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September 2012 Thornton weather recap: Warmer and wetter than normal

Thornton saw yet another month with above normal temperatures during the month of September 2012.  The one saving grace was that it was also a wet one with above normal precipitation.

The month started out with three out of the first six days of the month recording temperatures above 90 degrees and the other three warming to above 85 degrees.

Cooler weather arrived on the 12th and Thornton saw a high of only 59.6 degrees.  Rain began late on the 11th and continued into the 12th as we recorded 1.32 inches of precipitation in our bucket during the period.  Denver officially recorded 0.95 inch on the 12th which was a record for the date.

Above normal temperatures soon returned however and overall we recorded 15 days of high temperatures of at least 80 degrees during the month.

Another storm system moved in on the 25th and 26th and brought more precipitation.  Thornton recorded 0.81 inch during the period.  At Denver International Airport 1.95 inch was recorded over the two day period.  On the 26th alone the airport recorded 1.41 inches, a record for the date.

The average temperature for the month was 64.0 degrees in Thornton.  DIA averaged 66.3 degrees which was 2.9 degrees above normal.

Temperatures in Thornton ranged from a high of 94.6 degrees on the first down to a low of 41.6 degrees on the 18th.  Denver saw its warmest temperature of 95 degrees on the 1st as well and its lowest of 45 degrees on the 22nd and 28th.

Thornton ended the month with a welcome 2.17 inches of precipitation.  Denver fared better with 2.95 inches, well above the September normal of 0.96 inch.  Officially the month went into the books as the 5th wettest October on record in Denver.

For the 12th consecutive September no snow was recorded in Denver.  The last time we went such a long period without September snow was from 1914 to 1926.

Click here to view the ThorntonWeather.com climatology report for September 2012.

ThorntonWeather.com September 2012 Temperatures

ThorntonWeather.com September 2012 Precipitation

Denver’s Official September 2012 Climate Summary

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2012... 

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2012

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................ 
TEMPERATURE (F)
RECORD
HIGH               97   09/01 1995
                        09/04/1995
                        09/05/1899
 LOW               17   09/29/1985
HIGHEST            95   09/01        97      -2       96  09/01
LOWEST             45   09/28        17      28       38  09/21
                        09/22
AVG. MAXIMUM     80.3              78.5     1.8     78.6
AVG. MINIMUM     52.3              48.3     4.0     49.9
MEAN             66.3              63.4     2.9     64.2
DAYS MAX >= 90      7               3.4     3.6        1
DAYS MAX = .01         5               6.5    -1.5        6
DAYS >= .10         3               3.3    -0.3        2
DAYS >= .50         3               0.6     2.4        1
DAYS >= 1.00        1               0.1     0.9        0

GREATEST
 24 HR. TOTAL    1.63   09/25 TO 09/26

SNOWFALL (INCHES)
RECORDS
TOTAL             0.0
TOTALS            0.0               1.3

DEGREE_DAYS
HEATING TOTAL      69               125     -56       95
 SINCE 7/1         69               141     -72       95
COOLING TOTAL     113                76      37       78
 SINCE 1/1       1235               764     471      941

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05
...................................................... 

WIND (MPH)
AVERAGE WIND SPEED              8.8
RESULTANT WIND SPEED/DIRECTION   3/197
HIGHEST WIND SPEED/DIRECTION    30/300    DATE  09/01
HIGHEST GUST SPEED/DIRECTION    37/290    DATE  09/01

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR           10
NUMBER OF DAYS PC             16
NUMBER OF DAYS CLOUDY          4

AVERAGE RH (PERCENT)     40

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              5    MIXED PRECIP                0
HEAVY RAIN                2     RAIN                       2
LIGHT RAIN                7     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       1
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                       6     FOG W/VIS

Thornton’s October weather preview: Normally calm but susceptible to extremes

Thornton, Colorado's October weatherWith 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.

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.

September 30 to October 6 – This Week in Denver Weather History

This Week In Denver Weather History
September 29 to October 6 - This Week in Denver Weather History

Our look back at this week in Denver weather history shows what has historically been a relatively quiet week. However that isn’t to say there aren’t events of note including days with severe thunderstorms, including one date that brought multiple tornadoes.

