The Weather Wire

 

June 2007                                                                                                            Volume 15 Number 06

 

Contents

 

·   Watches and Warnings

 
·   Safety Classes
 

·   Drought Monitor

 

·   May

    Summary

 

·   May Stats

 

·   June Preview

 

·   Sunrise/Sunset

 

·   Snow Totals

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

May 2007

 

Avg High 71.4

Avg Low 44.6

Snow - 0.0"

Season Snow - 72.6"

Precipitation - 1.79"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

June

Avg High 82.1

Avg Low 53.0

Avg Snow -  0"

Avg Precip - 1.56"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Skyview Weather 

2350 Rocky View Rd

Castle Rock, CO 80108

 

Phone: (303) 688-9175

Fax: (303) 660-0548

 

E-mail:    

tim@skyview-wx.com

 

We’re on the Web!

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

 

Copyright 2007

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.  So below find the definitions for 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. 

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 ¾ inch or larger, and/or winds GE 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 ¾ inch or large, 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).

 

Skyview Offers Safety Classes

As in many endeavors, awareness equals safety.  One component of awareness is education, and Skyview Weather has a number of educational classes intended to promote weather awareness and increased safety.  At this time, the following classes are available. We highly recommend these safety classes for your facility, please contact us for more information!

Basic Weather Safety - This 1 hour safety oriented class reviews basic weather safety, including flash flood safety, lightning safety, and tornado safety as well as reviewing NWS products, with specific emphasis on watches and warnings.

Basic Weather Safety and Severe Weather Spotting - This 3 hour class begins with basic weather safety, including flash flood safety, lightning safety, and tornado safety as well as reviewing NWS products, with specific emphasis on watches and warnings. Basic weather concepts  and basic weather spotting is included, with emphasis on thunderstorm features.

Basic Weather Safety for Coaches - This 60-90 minute safety oriented class is similar to Basic Weather Safety, but designed for coaches and other administrators that must determine whether to suspend or cancel outdoor sports events.  Heavy emphasis on lightning safety, as well as severe thunderstorm safety is presented. A review of NWS publicly disseminated products, including watches and warnings, is included. Basic weather safety, including flash flood safety, lightning safety, and tornado safety is discussed.

Extended Weather Safety and Spotting - As with the above classes, this all day class begins with basic weather safety, including flash flood safety, lightning safety, and tornado safety as well as reviewing NWS products, with specific emphasis on watches and warnings.  Basic weather concepts and definitions are discussed, with extensive time on the role of spotters, and key spotting features of developing severe storms. Video presentations are included as well.

Radar 101 - Everyone utilizes radar on the internet, but just what exactly are you looking at?  This 2 hour class answers that question, providing an introduction to radar,  a review of publicly available radar products on the internet, and how to interpret what the radar.  This class is critical for those organizations attempting to use publicly available internet weather for client and employee safety.

Getting the most from Skyview Weather ... Client-Skyview interaction - This 2 hour class focuses on how existing clients of Skyview Weather can get the most from Skyview Weathers extensive services.  A review of what Skyview offers, product delivery, and Skyview Weather terms is presented.

All classes are presented using PowerPoint, and include handouts.  Questions are always welcome, and encourage..  Selected classes include video as well.  Please contact Skyview Weather for scheduling and pricing information.  As always, you can reach us at 303-688-9175 or via email at tim@skyview-wx.com .

Drought Update

Little change, or perhaps improvement, in overall drought conditions across Colorado occurred in May.

The map below shows forecasted temperature deviances for June 2007. As can be seen,  .normal  temperatures are expected for Eastern Colorado for June 2007, with Central and Western portions of Colorado expected to have above normal temperatures.

The map below shows forecasted precipitation deviances for June2007.  Normal precipitation is expected for  much of Colorado for June 2007, though extreme Western Colorado may see below normal precipitation.

As can be seen in the below map, little overall change is anticipated for much of Colorado through August, though some worsening of drought conditions possible extreme Western Colorado.

