Thornton is once again set to enjoy a pleasant fall day. We will see mercury readings well above normal although there will be a little bit of wind.

Sunny skies once again start us off and will remain throughout the day. Winds will be light this morning, becoming breezy by mid-afternoon. High temperatures will top out in the mid-70s.

Tonight, winds will ease by around sunset. Skies will remain clear and overnight lows will dip to around the 40-degree mark.

Winter winds can not only make it miserable to be outside, they can also be dangerous.

As we often experience, high winds in Colorado can cause conditions to deteriorate rapidly.  They present a very real danger to life and property, especially when coupled with other winter conditions like snow.

Why does it seem like we get so much wind in the winter?  What causes this?  How can you prepare and protect yourself and your property?

In this third in a series on winter weather preparedness from the National Weather Service, ThorntonWeather.com helps you understand why we receive so much wind and how to prepare for it.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BOULDER CO
ISSUED BY NATIONAL WEATHER SERVICE PUEBLO CO
600 AM MDT WED OCT 19 2022

…WIDESPREAD HIGH WINDS VISIT COLORADO DURING THE WINTER…

This week through October 22nd is Winter Weather Preparedness Week in Colorado.

The two main causes of high winds in Colorado during the cold season are the air pressure difference between strong low pressure and cold high pressure systems, and Chinook winds developing across the Front Range and other eastern mountain ranges.

» Click here to read the rest of High winds a major threat in Colorado during the winter

Calm, dry conditions, lots of blue above and temperatures a bit above average. All of that will make for a very nice day for us today.

Sunny skies start us off and there shouldn’t be hardly a cloud visible throughout the day. Winds will be light and out of the northeast. High temperatures will top out in the mid to upper 60s.

Tonight, skies will remain clear. Look for lows to dip to around 40 degrees.

Enjoy it!

You have seen and heard the warnings but do you know what they really mean?

We all are familiar with the crawls on the TV screen or the announcements on the radio for winter weather advisories such as Winter Storm Watch, Blizzard Warning, Freeze Warning and more. But, how many of us really know what those mean? There is very specific criteria the National Weather Service follows in issuing these watches and warnings and there are important differences between all of them.

In this second in a series on Winter Weather Preparedness from the National Weather Service, ThorntonWeather.com helps you understand what all of these mean so you can be better prepared.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BOULDER CO
600 AM TUE OCT 18 2022

From the National Weather Service:

What does that warning mean?

When a warning is issued during the winter season, will you know what it means, and will you know how to respond? During this Colorado Winter Weather Preparedness Week, please become familiar with our list of potentially life-saving winter weather products.

OUTLOOKS

A Hazardous Weather Outlook is issued daily by the National Weather Service office in Boulder Colorado. The outlook provides information on potentially hazardous weather out to 7 days into the future. Also, the Weather Story, a graphic of expected hazardous weather, is posted daily on National Weather Service web sites.

WATCHES AND WARNINGS

A Winter Storm Watch is issued when hazardous winter storm conditions are possible within the next 3 to 4 days, but the timing, intensity, or occurrence may still be uncertain. In contrast, a Winter Storm Warning is issued for potentially life-threatening winter storm conditions, such as heavy snowfall or a combination of snowfall and blowing snow, which are likely to occur within the next 1 to 2 days. Impacts such as timing of winter weather on rush hour are also considered when issuing Watches and Warnings.

Winter Storm
Plains: 6″ in 12 hours, 8″ in 24 hrs
Mountains: 8″ in 12 hours, 12″ in 24 hours
And Impacts

Winter Weather Advisory
Plains: 3-6″ in 12 hours, 4-8″ in 24 hours
Mountains: 4-8″ in 12 hours, 6-12″ in 24 hours
And Impacts

Blizzard
Sustained wind or frequent gusts 35 mph or greater, AND
Considerable falling/blowing snow with visibility less than 1/4 mile, for at least 3 hours

ADVISORIES

Advisories for winter weather are issued for potentially hazardous conditions which are considered more of a nuisance than a life-threatening situation. However, if caution is not taken the advisory events could become life-threatening. Impacts such as timing of winter weather on rush hour are also considered when issuing Advisories.

