We start off the week with some cool and unsettled weather. Temps today will be below normal and some scattered shower activity will be possible.

Partly sunny to mostly cloudy skies will be with us this morning with more clouds later in the day. High temperatures will reach the low 60s. Breezy north winds will make it feel a bit cooler. Isolated to scattered shower activity will be seen throughout the day but none are expected to be very strong.

Tonight, some shower activity will be possible overnight. Low temperatures will be around the 40 degree mark.

Ready or not, here it comes. Mother Nature is set to deliver a potent dose of wintry weather with much colder temperatures, rain, and yes, snow.

Things are already starting up this morning with drizzle. Rain coverage and intensity will be increasing through the morning. By late afternoon we will begin to see a transition to snow, possibly impacting the evening commute.

The Winter Storm Warning will be going into effect at 4:00pm and run through noon Saturday. From this afternoon through sunrise tomorrow, Thornton is looking to receive 2 to 5 inches of the white stuff with a chance to exceed that. Temperatures will be dropping and as such a Freeze Warning will be in effect tonight as well.

Saturday, things will slowly wind down. Some snow will continue to fall during the daytime hours, perhaps adding in inch or so to the totals. Some clearing should be seen late. Saturday night, lows again will dip well below freezing.

Sunday the storm will have moved out but it will remain on the cool side. Highs will be in the mid-50s with a chance for a PM shower and thunderstorm.

As we have been talking about in recent days, there is good potential for this storm to cause damage to trees and foliage and possibly cause power outages. You should certainly be prepared and do your best to knock the snow off your trees as often as possible. Our Winter Weather Briefing Page will be your one-stop-shop for the event.

* Winter Storm Warning 4:00pm Friday to noon Saturday
* Freeze Warning 9:00pm Friday to 10:00am Saturday

The warm before the storm or perhaps it could be called the days of fire and ice. Today we again will see mercury readings well above normal but the focus is on tomorrow and Saturday when Mother Nature looks to chill things out and bring a late May snow.

For today, mostly to partly sunny skies will be above. High temperatures today will be topping out in the upper 80s. Winds will be picking up this morning becoming quite breezy this afternoon. The wind, low humidity and dry fuel have prompted a Red Flag Warning to be issued.

Tonight, a cold front will push through ushering in big changes. We will have just a slight chance for a rain shower after midnight and overnight lows will dip to around 40 degrees.

That cold front is certainly going to be the talk of the town for the next couple of days. Temperatures are going to be significantly cooler and we will finally be receiving some much-needed precipitation. Some of that precipitation will, potentially, come in the form of snow.

We’re thinking Thornton could see 2 to 4 inches from Friday evening through Saturday morning. Much of that will melt due to warm ground temperatures, however, it will have the potential to coat trees and powerlines causing damage.

A Winter Storm Watch has been issued for Friday at noon to Saturday at noon. You certainly will want to prepare and work to protect any sensitive foliage as temperatures Friday night will dip to around freezing.

All the latest on our Winter Weather Briefing Page.

Springtime in Denver brings a variety of weather and flooding becomes a very real threat. In our look back at this week in Denver weather history we see many such events including one in 1864 that killed 19 people and destroyed the Rocky Mountain News building.

From the National Weather Service:

14-15

In 1977…high winds up to 100 mph felled hundreds of trees in Gilpin County and caused extensive damage to telephone and power lines. Lumber and steel tanks were blown around in Boulder Canyon. West winds gusted to 46 mph at Stapleton International Airport on the 15th.

14-18

In 1996…a period of unusually warm weather resulted in 4 record maximum temperatures in 5 days. The record high temperatures were 87 degrees on the 14th…89 degrees on the 15th…and 93 degrees on both the 16th and 18th. The temperature climbed to only 81 degrees on the 17th which was not a record.

15

In 1894…southwest winds were sustained to 38 mph with gusts to 50 mph.

In 1910…an apparent cold front produced sustained northeast winds to 48 mph.

In 1986…a thunderstorm dumped an inch of rain in an hour over the eastern part of Aurora. Total rainfall from the storm was 1.62 inches.

In 1989…a 47 year old man…a Lakewood police officer…was struck and injured by lightning. Small hail piled up 3 to 4 inches deep near Golden. There was reported street flooding from heavy thunderstorm rains over western metro Denver. Rainfall totaled 0.76 inch at Stapleton International Airport.

