August 12 to August 18 - This Week in Denver Weather History
Denver’s weather calms considerably in August as compared to many other months but the history books show plenty of notable events in our past. Lightning, flooding rain and even a tornado highlight this week in Denver weather history.
8-13
In 1875…clouds of grasshoppers were seen flying through the air on the prevailing winds during each day.
12
In 1876…the temperature climbed to a high of 100 degrees in downtown Denver.
In 1941…excessive thunderstorm rainfall flooded streets and delayed traffic for a few hours in some sections of the city. The basements of a considerable number of homes and commercial buildings were flooded. The total value of the damage was unknown. Only 0.94 inch of thunderstorm rainfall was recorded downtown.
In 1969…a man and a 9-year old boy were injured…when lightning struck a tree near where they were standing. Both were revived after treatment…but the boy later died of respiratory failure due to electrical shock.
In 1984…heavy thunderstorm rains drenched southern metro Denver. Rural roads in Douglas County received minor washouts. Hail…as large as 3/4 inch in diameter…was reported in southeast Aurora with one inch diameter hail reported near Parker. Rainfall totaled 1.00 inch at Stapleton International Airport.
12-13 in 1975…heavy rains caused flash flooding along the foothills from Denver north. Thunderstorm rainfall totaled 1.56 inches at Stapleton International Airport.
In 2004…a brief cool spell resulted in two daily temperature records. The low temperature of 49 degrees was a record minimum for the 12th…as was the low temperature of 48 degrees on the 13th.
13
In 1959…thunderstorm winds gusted to 53 mph at Stapleton Airport.
In 1983…thunderstorms dumped torrential rain in Northglenn… Thornton…and Broomfield. Northglenn was drenched with 1.72 inches in 30 minutes. Street flooding was widespread. Hail…as large as 3/4 inch in diameter…was reported 7 miles northeast of Boulder along with heavy rain which caused some street flooding.
In 2000…lightning sparked 3 small grass fires near Golden. The fires were quickly contained. Hail as large as 3/4 inch in diameter fell in Castle Rock.
NASA's Curiosity rover and its parachute were spotted by NASA's Mars Reconnaissance Orbiter as Curiosity descended to the surface on Aug. 5 PDT (Aug. 6 EDT). Image Credit: NASA/JPL-Caltech/Univ. of Arizona
Landing on Mars has proven over the years to be an extremely difficult task with few space probes seeing success. NASA’s Curiosity rover beat the odds completing its 352 million mile journey with a perfect landing early Monday morning.
The probe was launched on November 26 and as it neared its touchdown on the Red Planet, NASA had been discussing the “7 minutes of terror” involved in inserting the probe into the Martian atmosphere and successfully landing. The craft used an amazing array of equipment to land including a sky crane and a supersonic parachute.
The image above was taken by the Mars Reconnaissance Orbiter in a perfectly choreographed event designed to capture just an image. The photo shows Curiosity dangling under its massive parachute as it descends to the surface.
NASA’s Curiosity rover and its parachute were spotted by NASA’s Mars Reconnaissance Orbiter as Curiosity descended to the surface on Aug. 5 PDT (Aug. 6 EDT). The High-Resolution Imaging Science Experiment (HiRISE) camera captured this image of Curiosity while the orbiter was listening to transmissions from the rover. Curiosity and its parachute are in the center of the white box; the inset image is a cutout of the rover stretched to avoid saturation. The rover is descending toward the etched plains just north of the sand dunes that fringe “Mt. Sharp.” From the perspective of the orbiter, the parachute and Curiosity are flying at an angle relative to the surface, so the landing site does not appear directly below the rover.
The parachute appears fully inflated and performing perfectly. Details in the parachute, such as the band gap at the edges and the central hole, are clearly seen. The cords connecting the parachute to the back shell cannot be seen, although they were seen in the image of NASA’s Phoenix lander descending, perhaps due to the difference in lighting angles. The bright spot on the back shell containing Curiosity might be a specular reflection off of a shiny area. Curiosity was released from the back shell sometime after this image was acquired.