Winter Weather Preparedness Week in Colorado will continue through Saturday.

We are starting out the day with the coldest temperatures we have seen in five months. However, we will be warming up nicely and enjoy a nice start to the workweek.

Clear skies overnight have allowed us to dip close to freezing in the early morning hours. Daytime will see us remain clear with nary a cloud to be seen throughout. Temperatures will warm up nicely with highs in the mid-60s. Conditions will be calm and dry.

Tonight, skies will remain clear and the mercury will again dip a good bit. Look for overnight lows in the mid-30s.

Have a great Monday and go Broncos!

Are you and your vehicle ready for the winter weather ahead?

Before hitting the road, Coloradans need to ensure that they and their vehicles are prepared should inclement weather strike.

ThorntonWeather.com presents the first in a series from the National Weather Service (NWS) as part of Winter Weather Preparedness Week has declared by Colorado’s Governor.  Check back throughout the week for more winter preparedness stories.

Today’s message from the NWS highlights the importance of having a proper emergency kit in your vehicle and should the worst-case scenario occur where you get stuck, what you should do to survive.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
601 AM MDT MON OCT 17 2022

Winter Travel Safety

Winter Weather Preparedness Week continues through Saturday October 23rd. Preparedness is a big part of this campaign. Before winter weather arrives in earnest, it is highly recommended that you prepare your car or truck for winter travel. This includes a winter survival kit and good snow tires.

Before winter weather arrives in earnest, it is highly recommended that you prepare your car or truck for winter travel.

A well-equipped vehicle has adequate tires, tire chains, tow rope, sand or cat litter for traction, shovel, tool kit, windshield scraper and brush, battery cables, first aid kit, flashlight, extra batteries, blankets and/or sleeping bags, extra clothing, candles, waterproof matches, jug of water, high calorie packaged food for quick energy, and an empty can to melt snow for drinking.

And during winter weather events, the best way to prevent treacherous winter travel is to avoid it. This can be done by staying informed about current weather and road conditions as well as the latest weather forecasts. Information on road conditions in Colorado is available on the web at www.cotrip.org or from the toll free number 1-877-315-7623. When calling from anywhere in Colorado, dialing 511 will also access the Colorado road reports. Additionally, a free smartphone application, CDOT Mobile, is available.

If you should become stranded during a winter storm, stay with your vehicle and do not panic. If accompanied by others, take turns sleeping. Run the motor every hour for about ten minutes to maintain warmth, but keep windows open a little to prevent the buildup of carbon monoxide. Make sure the exhaust pipe is not blocked. Keep the car visible with brightly colored cloths tied to the side view mirrors, door handles, or external antenna. At night, turn on the dome light when running the engine. Exercise periodically by vigorously moving arms, legs, toes and fingers.

In the mountains, avalanches become a possibility in the winter, especially below steep slopes. Avalanches occasionally come down across roads, with little or no warning. However, avalanche control work is performed on many avalanche prone roads in Colorado, making the roads safer to travel. Caution is advised when traveling along avalanche prone roads, especially during and shortly after a heavy snowstorm, as well as during periods of rapid snowmelt.

Very strong downslope winds occur at times mainly along the front range of Colorado. These Chinook and Bora winds can have gusts exceeding 100 mph. Persons planning travel in lightweight or high-profile vehicles should avoid travel during these strong wind events especially on north-south oriented roads.

Roads which appear to be clear in the wintertime may actually be coated with a thin layer of ice, commonly known as black ice. This nearly invisible ice layer can cause you to rapidly lose control of your vehicle. Black ice is most common during the nighttime hours. If you detect black ice you should reduce your speed.

Please follow these winter travel safety recommendations which could save your life.

Winter Weather Awareness Week – Winter Travel Safety. (National Weather Service)

Snow and wind are two common conditions we see this time of year and our look back at this week in Denver weather history certainly has those type of events. Also notable is a surprising October hail storm 13 years ago that went into the books as one of the costliest in history.

From the National Weather Service:

13-16

In 1873…smoke from several large forest fires in the mountains made the air very hazy in the city.

