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Video: NASA animation shows polar vortex and its far reaching effects
Unseasonably cold weather gripped much of the nation in January and brought a term to public’s consciousness they may not have heard before: polar vortex. As explained in a video from NASA, the ‘stretching’ of the vortex was responsible for the record-setting cold seen last month.
NASA writes:
This movie of temperature observations from NASA’s Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua spacecraft depicts the first major North American weather event of 2014: cold air moving out of the Arctic and south to cover much of the continent. The temperatures shown are at a pressure of 850 hectopascals (hPa, formerly knows as millibars; sea level pressure is normally around 1000 hPa). Pressures of 850 hPa correspond to an altitude of about 3,000 feet (1 kilometer) above sea level. The temperatures in the movie range from about minus 18 degrees Fahrenheit (245 Kelvin or minus 28 degrees Celsius) to warmer than 66 degrees Fahrenheit (290 Kelvin or about 17 degrees Celsius). The very coldest temperatures in purples and blues are minus 18 to 17 degrees Fahrenheit (minus 28 to about minus 8 degrees Celsius).
The most obvious feature of the movie is the tongue of cold air moving out of Canada and southward to cover much of the eastern United States during early January 2014. This event was covered extensively in the media, and introduced the term ‘polar vortex’ to a broader audience.
This global perspective illustrates some features not noted in all the recent media attention. Perhaps most obvious: this is not a global phenomenon. The eastern half of the United States includes only about one percent of the total surface area of the planet (about two million of 197 million square miles). One advantage of satellite observations, as from AIRS, is coverage of the entire planet. A truly global perspective is required when studying variations in climate, and this event must be compared against a number of other phenomena occurring around the planet. Note that Alaska and northern Eurasia were warm during this period of unusual cold over the eastern United States.
Photo: Bald eagle and afternoon iridescent clouds
One of our friends was hanging out along the South Platte again this afternoon. Had to shoot pictures into the sun but with the iridescent clouds in the background it looks really cool.
Cloud iridescence is caused by clouds (usually cirrus) that have small water droplets or ice crystals in them causing the light to be diffracted, or spread out. The phenomena is much like the rainbow colors seen with oil in water.
Remember we are always looking for pics of just about anything to add to our monthly slideshow. Be sure to email or post them so we can add them. Check out this month’s slideshow here.
Denver sets record coldest high temperature for February 6
The big chill continued on Thursday as for the second day in a row the Mile High City’s high temperature set a record as the coldest for the date.
As officially measured at DIA, Denver’s high temperature today was 1 degree. That easily bested the previous record low maximum for February 6 of 5 degrees set in 1929 and years prior.
The mark was an improvement, albeit a slight one, over yesterday’s high of 1 degree below zero which also set a record.
Here in Thornton we fared slightly better with our high temperature topping out at 4 degrees today and 1.9 degrees on Wednesday.
Warmer weather is on the way as the cold Arctic air mass is expected to be pushed out tomorrow. Temperatures on Friday should climb above freezing for the first time in eight days.
Arctic chill breaks cold temperature record in Denver
With a large, cold air mass settled in across much of the nation’s midsection, weather records are bound to fall. In the Mile High City the record for coldest high temperature for the date was not just broken but smashed.
The so-called high temperature for the day was 1 degree below zero in Denver. This shattered the previous coldest high temperature for February 5 of 5 degrees set in 1989 and years prior.
- Article adapted from the Denver Weather Examiner with permission
Overnight temperatures Tuesday night into Wednesday morning dropped to a bone-chilling 19 degrees below zero as measured at Denver’s official weather station at Denver International Airport. Daytime provided little relief as the mercury remained stubbornly below zero.
Here in Thornton we fared slightly better with a daytime high temperature of 2 degrees above zero. Our low temperature this morning was a nasty cold 12.6 degrees below.
- How cold is it? Live weather gauges
- Winter Weather Preparedness: Hazards of wind chill, hypothermia and frostbite
With temperatures Wednesday night expected to plunge to 10 below or lower, a Wind Chill Advisory has been issued for much of northeastern Colorado including Denver. Wind chill temperatures of 25 below will be possible.
