The Weather Wire

 

May 2009                                                                                                            Volume 17 Number 05

 

Contents

 

 

 
·   Winter in Review
 

·   Drought Monitor

 

·   April

    Summary

 

·   April Stats

 

·   May Preview

 

·   Sunrise/Sunset

 

·   Snow Totals

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April

Avg High - 58.9

Avg Low - 32.9

Snow - 7.4"

Season Snow - 38.1"

Precipitation - 3.22"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

May

Avg High - 70.5

Avg Low - 43.8

Avg Snow -  1.3"

Avg Precip - 2.32"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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

2008-2009 Winter in Review

The start of the snow season can begin as early as mid to late September as the Denver Metro area averages 2.1” of snow for the month.  September of 2008 was not one of those years as there was no measurable snowfall anywhere along the Front Range.  Temperatures never even dropped below freezing in Denver for the entire month.  Many years the Denver area can experience its first frost/freeze sometime in late September, but not in 2008. 

October of 2008 continued to lack snowfall at lower elevations, but areas above 6000-6500’ did receive their first snow of the season on the 11th into the 12th including Colorado Springs with up to 3” reported in northern areas of the city.  Even though there was a lack of snowfall, October was above normal in precipitation in the Denver area, but at month’s end the precipitation deficit for the year stood at -3.89”.  Without snow during the month we quickly began to fall into a snowfall deficit that would not be easily be made up through the remainder of the winter season. 

Some measurable snow occurred in the Denver area by the second week of November, but the month only ended up with 1.7” at DIA.  Many areas of the city fared much better with 2-8” in many locations and up to a foot of snow or more in Castle Rock and higher amounts in the foothills.  By month’s end our snow deficit stood at -15.2” at DIA.  Precipitation for the month was very low with only 0.18” measured which took the yearly precipitation deficit to -4.69”. 

More meaningful snowfall amounts occurred in December with 10.3” reported at DIA, but overall precipitation once again was below normal which resulted in a yearly precipitation of 10.21” versus a normal is 15.29”, resulting in a yearly deficit of -5.08”, right around 33% below normal.  With the above normal snowfall in December things were looking better, but the following months would prove to provide little in the way of snow. 

January was unseasonably warm with average high temperatures running 5 degrees above normal.  Some snow occurred with 4.9” at DIA, but only 0.13” of liquid water equivalent was tallied.  Once again, below normal precipitation was recorded in snowfall and precipitation. 

February certainly did not help snowfall amounts, as it was the least snowiest in Denver history!  Only a trace of snowfall was reported at DIA and 0.04” of precipitation.  Temperatures were well above normal with average highs 5.8 degrees above the norm.  With the seasonal snowfall and precipitation well below normal, it appear unlikely that snowfall amounts could recover from below normal. The snowfall deficit for the 2008-2009 winter season now stood at -22.7” and we were -0.83” behind in precipitation.  

March began warm and dry, but relief finally came the very last week of the month which would continue all the way through April.  For March of 2009 there was 13.8” of snow compared to 11.7” on average.  Almost all of the snow fell between the 25th and the 27th as one of our famous Front Range blizzards brought over a foot of snow to many locations.  Precipitation fell short with 0.83” of snow water equivalent at DIA.  This brought our yearly precipitation to -1.28” below normal. 

A very active weather pattern persisted through the month of April with measurable snow and rain occurring 1 out of every 3 days!  The largest snowfall of the year for many Front Range locations occurred from the 16th into the 18th with 1 to 2 feet of snow above 6000’, but DIA only came in with 2.6” for that storm due to rain mixing with snow below 5500’.  This storm was loaded with moisture as we set a daily precipitation record for the day on the 16th with 1.16” in a 24 hour period.  For the month DIA measured 7.4” of snow which was below the normal of 9.1” but much needed precipitation occurred with 3.22” for the month.  This was 1.93” above normal and brought us right back to average in the precipitation department for the year.  This was much needed moisture as we were below average last year and it was looking like we may be entering a severe drought!  Many areas in and around Denver received more than 5.0” of liquid for the month!  Our snowfall for 2008-2009 winter season at the end of April stood at 38.1” and normal is 60.4” resulting in 22.3” below normal snowfall. 

