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Thornton, Colorado, USA
UpdatedSun, 24-Mar-2019 10:15pm MDT 
 

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Warmer temperatures, calm conditions on Thursday for Thornton

Thursday, March 7th, 2019 5:05am MDT

Following our overnight rain / freezing rain / snow, we will experience a nice little warm up today.

Some early fog may be seen and roads will be slick initially. You will certainly want to adjust your morning commute as needed and take your time.

After that, skies will be partly sunny for the balance of the day with some easing in the cloud cover late. Temperatures will top out in the upper 40s.

Tonight, skies will be partly cloudy with lows in the low 20s.

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Wildfire Awareness – Colorado Flood Safety and Wildfire Preparedness Week

Thursday, March 7th, 2019 4:07am MDT

WildfiresFloods and wildfires are arguably the two most common disasters Coloradans face with numerous such events occurring each year.  To better prepare residents for the danger of these disasters, this week is Colorado Flood Safety and Wildfire Preparedness Week.

Each day this week the National Weather Service will be posting public information statements covering a number of different topics about floods and wildfires.  These important messages should be required reading for all Coloradans so they know what to do to prepare for these events and handle them when they occur.

ThorntonWeather.com will be posting each of these messages as a service to our readers.  Please check back daily for a new topic.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BOULDER CO
600 AM MDT THU MARCH 7 2019

…Wildfire in Colorado…where do you get your information…

A mixture of large and small wildfires occurred across Colorado in 2018. These fires were due to a mixture of dry conditions, combined with gusty, warm winds and, sometimes, careless fire prevention efforts. There were instances when residents had to be evacuated as a large wildfire moved toward larger communities. Would you know what to do to protect yourself and your loved ones in this situation? In addition, if you live in an area that is susceptible to wildfires, how can you prepare yourself and your home?

To assist in your preparation for fire…the National Weather Service provides a variety of fire weather forecast products. Twice a day in Colorado…fire weather planning forecasts are made from each weather service office serving the state.

A Fire Weather Watch may be issued if in the next 12 to 48 hours the forecast includes gusty winds of 25 mph or greater…relative humidities of less than 15 percent for at least three hours, dry lightning, or a combination of weather and fuel conditions that may make large wildfires possible.

A Red Flag Warning will be issued if these same critical fire conditions are forecast within the next 24 hours. Both Fire Weather Watches and Red Flag Warnings are issued in coordination with land management agencies.

The fire weather spot program supports land management agencies for both prescribed burns and for wildfires. A fire weather spot forecast is a detailed forecast for an individual fire. For national type 2 or type 1 fires the National Weather Service will detail an IMET…incident meteorologist to a fire team to provide onsite weather support and detailed fire forecasts.

If you live in the urban interface there are a number of actions you can take to reduce your personal fire threat including reducing vegetation near the home and putting a fire resistant roof on your home. More information is available from your National Weather Service at: http://www.nws.noaa.gov/om/fire or from your Department of Homeland Security at: http://www.ready.gov/wildfires.

When a fire occurs, there may be years of increased flood threat on the burn scar, as a healthy forest can handle an inch to inch and a half of rain with no flood risk. Once the litter and vegetation is removed by fire…as little as a half inch of rain in a short period can cause serious and possibly life threatening flooding.

Colorado Flood Safety and Wildfire Preparedness Week continues through this Saturday

Colorado Flood Safety and Wildfire Preparedness Week

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Thornton’s Wednesday will warm only slightly, late day offers a chance for showers

Wednesday, March 6th, 2019 5:11am MDT

Moisture streaming in from the west coupled with cold air that just doesn’t move out will be the key factors in our weather today. We should see temperatures warm a bit from yesterday but not by a lot and the late afternoon and evening may bring some precipitation.

Partly cloudy skies start things off and similar sky conditions will be with us throughout the day. Winds will initially be out of the south shifting to come from the northeast in the afternoon.

