Thornton, Colorado, USA
UpdatedTue, 25-Oct-2016 4:35pm MDT 


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Deadly Hurricane Matthew downgraded, but still dangerous

Sunday, October 9th, 2016 12:24pm MDT

WILMINGTON, N.C. — Hurricane Matthew was downgraded to a post-tropical cyclone Sunday morning but still had some dangerous fight left in it, dumping more than a foot of rain on North Carolina in a deluge that flooded homes and businesses as far as 100 miles inland. What will go down as one of the most potent… » Click here to read the rest of Deadly Hurricane Matthew downgraded, but still dangerous

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October 9 to October 15: This Week in Denver Weather History

Sunday, October 9th, 2016 4:00am MDT
This Week In Denver Weather History

October 9 to October 15: This Week in Denver Weather History

Denver has yet to get a taste of wintry weather this year as we continue what has been a very dry period the last few months. In the past that hasn’t always been the case and our look back at this week in Denver weather history shows that heavy, winter-like snowstorms can and do strike in October.

From the National Weather Service:


In 1910…light smoke from forest fires in the mountains was sighted over the city.

In 1982…northwest winds gusted to 49 mph at Stapleton International Airport.


In 2005…a major winter storm brought heavy…wet snowfall to the Front Range mountains…eastern foothills…portions of metro Denver…and the Palmer Divide. Snow accumulations ranged from 8 to 26 inches with drifts from 3 to 4 feet in places. The heaviest snow occurred to the east and southeast of the city…closing most major highways in that area…including I-70 from Denver to Limon. The Red Cross opened four shelters for people who were stranded along I-70 in eastern Colorado. Since many trees had not yet shed their leaves…the storm caused significant tree damage. One woman in Denver was killed when a tree branch… 8 to 10 inches in diameter…snapped under the weight of the heavy…wet snow and struck her as she was shoveling her driveway. Xcel Energy reported power outages to about 35 thousand customers. Several incoming flights were delayed at Denver International Airport. Snow totals included: 16 inches in the foothills near Boulder…12 inches at Genesee and near Golden…22 inches near Watkins…19 inches near Bennett…17 inches southeast of Aurora…14 inches near Parker…13 inches near Castle Rock…12 inches in centennial… 11 inches in Parker…and 10 inches at Denver International Airport and in Littleton. While many areas of metro Denver received heavy snow…others experienced almost entirely rain. This included west and northwest metro Denver…Boulder…and Longmont. Rainfall amounts were significant as storm totals ranged between 1.50 and 2.50 inches. The steady rainfall triggered 3 rockslides in foothills canyons. Two of the slides occurred on State Highway 119 in Boulder Canyon and the longest slide…7 feet in length…on State Highway 74 in Bear Creek Canyon at Idledale. North winds were sustained to around 23 mph with gusts to 31 mph at Denver International Airport on the 9th. The high temperature of only 34 degrees on the 10th was a record low maximum for the date. The low temperature on both days was 32 degrees.


In 1901…an evening thunderstorm produced east winds to 43 mph with gusts to 48 mph.

In 1949…strong winds believed to be the worst in Boulder’s history at the time caused over 100 thousand dollars damage in the city. Peak winds were estimated to 85 mph at Valmont…just east of Boulder. High winds also occurred over most of metro Denver and caused damage to trees…window glass…and utility lines. The damage was most pronounced over the northwest metro area…including north Denver and Lakewood. Falling tree branches caused damage to parked autos and houses. Wind gusts to 70 mph were recorded at Stapleton Airport.

In 1964…lightning struck and killed a 13-year-old boy…while he was riding his bicycle along a tree-lined residential street in south Denver. Apparent microburst winds gusted to 54 mph at Stapleton International Airport.


In 1986…the first significant snowstorm of the season produced 2 to 5 inches of snow over metro Denver with 5 to 10 inches in the foothills west of Denver. Wondervu recorded the most snow from the storm…13 inches. The heavy wet snow caused numerous power outages. The storm was accompanied by strong north winds with gusts to 41 mph recorded on the 10th. The first snowfall of the season totaled 3.1 inches at Stapleton International Airport with only one inch on the ground due to melting. The strong cold front accompanying the storm cooled the temperature from a high of 73 degrees on the 10th to a high of only 33 degrees on the 11th…which was a record low maximum for the date.