Once example of how much snow fell in a short time is to look at Skyview Weather's office in Castle Rock.  On March 26, 2009, the total snowfall for the 2008/2009 snow season was at 33.9", well below normal (seasonal snowfall for Castle Rock averages approximately 65"). Just over 1 month later on April 29, 2009 total snowfall for the season was at 76.8", an amazing increase of 42.9"!  This resulted in total snowfall for the season above normal.  This was not unique, many areas above approximately 5500 feet saw similar heavy snow amounts for the period (though areas below 5500 feet received less snow and more rain).

Now that we are in May our chances for snowfall are diminishing quickly, but we still average 1.3”.  It is unlikely that we will add any more snow this month bringing our season total to 23.6” below the normal of 61.7”.  Despite the large snow deficit at DIA many Front Range locations from the Palmer Divide northward are near or slightly above normal snowfall for the year with Castle Rock seeing  67.8” in town and 76.8” 3 miles northeast at the Skyview Weather headquarters, Golden at 90.1”, Arvada 69.7”, Cherry Hills North 50.8”, Boulder 75.0”, Greenwood Village 62.0”, Morrison 94.9”, Thornton 53.1”, Littleton 72.8, Westminster 66.1”, Wheatridge 78.8”, Lakewood Central 59.3”, Lone Tree 69.7” and some higher amounts in the foothills of 87.5” in Evergreen, 121.2” at Monument Hill, 84.5” in Estes Park and 116.6” in Conifer.

One main reason for the well below normal snowfall officially in Denver is due to the fact that old Stapleton is no longer the official site for snow measurements.  This is due to lower elevation and its distance away from the foothills.  It cannot be stressed enough how much this may change our official snow amounts!  Snow amounts will likely come in lower than what the rest of Denver is experiencing for years to come and with time our average snowfall will drop below 60” on average.  Take this into account as the media will play games with these official numbers and we are now comparing apples to oranges when it comes to Denver snowfall climatology.

South of the Palmer Divide in Colorado Springs the airport only reported 17.9” of snow for the entire 2008-2009 season!   Meaningful snow simply did not fall  at the airport for the entire winter season.  Just north of the city form the Air Force Academy northward into Monument conditions improved dramatically with near normal snowfall amounts. 

Disclaimer:  Skyview weather receives snowfall amounts from reliable human spotters and we use them to make generalities for certain areas and where you are located amounts may differ from the information our spotters have provided.  Human errors also need to be taken into account for blowing and drifting snow and measurements reflect what falls on grass, not pavement.   

                     

Drought Update

Areas of drought have spread across much of eastern Colorado as well as northwest Colorado as a result of our precipitation deficit year to date. 

The map below shows forecasted temperature deviances for May2009. As can be seen, it is expected that much of Colorado to have normal temperatures for the month of May 2009, with far southwestern Colorado expected to have above normal temperatures. 

The map below shows forecasted precipitation deviances for May 2009.  Normal precipitation is anticipated for most of Colorado May 2009, except for far southeast Colorado where above normal precipitation is forecast.

Some improvement in drought conditions is expected along the Front Range of Colorado during the May to July time period.