May Summary

May 2007 had an unusually high number of thunderstorm days with a total of 17.  This compares to a normal total of only 6.  There were two days with small hail reported at DIA the 5th and the 29th.  Total rainfall for the month finished below normal with a total of 1.79 inches, which was 0.53 inch below normal. May 2007 marked the 6th May in a row with below normal precipitation.  Again we must note that many areas in the Metro area and along the Front Range had much more precipitation than did DIA.  No snow fell during the month which is 1.3 inches below normal.  No rain or snow records set during the month.

The temperatures during May 2007 were near normal with an average temperature of 58.0 degrees, which is only 0.8 degrees above the normal of 57.2 degrees.  Temperatures ranged from a high of 85 degrees on the 13th down to a low of 35 degrees registered on the 24th.  There are normally around 2 days with low temperatures dropping below the freezing mark, but not this year.  Normally May is the first occurrence of the year with a 90 degree reading, but again not this year.

May Stats

TEMPERATURE (IN DEGREES F)

 

 

 

 

 

 

AVERAGE MAX

71.4

NORMAL

70.5

DEPARTURE

0.9

AVERAGE MIN

44.6

NORMAL

43.8

DEPARTURE

0.8

MONTHLY MEAN

58.0

NORMAL

57.2

DEPARTURE

0.8

HIGHEST

85 on the 13th

LOWEST

35 on the 24th

 

 

 

 

 

 

DAYS WITH MAX 90 OR ABOVE

0

NORMAL

LT 1

DAYS WITH MAX 32 OR BELOW

0

NORMAL

0

DAYS WITH MIN 32 OR BELOW

0

NORMAL

2

DAYS WITH MIN ZERO OR BELOW

0

NORMAL

0

 

 

 

 

 

 

TEMPERATURE RECORDS

 
 
None

 

 

 

 

 

 

HEATING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

223

NORMAL

267

DEPARTURE

-44

SEASONAL TOTAL

6163

NORMAL

6068

DEPARTURE

95

 

 

 

 

 

 

COOLING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

15

NORMAL

23

DEPARTURE

-8

YEARLY TOTAL

20

NORMAL

25

DEPARTURE

-5

 

 

 

 

 

 

PRECIPITATION (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

1.79"

NORMAL

2.32"

DEPARTURE

-0.53"

YEARLY TOTAL

5.92"

NORMAL

6.53"

DEPARTURE

-0.61"

GREATEST IN 24 HOURS

0.53" on 29th

DAYS WITH MEASURABLE PRECIPITATION

10

 

 

 

 

SNOWFALL (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

0.0"

NORMAL

1.3"

DEPARTURE

-1.3"

SEASONAL TOTAL

72.6"

NORMAL

63.0"

DEPARTURE

9.6"

GREATEST IN 24 HOURS

0.0"

GREATEST DEPTH

0"

 

 

 

 

 

 

WIND (IN MILES PER HOUR)

 

 

 

 

 

 

AVERAGE SPEED

9.8

       

PEAK WIND GUST

48 from north on 5/14

 

 

 

 

 

 

MISCELLANEOUS WEATHER

 

 

 

 

 

 

NUMBER OF DAYS WITH THUNDERSTORMS

17

 

6

NUMBER OF DAYS WITH HEAVY FOG

0

 NORMAL

1

NUMBER OF DAYS WITH HAIL

2

 

 

PERCENT OF SUNSHINE

75

NORMAL

64

 

 

 

June Preview

June is severe weather month for Denver.  Severe thunderstorms and tornadoes are notorious in Denver and across eastern Colorado during June.  Over 40 percent of the tornadoes that occur in Colorado are observed during  June.  June tornadoes and severe thunderstorms have caused extensive property damage in and near the Denver metro area in years past.

Some of the more notable tornadoes occurred in:  Thornton on June 3, 1981, southeast Denver and Aurora on June 8, 1986 and east Denver on June 13, 1984.  In addition, on June 13, 1984 powerful thunderstorms dumped large hail, making it one of the worst and costliest hail storms in Denver history.  During June 2001, a major hail storm moved across Denver International Airport on the 20th, dropping hailstones as big as two inches in diameter. 

