The Weather Wire

 

May 2010                                                                                                            Volume 17 Number 05

 

Contents

 

 

 
·   Watches and Warnings
 

·   Drought Monitor

 

·   April

    Summary

 

·   April Stats

 

·   May Preview

 

·   Sunrise/Sunset

 

·   Snow Totals

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April

Avg High - 61.7

Avg Low - 33.9

Snow - 0.5"

Season Snow - 59.3"

Precipitation - 2.51"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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 2010

Skyview Weather

Watches and Warnings

There always seems to be some confusion when weather watches and warnings are issued.  Not to mention what constitutes a severe thunderstorm.  A review of summertime watches and warnings and their definitions may be helpful for future severe weather events. 

In general a watch means conditions are favorable for that event, while a warning means that the event is already occurring or is imminent and action may need to be taken. 

Definitions used with Summer Severe Events 

Severe Thunderstorm Watch: Conditions are favorable for the formation of severe thunderstorms in AND NEAR the watch area.  By definition, a severe thunderstorm has hail 1" inch or larger, and/or winds greater than or equal to 58mph.  Note heavy rain is not a necessary component of a severe thunderstorm. Watch the sky and stay tuned to know when warnings are issued. 

Severe Thunderstorm Warning: Issued when severe weather has been reported by spotters or indicated by radar. A severe thunderstorm warning indicates the storm has hail 1 inch or larger, and/or winds GE 58mph. Warnings indicate imminent danger to life and property to those in the path of the storm.

 Tornado Watch: Conditions are favorable for the formation of tornadoes in AND NEAR the watch area.  Implicit in this watch are the possibility of severe thunderstorms, as defined above. Remain alert for approaching storms.  Know what counties are in the watch area by listening to NOAA Weather Radio or your local radio/television outlets.

 Tornado Warning: A tornado has been sighted by spotters in the field, or indicated by NWS Doppler radar.

 Flash Flood Watch: Issued when heavy rain may develop and result in flash flooding in or near the watch area.

 Flash Flood Warning: Flash flooding in the warning area has developed or is imminent!

 Urban and Small Stream Flood Advisory: Local flooding of small streams, streets, or low lying areas such as railroad underpasses is occurring or is imminent.  Note: this is issued for lesser rainfall events than a flash flood, though danger to life and property still may exist.

 Note: Watches tend to cover a large geographic area (many counties), and tend to be issued for moderately long time periods (3-6 hours).  Warnings cover a much smaller area (portion of a county or portions of several counties) for a much shorter time period (30-60 minutes typical).

 Drought Update

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

The map below shows forecasted temperature deviances for May 2010. As can be seen, normal temperatures are expected for much of the state, though the southwestern areas of the state are expected to have above normal temperatures.

The map below shows forecasted precipitation deviances for May 2010.  All of Colorado is expected to have above normal precipitation for the month..

Little in the way of drought remains in Colorado.

April Summary

April of 2010 came in right around normal for temperatures with above normal precipitation and below normal snowfall with only 0.5" reported at DIA.  For the month there was an average high of 61.7 degrees compared to 60.9 and an average low of  33.9 which was slightly below the normal of 34.2, this resulted in a monthly mean of 47.8 which is 0.2 degrees above normal.  Precipitation for the month was 2.51" at DIA compared to 1.93" on a normal year resulting in 0.58" above normal precipitation even with the surplus of over half an inch for the year DIA is still below average.  The snowfall of only 0.5" was well below the normal of 7.4" and now results in below normal snowfall through the end of April for DIA.  This snowfall amount does not represent the rest of Denver very well at all as there are many  Denver suburbs with 70-100" so far this winter season and that does not include the snow so far this month of May. The most significant rain/snow event occurred on the 23rd-24th with heavy snowfall in the foothills and over Douglas County where there were snowfall rates of 3-4" per hour occurred with snow totals of 10-20" or more.  DIA reported most of the months precipitation during this time with 1.57" of rainfall and only a trace of snow.