April Summary

What a difference a month makes!  By the end of March we were 1.28" below normal for precipitation for the year.  At the end of April Denver was right at normal, erasing the precipitation deficit.  Rainfall and snow water equivalent tallied up to 3.22" which was 1.29" above normal.  Many areas of Denver and surrounding areas received much higher precipitation amounts than the 3.22" that what was reported at DIA.  Snowfall on the on the other hand fell short with only 7.4" of snow compared with 9.1" being normal, this is due to the fact that old Stapleton is no longer the official measurement site for snow, DIA currently is.  If the Stapleton snow numbers were used then we would have been well above normal snowfall for the month like everywhere else in town and most likely around normal for the year instead of 22.3" short.  The local media is was using this change in locations to play up the drought earlier in the month and make it appear worse than it really was!  The active weather resulted in temperatures being below normal for the first time this year and there was only 62% of possible sunshine.  There were 10 days in the month with measurable precipitation which works out to be 1 out of 3 days for the month provided moisture.

April Stats

TEMPERATURE (IN DEGREES F)

 

 

 

 

 

 

AVERAGE MAX

58.9

NORMAL

60.9

DEPARTURE

-2.0

AVERAGE MIN

32.9

NORMAL

34.2

DEPARTURE

-1.3

MONTHLY MEAN

45.9

NORMAL

47.6

DEPARTURE

-1.7

HIGHEST

79 on the 23rd

LOWEST

16 on the 6th

 

 

 

 

 

 

DAYS WITH MAX 90 OR ABOVE

0

NORMAL

0.2

DAYS WITH MAX 32 OR BELOW

1

NORMAL

0.2

DAYS WITH MIN 32 OR BELOW

14

NORMAL

11.4

DAYS WITH MIN ZERO OR BELOW

0

NORMAL

0.1

 

 

 

 

 

 

TEMPERATURE RECORDS

 
No temperature records tied or broken.
Single day precipitation record of 1.16" on the 17th, old record was 1.00"
           

HEATING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

566

NORMAL

524

DEPARTURE

42

SEASONAL TOTAL

5334

NORMAL

5801

DEPARTURE

-467

 

 

 

 

 

 

COOLING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

0

NORMAL

2

DEPARTURE

-2

YEARLY TOTAL

0

NORMAL

2

DEPARTURE

-2

 

 

 

 

 

 

PRECIPITATION (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

3.22

NORMAL

1.93

DEPARTURE

1.29

YEARLY TOTAL

4.22

NORMAL

4.21

DEPARTURE

0.01

GREATEST IN 24 HOURS

1.42" on the 16th into the 17th

DAYS WITH MEASURABLE PRECIPITATION

10

 

 

 

 

 

SNOWFALL (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

7.4

NORMAL

9.1

DEPARTURE

-1.7

SEASONAL TOTAL

38.1

NORMAL

60.4

DEPARTURE

-22.3

GREATEST IN 24 HOURS

4.5" on the 27th

GREATEST DEPTH

4.0" on the 27th

 

 

 

 

 

 

WIND (IN MILES PER HOUR)

 

 

 

 

 

 

AVERAGE SPEED 12.3 mph

PEAK WIND GUST

63mph on the 4th from the N

 

 

 

 

 

 

MISCELLANEOUS WEATHER

 

 

 

 

 

 

NUMBER OF DAYS WITH THUNDERSTORMS

2

NORMAL

2

NUMBER OF DAYS WITH HEAVY FOG

3

NORMAL

1

NUMBER OF DAYS WITH HAIL

0

 

 

PERCENT OF SUNSHINE

62%

NORMAL

67%

 

 

 

May Preview

Many people may not think of May as a very wet month because most of the precipitation does not fall as snow, but May is usually the wettest month of the year with 2.32" on average.  Snowfall is possible with 1.3" of snow on average, but there are many years with no measurable snowfall at all.  Temperatures really warm up this month with a 10 degree temperature gain for average highs compared to April.  May is also when we typically get our last freeze or frost for the season and people can begin to plant tender vegetation at the lower elevations.  The foothills are a different story with wet spring snow common and a threat for freezing up to the end of the month.  May is tied with November as the least sunny month on the calendar year with 64% of possible sunshine on average.  Thunderstorms become more common with 6 thunderstorm days on average throughout the month.  With the active weather from the end of March through the month of April it is unlikely that this weather pattern can continue which makes me think that this month will be slightly drier than average, but we should still get some good rainfall with some wet snow still likely in the mountains and foothills.