15-16

In 1928…a thunderstorm produced hail shortly after midnight on the 15th. Rain changed to snow by evening. Through the afternoon of the 16th…the heavy snowfall totaled 7.3 inches in the city. North winds were sustained to 23 mph on the 15th.

In 1984…the heaviest October snowstorm in several years hit eastern Colorado with a vengeance. The storm was known as the “Bronco Blizzard” since it occurred during a nationally televised Monday Night Football game in Denver. One to two feet of snow fell near the foothills in west metro Denver with 2 to 3 feet in the foothills. Wind gusts up to 55 mph whipped the snow into drifts as high as 4 feet. The storm closed schools…roads…and airports. I-70 was closed both east and west of Denver. I-25 was closed south to Colorado Springs. Flights were delayed for several hours at Stapleton International Airport. Power outages were widespread. Snowfall totaled 9.2 inches at Stapleton International Airport where north winds gusting as high as 40 mph caused frequent surface visibilities of 1/4 to 1/2 mile in moderate to heavy snow and blowing snow overnight. The high temperature of only 35 degrees on the 15th was a record low maximum for the date.

15-17

In 1989…an autumn snowstorm hit metro Denver with 2 to 6 inches of snow. Snowfall totaled 4.4 inches at Stapleton International Airport where the maximum snow depth on the ground was only 3 inches due to melting and north winds gusted to 25 mph on the 15th. The heavy wet snow caused leafy branches to sag onto power lines…resulting in a number of power outages. Five thousand homes were blacked out in Boulder on the 16th. Up to a foot of snow fell in the higher foothills with 19 inches recorded at Echo Lake.

16

In 1878…high winds reached sustained speeds of 60 mph.

In 1998…one of the costliest hail storms to ever hit metro Denver caused an estimated total of 87.8 million dollars in damage to homes…commercial buildings…and motor vehicles. At the time the storm was ranked as the 7th costliest ever. The hailstorm…rare for so late in the season…began over portions of Arvada…Wheat Ridge…and northwest Denver where mostly pea sized hail accumulated up to a depth of 6 inches near I-70. Several accidents were attributed… At least in part…to the hailstorm. Snowplows had to be called out to clear several city streets. The storm intensified as it moved to the east…into the Denver and Aurora areas. Large hail…up to 2.00 inches in diameter pounded east and southeast metro Denver. Two inch diameter hail fell in the city of Denver and at Buckley Field. Hail as large as 1 1/2 inches was measured in south Denver with 1 inch diameter hail in northern Aurora.

In 1999…upslope conditions produced snow across metro Denver with heavy amounts in the nearby foothills. Snowfall totals included: 9 inches at Eldorado Springs; 8 inches at Genesee… Golden Gate Canyon…Littleton and near Morrison; 7 inches near Nederland; and 6 inches in Louisville. Snowfall totaled 3.6 inches at the site of the former Stapleton International Airport.

16-17

In 1990…strong downslope winds raked the eastern foothills. Wind gusts from 60 to 75 mph were common. Strong winds in metro Denver resulted in wave damage to a dock used to moor several private sail boats at Cheery Creek Reservoir. Damage was confined to the dock and two anchor cables. A northwest wind gust to 43 mph was recorded at Stapleton International Airport.

17

In 1878…strong winds reached sustained speeds of 48 mph.

In 1988…a wind gust to 62 mph was recorded in central Boulder. The strong winds caused a few brief power outages. An old smoldering brush fire in the foothills west of Boulder was re-ignited by the wind gusts.

In 1994…winds gusted to 85 mph atop Squaw Mountain…5 miles south of Idaho Springs.

In 2006…a potent storm system brought heavy snowfall to the mountains and eastern foothills. Snowfall totals in the foothills included: 14 inches at Blackhawk…13.5 inches near Idaho Springs…13 inches at cabin creek…12.5 inches at Aspen Springs and Echo Lake…11.5 inches at Georgetown and Rollinsville…10.5 inches near Jamestown…and 10 inches at grant and Lake Eldora. Lesser snow amounts…from 4 to 9 inches…were recorded elsewhere in the foothills. Snowfall totaled only 3.5 inches in the Denver Stapleton area. At Denver International Airport…north winds gusted to 31 mph.

