The Weather Wire

 

July 2004                                                                                                                      Volume 11 Number 7

 

Contents

 

·   Watches and Warnings

 

·   Drought Monitor

 

·   June

    Summary

 

·   June Stats

 

·   July Preview

 

·   Sunrise/Sunset

 

·   Rainfall Totals

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

June 2004

 

Avg High 76.9

Avg Low 50.5

Snow - 0.0"

Season Snow - 38.0"

Precipitation - 2.33"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July

Avg High 82.1

Avg Low 53.0

Avg Snow - 0

Avg Precip - 1.56"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Skyview Weather 

2350 N Rocky View Rd

Castle Rock, CO 80104

 

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 2004

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).

Drought Update

In many portions of Colorado, June 2004  saw above normal precipitation.  With the abundant moisture, the drought situation improved considerably across the entire state.

The map below shows forecasted temperature deviances for the July 2004 time period. As can be seen, normal or near normal temperatures are expected for  most of Colorado for July, though areas in the western 1/3 of the state have forecasted temperatures above normal..

The map below shows forecasted precipitation deviances for July 2004.  Normal or near normal precipitation is expected for July 2004 all of Colorado.

As can be seen in the below map, drought conditions are expected to continue to persist across the western 2/3s of the state, though some improvement is noted in the eastern 1/3 of Colorado through September.

June Summary

Finally an above normal month for rainfall!!!

 The below normal monthly precipitation streak for Denver ends at 11.  2.33 inches of rainfall fell in the rain gage which was 0.77 inch above normal.  There were 13 days with measurable precipitation which is 4 above normal.  From the 16th through the 21st, each day recorded measurable rainfall for a total of 1.31 inches.  Although above normal it was not enough to get into the top 10 wettest Junes.  Even though we had above normal rainfall for June the year as a whole is still below normal by 2.12 inches.  Again as we have stressed in this newsletter many times DIA is not the best representative of the metro area as a whole as many areas had 4 inches or more from heavy storms.

June 2004 finished with an average temperature of 63.7 degrees which is 3.9 degrees below normal.  Temperatures ranged from a record setting 98 degrees down to a low of 41 degrees.  Only 3 90 degree days were seen for June so yes it did feel a bit on the cool side for the month as a whole.

On the 15th, a funnel cloud was observed at DIA and there were 13 thunderstorms reported.  No hail was reported at DIA, but as many homeowners in the southwest metro area know hail the size of golf balls did a fair amount of damage to homes throughout the area.  Also heavy rains caused flooding in portions of Jefferson Country including Ken Caryl, Golden and portions of Lakewood.

June Stats

TEMPERATURE (IN DEGREES F)

 

 

 

 

 

 

AVERAGE MAX

76.9

NORMAL

82.1

DEPARTURE

-5.2

AVERAGE MIN

50.5

NORMAL

53.0

DEPARTURE

-2.5

MONTHLY MEAN

63.7

NORMAL

67.6

DEPARTURE

-2.9

HIGHEST

98 on the 7th

LOWEST

41 on the 1th and 18th

 

 

 

 

 

 

DAYS WITH MAX 90 OR ABOVE

0

NORMAL

0

DAYS WITH MAX 32 OR BELOW

0

NORMAL

0

DAYS WITH MIN 32 OR BELOW

4

NORMAL

2

DAYS WITH MIN ZERO OR BELOW

0

NORMAL

0

 

 

 

 

 

 

TEMPERATURE RECORDS

 

Record high of 95 on the 6th

Record high minimum of 68 on the 7th

Record high of 98 on the 7th

Tied record low max of 53 on the 18th

Record high minimum of 68 on the 7th  

 

 

 

 

 

 

HEATING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

99

NORMAL

61

DEPARTURE

38

SEASONAL TOTAL

5748

NORMAL

6128

DEPARTURE

-380

 

 

 

 

 

 

COOLING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

67

NORMAL

136

DEPARTURE

-69

YEARLY TOTAL

90

NORMAL

161

DEPARTURE

-71

 

 

 

 

 

 

PRECIPITATION (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

2.33

NORMAL

1.56

DEPARTURE

0.77

YEARLY TOTAL

5.97

NORMAL

8.09

DEPARTURE

-2.12

GREATEST IN 24 HOURS

0.77 on the 17th to 18th

DAYS WITH MEASURABLE PRECIPITATION

13

 

 

 

 

SNOWFALL (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

0.0

NORMAL

Trace

DEPARTURE

 

SEASONAL TOTAL

38.0

NORMAL

61.7

DEPARTURE

-23.7

GREATEST IN 24 HOURS

 