In 1990…a thunderstorm produced a wind gust to 69 mph at Jefferson County Airport in Broomfield. Thunderstorm winds gusting to 49 mph at Stapleton International Airport produced some blowing dust.

In 1991…a funnel cloud was sighted near Morrison. Later… Hail up to 2 inches deep covered U.S. Highway 285 at South Turkey Creek Road in west metro Denver. Baseball size hail was reported on the east side of Littleton. Dime size hail was reported in Boulder.

In 1993…lightning started a fire which damaged a home in Boulder. No one was injured.

In 1997…a wind gust to 58 mph was recorded at the site of the former Stapleton International Airport. A street sign was blown down at the Havana Street exit along I-70.

In 1999…lightning ignited a small fire in a 3-story structure in sunshine canyon above Boulder. The fire was quickly extinguished and caused only minor damage.

In 2003…thunderstorms produced very heavy rainfall and localized flash flooding in the foothills of central Boulder County. Rainfall ranged from 1.5 to 2.5 inches in less than 2 hours. Water ranging in depth from 6 to 9 inches covered State Highway 119 in Boulder Canyon. Dirt and rocks also washed over the roadway. Some basements were flooded in the sugarloaf area. Rockslides were also reported at Boulder falls…Lefthand Canyon…and Fourmile Canyon.

15-16

In 1957…heavy snowfall totaled 8.8 inches at Stapleton Airport. The greatest amount on the ground was 3 inches.

In 1986…a spring storm dumped 1 to 2 inches of rain over metro Denver…but 2.71 inches fell at Buckley Field in Aurora. Rainfall only totaled 0.84 inch at Stapleton International Airport. Snow fell in the foothills with 7 inches recorded in Coal Creek Canyon southwest of Boulder.

16

In 1875…a heavy hail storm turned into heavy rain during the afternoon. Rainfall totaled 0.86 inch in just 37 minutes…while the temperature dropped 22 degrees in 22 minutes. Precipitation totaled 0.90 inch.

In 1894…west winds were sustained to 48 mph with gusts to 56 mph.

In 1949…a tornado was observed for 16 minutes…20 miles to the southeast of Stapleton Airport. The tornado moved 5 miles to the northeast before dissipating. No damage was reported.

In 1963…intense lightning started several forest fires in the foothills southwest of Denver near Deckers and Cheeseman Lake. Little precipitation fell from the storms to alleviate the unusual dry conditions so early in the season.

In 1978…thunderstorm winds caused damage in southeast Aurora. Winds of 60 to 80 mph blew down numerous fences and damaged several homes under construction. High winds tore docks loose at Cheery Creek Reservoir…sinking 3 or 4 boats and damaging about 15 others. At Stapleton International Airport where winds gusted to 60 mph…a 727 jet suffered 15 hundred dollars damage when wind toppled a runway light onto it. The public reported an unconfirmed tornado 7 miles south-southwest of Stapleton International Airport.

In 1990…a line of thunderstorms moving across metro Denver uprooted a large ash tree…which fell and blocked the outside doors to a Denver elementary school…briefly trapping the students inside. Thunderstorm wind gusts to 69 mph were reported at Jefferson County Airport. Northwest winds gusted to 44 mph at Stapleton International Airport.

In 1991…two tornadoes touched down briefly in Castle Rock… But no injuries or damage were recorded. Heavy thunderstorm rains of 0.50 to 1.10 inches in a couple of hours caused Lena Gulch near Golden to flood. No damage was reported.

In 1996…dry microburst winds of unknown strength overturned a trailer and damaged storage sheds in Strasburg east of Denver.

16-17 In 1981…a heavy rain storm dumped 1 to 2 1/2 inches of rain across metro Denver. Rainfall totaled 1.27 inches at Stapleton International Airport where north winds gusted to 38 mph on 17th.