Be sure to scroll down to the bottom to check out video of one of the tornadoes that struck near Brighton on October 4, 2004.

From the National Weather Service:

30

In 1898…south winds were sustained to 41 mph with gusts to 54 mph.

In 1940…a late season thunderstorm in the city caused one lightning death.

In 1944…the month ended with a trace of rain on this date and for the month. A trace of rain also occurred on the 4th…9th…and 10th. There was no measurable precipitation for the month. The total of a trace of precipitation for the month equaled the driest September on record first set in 1892.

In 2009…a trained spotter in Coal Creek Canyon…recorded a peak wind gust to 88 mph.

30-1

In 1959…heavy snowfall totaled 5.9 inches at Stapleton Airport. Winds were light.

1

In 1892…the highest temperature ever recorded in October… 90 degrees…occurred. This is also the latest 90 degree reading of the season.

In 1898…southwest winds were sustained to 40 mph with gusts to 49 mph in the city.

In 1927…a trace of snow was the only snow of the month… Ranking the year…amongst several other years…the second least snowiest on record.

In 1971…a wind gust to 90 mph was recorded at Buckley Field in Aurora. The severe winds caused damage in northeast metro Denver. A brick wall of a bowling alley was blown down…the roof was blown off a garage…and some business signs were damaged. A man in the bowling alley was injured by flying glass. Northwest winds gusted to 43 mph at Stapleton International Airport.

In 1994…unusually strong thunderstorms for so late in the season pummeled metro Denver with large hail. The largest hail…2 inches in diameter…fell at Buckley Field. Hail 1 3/4 inches in diameter fell 7 miles northeast of Boulder and at Niwot. Hail 3/4 to 1 1/2 inches in diameter fell in Boulder…Arvada…wheat Ridge…Edgewater…capitol hill and northwest Denver…Bennett…and Strasburg. Hail of unknown size damaged a Boeing 737 aircraft and injured both pilots at Stapleton International Airport when the windshield was broken out on takeoff. Half inch diameter hail fell at Stapleton International Airport where northwest winds gusted to 40 mph and rainfall totaled 0.82 inch.

In 2009…strong downslope winds near the foothills produced a peak wind gust to 84 mph at the national wind technology center near Rocky Flats.

Continue reading September 30 to October 6 – This Week in Denver Weather History

Unusual late September severe weather visits Colorado bringing tornadoes & hail

Severe weather more typical of June than late September hit Colorado yesterday.
Severe weather more typical of June than late September hit Colorado yesterday.

September weather in Colorado is typically tranquil and one of the more pleasant months in the state.  This week however that wasn’t the case, especially yesterday when severe thunderstorms rumbled across the parts of the state.

Tuesday and Wednesday brought heavy rains to parts of the northern Front Range.  The precipitation was welcomed as it provided much-needed relief from the recently dry conditions.

Yesterday in Colorado Springs and La Junta thunderstorms brought hail that accumulated up to 6 inches deep.  Mother Nature however held more surprises as she brought tornadoes to other parts of the state.

Three tornadoes were reported in northeastern Colorado – one each in Adams, Douglas, and Weld counties.  None of the three caused any damage.

A fourth twister however occurred in southern Colorado near Del Norte in Rio Grande County northwest of Alamosa.  Local resident Julie Sauvigne captured amazing video of the tornado as it ripped through her property causing EF0 level damage to her home.

Watch the video below.  Notice how the visible funnel is almost directly above Sauvigne while the circulation on the ground was occurring in a field nearly a mile away!

September 23 to September 29 – This Week in Denver Weather History

This Week In Denver Weather History
September 23 to September 29 - This Week in Denver Weather History

While typically the last week of September is calm, that isn’t always the case. In our look back at this week in Denver weather history we see damaging wind, dangerous lightning and September’s biggest snowfall on record in the Mile High City.