GREATEST DEPTH

 

 

 

 

 

 

 

WIND (IN MILES PER HOUR)

 

 

 

 

 

 

AVERAGE SPEED

10.0

       

PEAK WIND GUST

45mph from NW on the 14th

 

 

 

 

 

 

MISCELLANEOUS WEATHER

 

 

 

 

 

 

NUMBER OF DAYS WITH THUNDERSTORMS

13

NORMAL

10

NUMBER OF DAYS WITH HEAVY FOG

11

NORMAL

0

NUMBER OF DAYS WITH HAIL

0

 

 

PERCENT OF SUNSHINE

65

NORMAL

67

 

 

 

July Preview

July is normally a stormy month in Denver.

Denver’s weather is notorious for being changeable.  However, this is not the case during July.  Most July mornings are sunny with clouds developing during the late morning and early afternoon.  By mid afternoon, thunderstorms have developed over the foothills and drift across the Denver metro area and onto the eastern plains.  Severe thunderstorms containing large hail, strong gusty winds and heavy downpours are not uncommon during July for the Denver metro area.

The worst hail storm on record in Denver history moved across the western sections of the city on July 8th, 1990. This storm dropped baseball to softball sized hail and caused millions of dollars worth of property damage.

July is the stormiest month of the year with thunderstorms occurring about every third day or usually 11 days per month.  Most of the rainfall during the month is the result of slow moving thunderstorms, which cause precipitation amounts to vary tremendously at different locations across the metro area.  It is not unusual for some areas of the city to receive two or three times as much rainfall as other areas.   Flash flooding is also quite possible during July.

The 30 day outlook for July calls for near normal precipitation and near normal temperatures.

DENVER'S JULY CLIMATOLOGICALLY NORMAL

(NORMAL PERIOD 1971-2000)

 

 

TEMPERATURE

 

 

 

AVERAGE HIGH

88.0

AVERAGE LOW

58.7

MONTHLY MEAN

73.4

DAYS WITH HIGH 90 OR ABOVE

15

DAYS WITH HIGH 32 OR BELOW

0

DAYS WITH LOW 32 OR BELOW

0

DAYS WITH LOWS ZERO OR BELOW

0

 

 

PRECIPITATION

 

 

 

MONTHLY MEAN

2.16 inches

DAYS WITH MEASURABLE PRECIPITATION

9

AVERAGE SNOWFALL IN INCHES

0

DAYS WITH 1.0 INCH OF SNOW OR MORE

0

 

 

MISCELLANEOUS JULY AVERAGES

 

 

 

HEATING DEGREE DAYS

1

COOLING DEGREE DAYS

261

WIND SPEED (MPH)

8.3

WIND DIRECTION

SOUTH

DAYS WITH THUNDERSTORMS

11

DAYS WITH DENSE FOG

0

PERCENT OF SUNSHINE POSSIBLE

71

 

 

JULY EXTREMES

 

 

 

RECORD HIGH

103 DEGREES ON 7/08/1989

RECORD LOW

42 DEGREES ON 7/4/1903

WARMEST

77.8 DEGREES IN 1934

COLDEST

64.4 DEGREES IN 1895

WETTEST

6.41 INCHES IN 1965

DRIEST

0.01 IN 1901

SNOWIEST

0.0

LEAST SNOWIEST

0.0

Sunrise/Sunset (Denver area)

     Date

Sunrise

Sunset

     July 1  

05:35

20:31

     July 5

05:38

20:31

     July10

05:40

20:29

     July 15

05:44

20:27

     July 20

05:48

20:24

     July 25

05:53

20:20

     July 30

05:57

20:15

 Rainfall

City

May 

June

July

Aug Sept

May - September Totals

Arvada

1.06

3.07

 

   

4.13

Aurora (Central)

0.83

1.93

     

2.76

Castle Rock 4 NE

0.41

3.63

 

   

4.04

Colorado Springs

0.61

6.01

 

   

6.62

Denver DIA 1.30 2.33      

3.63

Denver Downtown

1.06

2.17

 

   

3.23

Golden

1.10

4.77

 

   

5.87

Highlands Ranch

0.95

2.88

 

   

3.83

Lakewood

1.10

3.63

 

   

4.73

Littleton

0.87

2.09

 

   

2.96

Louisville

1.38

3.78

 

   

5.16

Parker

1.02

2.13

 

   

3.15

Sedalia

1.18

4.06

 

   

5.24

Thornton

0.67

1.81

 

   

2.48

Westminster

0.79

1.06

 

   

1.85

Wheatridge

1.22

1.42

 

   

2.64