This view is one product from an observation made by HiRISE targeted to the expected location of Curiosity about one minute prior to landing. It was captured in HiRISE CCD RED1, near the eastern edge of the swath width (there is a RED0 at the very edge). This means that the rover was a bit further east or downrange than predicted.
The image scale is 13.2 inches (33.6 centimeters) per pixel .
HiRISE is one of six instruments on NASA’s Mars Reconnaissance Orbiter. The University of Arizona, Tucson, operates the orbiter’s HiRISE camera, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project for NASA’s Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the spacecraft.
August 5 to August 11 - This Week in Denver Weather History
As we enter August the weather typical is a bit calmer as the atmosphere settles down. However our look back at this week in Denver weather history shows that Mother Nature can still visit plenty of excitement on us.
From the National Weather Service:
5
In 1881…the low temperature cooled to only 76 degrees…the record high minimum temperature for the month.
In 1889…southwest winds were sustained to 42 mph.
In 1918…hail pelted the city…but was light and caused no damage. Precipitation totaled 0.25 inch. Northwest winds were sustained to 31 mph.
In 1964…lightning struck two boys in Denver while playing ball. One was treated and released from the hospital…but the other boy suffered second degree electrical shock and cardiac arrest and was hospitalized in critical condition for several days.
In 1969…two tornadoes touched down briefly in an open field southeast of Buckley Field in Aurora. No damage was reported.
In 1970…heavy rain in the Indian Hills area in the foothills west of Denver caused flash flooding…which washed out roads and damaged other property. Hail accumulated to a 3 inch depth with stones up to golf ball size; however…most of the damage was from flooding.
In 1982…2.38 inches of rain fell in an hour in Arvada… Causing minor flooding on Ralston Creek. In Westminster… 1 1/2 inches of rain fell…causing damage to streets and culverts. In addition…lightning caused some minor power outages across metro Denver.
In 1983…very heavy thunderstorms hit the southern portion of metro Denver. Heavy rainfall…as much as 2.89 inches in 38 minutes…caused widespread street flooding in southeast Denver. Two feet of water covered a section of I-25. Hail up to golf ball size accompanied the storm in Littleton and Englewood…along with 60 mph winds.
In 1984…a heavy thunderstorm drenched Littleton with up to 2.35 inches of rain in an hour…along with small hail that piled up to 2 inches deep. Flood waters were up to 4 feet deep in parts of town with many basements flooded. There were some power outages caused by lightning.
In 1990…a thunderstorm dumped 1.25 inches of rain in 12 minutes near tower and smoky hill roads in southeast Aurora. Minor street flooding was reported in the area.
In 1992…a pilot reported two funnel clouds near Cheery Creek Reservoir. Both dissipated quickly. Dime size hail fell near Franktown.
In 1994…one inch diameter hail fell near Strasburg. No damage was reported.
In 1999…a dog kennel east of Denver International Airport… Was flooded when a small dam…upstream in Elbert County… Was breached. The floodwaters…up to 4 feet deep…washed away some 6-foot fences and other small buildings. Ten of the 70 dogs boarded at the kennel drowned.
In 2002…a mail carrier was struck by lightning as he inserted a key into a multi-unit mailbox in Bailey. The shock knocked the man back against the mail truck. He suffered minor injuries. Lightning struck a residence in Commerce City. The resulting fire destroyed the roof of a detached garage and damaged much of its contents. Hail as large as 1 3/4 inches in diameter pelted pine. One inch diameter hail fell in Arvada and southwest Denver. Heavy rain triggered a mudslide along U.S. Highway 285 near Bailey. Both lanes of traffic had to be closed until debris could be removed from the highway. Several residences in the Bailey and Glenisle areas were also flooded.