With the flow from east / northeast, cold air is not going to be moving out. As a result, highs today will likely only top out in the mid to upper 30s.

Late afternoon and evening may bring us a sprinkle of rain initially, then, as temperatures drop, a change to freezing drizzle may occur. If it does, road conditions may be impacted. Some light snow will then be possible through midnight but minimal, if any at all, accumulation is expected.

Tonight, we will see some clearing after midnight with overnight lows near 20 degrees.

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Flash Flooding – Colorado Flood Safety and Wildfire Preparedness Week

Wednesday, March 6th, 2019 3:04am MDT

Floods and Flash FloodsFloods and wildfires are arguably the two most common disasters Coloradans face with numerous such events occurring each year.  To better prepare residents for the danger of these disasters, this week is Colorado Flood Safety and Wildfire Preparedness Week.

Each day this week the National Weather Service will be posting public information statements covering a number of different topics about floods and wildfires.  These important messages should be required reading for all Coloradans so they know what to do to prepare for these events and handle them when they occur.

ThorntonWeather.com will be posting each of these messages as a service to our readers.  Please check back daily for a new topic.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE PUEBLO CO
600 AM MDT WED MARCH 6 2019

Today’s topic during this Flood Safety and Wildfire Preparedness week is flash floods.

Flash floods are no strangers to Colorado. Since the year 1900, nearly 300 people have been killed in flash floods across the Centennial state.

In terms of lives lost, the worst flash flood occurred on July 31, 1976 in the Big Thompson Canyon between Estes Park and Loveland. A nearly stationary storm produced around 12 inches of rain in 4 hours, claiming 144 lives.

Three other notable flash floods in Colorado were:

In 1904, just north of Pueblo, a bridge failed and around 100 people drowned when a passenger train plunged into Fountain Creek.

The 1997 Fort Collins episode drowned 5 people and caused 200 million dollars of property damage.

In 2013, 9 people drowned during the historic September rain episode, which was a combination of flash floods and river floods. These floods were much more extensive than the Big Thompson Canyon flood of 1976, but because of timely and accurate warnings, many people stayed out of harms way and lives were saved.

A flash flood is defined as a rapid rise in water levels, generally occurring in less than 6 hours, along large creeks, normally dry washes, arroyos, or over normally dry land areas, and can occur with little advanced notice.

Flash floods frequently result from high rainfall rates, and infrequently result from dam failures, levee failures, or sudden breaks in river ice jams. Flash floods are very destructive, due to the force of the moving water, and the accompanying debris. This tremendous force can easily damage or destroy roadways, bridges, and buildings.

In recent years, Colorado has seen major flooding and damage when heavy rains have occurred on wildfire burn scar areas. If you are in or near a burn scar area, you need to plan ahead. Be aware of general flash flood plans and procedures that have been developed and implemented by your local emergency management officials. You should know your flash flood risks, and make your plans to save your life and those around you.

The National Weather Service forecast offices will discuss flash flood potential in daily hazardous weather outlooks, and in graphical weather stories on National Weather Service forecast office web sites.

During days when flash flooding is possible a Flash Flood Watch will be issued.

During days when flash flooding is likely or occurring, a Flash Flood Warning will be issued.

When a Flash Flood Warning is issued for your area, you need to act quickly if you are in a drainage area or in other low spots. Know your escape routes to higher ground and act as quickly as possible. It may be just a short walk or climb to that higher ground.

Many flash flood deaths occur in vehicles. Do not drive through a flooded roadway. The water may be much deeper than you think, because the roadway may be damaged or washed away. One to two feet of water will carry away most vehicles. Instead turn around, do not drown.

For more information on flood safety go to…

http://www.floodsafety.noaa.gov

Tom Magnuson
Warning Coordination Meteorlogist
National Weather Service Pueblo

Colorado Flood Safety and Wildfire Preparedness Week

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Warmer temperatures for Thornton’s Tuesday but readings will remain well below normal

Tuesday, March 5th, 2019 5:02am MDT

The chill continues to linger today with temperatures about 20 degrees below normal. That is, at least, a decent improvement over recent days.