In 1983…a very strong late spring storm dumped heavy snow over the Front Range. Strong winds with the storm produced blizzard conditions at times. Sustained winds were 20 to 40 mph with a peak gust to 55 mph at Stapleton International Airport. The foothills received 1 to 2 feet of snow with 4 to 12 inches along the foothills. Howling winds whipped the snow into drifts several feet deep…closing schools and highways. Stapleton International Airport was forced to reduce flight operations…closing 2 of 4 runways and stranding hundreds of travelers. Most of the damage and inconvenience caused by the storm was in power outages… Which occurred when wind and heavy wet snow caused hundreds of power poles to snap and topple. About 20 square miles of Denver were blacked out. Precipitation from the storm totaled 1 to 3 inches. At Stapleton International Airport… Snowfall totaled 7.1 inches with a maximum snow depth on the ground of only 2 inches due to melting. The high temperature of 40 degrees on the 17th was a record low maximum for the date. Due to the heavy moisture content of the storm…widespread street flooding occurred on the 18th when much of the snow melted under the warm May sun and temperatures climbed to a high of 57 degrees.

In 1995…significant moisture and upslope flow caused flooding across metro Denver. Moderate to heavy rains… Which began on the evening of the 16th…developed in the foothills and spread eastward over metro Denver throughout the night. The heavy rains brought many creeks and small streams to bankfull or slightly over. Locations along the foothills received between 3 and 4 inches of rainfall from the storm. Boulder received 3.60 inches of rainfall for the 24-hour period…causing minor street flooding near small streams. To the northwest of Boulder…a bridge which crossed Fourmile Creek was washed out. Numerous rock and mudslides occurred in foothills canyons…closing portions of U.S. Highways 6 and 40 and State Highway 119 for a few hours at a time. Rocks were piled 6 feet deep on a stretch of State Highway 119 along with Boulders as large as cars on U.S. Highway 6. A parking lot near a creek in Golden caved in leaving a hole the size of an 18-wheeler. Rushing water washed out a 50-foot stretch of a road in Westminster. Rainfall totaled 1.75 inches at Denver International Airport…but only 1.42 inches at the site of the former Stapleton International Airport.

17

In 1903…southwest winds were sustained to 42 mph with gusts to 45 mph from an apparent microburst which produced only a trace of rain.

In 1960…hail to 3/4 inch diameter was measured in Thornton. Golf ball size hail fell in Arvada.

In 1972…microburst winds gusted to 51 mph at Stapleton International Airport.

In 1975…hail 1/2 to 3/4 inch in diameter fell over western metro Denver.

In 1978…a small tornado touched down in south Aurora damaging 40 homes…6 to a considerable extent. One garage was demolished and blown across the street. Parts of roofs were completely blown away. Several 2×4-inch boards were blown into the sides of houses. Another small tornado in Parker damaged two airplanes. Other funnel clouds were sighted over Northglenn and near Golden.

In 1985…a thunderstorm produced a total of 1.50 inches of rain in Brighton where 0.72 inches fell in 40 minutes. Small hail covered the ground…and there was some street and basement flooding.

In 1987…small hail piled up 4 inches deep in southwest Aurora. There was also widespread street flooding and a few power outages. Hail as large as 3/4 inch in diameter fell at Castle Rock.

In 2000…high winds occurred along and east of the Front Range foothills…as a deep surface low pressure center formed over the northeast plains of Colorado. An amusement park in north Boulder received about 25 thousand dollars in property damage. Peak wind reports included: 88 mph at the national wind technology center…84 mph in Boulder…and 80 mph at the National Center for Atmospheric Research Mesa Laboratory. A powder keg of severe weather…including tornadoes and thunderstorms producing large hail…damaging winds and heavy rain…occurred over the plains to the northeast of Denver. The only severe weather reported across metro Denver was 1 inch diameter hail in Littleton.

17-19

In 2017…a strong spring storm dropped across the Great Basin… and then moved eastward across Colorado. Isolated but strong thunderstorms preceded the system on the 17th with hail up to nickel size near Boulder Airport and Brighton. Significant snow fell across the Front Range mountains and foothills over the next couple of days. Along the Interstate 25 Corridor… rain turned to snow on the morning of the 18th…heaviest from around Broomfield northward. The heavy wet snow snapped the limbs of fully leaved trees and caused scattered power outages. A barns collapsed in northeast Loveland. Fifty-five head of cattle were inside the collapsed barn; three were injured and later euthanized. Numerous branches and trees snapped in the foothills. Elsewhere…several scattered smaller power outages were reported. Three to nearly five inches of liquid precipitation occurred…as rain or a mix of rain and snow…fell around Greeley. Storm totals in the Front Range mountains and foothills included: 42.0 inches near Allenspark…41.5 inches near Ward…36 inches at Estes Park… 32 inches near Pinecliffe…30.5 inches northwest of Golden… 30 inches near Nederland…26 inches near Breckenridge…25 inches near Aspen Springs and Bear Lake State Park…14 inches at Aspen Springs…with 9.5 inches near Evergreen. On the west side of the Interstate 25 Corridor…storm totals included: 10 inches near Superior and Louisville…6 to 8 inches in and around Fort Collins…6 inches in Lafayette… 5 inches in Broomfield and Loveland…and 4 inches near Niwot.