In 2004…heavy thunderstorm rainfall caused localized flash flooding in Virginia canyon near Idaho Springs. Sections of the Virginia Canyon Road had to be closed due to the floodwaters.
In 2008…a severe thunderstorm produced large hail…up to 1 1/4 inches in diameter…northeast of Parker. Several automobiles were damaged.
Thornton recorded its hottest month of the past six years during July 2012.
For the second month in a row, Thornton saw extraordinarily warm temperatures in July. The month not only was the warmest July ever recorded by ThorntonWeather.com, it was the warmest month recorded since we began operation.
The average temperature for July 2012 was an astonishing 75.5 degrees. This was 1.8 degrees above Thornton’s average for July over the past six years, a significant increase.
Temperatures ranged from a high of 98.7 degrees on July 1 down to a low of 56.6 degrees on July 11.
In all we recorded 23 days with high temperatures at or above 90 degrees. We did however manage to escape the month without breaking the century mark.
In terms of precipitation Thornton didn’t fare too poorly. We recorded 1.92 inches of precipitation in our rain bucket. This was only 0.03” below the six year average of 1.95 inches.
July 29 to August 4 - This Week in Denver Weather History
The effects of our annual monsoon season are portrayed in detail in our look back at this week in Denver weather history. Numerous cases of flooding resulting from heavy rainfall are seen as are other severe weather events including hail and even tornadoes.
From the National Weather Service:
13-5
In 2008…a streak of 24 consecutive days of 90 degrees shattered the previous record of 18 consecutive days established in 1901 and 1874. Ironically…no new single day record high temperatures were set in the month of July. In August however…a record of 104 degrees was set on the 1st…and another record of 103 degrees was set on the 2nd. In addition…a record low min of 70 degrees was set on August 2nd.
18-2
In 1987…a streak of 16 consecutive days of 90 degrees ranked 4th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.
27-31 in 1956…96 percent of the total precipitation for the month of July occurred over the last five days of the month. Heavy thunderstorms produced 4.00 inches of rainfall at Stapleton Airport. This amount of precipitation in 5 days or less had been exceeded only 3 times in previous record. The last time had been in December of 1913 as snow. Considerable property damage occurred across metro Denver from flooding.
28-30
In 1889…dense smoke from forest fires in the mountains obscured the sun over the city for three days.
In 1971…a vigorous cold front late on the 28th produced northeast wind gusts to 39 mph and record breaking cold temperatures on the 29th and 30th. The temperature dipped to 47 degrees on the 29th and 43 degrees on the 30th… Setting record minimums for the dates. Upslope cloudiness along with rain and fog early on the 29th helped set a record low maximum temperature of 58 degrees for the date.
29
In 1878…a total eclipse of the sun was observed at 2:20 pm. From before to during the eclipse…the temperature in the sun fell from 114 degrees to 82 degrees…while the shade temperature fell from 89 degrees to 83 degrees.
In 1880…heavy thunderstorm rain and hail flooded streets and ditches.
In 25 minutes…0.76 inch of rain fell on the city along with large hail to 3/4 inch in diameter. There were no strong winds with the storm.
In 1890…a thunderstorm produced sustained west winds to 48 mph with gusts to 60 mph…but only 0.01 inch of rain.
In 1956…heavy rain and hail fell over west and north Denver.
In 1964…hail to 3/4 inch in diameter fell at Lowry Airfield.
In 1978…a small tornado was sighted just east of Parker. No damage was reported.
In 1989…heavy rain drenched all areas of the Front Range… Both in the foothills and adjacent plains. Amounts of 1 to 3 inches were general over the area. Damage was confined to a few minor road washouts and some street…basement…and crop flooding. Thunderstorm rainfall totaled 1.44 inches at Stapleton International Airport where north winds gusted to 43 mph. Lightning struck a 250 thousand dollar home near Nederland and started a fire which destroyed all of it except two garages. Lightning started a fire in a home in Evergreen. It reached the house by hitting a tree…then traveling through a metal clothesline strung between the tree and the building.