April Stats

TEMPERATURE (IN DEGREES F)

 

 

 

 

 

 

AVERAGE MAX

61.7

NORMAL

60.9

DEPARTURE

0.8

AVERAGE MIN

33.9

NORMAL

34.2

DEPARTURE

-0.3

MONTHLY MEAN

47.8

NORMAL

47.6

DEPARTURE

0.2

HIGHEST

79 on the 28th

LOWEST

26 on the 2nd

 

 

 

 

 

 

DAYS WITH MAX 90 OR ABOVE

0

NORMAL

0.2

DAYS WITH MAX 32 OR BELOW

0

NORMAL

0.2

DAYS WITH MIN 32 OR BELOW

15

NORMAL

11.4

DAYS WITH MIN ZERO OR BELOW

0

NORMAL

0.1

 

 

 

 

 

 

TEMPERATURE RECORDS

 

No new temperature records tied or broken

 

 

 

 

 

 

 

HEATING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

509

NORMAL

524

DEPARTURE

-15

SEASONAL TOTAL

6053

NORMAL

5801

DEPARTURE

252

 

 

 

 

 

 

COOLING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

0

NORMAL

2

DEPARTURE

-2

YEARLY TOTAL

0

NORMAL

2

DEPARTURE

-2

 

 

 

 

 

 

PRECIPITATION (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

2.51

NORMAL

1.93

DEPARTURE

0.58

YEARLY TOTAL

3.68

NORMAL

4.21

DEPARTURE

-0.53

GREATEST IN 24 HOURS

1.57" 4/22-4/23

DAYS WITH MEASURABLE PRECIPITATION

8

 

 

 

 

 

SNOWFALL (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

0.5

NORMAL

7.4

DEPARTURE

-6.9

SEASONAL TOTAL

59.3

NORMAL

61.0

DEPARTURE

-1.7

GREATEST IN 24 HOURS

0.5" 4/6-4/7

GREATEST DEPTH

NA

 

 

 

 

 

 

WIND (IN MILES PER HOUR)

 

 

 

 

 

 

AVERAGE SPEED

12.1 from the SW

PEAK WIND GUST

54mph from the NNW on the 23rd

 

 

 

 

 

 

MISCELLANEOUS WEATHER

 

 

 

 

 

 

NUMBER OF DAYS WITH THUNDERSTORMS

3

NORMAL

2

NUMBER OF DAYS WITH HEAVY FOG

4

NORMAL

1

NUMBER OF DAYS WITH HAIL

2

 

 

PERCENT OF SUNSHINE

NA

NORMAL

67%

May Preview

Now that we are already into the second week of May it may be safe to assume that this month will be colder than normal with above normal snowfall for many locations.  Up to this point temperatures are 7 degrees below normal but with warmer weather ahead this will change but temperatures will not be warm enough to get back to even.  Monthly totals so far for DIA during the month of May stand at 1.05" of precipitation and 1.3" of snow.  Average precipitation for May is 2.32"

and is Denver's wettest month of the year.  There is still a ways to go if we are to have normal precipitation for the month but we should get there.  The 1.3" of snow is on par with average and there may not be any more measurable snow for the lower elevations.  Typically people say, "Wait till mothers day to plant outdoors."  Well this year we have had to wait till after mothers day and another freeze or frost during the month cannot be ruled out so keep a close eye on temperatures and cover plants if necessary.

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

<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

<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" Numerous years
 

Sunrise/Sunset (Jan - June 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 | 0632-0550 | 0544-0623 | 0600-0753 | 0534-0821  01
 02  0721-0447 | 0706-0519 | 0631-0551 | 0542-0624 | 0559-0754 | 0533-0822  02
 03  0721-0448 | 0705-0520 | 0629-0553 | 0540-0625 | 0558-0755 | 0533-0822  03
 04  0721-0448 | 0704-0522 | 0628-0554 | 0639-0726 | 0556-0756 | 0533-0823  04
 
 05  0721-0449 | 0703-0523 | 0626-0555 | 0637-0727 | 0555-0757 | 0532-0824  05
 06  0721-0450 | 0702-0524 | 0625-0556 | 0636-0728 | 0554-0758 | 0532-0824  06
 07  0721-0451 | 0701-0525 | 0623-0557 | 0634-0729 | 0553-0759 | 0532-0825  07
 08  0720-0452 | 0700-0526 | 0622-0558 | 0633-0730 | 0552-0800 | 0532-0825  08
 
 09  0720-0453 | 0659-0527 | 0620-0559 | 0631-0731 | 0551-0801 | 0531-0826  09
 10  0720-0454 | 0658-0529 | 0619-0600 | 0630-0732 | 0550-0802 | 0531-0827  10
 11  0720-0455 | 0657-0530 | 0617-0601 | 0628-0733 | 0549-0803 | 0531-0827  11
 12  0720-0456 | 0655-0531 | 0616-0602 | 0626-0734 | 0548-0804 | 0531-0828  12
 