In 2012…A brief but powerful windstorm associated with a fast moving cold front across the Urban Corridor and adjacent plains during in the evening. Peak wind gusts ranging from 58 to 71 mph downed trees and power lines which damaged homes and vehicles. Several temporary structures were also damaged. Approximately fifty thousand were left without power in the Denver…Fort Collins and Greeley areas. Some schools were closed the following day until power could be restored. Around the Denver area…peak wind gusts included: 69 mph in Golden…64 mph at Littleton…62 mph at Buckley AFB and in Denver…near the intersection of Walnut St. and Interstate 25…and Longmont; 59 mph at Centennial Airport…58 mph at Denver City Park… Highlands Ranch.  At Denver International Airport…a peak wind gust to 35 mph was observed from the northwest.

17-19

In 1908…a moist…heavy…wet snowfall totaled 13.0 inches in downtown Denver over the 3 days. Rain from early morning on the 17th changed to snow by late afternoon and continued through the late morning of the 19th. Due to temperatures in the 30’s and melting…the most snow on the ground was only 5.0 inches at 6:00 pm on the 18th. Northwest to northeast winds were sustained between 12 and 20 mph during the storm. Precipitation totaled 1.82 inches.

18

In 1875…the haze was so dense that the mountains were not visible from downtown Denver for most of the day.

In 1937…a vigorous cold front produced north winds sustained to 32 mph with gusts to 41 mph. Rain and snow totaled 0.16 inch. Post-frontal snowfall of 0.8 inch was the only snowfall of the month.

In 1960…post-frontal upslope rain changed to snow. Snowfall was 2.2 inches at Stapleton Airport where precipitation (rain and melted snow) totaled 1.58 inches.

In 1971…wind gusts to 48 mph were recorded in downtown Boulder. West winds gusted to 30 mph at Stapleton International Airport.

In 1999…heavy snow developed in the foothills west of metro Denver with lesser amounts across the city. Snowfall totals included: 7 inches near Nederland…6 inches in Boulder…and 5 inches at Chief Hosa. Only 1.2 inches of snow were measured at the site of the former Stapleton International Airport.

18-23

In 2003…an extended warm spell resulted in 5 new temperature records. The high temperature of 84 degrees on the 18th equaled the record high for the date. High temperatures of 86 degrees on the 19th…83 degrees on the 21st…and 84 degrees on the 22nd were record highs for the dates. Low temperature of 49 degrees on the 23rd was a record high minimum for the date. Low temperatures during the period were in the 40’s and lower 50’s.

19

In 1887…northwest winds sustained to 42 mph were recorded in the city.

In 1982…3 to 6 inches of snow fell over northwest metro Denver…including Boulder. Only 1.2 inches of snowfall were recorded at Stapleton International Airport where north winds gusted to 35 mph. This was the first measurable snowfall of the season.

19-20

In 1990…an early winter storm dumped heavy snow across metro Denver. Snowfall amounts ranged from 4 to 8 inches in the foothills above 6500 feet elevation…4 to 7 inches in the Castle Rock area…and 2 to 5 inches across most of metro Denver and Boulder. Snowfall totaled 3.6 inches at Stapleton International Airport where northwest winds gusting to 48 mph kicked up some blowing dust shortly after a cold frontal passage on the 19th. However… Temperatures were warm enough to keep most roadways wet and slushy at lower elevations.

19-23

In 1906…heavy snowfall totaled 22.7 inches in the city over the 5 days. Rain changed to snow on the evening of the 19th…and snow continued through the late afternoon of the 23rd. The heaviest amount of snowfall…16.0 inches…fell from 8:00 pm on the 20th to 8:00 pm on the 22nd. The most snow on the ground was 13.3 inches on the evening of the 23rd. This was the first snow of the season and the only snow of the month. Winds during the storm were from the north at sustained speeds of 20 to 30 mph each day. Temperatures during the storm were generally in the 20’s. » Click here to read the rest of October 16 to October 22: This Week in Denver Weather History

Don’t be caught off guard by winter weather! Remember the Christmas Eve Blizzard of 1982? Be prepared!