In 1995…thunderstorm winds gusted to 59 mph in Brighton. Thunderstorm winds from the south-southeast gusted to 41 mph at Denver International Airport. High temperature of 99 degrees was a new record maximum for the date in Denver.
In 1997…heavy rain caused flooding in an apartment building in Westminster. Several residents had to be evacuated from their apartments. A woman in aspen park received minor injuries…when lightning passed through an office window and struck her. She suffered temporary blindness for about 15 minutes.
In 2003…hail as large as 1 inch in diameter pelted Conifer… Highlands Ranch…and Franktown.
The old saying says not to mess with Mother Nature and she apparently wanted to drive that point home in Boston yesterday. During a live weather forecast on WBZ-TV yesterday a lightning strike knocked the lights out in the studio.
Thunderstorms rolled through much of the northeastern United States yesterday. The storms brought heavy rain, strong wind and plenty of lightning.
Ironically Chief Meteorologist Todd Gutner was discussing those exact weather conditions when the bolt hit.
Following the boom of thunder and a burst of static the lights went out and some of the displays flickered. Amazingly enough the station was able to continue broadcasting and Gutner finished his forecast, albeit a bit in the dark.
A large solar flare on Thursday was expected to lead to heightened aurora activity this weekend but not as far south as Colorado. One Thornton resident however appears to have captured images of the northern lights Sunday morning.
The images by Justin Whitesel show a purple sky over the city as the geomagnetic storm hits the Earth. You can view an animation Whitesel put together here.
July 15 to July 21 - This Week in Denver Weather History
Denver’s weather is rarely boring and our look back at this week in Denver weather history shows that. There have certainly been many notable thunderstorms with hail and damaging wind. However the most interesting item is the first – and only – recorded instance of snow during the month of July in the Mile High City.
7-25
In 1934…a streak of 15 consecutive days of 90 degrees ranked 5th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.
13-5
In 2008…a streak of 24 consecutive days of 90 degrees shattered the previous record of 18 consecutive days established in 1901 and 1874. Ironically…no new single day record high temperatures were set in the month of July. In August however…a record of 104 degrees was set on the 1st…and another record of 103 degrees was set on the 2nd. In addition…a record low min of 70 degrees was set on August 2nd.
14-15
In 1985…thunderstorms dumped heavy rain and hail at numerous locations along the Front Range from Denver north. Some of the heaviest rain fell in northern and western suburbs of Denver. Up to 2.6 inches of rain drenched Arvada…and Thornton was soaked with 2 inches in 45 minutes. At least 5 homes in Arvada suffered extensive damage from water and mud…and many streets and basements were flooded. In southern Jefferson County…11 homes were struck by lightning.
15
In 1879…a terrific hail storm occurred in the vicinity of Buffalo Station on the south park railroad in the South Platte River canyon about 39 miles south of Denver. Stones as large as hen’s eggs fell thick and fast and broke nearly every pane of glass in the windows of the building. A “waterspout” or cloudburst caused much loss of property from flash flooding on a nearby gulch. The torrent of water caused a deafening roar as it uprooted trees and carried huge Boulders and other debris. It struck the house and sawmill simultaneously and carried them away like straws…leaving little behind. The water continued to rush down the gulch for several hours. Serious damage was done to the south park railroad. The track and roadbed were destroyed for several miles. At about the same time…heavy rains in the vicinity of the headwaters of Cherry Creek produced a rapid rise in the creek…which drowned a few head of cattle and washed away two footbridges and some fences. Only 0.10 inch of rainfall was recorded in Denver.
In 1896…a thunderstorm produced sustained southwest winds to 40 mph with gusts to 46 mph.
In 1902…the temperature reached a high of 100 degrees in downtown Denver…which was a record maximum for the date.
