The Weather Wire

 

November 2009                                                                                                            Volume 17 Number 11

 

Contents

 

 

 
·   How to Properly Measure Snow
 

·   Drought Monitor

 

·   October

    Summary

 

·   October Stats

 

·   September Preview

 

·   Sunrise/Sunset

 

·   Snow Totals

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October

Avg High - 54.

Avg Low - 31.1

Snow - 17.2"

Season Snow - 17.2"

Precipitation - 1.36"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

November

Avg High - 51.5

Avg Low - 23.5

Avg Snow -  10.7"

Avg Precip - 0.98"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Skyview Weather 

2350 N Rocky View Rd

Castle Rock, CO 80108

 

Phone: (303) 688-9175

Fax: (303) 380-3338

 

E-mail:    

tim@skyview-wx.com

 

We’re on the Web!

http://www.skyview-wx.com/

 

Copyright 2009

Skyview Weather

How to Properly Measure Snow 

After the big October snowstorm and looking at all the varying snowfall reports from citizens and trained weather spotters I thought it would be helpful to go over how to properly measure snowfall.

Measuring snow can be fun and it is relatively easy to get a good measurement if you follow just a few simple guidelines.  Measuring snow is fun since the best time to measure snow is while it is snowing or shortly thereafter so you will get to enjoy the snow covered scenery.  One of the two biggest mistakes made by people who measure snow is that they may measure the snow the next morning after the snow has ended or melted some resulting in a lower measurement or they measure drifted snowfall resulting in higher measurements.  For instance if 5” of snow fell while you were at work during the day and then you came home and 2” had melted resulting in 3” measured when you got back then the 2” would be lost.  Another issue is that homes and their interaction with the wind result in drifting and in some cases the “spotter” may measure a drifted area instead of the average.  Below are some quick and easy guidelines on how to measure snowfall taken from NWS website:  http://www.erh.noaa.gov/gyx/measuring_snow.htm .

MEASURE SNOW WITH A MEASURING STICK

Find a location where the snow appears to be near its average depth. Avoid drifts or valleys. Look for a flat, somewhat open area away from buildings and trees. Some trees in the distance may be helpful in making a wind break, preventing drifting, and thus providing for a more even distribution of the snow. Measure the depth with the snow measuring stick (aka "the common household ruler") at several locations and use an average. Traditionally ten measurements are made and the average value is the snow depth. When snow has fallen between observation times and has been melting, measure its greatest depth on the ground while it is snowing, or estimate the greatest depth. During heavy snowfall some of the actual total may be lost due to compaction of the column by the weight of the snow, during these times it may be best to estimate a slightly higher value if snow has been falling at a heavy rate for several hours since the last actual measurement. If all snow melted as it fell, you can report a trace for the snowfall.

MEASURING NEW SNOW FALLING ON TOP OF OLD SNOW

When fresh snow has fallen on old snow, it is necessary to measure the depth of the new snow (in tenths of inches). Snow boards provide the best method of taking measurements in this case. Sometimes if the old snow has settled or partially melted enough to develop a crust or to be noticeably denser than the new snow, it may be possible to insert the snow stick until it meets the greater resistance of the crust of old snow, and to use this depth as the amount of new snow having fallen.

USE OF A SNOW BOARD

Snow boards are laid on top of the old snow when there is any possibility of new snow falling. Push them into the snow just far enough that the top of the board is nearly level or just above the top of the old snow. After each observation, boards should be cleaned and placed in a new location. Because of evaporation or drifting, they may need adjusting daily to assure that the top of the board remains flush with the old snow. A clean sidewalk or open cement area where there is some protection from the wind and drifting is a good alternative (if the ground is frozen) to using a snow board. You still need to clean an area off before the snow starts and between measurements in order to accurately measure the newly fallen snow.

Just by being timely and aware of drifting can be very helpful in measuring new snow.  Skyview would like to thank all of our spotters for their valuable information and the time they spend on snow measurements.  

Drought Update

With the widespread precipitation of the last several months, little areas of drought remain in Colorado, though some dry areas have developed in southwestern Colorado.

The map below shows forecasted temperature deviances for November 2009. As can be seen, it is expected that all of Colorado to have above normal temperatures for the month of November 2009.

The map below shows forecasted precipitation deviances for November 2009.  All of Colorado is expected to have normal precipitation for November 2009.

Little in the way of drought remains in Colorado, with no changes expected.

October Summary

October of 2009 provided plenty of weather highlights with numerous records tied or broken and a major winter storm for the latter part of the month producing up to 20" of snow or more in the Denver Metro area.  This October was also very cold becoming the 2nd coldest October on record with average highs more than 11 degrees below normal.  Average lows were only 4.8 degrees below normal resulting in a monthly mean temperature of 42.9 compared to 51.0 on average.  Much of the cold can be attributed to the multiple day storm with 5 record lows tied or broken.  For the month Denver ended up with 17.2" of snow at DIA with 15.3" coming during the big storm.  The 17.2" is 13.1" above normal and makes up for the lack of snow at DIA during the month of September, but on the season DIA is only 9.7" above normal.  Many other Front Range locations have reported much higher snowfall with around 33% of an average year already.  The total precipitation for the month was 1.36" compared to 0.99" on average and pushes our yearly total to 17.18" which is 4.0" above normal.  What a change compared to the past few years.  There was only one high temperature record tied during the month and it came just ahead of the big snow with a high of 84 on the 18th of the month.  Percent of possible sunshine was not recorded this month, but I would have to think that it was well below normal as well. 