Winter weather in Colorado can be an inconvenience but more than that it can be deadly.  Emergency preparedness for major winter storms – as well as for other types of severe weather – is an important part of living in a state where conditions can change wildly from one moment to the next.

To help raise awareness of the need to be prepared for these occasions, the week of October 16th to October 22nd has been proclaimed Winter Weather Preparedness Week in Colorado.

The National Weather Service will be issuing Public Information Statements each day this week to highlight the dangers of winter weather and how best to be prepared.  ThorntonWeather.com will be posting these important messages here to help you be prepared.  Please take the time to read and heed these messages – your life and the lives of your loved ones could depend on it.

• Stay up to date with Thornton’s weather: ‘Like’ us on Facebook and follow us on Twitter.

From the National Weather Service:

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BOULDER CO
600 AM MDT SUN OCT 16 2022

..Winter Weather Preparedness Week in Colorado…

The week of October 16th through October 22nd is Winter Weather Preparedness Week in Colorado. This is an excellent time for all individuals, families, businesses, schools, and media outlets to review their winter storm preparedness plans. It is especially important for all new arrivals to the state to become familiar with the National Weather Service watch and warning definitions, as well as winter safety procedures.

Snow in Colorado is important to the farmers, the ski areas, and for filling up reservoirs. However, winter storms often bring heavy snow, bitter cold air, high winds, low visibilities and slick roads. This can lead to dangerous travel conditions and other life threatening situations such as avalanches and very frigid wind chill temperatures.

To help you prepare for these hazards this coming winter, the National Weather Service will issue statements throughout the week to discuss:

Overall, our weather will remain calm and dry for the three day period. However, after a mild start, we will see temperatures cool over the balance of the weekend.

For Friday, look for sunny skies followed by a few PM clouds. There will be some breezy winds in the afternoon and early evening. Temperatures will top out at the mid to upper 70s. Tonight, skies will be mostly clear and lows will dip to around 40 degrees.

Saturday starts out mostly clear then will see cloud cover increase in the late morning. Look for highs in the mid-60s. Saturday night, skies will be mostly cloudy with lows in the upper 30s.

Sunday will be the coolest day of the period. We will start out with partly clear skies but cover will decrease through the day. Highs will be in the low to mid-60s.

Have a great weekend!

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:

8-9

In 2017…an early season snowstorm produced heavy wet snow which broke branches and downed power lines. About ninety- eight thousand outages occurred in Denver and the surrounding metro area. Almost half the outages were very short…while 54210 were sustained outages that lasted longer than five minutes. Some however lasted for several hours. Snow amounts varied greatly along the Interstate 25 Corridor. West of I-25…storm totals included: 7.5 inches in Arvada…7 inches in Broomfield…6 inches Boulder and Louisville…with 5 inches at Ralston Reservoir. East of I-25…storm totals ranged from a trace to 4 inches. In the mountains and foothills…storm totals included: 12.5 inches near Genesee…10 inches at Eldorado Springs… Idledale and Nederland…with 8.5 inches near Jamestown.

9

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.

9-10

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 2019…a vigorous winter like storm system brought intense northerly winds and the cold front blasted through the urban corridor. Peak wind gusts from 50 to 60 mph accompanied the front. Some trees in Denver were uprooted by the strong winds. Light rain and drizzle overnight…changed over to the season`s first snow during the predawn hours of the 10th. Bands of moderate to heavy snow brought 2 to 6 inches of snow in the Front Range mountains…foothills and urban corridor. The morning commute was especially hazardous as falling temperatures froze wet roads. Multiple crashes occurred including: I-25 in Denver…I-70 from Denver west to the Eisenhower Tunnel and State Highway 285 towards Fairplay. Over 300 crashes were reported in Denver and Aurora alone. After reaching a maximum temperatures of 83 degrees on the afternoon of the 9th…the temperature plummeted to 13 degrees on the 10th. A temperature change of 70 degrees…the second largest 2-day swing for the month of October in Denver weather history.

10

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.

10-11

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.

10-12

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