In 1929…a thunderstorm did considerable damage to property in the eastern portion of the city. Heavy hail ranging in size from 1/4 to 3/4 inch in diameter…severe lightning… And high winds accompanied the heavy rain. Basements were flooded…and streets were impassable in places for several hours due to the heavy rainfall. Lightning damaged several telephone poles. Hail did extensive damage to gardens and flowers. The hail was up to a foot deep in places. There was no estimate of damage from the storm. A thunderstorm produced only a trace of rain and east winds to 24 mph in downtown Denver.
In 1959…thunderstorm rain totaled 0.41 inch in 8 minutes and winds gusted to an estimated 50 mph near downtown Aurora where half inch diameter hail was also reported. After the storm moved to the east…complete double rainbows were observed from the weather bureau office at Stapleton Airport.
In 1962…hail pelted the area in Adams County around Henderson and Brighton…causing extensive damage to corn…grain…beets…and row crops. Crop damage was estimated at 250 thousand dollars.
In 1963…a man received severe burns when struck by lightning while painting a building in south Denver.
In 1965…a state patrolman sighted a tornado near Bennett. It touched down over open ground…but caused no damage.
In 1967…heavy rains flooded streets and underpasses in south Denver. Heavy rain and minor wind damage were reported in wheat ridge…Aurora…Englewood…and Littleton. Basements were flooded and power disrupted. The clouds and rain resulted in a high temperature of only 72 degrees…which was a record low maximum for the date.
In 1974…a severe lightning storm damaged several homes and caused a number of power outages in both Denver and western Arapahoe counties.
In 1975…lightning killed a girl west of Boulder.
In 1982…winds gusted to 60 mph at Stapleton International Airport…and strong winds blew down walls at a construction site in Aurora where a nearby tree was uprooted.
In 1985…0.79 inch of rain fell in 30 minutes at Castle Rock. Much of the town lost power when lightning struck the town’s transformer.
In 1992…a man was struck by lightning while horseback riding near Castle Rock. Two people were struck by lightning near Highlands Ranch in south metro Denver. A man was struck by lightning while riding in the back of a pick-up truck in Franktown. All received minor injuries. Strong thunderstorms moved through east metro Denver…producing large hail and flash flooding. Hail up to 1 1/4 inches in diameter fell near Buckley Air National Guard base. Rainfall of 1 to 3 inches fell in Aurora in less than an hour…leaving water up to 18 inches deep in some areas. Thunderstorm rainfall was measured at 0.97 inch at Stapleton International Airport…where 3/8th inch diameter hail fell and south winds gusted to 44 mph.
An X1.4 flare was observed on the sun by NASA's SDO on Thursday, July 12, 2012.
The coronal mass ejection (CME) that resulted from the solar flare on Thursday has begun hitting the Earth. Satellite and terrestrial stations began picking up the increase in geomagnetic activity at around 1:00pm MDT Saturday.
The solar flare was a significant one as is the CME however it is not expected to be powerful enough to have any ill effects on earth. More significant events can affect satellites and even bring down power grids.
Here on Earth the most notable effect will be an increase in aurora activity. Unfortunately it doesn’t appear the CME is strong enough to push the aurora down to Colorado but areas across the northern latitudes of the contiguous United States may be treated to a show.
NASA depiction of a solar flare and the resultant coronal mass ejection (CME) hitting the Earth. (NASA)
A very large solar flare erupted on the Sun yesterday and the Coronal Mass Ejection (CME) is speeding toward the Earth right now. It is expected to arrive early Saturday morning (4:30am MDT + / – 7 hours) and if you can get away from the city lights, even northern Colorado has a chance to see the heightened aurorae. Here is some good background info on solar flares and CMEs from NASA.
Space weather starts at the Sun. It begins with an eruption such as a huge burst of light and radiation called a solar flare or a gigantic cloud of solar material called a coronal mass ejection (CME). But the effects of those eruptions happen at Earth, or at least near-Earth space. Scientists monitor several kinds of space “weather” events — geomagnetic storms, solar radiation storms, and radio blackouts – all caused by these immense explosions on the Sun.
