rest of the week has brought. Temps will be a bit above normal and we have a chance to see some afternoon and evening thunderstorm activity.

We start out with mostly sunny skies in the morning to be followed by a few more clouds later as the day progresses. Temperatures will be heading toward a high around 94 degrees (average for the date is 90 degrees).

Mid-afternoon into the evening will bring just a chance of thunderstorms although overall activity is not expected to be particularly widespread. The last couple of days saw activity largely miss us, maybe we will get lucky today but we aren’t hopeful.

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Wednesday brings more heat, another chance for storms

Wednesday, July 20th, 2016 4:59am MST

Not much change in Thornton’s weather forecast for hump day. Temperatures will again be a bit above normal and the afternoon and evening bring another round of thunderstorms.

We start out the day with mostly sunny skies which will be followed by a bit of an increase in cloud cover by mid-morning. Temperatures will be warming quickly this morning as we head toward an afternoon high temperature around 94 degrees.

Thunderstorms with gusty winds and brief, heavy rain will again threaten. Today the best chances come a bit later than the last couple of days.

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Warm temps, thunderstorms main weather features Tuesday

Tuesday, July 19th, 2016 5:30am MST

Thornton finally received a decent little shot of rain yesterday, our first respectable amount since the beginning of the month. Thunderstorms again will threaten this afternoon and give us another chance for much-needed moisture.

We start out the day with partly cloudy skies then will see coverage increase in the afternoon. The clouds won’t do much to suppress temperatures though as we still anticipate seeing a high temperature of around 93 degrees, a few above normal for the date.

Around the noon hour we should start seeing storms develop in the foothills then move on to lower elevations. Like yesterday, best chances for us come from about 3:00pm into the evening. Brief, heavy rain and gusty winds will be the biggest threat from any storms that move through.

Keep an eye on the sky with our live radar.

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Thornton’s workweek starts with seasonal temps, good chance for thunderstorms

Monday, July 18th, 2016 5:07am MST

We are looking at what could be an interesting day of weather along the Colorado Front Range. Monsoonal flow is bringing a good dose of moisture into the area and that is going to usher in the best chance for precipitation we have seen in quite a while.

We start out with mostly sunny skies but then will soon see clouds increasing as the morning progresses. Temperatures are going to be climbing to a high in the upper 80s, just below or right at the average for the date.

A good bit of moisture aloft coupled with instability will bring scattered thunderstorm activity this afternoon with the best chances coming after 2:00pm. As is the norm, areas to our south and east will have the best chances but we stand a good chance to see activity in our area as well. Gusty winds and heavy rain will be a possibility as these storms move through.

Our Severe Weather Briefing Page is your one-stop-shop to keep an eye on the storm activity.

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