Clear skies start us out but we will see a steady, slow increase in cloud cover as the day progresses. The coverage may inhibit the warming a bit.

As is, highs today right around the freezing mark are expected. The average high for today’s date is 51 degrees so while we will be warmer than yesterday, we are still much colder than normal.

Tonight, mostly cloudy skies will be above with lows dipping to the teens.

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Long Time Frame Flooding – Colorado Flood Safety and Wildfire Preparedness Week

Tuesday, March 5th, 2019 4:10am MDT

Floods and Flash FloodsFloods and wildfires are arguably the two most common disasters Coloradans face with numerous such events occurring each year.  To better prepare residents for the danger of these disasters, this week is Colorado Flood Safety and Wildfire Preparedness Week.

Each day this week the National Weather Service will be posting public information statements covering a number of different topics about floods and wildfires.  These important messages should be required reading for all Coloradans so they know what to do to prepare for these events and handle them when they occur.

ThorntonWeather.com will be posting each of these messages as a service to our readers.  Please check back daily for a new topic.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE PUEBLO CO
600 AM MDT TUESDAY MARCH 5 2019

Today’s topic during Colorado Flood Safety and Wildfire Preparedness Week is flooding which develops in the time frame of longer than 6 hours to several days.

Long duration floods in Colorado can result from snow melt…a combination of snow melt and heavy rain…or just heavy rain.

There have been some notable floods across the Centennial State…

In early June of 1921…a flood along the Arkansas River devastated the city of Pueblo. Estimates of drownings ranged from over 100 to over 300.

Around Memorial Day…1935…catastrophic flooding occurred on the Palmer Divide and the Colorado Springs area…causing millions of dollars of damage…and killing at least 18 people.

The mid-June 1965 flood was widespread across eastern Colorado…taking several lives…and causing over 500 million dollars of damage.

During late April and early May of 1999…after up to 14 inches of rain fell…a major flood occurred across southeast Colorado from Colorado Springs to La Junta.

In 2013, the historic rains and floods in September caused over 3 billion dollars of damage, and took 9 lives.

Just this last year during May, multiple days of heavy rain and snow caused flooding across many areas of eastern Colorado.

Floods in Colorado can result from rapid snow melt, ice jams, a combination of snow melt and heavy rain, or just heavy rain.

National Weather Service forecast offices in Colorado closely collaborate with regional river forecast centers that monitor the Colorado River…South Platte River…Arkansas River…and Rio Grande to come to a consensus on the likelihood of flooding along rivers and large creeks.

The National Weather Service will discuss flood potential in hydrologic outlooks…daily hazardous weather outlooks…and in graphical weather stories on National Weather Service forecast office web sites. Hydrologic statements may be issued for high flows that are within the banks of a river or large creek.

When flooding is possible on a river or large creek…a Flood Watch will be issued…meaning flooding is possible within the designated watch area.

When flooding is likely or occurring on a river or large creek…a Flood Warning will be issued…meaning flooding is expected or has been reported at designated river forecast points.

Flood Advisories may be issued for minor flooding on rivers and creeks.

An Areal Flood Warning may also be issued for flooding on a river or large creek in areas away from the designated river forecast points.

You can easily monitor potential flooding along rivers in Colorado and large creeks using the Advanced Hydrologic Prediction Service monitoring system. Information on this monitoring system can be obtained from this web site…

http://water.weather.gov/ahps

This monitoring system can be accessed on Colorado National Weather Service forecast office web sites from the left hand menu…by clicking…rivers and lakes under the hydrology banner.

At each river and large creek gauge…you can easily look at current and forecast water levels…flood categories…historic crests…and flood impacts. Probabilities of exceedance of certain water levels by week or over the long term are also available.