» Click here to read the rest of May 15 to May 21: This Week in Denver Weather History

A weak disturbance will bring a slight change in the weather today. Temperatures will cool some but we still only see minimal chances for precipitation.

Partly sunny skies start us off then we will see some clearing later in the morning. The afternoon will then see a few more clouds return. Showers look to be isolated and very limited this afternoon. High temperatures will top out in the low 80s.

Tonight, skies will be partly cloudy with lows in the low to mid-50s.

The storm system we have been talking about continues to look largely on track for Friday and Saturday. Temperatures will be dropping considerably and precipitation chances increasing during that period.

Today’s weather looks to be pretty much a carbon copy of yesterday. We will see temps again well above normal and the afternoon and evening may bring a thunderstorm.

Mostly sunny skies start us off then cloud cover will increase after noon. High temperatures will top out in the mid-70s, more than 10 degrees above normal.

Some isolated thunderstorm activity is expected this afternoon. We aren’t expected much in the way of precipitation though in our area, probably seeing just gusty winds.

Tonight, some isolated shower and thunderstorm activity will continue. Skies will be partly clear with overnight lows around 50 degrees.

The big focus right now is on a significant change in the weather expected for Friday and the weekend. A potent cold front will have the potential to bring significantly cooler temperatures, possibly even dropping us to near freezing Friday night / Saturday morning. Most importantly, if things remain on track, we do stand a good chance to see some precipitation.

More in the extended forecast here.

Following on a beautiful weekend, we kick off the workweek with a very mild day. Temps will be a good bit above normal and we stand just a bit of a chance for a PM shower.

Mostly sunny skies start us off then it becomes partly sunny for much of the afternoon. High temperatures will top out in the low to mid-80s. The afternoon will see just a slight chance for a thunderstorm / shower. Breezy winds will be along as well.

Tonight, partly clear skies will be above with overnight lows in the low 50s.

More of the same for our weekend. The three-day period will feature above normal temps, a good bit of sun and, unfortunately, some breezy winds.

For Friday, we start out sunny then will see a few clouds. High temperatures will be in the mid-70s. Winds will again be breezy. A Red Flag Warning will be in effect due to the heightened fire danger. Tonight, winds will ease after dark. Skies will be mostly cloudy with lows dropping to the mid-40s.

Saturday continues the mild, breezy weather. Temperatures will top out around 80 degrees under mostly sunny skies. Winds will be breezy, mainly in the afternoon and evening. Saturday night, we will again see some cloud cover with lows in the upper 40s.

The weekend closes out with some nice weather Sunday. Sunny skies will be above with highs again near 80 degrees. There will, again, be breezy winds.

Have a great weekend!

Following yesterday’s record-tying heat, a cold front brings cooler temperatures today. We will, however, continue with the wind and as a result, fire danger remains high.

We start off with a few clouds but soon those will be gone and sunny skies will be the rule for most of the day. High temperatures will top out in the low to mid-70s.

Downslope winds will be increasing by mid-morning, then become quite breezy with gusts from 30 to 40mph being possible for much of the day. Once again, fire danger remains very high and a Red Flag Warning is in effect.

Tonight, winds will ease in the evening, becoming calm by midnight. Overnight, skies will be mostly clear and lows will dip to around 40 degrees.

Summer-like conditions took hold today and the mercury climbed to record-setting territory.

As measured at Denver International Airport, the high temperature in the Mile High City topped out at 90 degrees today. This ties the record high for May 11 set in 1961.

The reading was the first 90 degree reading of the season and the fifth earliest we have hit that mark. On average, Denver sees its first 90 degree reading on June 10.

Here in Thornton, we were just a little cooler with a high of 89 degrees.