October Stats

TEMPERATURE (IN DEGREES F)

 

 

 

 

 

 

AVERAGE MAX

54.7

NORMAL

66.0

DEPARTURE

-11.3

AVERAGE MIN

31.1

NORMAL

35.9

DEPARTURE

-4.8

MONTHLY MEAN

42.9

NORMAL

51.0

DEPARTURE

-8.1

HIGHEST

84 on the 18th

LOWEST

17 on the 10th

 

 

 

 

 

 

DAYS WITH MAX 90 OR ABOVE

0

NORMAL

0

DAYS WITH MAX 32 OR BELOW

3

NORMAL

0.3

DAYS WITH MIN 32 OR BELOW

17

NORMAL

8.6

DAYS WITH MIN ZERO OR BELOW

0

NORMAL

0

 

 

 

 

 

 

TEMPERATURE RECORDS

 

5 low temperature records tied or broken and 1 high temperature record.  Record lows set on the 2nd, 9th and 10th and a record low was tied on the 3rd.  Record low maximum temperature was set on the 26th.  The record high temperature was tied on the 18th

 

 

 

 

 

 

 

HEATING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

676

NORMAL

436

DEPARTURE

240

SEASONAL TOTAL

815

NORMAL

582

DEPARTURE

233

 

 

 

 

 

 

COOLING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

0

NORMAL

0

DEPARTURE

0

YEARLY TOTAL

533

NORMAL

696

DEPARTURE

-163

 

 

 

 

 

 

PRECIPITATION (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

1.36

NORMAL

0.99

DEPARTURE

0.37

YEARLY TOTAL

17.18

NORMAL

13.18

DEPARTURE

4.00

GREATEST IN 24 HOURS

0.39" from 10/20 to 10/21

DAYS WITH MEASURABLE PRECIPITATION

8

 

 

 

 

 

SNOWFALL (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

17.2

NORMAL

4.1

DEPARTURE

13.1

SEASONAL TOTAL

17.2

NORMAL

7.5

DEPARTURE

9.7

GREATEST IN 24 HOURS

NA

GREATEST DEPTH

NA

 

 

 

 

 

 

WIND (IN MILES PER HOUR)

 

 

 

 

 

 

AVERAGE SPEED

9.6mph

PEAK WIND GUST

54mph from the SW

 

 

 

 

 

 

MISCELLANEOUS WEATHER

 

 

 

 

 

 

NUMBER OF DAYS WITH THUNDERSTORMS

0

NORMAL

1

NUMBER OF DAYS WITH HEAVY FOG

9

NORMAL

1

NUMBER OF DAYS WITH HAIL

0

 

 

PERCENT OF SUNSHINE

NA

NORMAL

72%

November Preview

After the big storm in October the weather pattern has been tranquil with record breaking heat the first week of November helping to melt all of the leftover  snow.  Don't let the nice weather fool you as November is typically the 2nd snowiest month of the year behind March.  The weather pattern will likely become more active towards over the next week and continue through the end of the month with a 2-4 measurable snows likely by month end.  There is around 0.98" of precipitation on average and will likely end up just a bit short of normal but we are well above normal for the year so anything extra will be gravy on the top of what already has been a good water year for the Front Range.   

 

DENVER'S NOVEMBER CLIMATOLOGICALLY NORMAL

(NORMAL PERIOD 1971-2000)

 

 

TEMPERATURE

 

 

 

AVERAGE HIGH

51.5

AVERAGE LOW

23.5

MONTHLY MEAN

37.5

DAYS WITH HIGH 90 OR ABOVE

0

DAYS WITH HIGH 32 OR BELOW

3

DAYS WITH LOW 32 OR BELOW

24

DAYS WITH LOWS ZERO OR BELOW

Less than 1

 

 

PRECIPITATION

 

 

 

MONTHLY MEAN

0.98"

DAYS WITH MEASURABLE PRECIPITATION

6

AVERAGE SNOWFALL IN INCHES

10.7"

DAYS WITH 1.0 INCH OF SNOW OR MORE

3

 

 

MISCELLANEOUS AVERAGES

 

 

 

HEATING DEGREE DAYS

826

COOLING DEGREE DAYS

0

WIND SPEED (MPH)

8.2mph

WIND DIRECTION

South

DAYS WITH THUNDERSTORMS

Less than 1

DAYS WITH DENSE FOG

1

PERCENT OF SUNSHINE POSSIBLE

64%

 

 

EXTREMES

 

 

 

RECORD HIGH

80 on 11/8/2006

RECORD LOW

-18 on 11/29/1877

WARMEST

50.9 degrees in 1949

COLDEST

22.0 degrees in 1880

WETTEST

3.21" in 1946

DRIEST

Trace in 1949, 1901, 1899

SNOWIEST

42.6" in 1946

LEAST SNOWIEST

0.0" in 1949
 

Sunrise/Sunset (Jul - December Denver area)