In general…there will be some time to prepare for river and large creek flooding…and emergency management in your area has plans in place to address flooding issues. Know these plans and how you should act accordingly when Flood Watches and Flood Warnings are in effect.

For more information on flood safety go to…

http://www.floodsafety.noaa.gov

Tom Magnuson
Warning Coordination Meteorologist
National Weather Service Pueblo

Colorado Flood Safety and Wildfire Preparedness Week

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Denver sets two cold weather record temperatures in two days

Monday, March 4th, 2019 5:12am MDT

Record Cold TemperaturesWe may have changed the calendar to March but it seems like we are receiving weather more common for January. The bone-chilling cold of recent weeks has continued and the Mile High City set two temperature records in as many days.

Yesterday, as measured at Denver International Airport, the Mile High City saw a high temperature of only 6 degrees. This easily broke the record for the coldest maximum (high) temperature for March 3rd. The previous record was 14 degrees set in 1978.

Thornton was slightly warmer yesterday with a high of 8 degrees.

Also of note, yesterday’s low temperature reading in Denver of -6 degrees, while not a record low for the date, was the coldest temperature reading in March since -7 degrees was recorded on March 2, 1960.

This morning, the mercury at DIA dropped to -5 degrees. That bested the record low temperature for March 4th of -3 degrees last set in 1978. Similarly, Thornton saw a low of -5 degrees.

Warmer weather is on its way but the warm up will be slow as the Arctic air and snow cover lingers. For what lies ahead, see the extended weather forecast here.

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The sun returns for Thornton’s Monday, warmth however does not

Monday, March 4th, 2019 5:01am MDT

The clouds and snow of the weekend will move out today and we will see a return of calm conditions and blue skies. Arctic air however will remain entrenched on the Front Range and temperatures will be well below normal.

We start out the day with mostly sunny skies and a few spots of patchy fog. A Wind Chilly Advisory remains in effect until 9:00am.

Mostly clear skies will be the rule through the balance of the day with light winds out of the east. Temperatures start out below zero and will warm, but only to the upper teens, perhaps the 20 degree mark.

Tonight, we will be in for another cold one. Partly cloudy skies will be above with lows dropping to near zero.

Keep an eye on the temperatures with our live weather gauges.

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Types of Floods – Colorado Flood Safety and Wildfire Preparedness Week

Monday, March 4th, 2019 3:20am MDT

Floods and Flash FloodsFloods and wildfires are arguably the two most common disasters Coloradans face with numerous such events occurring each year.  To better prepare residents for the danger of these disasters, this week is Colorado Flood Safety and Wildfire Preparedness Week.

Each day this week the National Weather Service will be posting public information statements covering a number of different topics about floods and wildfires.  These important messages should be required reading for all Coloradans so they know what to do to prepare for these events and handle them when they occur.

ThorntonWeather.com will be posting each of these messages as a service to our readers.  Check back each day for a new topic.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BOULDER CO
600 AM MDT MON MARCH 4 2019

Flooding can be a major problem in Colorado as we experienced in September 2013. Heavy rain fell over a large area of the foothills south to the Pikes Peak Region, resulting in flash flooding. Much of the water that fell across northeast Colorado eventually ended up in the South Platte River, with major river flooding having occurred from Greeley to the state line.

River flooding can result from heavy rain during the summer and from rapid snow melt or thunderstorm rain combining with runoff from melting snow. Flash flooding refers to a dangerous sudden rise in water within an urban area, in a canyon, or along a creek or wash over normally dry land area. Flash floods result from heavy rainfall, sudden breaks in river ice jams, and dam or levee failures.

Flash floods can occur within a few minutes or hours, and can move at surprisingly high speeds, striking with little warning. Flash floods are quite destructive because of the force of the moving water, and the debris that accumulates in flood waters, such as trees and boulders, which can destroy roadways, bridges and buildings.