From the National Weather Service:

23

In 1873…north to northwest winds blowing almost a gale spread clouds of dust and sand into the city during the afternoon and evening. From the roof of the weather observer’s building…houses a few hundred yards away were not visible and not even the sky could be seen through the clouds of sand. The wind reached sustained speeds of 35 mph…but only 28 mph was registered for any one hour.

In 1977…wind gusts from 50 to 80 mph were reported along the foothills. A northwest wind gust to 53 mph was recorded at Stapleton International Airport.

23-24

In 2000…the first snowstorm of the season brought heavy snow to areas in and near the foothills. While the heaviest snow fell north of metro Denver…6 inches were measured in Boulder…4 inches at both Castle Rock and Morrison…but only 0.2 inch at the site of the former Stapleton International Airport where most of the precipitation fell as rain. At Denver International Airport where drizzle and rain fell on the 23rd… Snowfall during the early morning of the 24th was estimated at 2.1 inches due to melting. The foothills west of Denver received more snow with 10 inches measured at conifer…9 inches 11 miles southwest of Morrison… 8 inches atop Crow Hill…7 inches at Chief Hosa…and 5 inches at Ralston Reservoir.

24

In 1901…northwest winds were sustained to 50 mph with gusts as high as 57 mph in the city.

In 1932…thunderstorm rainfall of only 0.11 inch was the only measurable precipitation for the month that year in the city.

In 1986…a very strong wind storm roared across metro Denver. Boulder was hit hardest. Winds peaked to 131 mph at the National Center for Atmospheric Research. This is thought to be the highest wind gust ever recorded in Boulder during September. A wind gust to 118 mph was clocked on Davidson Mesa and to 92 mph near Niwot. Gusts of 70 to 80 mph were common over all of Boulder where an estimated 70 to 90 large trees were uprooted. About a dozen of them hit cars. Two walls of a building under construction were toppled and solar panels were blown off a house. Traffic lights and power lines were downed. Damage to power equipment alone was estimated at 100 thousand dollars. Wind gusts to 87 mph at Jefferson County Airport damaged two planes. A woman was seriously injured in Boulder. She suffered a fractured skull when struck by a falling tree limb. Trees were also downed in Louisville and Lafayette. West wind gusts to 45 mph were recorded at Stapleton International Airport.

Continue reading September 23 to September 29 – This Week in Denver Weather History

September 16 to September 22 – This Week in Denver Weather History

This Week In Denver Weather History
September 16 to September 22 - This Week in Denver Weather History

Given our hot summer some may enjoy a look at what at times has been a cold and snowy week in Denver weather history. Not only one but two major snowstorms have occurred, both very damaging and both brought snowfall amounts we typically see in March, not September.

15-17

In 2000…unusually hot weather for so late in the season occurred when temperatures climbed into the 90’s setting daily record maximum temperatures on each of the 3 days. The high temperature was 92 degrees on the 15th and 95 degrees on both the 16th and 17th.

15-19

In 1906…rain on 5 consecutive days totaled 1.61 inches. A thunderstorm occurred on the 17th. High temperatures ranged from 48 degrees on the 16th to 65 degrees on the 15th. Low temperatures were in the lower to mid 40’s.

16

In 1874…a blast of west winds caused minor injuries during working hours in Boulder.

In Denver…the winds veered suddenly from the southwest to the northwest around noon and increased to a maximum sustained speed of 49 mph behind an apparent cold front. The winds remained strong and backed to the west for the remainder of the afternoon.

In 2000…the record high temperature of 95 degrees at Denver International Airport established or equaled 3 different record extremes: the high temperature broke the previous record high for the day of 92 degrees set over a century ago in 1895; it marked the warmest that it has been so late in September; it also marked the 60th day during the warm season that the temperature had reached 90 degrees or more…equaling the record first set on September 29…1994.

In 2006…strong Bora winds behind a pacific cold front raked the eastern slopes of the mountains and metro Denver during the afternoon. Northwest winds were sustained to 40 mph with gusts as high as 54 mph at Denver International Airport.

In 2007…a severe thunderstorm produced a peak wind gust of 67 mph…about one mile east of Bennett. At Denver International Airport…a peak wind gust of 48 mph was observed.