In 1969…the second heavy snowstorm in less than a week dumped nearly a foot of snow across metro Denver and plunged the area into extremely cold temperatures for so early in the season. Snowfall totaled 11.0 inches at Stapleton International Airport. North winds gusting to 26 mph produced drifts up to 2 feet deep. Temperatures dipped from a high of 52 degrees on the 10th to a record low for the date of 10 degrees on the 12th. There was additional damage to trees and power and telephone lines from heavy snow accumulations and icing. Travel was restricted or blocked by drifting snow in both the mountains and on the plains east of Denver.


In 1997…damaging winds ahead of an approaching storm system developed in the foothills and spread across metro Denver. Winds gusted to 88 mph at conifer…71 mph at the National Center for Atmospheric Research on the mesa in Boulder… And 53 mph at Denver International Airport. Several trees and street signs were blown down with scattered power outages reported throughout metro Denver. In Arvada…a car window was blown out by a strong wind gust.

In 2013…high winds occurred in and near the Front Range Foothills. Peak gusts included: 85 mph at Rooney Road…84 mph…2 miles south of Marshall; 82 mph at Rocky Flats National Wind Technology Center and Wondervu; 79 mph at the Mesa Lab at NCAR and 75 mph…3 miles south-southwest of Boulder; 73 mph in Superior and 68 mph in Golden. The wind downed trees and power lines. As a result…scattered electrical outages affected 20000 Xcel Energy customers through the morning hours. The main outages affected the cities of Boulder…Golden and Lakewood. Smaller outages were reported in areas of Gold Hill…Ward… Westminster and Wheat Ridge.


In 1901…an apparent cold front produced northeast winds sustained to 42 mph with gusts to 48 mph on the 11th. General rain changed to snow overnight and totaled 2.0 inches. This was the first snowfall of the season. Total precipitation was 0.32 inch.


In 1892…apparent post-frontal rainfall totaled 3.33 inches in downtown Denver over the 3 days. A trace of snow on the 12th melted as it fell. Rainfall of 2.58 inches on the 12th into the 13th was the greatest 24-hour precipitation ever recorded during the month of October. Northwest winds were sustained to 48 mph with gusts as high as 55 mph on the 12th.


In 1873…smoke from several very large forest fires was sighted along the mountains.

In 1923…post-frontal rain changed to snow and totaled 4.0 inches. North winds were sustained to 14 mph.

In 1978…northeast winds gusting to 35 mph with a strong cold front briefly reduced visibility to 2 miles in blowing dust at Stapleton International Airport.


In 2001…overnight peak wind gusts to 82 mph and 70 mph were measured atop Niwot Ridge and Squaw Mountain…respectively.


In 1969…record breaking extremely cold temperatures for so early in the season occurred. The high temperature of 26 degrees on the 13th was two degrees lower than the previous record minimum temperature of 28 degrees for the date set in 1885. The high temperature of 24 degrees on the 12th exceeded the record low temperature (22 degrees set in 1885) for the date by only 2 degrees. In addition… 3 new record low temperatures for the dates were set. The low temperature dipped to 10 degrees on the 12th breaking the old record (22 degrees in 1885) by 12 degrees. On the 13th the mercury plunged to a low of 3 degrees breaking the old record (28 degrees in 1885) by 25 degrees. On the 14th the temperature reached a minimum of 4 degrees breaking the old record (25 degrees in 1966) by 21 degrees.

» Click here to read the rest of October 9 to October 15: This Week in Denver Weather History

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Following a chilly start, Thornton’s weekend to warm up, bring pleasant conditions

Friday, October 7th, 2016 5:05am MDT

With the mercury flirting with the freezing mark this morning, we are starting the three-day period quite chilly. That however will be short-lived and warm, dry weather conditions are going to be the rule for the balance of the period.

Friday we start cold as mentioned but will be warming up to a high temperature in the mid-60s, just a bit below normal for the date. We’ll have sunny skies above and calm conditions.