Another complication in Colorado is the serious flooding that can result when heavy rain falls on recently burned areas. Anyone living downstream from a recently burned area should be aware of the changed conditions, which result in much faster, turbulent, debris and ash clogged waters from the burned area.

The National Weather Service will discuss flood and flash flood potential in daily Hazardous Weather Outlooks and in the graphical weather story on National Weather Service websites. On days with a high threat for flooding, you may hear of a Flash Flood or Flood Watch, which means that flash flooding or flooding is possible within the watch area.

A Flood Warning means that flooding is imminent or has been reported along a river.

A Flash Flood Warning means that flash flooding has been reported or is imminent.

When a Flash Flood Warning is issued for your area, act quickly. If advised to evacuate, do so immediately. Go to higher ground or climb to safety before access is cut off by flood waters. Go Up, Not Out. Nearly half of all flash flood fatalities are vehicle related. Do not enter a flooded roadway, instead Turn Around…Don’t Drown. In rapidly rising waters, backing up away from water would be safer. One to two feet of water will carry away most vehicles, and you also cannot tell if the road is damaged beneath the water.

More information on flooding hazards can be found on the National Weather Service Flood Safety page here.

Colorado Flood Safety and Wildfire Preparedness Week continues through this Saturday.

Colorado Flood Safety and Wildfire Preparedness Week

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March 3 to March 9: This Week in Denver Weather History

Sunday, March 3rd, 2019 5:45am MDT
This week in Denver weather history

March 3 to March 9: This Week in Denver Weather History

The month of March sometimes brings with it some of our most interesting weather with a wide variety of conditions possible. Our look back at this week in Denver weather history showcases this fact as we see damaging, high wind events, monster snow storms, and even thunderstorms.

From the National Weather Service:

2-3

In 1901…strong northwest winds raked the city for 2 days. On the 2nd…winds were sustained to 55 mph with gusts to 62 mph. The Chinook winds warmed the temperature to a high of 72 degrees…a record maximum for the date. On the 3rd…winds were sustained to 61 mph with gusts as high as 65 mph. The high temperature was 59 degrees.

In 1964…heavy snowfall of 6.3 inches was measured at Stapleton International Airport. East winds gusted to only 20 mph behind a cold front.

In 1978…5.0 inches of snowfall were measured at Stapleton International Airport where northeast winds gusted to 24 mph on the 2nd. The passage of a cold Canadian front kept temperatures only in the teens and 20’s on the 2nd after a high temperature of 33 degrees shortly after midnight. The temperature…after a morning low of 3 degrees below zero…climbed to only 14 degrees on the 3rd…setting a record low maximum for the date.

2-4

In 1963…heavy wet snow was accompanied by strong gusty winds across metro Denver. Snowfall totaled 11.6 inches at Stapleton Airport where north winds gusting to 44 mph caused much blowing and drifting snow. Hazardous driving conditions resulted in many traffic accidents.

In 1976…snowfall totaled 8.0 inches at Stapleton International Airport where…on the 4th…northeast winds gusted to 31 mph reducing the visibility to as low as 1/4 mile. Maximum snow depth on the ground was 7 inches. Nine inches of snow were measured in Boulder.

3

In 1875…six inches of snow fell in Georgetown.

In 1895…northwest bora winds were sustained to 45 mph with gusts to 58 mph in the city.

In 1966…cold northwest wind gusts of 50 to 90 mph occurred across metro Denver. Both cars and trucks were blown off an icy highway just east of Denver where some highways were closed by either blowing dust or blowing snow. A northwest wind gust to 43 mph was recorded at Stapleton International Airport. The strong winds caused limited minor damage.

In 1972…winds gusted to 55 mph in Boulder causing no reported damage. West winds gusted to 49 mph at Stapleton International Airport.

In 1985…snow struck metro Denver. Heaviest hit was Boulder where 6 to 8 inches were measured. Icy roads caused the closure of I-25 north and south of Denver due to traffic accidents. The snow also caused long delays at Stapleton International Airport where snowfall totaled only 2.6 inches.