16-19

In 1971…a record breaking early fall snow storm caused extensive damage to trees and utility lines. The heavy wet snow occurred with little wind…but caused record breaking cold temperatures for so early in the season. Snowfall totaled 15.6 inches at Stapleton International Airport with most of the snowfall…12.0 inches…occurring on the 17th. This was the heaviest first snow of the season. The maximum snow depth on the ground was 13 inches. Record low temperatures were set on three consecutive days: 31 degrees on the 17th…23 degrees on the 18th…and 20 degrees on the 19th…which was also a new all-time record minimum for the month at that time. Record low maximum temperatures were set on 4 consecutive days: 48 degrees on the 16th…35 degrees on the 17th…40 degrees on the 18th… And 42 degrees on the 19th.

Continue reading September 16 to September 22 – This Week in Denver Weather History

Remembering a national hero: NASA releases Neil Armstrong tribute video

It is fitting that Neil Armstrong's footprint will forever be on the moon just as the man remains in a nation's heart. (NASA)
It is fitting that Neil Armstrong's footprint will forever be on the moon just as the man remains in a nation's heart. (NASA)

There are few Americans who don’t know the name ‘Neil Armstrong’ and can’t cite the tremendous contribution the man made to exploration and our nation.  Following his passing last week, a memorial service was held today at the Washington National Cathedral and a new video tells much about the man.

On July 16, 1969, Neil Armstrong, Buzz Aldrin and Michael Collins took to the skies aboard their massive Saturn V rocket bound for the moon.  Five days later, Armstrong and Aldrin would lift the spirits of the nation and the imaginations of the world as they became the first men to walk on the moon.

Chosen because he was a civilian at the time, Armstrong would make that infamous ‘small step for [a] man, one giant leap for mankind’.  In doing so, the United States Navy veteran would forever be mentioned in the history books with the likes of Columbus, Polo, Lewis & Clark, Cook and Hillary.

We mourn the loss of this national hero but thank the Lord for a man who gave so much to his country.  As we wrote last week, “May he rest in peace and may one day our nation find the will to continue on the path which he and so many of his predecessors put us on.”

Rest in peace, Neil.

Storm brings much needed precipitation to Colorado Front Range

Following months of scorching heat and below normal precipitation, northeastern Colorado desperately needed precipitation.  Mother Nature finally provided relief as many locations recorded more than 1″ of rain over the past 24 hours.

Here in Thornton we recorded a welcome 1.32″ since yesterday.  Of that, 1.26″ was recorded since midnight today, the biggest single day precipitation event we have had since July 12, 2011.

Some other rainfall totals:

  • Denver International Airport: 0.97″
  • Denver City Park: 1.62″
  • Buckley Air Force Base: 0.38″
  • Rocky Mountain Metropolitan Airport (Broomfield): 0.61″
  • NCAR Table Mesa Boulder: 1.29″
  • Longmont Vance Brand Airport: 0.56″

View more totals for the metro area on the map below.

Snow was also recorded at higher elevations above 11,000 feet in the mountains southwest of Denver.  Pikes Peak was blanketed in white and received at least a few inches.

While the recent rain will provide some temporary relief, precipitation totals for the calendar year remain well behind normal.  For Denver an average year brings 14.92″ of liquid precipitation.  To date 2012 has only recorded 6.46″in the rain bucket.

24 hour rainfall totals for the Denver metro area from 5:30pm on Tuesday, September 11, 2012 to 5:30pm on Wednesday, September 12, 2012.
24 hour rainfall totals for the Denver metro area from 5:30pm on Tuesday, September 11, 2012 to 5:30pm on Wednesday, September 12, 2012.

NASA image: Spacewalking astronaut ‘touches the sun’

While they are viewed by the public these days as routine, there can hardly be a more dangerous – or thrilling – task for an astronaut to perform than a spacewalk.  The imagery captured by these modern day explorers is nothing short of amazing as seen in a photo of NASA astronaut Sunita Williams seemingly touching the sun during a spacewalk last week.