Even though there are frequent tornado occurrences in eastern Colorado during June, there has not been a tornado related death since 1960.  However, there have been several deaths attributed to lightning during June.

Cool weather can still occur in early June.  The latest freeze on record in Denver occurred on June 2, 1951 when the mercury dropped to 30 degrees.  This is also the record low temperature for June.  Snow has been reported in the city as late as June 11th when in 1947 a trace of snow was reported.  The wettest June was in 1882 when 4.96 inches of rain fell and the driest June was 1890 with only a trace of precipitation recorded.  The maximum 24 hour precipitation was 3.16 inches on June 11, 1970.

By the end of June, the mercury has been known to climb to 100 degrees or higher.  The record high temperature for June is 104 degrees set on June 26th 1994.  Other high temperature records reaching 100 degrees or higher are: 102 set June 23rd 1954, 102 set June 27th 1990,  June 29th 1990 and June 30th 1990, 100 degrees set June 25th 1991.  The warmest June occurred in 1994 with an average temperature of 73.5 degrees.  The coldest June was 60.6 degrees in 1967.

DENVER'S JUNE CLIMATOLOGICALLY NORMAL

(NORMAL PERIOD 1971-2000)

 

 

TEMPERATURE

 

 

 

AVERAGE HIGH

82.1

AVERAGE LOW

53.0

MONTHLY MEAN

67.6

DAYS WITH HIGH 90 OR ABOVE

6

DAYS WITH HIGH 32 OR BELOW

0

DAYS WITH LOW 32 OR BELOW

0

DAYS WITH LOWS ZERO OR BELOW

0

 

 

PRECIPITATION

 

 

 

MONTHLY MEAN

1.56"

DAYS WITH MEASURABLE PRECIPITATION

9

AVERAGE SNOWFALL IN INCHES

0"

DAYS WITH 1.0 INCH OF SNOW OR MORE

0

 

 

MISCELLANEOUS AVERAGES

 

 

 

HEATING DEGREE DAYS

60

COOLING DEGREE DAYS

136

WIND SPEED (MPH)

8.9

WIND DIRECTION

SOUTH

DAYS WITH THUNDERSTORMS

10

DAYS WITH DENSE FOG

0

PERCENT OF SUNSHINE POSSIBLE

70

 

 

EXTREMES

 

 

 

RECORD HIGH

104 DEGREES ON 06/26/1994

RECORD LOW

30 DEGREES ON 06/02/1951

WARMEST

73.5 DEGREES IN 1994

COLDEST

60.6 DEGREES IN 1967

WETTEST

4.96" IN 1882

DRIEST

TR IN 1890

SNOWIEST

0.4" INCHES in 1919

LEAST SNOWIEST

0.0" multiple years

Sunrise/Sunset (Denver area)

     Date

Sunrise

Sunset

     June 1  

05:34

20:21

     June 5

05:32

20:24

     June 10

05:31

20:27

     June 15

05:31

20:29

     June 20

05:31

20:31

     June 25

05:32

20:32

     June 30

05:34

20:32

 Rainfall

May 2007 to Sept 2007

City

May

June

July

August Sept

Seasonal Totals

Aurora (Central)

2.40"         2.40"
Brighton 1.14"         1.14"
Broomfield 2.17"         2.17"

Castle Rock 4 NE

2.14"         2.14"

Colorado Sprgs Airport

 2.35"         2.35"
Denver DIA  1.79"         1.79"

Denver Downtown

3.11"         3.11"

Golden

3.11"         3.11"

Highlands Ranch

2.64"         2.64"

Lakewood

 1.93"          1.93"

Littleton

 3.43"          3.43"

Parker

1.69"         1.69"

Sedalia - Hwy 67

 3.74"         3.74"

Thornton

 1.61"          1.61"

Westminster

 2.56"          2.56"

Wheatridge

 2.95"          2.95"