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

Long range forecasts portend an extended period of cooler weather for Denver

With the start of the month of October upon us it appears Mother Nature is set to deliver a healthy dose of fall weather conditions. Not only do short term forecasts indicate cooler temperatures and even a chance for snow, long range forecasts indicate the potential for an extended period of cooler weather.  Read the rest of this story on Examiner.com.  

The temperature outlook for the period from October 5 to October 9 indicates cooler than average temperatures for much of the nation. (CPC)
The temperature outlook for the period from October 5 to October 9 indicates cooler than average temperatures for much of the nation. (CPC) Click the image to read more about what long range forecasts predict for our coming weather.

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!

Green Bay TV parodies replacement referees with ‘replacement weather guy’

An arguably botched call by replacement referees during Monday night’s football game between the Green Bay Packers and Seattle Seahawks is now being parodied by a Titletown television station. The ‘replacement weather guy’ made an appearance during NBC26’s Tuesday morning news taking a jab at the NFL.  Read the rest of this story on Examiner.com and watch the hilarious video.

A 'replacement weather guy' in Green Bay does a poor job following the Packers' loss at the hands of replacement referees.
A 'replacement weather guy' in Green Bay does a poor job following the Packers' loss at the hands of replacement referees. Click to watch the video. (YouTube / NBC26)

Denver begins upgrade of tornado warning siren system

In an effort to keep up with new technology and improve warnings to residents, the city of Denver began a much-needed upgrade of its outdoor warning sirens yesterday. The system will feature improved reliability and the ability to target warnings.  Read about Denver’s new system on Examiner.com

What about Thornton?  The city that was the site of the most destructive tornado ever in the Denver metro area doesn’t have sirens.  The city did however implement an email warning system this past spring – click here to read more.

After fast start to year, number of tornadoes in 2012 drops to 400 below average

While the start of 2012 saw a number of deadly tornado outbreaks that seemed to portend a disastrous year to come, the number of tornadoes recorded since then has fallen to record low levels. Data from the Storm Prediction Center today shows the tornado count for the year is 400 twisters below average. Read the rest of this story on Examiner.com

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