DENVER'S NOVEMBER CLIMATOLOGICALLY NORMAL

(NORMAL PERIOD 1971-2000)

 

 

TEMPERATURE

 

 

 

AVERAGE HIGH

70.5

AVERAGE LOW

43.8

MONTHLY MEAN

57.2

DAYS WITH HIGH 90 OR ABOVE

Less than 1

DAYS WITH HIGH 32 OR BELOW

0

DAYS WITH LOW 32 OR BELOW

2

DAYS WITH LOWS ZERO OR BELOW

0

 

 

PRECIPITATION

 

 

 

MONTHLY MEAN

2.32"

DAYS WITH MEASURABLE PRECIPITATION

11

AVERAGE SNOWFALL IN INCHES

1.3"

DAYS WITH 1.0 INCH OF SNOW OR MORE

Less than 1

 

 

MISCELLANEOUS AVERAGES

 

 

 

HEATING DEGREE DAYS

267

COOLING DEGREE DAYS

23

WIND SPEED (MPH)

9.3 mph

WIND DIRECTION

South

DAYS WITH THUNDERSTORMS

6

DAYS WITH DENSE FOG

1

PERCENT OF SUNSHINE POSSIBLE

64%

 

 

EXTREMES

 

 

 

RECORD HIGH

95 on May 26, 1942

RECORD LOW

19 on May 3, 1907

WARMEST

64.6 in 1934

COLDEST

48.7 in 1917

WETTEST

8.57" in 1876

DRIEST

0.06" in 1974

SNOWIEST

15.5" in 1898

LEAST SNOWIEST

0.0" 40 years with Zero Snowfall
 

Sunrise/Sunset (Jul - December Denver area)

               JAN               FEB               MAR             APR                MAY              JUN
_______________________________________________________________________________
     sr - ss     sr - ss     sr - ss     sr - ss     sr - ss     sr - ss
 01  0721-0446 | 0707-0518 | 0632-0551 | 0643-0723 | 0600-0753 | 0534-0821  01
 02  0721-0447 | 0706-0519 | 0631-0552 | 0642-0724 | 0559-0754 | 0533-0822  02
 03  0721-0448 | 0705-0521 | 0629-0553 | 0640-0725 | 0557-0755 | 0533-0822  03
 04  0721-0449 | 0704-0522 | 0628-0554 | 0638-0726 | 0556-0756 | 0532-0823  04

 05  0721-0450 | 0703-0523 | 0626-0555 | 0637-0727 | 0555-0757 | 0532-0824  05
 06  0721-0451 | 0702-0524 | 0625-0556 | 0635-0728 | 0554-0758 | 0532-0824  06
 07  0721-0452 | 0701-0525 | 0623-0557 | 0634-0729 | 0553-0759 | 0532-0825  07
 08  0720-0452 | 0700-0527 | 0721-0658 | 0632-0730 | 0552-0800 | 0531-0826  08

 09  0720-0453 | 0659-0528 | 0720-0659 | 0631-0731 | 0551-0801 | 0531-0826  09
 10  0720-0454 | 0658-0529 | 0718-0700 | 0629-0732 | 0550-0802 | 0531-0827  10
 11  0720-0456 | 0656-0530 | 0717-0701 | 0628-0733 | 0549-0803 | 0531-0827  11
 12  0720-0457 | 0655-0531 | 0715-0702 | 0626-0734 | 0548-0804 | 0531-0828  12

 13  0719-0458 | 0654-0533 | 0714-0704 | 0625-0735 | 0547-0805 | 0531-0828  13
 14  0719-0459 | 0653-0534 | 0712-0705 | 0623-0736 | 0546-0806 | 0531-0829  14
 15  0719-0500 | 0651-0535 | 0710-0706 | 0622-0737 | 0545-0807 | 0531-0829  15
 16  0718-0501 | 0650-0536 | 0709-0707 | 0620-0738 | 0544-0808 | 0531-0829  16