Saturday continues the warming trend. Look for highs tomorrow in the low 70s. Again, sunny skies will be above and we’ll remain dry.

Closing out the weekend, Sunday offers fantastic weather, perfect for a Broncos victory against the Falcons. Mostly sunny skies will be above and temperatures will be topping out in the mid-70s.

Have a great weekend!

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Hurricane Matthew tracker

Thursday, October 6th, 2016 8:09am MDT

After devastating parts of Haiti and Cuba, Hurricane Matthew now has its sights set on the southeastern United States. Florida Governor Rick Scott has warned that the storm could be catastrophic and ordered the evacuation of nearly 2 million residents.

Follow the massive storm’s progress using the live tracker below. For more information, get the latest public advisories from the National Hurricane Center.

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Thornton’s October 2016 preview: Fall returns, hopefully with precipitation

Thursday, October 6th, 2016 6:20am MDT

Thornton, Colorado October weather preview.With the first full month of fall here, October usually brings one of the quietest weather months in the Denver area with plenty of mild, sunny days and clear, cool nights. Given the lack of precipitation of the last few months though, we certainly would welcome some moisture.

October is historically the second sunniest month and conditions are generally calm.

However we also will usually see our first taste of winter during the month with the first freeze and first snowfall of the season.  Temperatures as well will start to drop and by the end of the month the average nighttime lows are below freezing.

For complete details on our historical October weather and what we can expect in the coming month, read our complete October weather preview here.

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September 2016 weather recap: A very dry month with near normal temperatures

Thursday, October 6th, 2016 6:00am MDT

The month of September was overall a pleasant one however that came at a price.  A very distinct lack of precipitation led to dry conditions, a trend that had started earlier in the summer.

High pressure was the general rule for the month and that helped to ensure that any significant weather potential was steered away from the state.  A few troughs and cold fronts mixed things up but in the end, we only saw precipitation on three days during the month and the amounts were negligible.

Thornton’s average temperature for the month came in at 63.7 degrees.  This was just slightly above Denver’s long term average for September of 63.4 degrees.  Out at the airport where Denver’s official measurements are taken, it was a good bit warmer with an average of 66.0 degrees.

Temperatures here ranged from a high of 91.6 degrees on the 5th of the month down to a low of 39.8 degrees on the 24th.  DIA recorded a maximum of 93 degrees, also on the 5th, and a low of 37 degrees on the 10th.

In terms of precipitation, Thornton saw a measly 0.05 inches fall into our rain bucket.  The airport fared far better with 0.28 inches.  However, both measurements were well below the September average for Denver of 0.96 inches.  The reading in Thornton would have been low enough to tie for the third driest reading in Mile High City history.

Click here to view Thornton’s September 2016 climate report.

Thornton, Colorado's September 2016 temperature summary. (ThorntonWeather.com)

Thornton, Colorado’s September 2016 temperature summary. (ThorntonWeather.com)

Thornton, Colorado's September 2016 precipitation summary. (ThorntonWeather.com)

Thornton, Colorado’s September 2016 precipitation summary. (ThorntonWeather.com)

From the National Weather Service:

933 AM MDT SAT OCT 1 2016




                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
 HIGH              97   09/06/2013
 LOW               17   09/29/1985
HIGHEST            93   09/05        91       2       92  09/02
LOWEST             37   09/10        35       2       44  09/19
AVG. MAXIMUM     82.3              78.5     3.8     85.2
AVG. MINIMUM     49.7              48.3     1.4     53.5
MEAN             66.0              63.4     2.6     69.4
DAYS MAX >= 90      6               3.4     2.6        7
DAYS MAX <= 32      0               0.0     0.0        0
DAYS MIN <= 32      0               0.8    -0.8        0
DAYS MIN <= 0 0 0.0 0.0 0 PRECIPITATION (INCHES) RECORD MAXIMUM 5.61 2013 MINIMUM T 1892 1944 TOTALS 0.28 0.96 -0.68 0.11 DAILY AVG. 0.01 0.03 -0.02 0.00 DAYS >= .01         4               6.5    -2.5        3
DAYS >= .10         1               3.3    -2.3        0
DAYS >= .50         0               0.6    -0.6        0
DAYS >= 1.00        0               0.1    -0.1        0
 24 HR. TOTAL    0.18   09/12 TO 09/12           08/31 TO 09/01