 13  0719-0457 | 0654-0532 | 0614-0603 | 0625-0735 | 0547-0805 | 0531-0828  13
 14  0719-0458 | 0653-0533 | 0612-0604 | 0623-0736 | 0546-0806 | 0531-0828  14
 15  0719-0459 | 0652-0535 | 0611-0605 | 0622-0737 | 0545-0806 | 0531-0829  15
 16  0718-0501 | 0650-0536 | 0609-0606 | 0620-0738 | 0544-0807 | 0531-0829  16
 
 17  0718-0501 | 0649-0537 | 0608-0607 | 0619-0739 | 0543-0808 | 0531-0830  17
 18  0717-0502 | 0648-0538 | 0606-0608 | 0618-0740 | 0542-0809 | 0531-0830  18
 19  0717-0503 | 0647-0539 | 0604-0609 | 0616-0741 | 0542-0810 | 0531-0830  19
 20  0716-0504 | 0645-0540 | 0603-0610 | 0615-0742 | 0541-0811 | 0532-0830  20
 
 21  0716-0505 | 0644-0541 | 0601-0612 | 0613-0743 | 0540-0812 | 0532-0831  21
 22  0715-0506 | 0642-0543 | 0600-0613 | 0612-0744 | 0539-0813 | 0532-0831  22
 23  0714-0507 | 0641-0544 | 0558-0614 | 0611-0745 | 0539-0814 | 0532-0831  23
 24  0714-0509 | 0640-0545 | 0556-0615 | 0609-0746 | 0538-0815 | 0533-0831  24
 
 25  0713-0510 | 0638-0546 | 0555-0616 | 0608-0747 | 0537-0815 | 0533-0831  25
 26  0712-0511 | 0637-0547 | 0553-0617 | 0606-0748 | 0537-0816 | 0533-0831  26
 27  0712-0512 | 0635-0548 | 0552-0618 | 0605-0749 | 0536-0817 | 0534-0832  27
 28  0711-0513 | 0634-0549 | 0550-0619 | 0604-0750 | 0536-0818 | 0534-0832  28
 
 29  0710-0514 |                     | 0548-0620 | 0603-0751 | 0535-0819 | 0534-0832  29
 30  0709-0516 |                     | 0547-0621 | 0601-0752 | 0535-0819 | 0535-0831  30
 31  0708-0517 |                     | 0545-0622 |                      | 0534-0820 |                       31


Snowfall

Sept 2009 to Apr 2010

City

Sept-Oct

Nov

Dec

Jan

Feb

Mar Apr

Seasonal Totals

Aurora (Central)

20.2 9.3 13.8 1.8 12.4 15.9 1.8 89.4
Brighton 18.4 8.3 12.4 3.1 7.8 15.1 0.9 66.0
Broomfield 27.2 11.8 17.3 2.6 15.0 20.1 4.6 98.6

Castle Rock 4 NE

27.5 8.7 12.5 0.8 12.0 18.7 22.2 102.4

Colorado Sprgs Airport

1.8 1.5 9.4 1.9 9.7 7.2 0.3 31.8
Denver DIA 17.2 9.3 11.1 2.6 5.8 12.8 0.5 59.3

Denver Downtown

21.4 9.0 16.1 2.8 14.2 17.9 4.3 85.7

Golden

28.3 12.9 21.7 5.7 19.9 32.2 8.5 129.2

Fort Collins

25.5 6.6 19.5 3.3 12.4 12.5 3.3 83.1

Highlands Ranch

34.4 9.7 15.4 1.6 12.8 25.2 11.7 110.8

Lakewood

20.5 9.0 12.4 3.1 15.7 16.3 4.5 81.5

Littleton

25.9 12.2 16.0 2.3 15.9 19.5 5.2 97.0

Parker

22.5 8.2 12.8 1.0 8.7 19.5 11.0 83.7

Sedalia - Hwy 67

30.0 10.0 10.5 1.3 13.7 25.0 15.0 105.5

Thornton

22.8 8.3 16.6 1.5 11.2 17.1 3.0 80.5

Westminster

21.6 13.0 15.2 2.1 16.5 18.6 3.2 90.2

Wheatridge

28.8 10.9 15.6 3.4 19.3 17.3 4.7 100.0