 17  0718-0501 | 0649-0537 | 0707-0708 | 0619-0739 | 0543-0809 | 0531-0830  17
 18  0717-0502 | 0648-0538 | 0706-0709 | 0617-0740 | 0542-0809 | 0531-0830  18
 19  0717-0503 | 0646-0539 | 0704-0710 | 0616-0741 | 0541-0810 | 0531-0830  19
 20  0716-0504 | 0645-0541 | 0702-0711 | 0614-0742 | 0541-0811 | 0532-0831  20

 21  0716-0505 | 0644-0542 | 0701-0712 | 0613-0743 | 0540-0812 | 0532-0831  21
 22  0715-0507 | 0642-0543 | 0659-0713 | 0612-0744 | 0539-0813 | 0532-0831  22
 23  0714-0508 | 0641-0544 | 0658-0714 | 0610-0745 | 0538-0814 | 0532-0831  23
 24  0714-0509 | 0639-0545 | 0656-0715 | 0609-0746 | 0538-0815 | 0533-0831  24

 25  0713-0510 | 0638-0546 | 0654-0716 | 0608-0747 | 0537-0816 | 0533-0831  25
 26  0712-0511 | 0636-0547 | 0653-0717 | 0606-0748 | 0537-0816 | 0533-0831  26
 27  0711-0512 | 0635-0548 | 0651-0718 | 0605-0749 | 0536-0817 | 0534-0832  27
 28  0711-0514 | 0634-0550 | 0650-0719 | 0604-0750 | 0535-0818 | 0534-0832  28

 29  0710-0515 |                       | 0648-0720 | 0602-0751 | 0535-0819 | 0534-0832  29
 30  0709-0516 |                       | 0646-0721 | 0601-0752 | 0534-0820 | 0535-0831  30
 31  0708-0517 |                       | 0645-0722 |                      | 0534-0820 |                       31

 

 Snowfall

October 2008 to April 2009

City

Oct

Nov

Dec

Jan Feb Mar Apr

Seasonal Totals

Aurora (Central)

 0.0 7.6 12.3 5.8 2.6 11.5 14.3 54.1
Brighton  0.0 1.6 12.1 5.7 0.8 18.6 6.0 44.8
Broomfield  0.0 2.3 13.8 7.0 1.0 16.2 20.2 60.5

Castle Rock 4 NE

 0.3 12.0 9.7 6.6 3.2 15.3 29.7 76.8

Colorado Sprgs Airport

 TR 2.6 5.2 3.4 0.6 4.7 1.4  17.9
Denver DIA  TR 1.7 10.3 4.9 TR 13.8 7.4  38.1

Denver Downtown

 0.0 3.0 8.4 7.8 3.1 15.0 12.5 49.8

Golden

TR 9.3 19.5 14.9 3.5 18.8 24.1 90.1

Fort Collins

TR TR 10.5 5.8 4.1 12.2 9.7 42.3

Highlands Ranch

 0.0 13.9 9.7 8.9 6.0 20.9 22.8 82.2

Lakewood

 0.0 3.8 8.5 9.5 4.2 17.0 16.3 59.3

Littleton

 0.0 15.2 10.7 8.7 3.7 16.3 18.2 72.8

Parker

TR 9.3 14.5 12.4 3.2 13.1 18.3 70.8

Sedalia - Hwy 67

 TR 14.2 8.0 9.0 3.0 16.0 23.0 73.2

Thornton

 0.0 3.4 13.6 6.9 1.8 18.6 8.8 53.1

Westminster

 0.0 2.3 13.4 9.7 1.4 21.8 17.5 66.1

Wheatridge

 0.0 5.3 12.0 15.6 4.7 21.7 19.5 78.8