 TOTAL            0.0              1.3
RECORD SEPTEMBER 17.2                      1971

HEATING TOTAL      64               125     -61        9
 SINCE 7/1         79               141     -62       27
COOLING TOTAL      99                76      23      148
 SINCE 1/1        861               764      97      861

 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05

AVERAGE WIND SPEED              9.5

AVERAGE SKY COVER           0.40
NUMBER OF DAYS FAIR           13
NUMBER OF DAYS PC             13


THUNDERSTORM              6     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       0
LIGHT RAIN                6     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                       4     FOG W/VIS <= 1/4 MILE      3
HAZE                      4

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Cool, damp weather for Thornton’s Thursday, freezing temps possible tonight

Thursday, October 6th, 2016 5:14am MDT

A definite taste of fall weather is in store for us today as we cool considerably and expect to see a touch of precipitation. The system will move out quickly though leading to cold temperatures tonight and another Freeze Warning.

We start out the day under cloudy skies to be followed by some, limited clearing as the day progresses. Light showers and sprinkles are being seen in spots now and those will continue intermittently through the morning then taper off in the afternoon. Unfortunately we don’t expect a lot of precipitation out of this.

Temperatures today are going to be quite a bit cooler than recent days with highs topping out in the low to mid-50s. Tonight we will see skies clear and, if there is no wind, temperatures will drop to near freezing.

A Freeze Warning has been issued and will be in effect from midnight to 9:00am Friday so be sure to cover up or bring inside any sensitive plants. More details on the warning can be found here.

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Florida braces for Hurricane Matthew as track swings closer

Thursday, October 6th, 2016 2:02am MDT

MIAMI — Hurricane Matthew, a lethal storm already blamed for 11 deaths, delivered a sobering wake-up call to Florida on Wednesday: a hurricane warning up and down the Atlantic Coast that shuttered schools, triggered mandatory evacuations and put billions of dollars of property at risk. Tracking on a course that leaned closer and closer to Florida,… » Click here to read the rest of Florida braces for Hurricane Matthew as track swings closer

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Following a chilly start, Thornton to warm up nicely Wednesday

Wednesday, October 5th, 2016 5:08am MDT

There is definitely a bite of cold in the air this morning as we saw temperatures dip to near freezing bringing our coldest reading in five months. The chill will fade with the rising sun though as we head toward temperatures near normal today.

We start out with clear skies to be followed by a few clouds as the day progresses. Winds are going to be generally calm throughout. Temperatures will be warming up nicely to right near the average high for the date of 70 degrees.

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Looking beyond, a cold front will be moving in tonight and that will bring us a chance for showers overnight and through tomorrow. Unfortunately it does not look like any precipitation that falls will amount to much and we do not expect there to be snow in our area. Tomorrow’s will be a good bit cooler topping out in the mid-50s. We will then rebound nicely with warmer readings through the weekend.

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Tuesday’s weather brings cooler temps, less wind

Tuesday, October 4th, 2016 5:04am MDT

While yesterday was mild, that wind howled pretty good, particularly after dark. Today we see the winds die down and temperatures cool quite a bit following the passage of the front.

We’ll start out the day with mostly clear skies then see a few more clouds as the morning progresses. The coverage won’t be dominating though and mostly sunny skies will be the rule.

Winds are going to be lighter and out of the southwest shifting to the northwest in the afternoon. In terms of temperatures, look for highs to top out in the mid to upper 60s, a bit below average for the date.

Looking ahead, tomorrow looks to be a near clone of today with a good bit of sun and similar temperatures. We continue to watch a second trough coupled with a cold front set to arrive Wednesday night into Thursday. Right now it looks like any precipitation in our area will be rain but we can’t entirely rule out a touch of snow either.

In the wake of the system, overnight lows Thursday night could dip to below freezing so you may want to start making plans to cover up or bring in any sensitive plants. Friday will remain cool but dry and calm then we start to rebound nicely for what should be a mild, calm weekend.

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