In 1997…west winds gusted to 52 mph at Denver International Airport.

3-4

In 1932…a dust storm occurred on the 3rd during the late afternoon. North winds gusting as high as 38 mph behind a cold front kicked up much blowing dust. Light snow developed during the evening and continued through the early morning of the 4th. Snowfall totaled 2.7 inches.

In 1934…strong winds raked Boulder. A wind gust to 62 mph was recorded at Valmont just east of Boulder. The strong winds caused hundreds of dollars of damage in Boulder.

In 1981…the most vigorous snow storm of the season struck the state…closing many schools and most highways connecting Denver…Colorado Springs…and Limon. North winds gusting to 43 mph whipped nearly 10 inches of snow in Denver into 3-foot drifts and snarled traffic on the morning of the 4th. Snowfall totaled 9.8 inches at Stapleton International Airport.

In 1989…a storm dumped 2 to 6 inches of snow across metro Denver. The snow caused 2-hour air traffic delays at Stapleton International Airport where 3.0 inches of snow fell and north winds gusted to 23 mph on the 3rd. There were many traffic accidents across metro Denver. I-70 was closed east of Denver for a time on the 3rd.

In 1991…high winds raked the eastern foothills. Wind gusts of 60 to 90 mph were common with 119 mph recorded at Wondervu southwest of Boulder…106 mph on Shanahan Ridge and 92 mph at Table Mesa…both in southwest Boulder. Several trees were uprooted and traffic signs and lights blown over. Flying debris caused damage to homes… Buildings…and cars.

In Boulder…a stop sign was blown onto a car. There were no reports of injuries. Southwest winds gusting as high as 48 mph briefly reduced the prevailing visibility to as low as 1/16th mile in blowing dust at Stapleton International Airport on the 4th.

3-5

In 1961…snowfall totaled 8.3 inches at Stapleton Airport over the 3-day period with most of the snow…4.4 inches… Falling on the 3rd. Winds were generally light gusting to only 23 mph.

4

In 1887…snowfall was only 0.1 inch. This was the earliest last measurable snow of the season.

In 1971…a wind gust to 102 mph was recorded at the National Center for Atmospheric Research in Boulder. A wind gust to 83 mph was measured at the National Bureau of Standards. In downtown Boulder…sustained winds reached 35 mph with gusts as high as 57 mph. No significant damage was reported. West winds gusted to only 28 mph at Stapleton International Airport.

In 1982…brief heavy snow accompanied by a few thunderstorms struck metro Denver. Lightning struck a house in Arvada setting it afire. The thunderstorm produced 5 inches of snowfall in a 2-hour period in Wheat Ridge. The snow made roads very icy and slick causing a 59-car pile-up on I-70 in north Denver. Snowfall with thunder totaled only 1.3 inches at Stapleton International Airport.

In 1997…a fast moving pacific storm produced heavy snow in the foothills. Snowfall at Conifer measured 9 inches. Only light snow fell elsewhere over metro Denver. Snowfall totaled only 1.2 inches at the site of the former Stapleton International Airport. North northeast winds gusted to 28 mph at Denver International Airport.

4-5

In 1971…heavy post-frontal snowfall totaled 7.7 inches at Stapleton International Airport where north winds gusted to 28 mph.

In 1992…snow spread from the mountains into the eastern foothills where 19 inches fell in Coal Creek Canyon. Rain fell over lower elevations of metro Denver with 1.12 inches of precipitation recorded at Stapleton International Airport and only one half inch of snow. North winds gusted to 32 mph.

In 2004…snowfall totaled 1.8 inches at the Denver Stapleton site. This was the only measurable snowfall of the month. Northeast winds gusted to 29 mph at Denver International Airport.

» Click here to read the rest of March 3 to March 9: This Week in Denver Weather History

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