              JUL                AUG                SEP            OCT               NOV            DEC
______________________________________________________________________________
            sr - ss            sr - ss             sr - ss          sr - ss             sr - ss           sr - ss
 01  0535-0831 | 0559-0813 | 0628-0732 | 0656-0643 | 0629-0457 | 0702-0436  01
 02  0536-0831 | 0600-0812 | 0629-0730 | 0657-0641 | 0630-0456 | 0703-0435  02
 03  0536-0831 | 0601-0811 | 0630-0729 | 0658-0640 | 0631-0455 | 0704-0435  03
 04  0537-0831 | 0601-0810 | 0630-0727 | 0659-0638 | 0632-0454 | 0705-0435  04

 05  0538-0831 | 0602-0809 | 0631-0725 | 0700-0637 | 0633-0453 | 0706-0435  05
 06  0538-0830 | 0603-0808 | 0632-0724 | 0701-0635 | 0634-0452 | 0706-0435  06
 07  0539-0830 | 0604-0807 | 0633-0722 | 0702-0634 | 0635-0451 | 0707-0435  07
 08  0539-0830 | 0605-0805 | 0634-0721 | 0703-0632 | 0637-0450 | 0708-0435  08

 09  0540-0830 | 0606-0804 | 0635-0719 | 0704-0630 | 0638-0449 | 0709-0435  09
 10  0541-0829 | 0607-0803 | 0636-0717 | 0705-0629 | 0639-0448 | 0710-0435  10
 11  0541-0829 | 0608-0802 | 0637-0716 | 0706-0627 | 0640-0447 | 0711-0435  11
 12  0542-0828 | 0609-0800 | 0638-0714 | 0707-0626 | 0641-0446 | 0711-0435  12

 13  0543-0828 | 0610-0759 | 0639-0712 | 0708-0624 | 0642-0445 | 0712-0436  13
 14  0544-0827 | 0611-0758 | 0640-0711 | 0709-0623 | 0643-0444 | 0713-0436  14
 15  0544-0827 | 0612-0757 | 0641-0709 | 0710-0621 | 0644-0444 | 0714-0436  15
 16  0545-0826 | 0613-0755 | 0642-0708 | 0711-0620 | 0646-0443 | 0714-0436  16

 17  0546-0826 | 0614-0754 | 0643-0706 | 0712-0618 | 0647-0442 | 0715-0437  17
 18  0547-0825 | 0615-0752 | 0644-0704 | 0713-0617 | 0648-0442 | 0715-0437  18
 19  0547-0824 | 0616-0751 | 0644-0703 | 0714-0615 | 0649-0441 | 0716-0438  19
 20  0548-0824 | 0616-0750 | 0645-0701 | 0715-0614 | 0650-0440 | 0717-0438  20

 21  0549-0823 | 0617-0748 | 0646-0659 | 0716-0613 | 0651-0440 | 0717-0439  21
 22  0550-0822 | 0618-0747 | 0647-0658 | 0717-0611 | 0652-0439 | 0718-0439  22
 23  0551-0821 | 0619-0745 | 0648-0656 | 0719-0610 | 0653-0439 | 0718-0440  23
 24  0552-0821 | 0620-0744 | 0649-0654 | 0720-0609 | 0654-0438 | 0718-0440  24

 25  0552-0820 | 0621-0742 | 0650-0653 | 0721-0607 | 0656-0438 | 0719-0441  25
 26  0553-0819 | 0622-0741 | 0651-0651 | 0722-0606 | 0657-0437 | 0719-0441  26
 27  0554-0818 | 0623-0739 | 0652-0650 | 0723-0605 | 0658-0437 | 0720-0442  27
 28  0555-0817 | 0624-0738 | 0653-0648 | 0724-0603 | 0659-0436 | 0720-0443  28

 29  0556-0816 | 0625-0736 | 0654-0646 | 0725-0602 | 0700-0436 | 0720-0444  29
 30  0557-0815 | 0626-0735 | 0655-0645 | 0726-0600 | 0701-0436 | 0720-0444  30
 31  0558-0814 | 0627-0733 |                      | 0727-0558 |                      | 0720-0445  31

 

 Snowfall

Sept 2009 to Apr 2010

City

Sept-Oct

Nov

Dec

Jan

Feb

Mar Apr

Seasonal Totals

Aurora (Central)

20.2             20.2
Brighton 18.4             18.4
Broomfield 27.2             27.2

Castle Rock 4 NE

27.5             27.5

Colorado Sprgs Airport

1.8             1.8
Denver DIA 17.2             17.2

Denver Downtown

21.4             21.4

Golden

28.3             28.3

Fort Collins

25.5             25.5

Highlands Ranch

34.4             34.4

Lakewood

20.5             20.5

Littleton

25.9             25.9

Parker

22.5             22.5

Sedalia - Hwy 67

30.0             30.0

Thornton

22.8             22.8

Westminster

21.6             21.6

Wheatridge

28.8             28.8