During an extravehicular activity (EVA) aboard the International Space Station, Williams and Japan Aerospace Exploration Agency astronaut Aki Hoshide performed much-needed maintenance and repairs to the orbiting platform.  During the six-hour, 28-minute spacewalk Hoshide captured an image of Williams appearing to reach for the sun at one point during the EVA.

NASA astronaut Sunita Williams, Expedition 32 flight engineer, appears to touch the bright sun during the mission’s third session of extravehicular activity (EVA) on Sept. 5, 2012.  (NASA)
NASA astronaut Sunita Williams, Expedition 32 flight engineer, appears to touch the bright sun during the mission’s third session of extravehicular activity (EVA) on Sept. 5, 2012. (NASA) Click the image for a larger view.

September 9 to September 15 – This Week in Denver Weather History

This Week In Denver Weather History
September 9 to September 15 - This Week in Denver Weather History

Our look back at this week is shorter than usual owing to the calmer weather we typically see this time of year. That isn’t to say however that there aren’t notable events like a tornado, lightning at the Adams County Fairgrounds that severely injured a man and the Fourmile Canyon wildfire.

From the National Weather Service:

5-9

In 1988…layers of smoke aloft from large forest fires in Yellowstone National Park completely obliterated the sun at times. At Stapleton International Airport…surface visibility was reduced at times to 5 and 6 miles in smoke.

5-13

In 2010…the Fourmile Canyon wildfire…northwest of Boulder… Broke out on the morning of the 5th. It originated from an unattended fire pit at a local residence. The wildfire quickly consumed 5 1/2 square miles or 3500 acres the first day…and forced the evacuation of over three thousand residents. Erratic 45-mph gusts sent the fire in two directions at times. Very dry weather conditions preceded the fire. The combination of strong winds…low relative humidities and dry fuels allowed the wildfire spread rapidly through the steep…heavily forested terrain. The flames were reportedly 20 to 50 feet in length. Towns within the burn area included Salina…Wallstreet and Gold Hill. The dry conditions coupled with gusty winds ranging from 45 to 64 mph persisted for several more days. Fire managers used as many as 700 firefighters and support personnel from 35 agencies and seven air tankers to battle the wildfire. A total of 6181 square acres or approximately 10 square miles were burned. The Fourmile Canyon wildfire was the most destructive fire in Colorado history in terms of the damage to personal property. It destroyed 171 homes with an estimated cost of 217 million dollars.

9

In 1933…heavy rain in the foothills over the clear creek and Golden Gate Canyon watersheds caused flooding in Golden and damaged the roadway in Golden Gate Canyon… Which resulted in its closure.

In 1969…a funnel cloud was sighted in southeast Denver. There was also considerable thunderstorm activity and local heavy rain across metro Denver. Rainfall totaled 1.30 inches at Stapleton International Airport where small hail also fell.

In 1973…hail from 3/4 inch to 1 3/4 inches in diameter fell in Westminster and south of Broomfield.

In 2009…a man was critically injured when he was struck by lightning while riding his bicycle. He was nearing a paramedic van when he was hit. His heart stopped but paramedics quickly responded and were able to resuscitate him.

In 2011…a man was struck by lightning at the Adams County fairgrounds. He was leaning against a tree while watching a cross country meet when the tree was hit. The lightning traveled down the tree and up through the ground…using him as a conductor. The victim received second and third degree burns.

9-10

In 1933…heavy rain over the Cherry Creek…plum creek…big dry creek…and little dry creek watersheds caused flooding on the South Platte River in Denver overnight. Nearly an inch of rain…0.98 inch…fell in the city.

In 1944…a trace of rain fell on each day. This together with a trace of rain on the 4th and 30th was the only precipitation for the month. The total of a trace of precipitation for the month equaled the driest September on record first set in 1892.

In 1994…unusually very warm weather resulted in three temperature records being equaled. High temperatures of 94 degrees on the 9th and 93 degrees on the 10th equaled record maximums for the dates. Low temperature of 63 degrees on the 9th equaled the record high minimum for the date.

Continue reading September 9 to September 15 – This Week in Denver Weather History