This type of cold comes with it the very real danger of hypothermia and frostbite. Area residents need to exercise extreme caution and avoid prolonged exposure. Pets as well need to be remembered and their time outside should be limited.
Photos: Sunrise sun dog appears in Denver
If you happened to look to the east at about 7:45 a.m. this morning you were treated to something pretty cool – a sun dog.
A sun dog is also called a ‘mock sun’, ‘phantom sun’ or ‘parhelia.’ These appear as bright spots to either side of the sun at the same distance above the horizon. They are caused by sunlight refracting through hexagonal ice crystals, usually in cirrus clouds. As the light hits the crystals, it is bent 22 degrees before reaching your eyes, thus creating the phenomena.
We took these images in north Denver.
January 2014 weather recap: Near average temps but well above normal snowfall
January 2014 could be remembered as a month that brought a weather rollercoaster. Looking back it seems as if we were constantly jumping between mild temperatures to cold to warmth and back to cold again.
The month started out cooler than normal for the first two days with a light shot of snow on New Year’s Day. Temperatures then shot into the 60s on the 3rd but were followed by colder temperatures and more snow on the 4th. On the 5th we registered our coldest day of the month.
From the 7th to the 16th we experienced relatively calm conditions and only very light snow on one day. We saw above normal temperatures from the 15th to the 21st. Two cold days followed with snow falling on the 23rd.
Alternating above-normal and below-normal temperatures closed out the month. Four of the last five days saw snowfall.
Thornton recorded an average monthly temperature of 31.3 degrees. This was slightly higher than Denver’s official recording of 31.2 degrees. Both were slightly above the historical average January temperature of 30.7 degrees.
Temperatures in Thornton ranged from a high of 67.0 degrees on the 19th down to a low of -5.5 degrees on the 6th. Denver’s warmest temperature of 65 degrees also occurred on the 19th and it recorded its coldest of -10 degrees on the 5th.
All 31 days of the month saw low temperatures below freezing in Thornton and four days saw high temperatures fail to reach 32 degrees. Two days saw readings below zero. Denver’s readings were similar with four days staying below freezing and three seeing lows below zero.
Precipitation for the month was nearly double of the Denver historical average thanks to snowfall that was about double of normal.
Thornton recorded 1.06 inch of liquid precipitation, well above the average of 0.41 inch. Denver saw a bit less with 0.94 inch.
While no major snowstorms were seen, there were plenty of smaller events. These gave Thornton 13.4 inches of the white stuff during the month, Denver saw 14.3 inches. Both were about double the January average of 7.1 inches. The official Denver measurement propelled January 2014 into the books as the 11th snowiest January on record.
CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO
517 AM MST SAT FEB 1 2014
...................................
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF JANUARY 2014...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2014
WEATHER OBSERVED NORMAL DEPART LAST YEAR`S
VALUE DATE(S) VALUE FROM VALUE DATE(S)
NORMAL
................................................................
TEMPERATURE (F)
RECORD
HIGH 76 01/27/1888
LOW -29 01/09/1875
HIGHEST 65 01/19 76 -11 66 01/24
LOWEST -10 01/05 -29 19 -12 01/12
AVG. MAXIMUM 44.9 44.0 0.9 44.6
AVG. MINIMUM 17.3 17.4 -0.1 16.0
MEAN 31.1 30.7 0.4 30.3
DAYS MAX >= 90 0 0.0 0.0 0
DAYS MAX <= 32 4 5.5 -1.5 6
DAYS MIN <= 32 30 29.4 0.6 30
DAYS MIN <= 0 3 1.7 1.3 5
PRECIPITATION (INCHES)
RECORD
MAXIMUM 2.35 1883
MINIMUM 0.01 1933
1934
1952
TOTALS 0.94 0.41 0.53 0.31
DAILY AVG. 0.03 0.01 0.02 0.01
DAYS >= .01 9 4.1 4.9 4
DAYS >= .10 3 0.9 2.1 1
DAYS >= .50 0 0.0 0.0 0
DAYS >= 1.00 0 0.0 0.0 0
GREATEST
24 HR. TOTAL 0.26 01/30 TO 01/31 01/28 TO 01/29
01/29 TO 01/29
01/29 TO 01/29
STORM TOTAL MM MM
(MM/DD(HH)) MM 01/29(00) TO 01/29(00)
01/29(00) TO 01/29(00)9
01/29(00) TO 01/29(00)9
SNOWFALL (INCHES)
RECORDS
TOTAL MM MM
TOTALS 14.3 7.0
DEGREE_DAYS
HEATING TOTAL 1046 1063 -17 1067
SINCE 7/1 3497 3531 -34 3300
COOLING TOTAL 0 0 0 0
SINCE 1/1 0 0 0 0
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/07
LATEST 05/05
..........................................................