One of the most common forms of space weather, a geomagnetic storm refers to any time Earth’s magnetic environment, the magnetosphere, undergoes sudden and repeated change. This is a time when magnetic fields continually re-align and energy dances quickly from one area to another.
Geomagnetic storms occur when certain types of CMEs connect up with the outside of the magnetosphere for an extended period of time. The solar material in a CME travels with its own set of magnetic fields. If the fields point northward, they align with the magnetosphere’s own fields and the energy and particles simply slide around Earth, causing little change. But if the magnetic fields point southward, in the opposite direction of Earth’s fields, the effects can be dramatic. The sun’s magnetic fields peel back the outermost layers of Earth’s fields changing the whole shape of the magnetosphere. This is the initial phase of a geomagnetic storm.
The next phase, the main phase, can last hours to days, as charged particles sweeping into the magnetosphere accumulate more energy and more speed. These particles penetrate closer and closer to the planet. During this phase viewers on Earth may see bright aurora at lower latitudes than usual. The increase – and lower altitude – of radiation can also damage satellites traveling around Earth.
The final stage of a geomagnetic storm lasts a few days as the magnetosphere returns to its original state.
Geomagnetic storms do not always require a CME. Mild storms can also be caused by something called a corotating interaction region (CIR). These intense magnetic regions form when high-speed solar winds overtake slower ones, thus creating complicated patterns of fluctuating magnetic fields. These, too, can interact with the edges of Earth’s magnetosphere and create weak to moderate geomagnetic storms.
Geomagnetic storms are measured by ground-based instruments that observe how much the horizontal component of Earth’s magnetic field varies. Based on this measurement, the storms are categorized from G1 (minor) to G5 (extreme). In the most extreme cases transformers in power grids may be damaged, spacecraft operation and satellite tracking can be hindered, high frequency radio propagation and satellite navigation systems can be blocked, and auroras may appear much further south than normal.
Solar Radiation Storms
A solar radiation storm, which is also sometimes called a solar energetic particle (SEP) event, is much what it sounds like: an intense inflow of radiation from the sun. Both CME’s and solar flares can carry such radiation, made up of protons and other charged particles. The radiation is blocked by the magnetosphere and atmosphere, so cannot reach humans on Earth. Such a storm could, however, harm humans traveling from Earth to the moon or Mars, though it has little to no effect on airplane passengers or astronauts within Earth’s magnetosphere. Solar radiation storms can also disturb the regions through which high frequency radio communications travel. Therefore, during a solar radiation storm, airplanes traveling routes near the poles – which cannot use GPS, but rely exclusively on radio communications – may be re-routed.
Solar radiation storms are rated on a scale from S1 (minor) to S5 (extreme), determined by how many very energetic, fast solar particles move through a given space in the atmosphere. At their most extreme, solar radiation storms can cause complete high frequency radio blackouts, damage to electronics, memory and imaging systems on satellites, and radiation poisoning to astronauts outside of Earth’s magnetosphere.
Radio Blackouts
Radio blackouts occur when the strong, sudden burst of x-rays from a solar flare hits Earth’s atmosphere, jamming both high and low frequency radio signals. The X-rays disturb a layer of Earth’s atmosphere known as the ionosphere, through which radio waves travel. The constant changes in the ionosphere change the paths of the radio waves as they move, thus degrading the information they carry. This affects both high and low frequency radio waves alike. The loss of low frequency radio communication causes GPS measurements to be off by feet to miles, and can also affect the applications that govern satellite positioning.
Radio blackouts are rated on a scale from R1 (minor) to R5 (extreme). The strongest radio blackouts can result in no radio communication and faulty GPS for hours at a time.
The old saying says not to mess with Mother Nature and she apparently wanted to drive that point home in Boston yesterday. During a live weather forecast on WBZ-TV yesterday a lightning strike knocked the lights out in the studio.