WIND (MPH)
AVERAGE WIND SPEED 10.7
RESULTANT WIND SPEED/DIRECTION 4/230
HIGHEST WIND SPEED/DIRECTION 36/290 DATE 01/12
HIGHEST GUST SPEED/DIRECTION 44/280 DATE 01/12
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.50
NUMBER OF DAYS FAIR 10
NUMBER OF DAYS PC 14
NUMBER OF DAYS CLOUDY 7
AVERAGE RH (PERCENT) 56
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 0 MIXED PRECIP 0
HEAVY RAIN 0 RAIN 0
LIGHT RAIN 0 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 2 SNOW 5
LIGHT SNOW 11 SLEET 0
FOG 11 FOG W/VIS <= 1/4 MILE 4
HAZE 4
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
Thornton’s February weather preview: Month usually brings warmer temps, dry conditions
February in Colorado typically brings to an end an extended period when average temperatures are at their lowest. Winter begins to loosen its grip and temperatures get warmer but precipitation is not a particularly common event during the month.
Thanks to some late January snows, Denver’s seasonal snowfall has started to rebound but still remains below normal. February is only our sixth snowiest month so it may not provide much help on the precipitation month.
Temperatures however do usually see a nice rebound during the month. Average high temperatures climb from an average of 44 degrees at the start to 50 degrees by the end of February.
January 2014 in pictures: Monthly photo slideshow
While typically a cold month, January is oftentimes lacking in terms of weather drama. Living in Colorado however provides plenty of opportunity to capture a wide variety of weather-related imagery as we see in our January 2014 slideshow.
- Slideshow updated January 31, 2014
In this, our first monthly photo slideshow, we feature photos that not only we have taken but also those taken by ThorntonWeather.com fans.
Throughout the month we will gather the images sent to us via email or shared with us via our various social media outlets and post them in the slideshow below.
With us only being one week into the month, great photos of sunsets, wildlife, pets and wintry conditions have emerged. We love them all!
To learn more about getting your photos added to our monthly slideshow, click here.
Click the play button below and sit back and enjoy the images.
January 2014 becomes 11th snowiest January on record
Thanks to a snowy start and a similarly snowy finish, the month of January 2014 climbed onto the list of top 10 January snow measurements in the Mile High City.
Officially the month ended with 14.3 inches of snowfall as measured at Denver International Airport. It was just enough to bump January 1991 from the number 10 spot (14.1 inches).
Here in Thornton we received just a bit less as we saw 13.4 inches of the white stuff.
January is only our fourth snowiest month with an average of 7.0 inches (based on 1981 to 2010 normals). The snowiest January on record occurred in 1992 when 24.3 inches of snow fell.
Looking at the 2013 / 2014 snow season, January helped make up some lost ground from the previous dry months.
The seasonal total now stands at 22.4 inches, 5.4 inches below the long term average of 27.8 inches we normally receive by the end of January. Thornton’s seasonal total is a bit better but still below normal at 24.2 inches.
Click here to view Thornton’s seasonal snow summary.
TOP TEN SNOWIEST JANUARYS:
24.3 INCHES 1992
22.2 INCHES 1949
20.5 INCHES 1883
19.2 INCHES 1948
17.4 INCHES 1959
17.2 INCHES 1962
17.0 INCHES 1891 AND 1987
15.9 INCHES 2007
15.7 INCHES 1951
14.3 INCHES 2014