The Weather Wire

 

August 2005                                                                                                              Volume 13 Number 08

 

Contents

 

·   Terms and Definitions

 

·   Online Forecasts
 

·   Drought Monitor

 

·   July

    Summary

 

·   July Stats

 

·   August Preview

 

·   Sunrise/Sunset

 

·   Snow Totals

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2005

 

Avg High 94.5

Avg Low 60.9

Snow - 0.0"

Season Snow - 39.3"

Precipitation - 0.27"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

August

Avg High 86.0

Avg Low 57.4

Avg Snow -  0.0"

Avg Precip - 1.82"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Skyview Weather 

2350 N 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 2005

Skyview Weather

Terms and Definitions

Sometimes it is good to review some of the terms that we as weathermen use everyday to make sure we are all on the same page, so to speak.  Weather in many ways has its own language and we as weathermen know because we use it every day, sometimes we assume everyone understands what we are telling them when we talk weather, but that is not always the case.

Dew Point – We use the dew point quite often in the summer months in regard to severe weather.  It tells us how much moisture is in the air around us.  Quite simply it is the temperature at which the air can no longer hold any moisture and the moisture condenses from a gas to liquid form, as clouds, fog or as dew (frost in the winter) on the ground.  Hence ‘dew point’.  So if the dew point of the air is 40 degrees when the air temperature hits 40 degrees we would expect fog to form.

Humidity – This is another way to measure the amount of water in the surrounding air.  It is use as a percentage of the amount of water the air can hold.  So 50% humidity means the air is holding 50% of what it is capable of holding.  At 100% it is holding all it can and any more condenses out as clouds or fog.

Wind Chill – This is an index of the effect that wind and temperature has on the human body.  Used only during the winter months to indicate to those venturing outside an apparent temperature related to chilling effects on the human body.  Here is how this works.  Under no wind condition the body heats a small layer of air right next to the skin to near body temperature.  Anytime the air temperature is below 98.6 degrees the body is loosing heat to the surrounding air.  This thin layer of heated air right next to the skin slows this process.  As we introduce wind to the scenario this warm layer next to the skin is blown away causing the body to loose heat faster.  As temperatures decrease and wind increases it can cause dangerous conditions of freezing of the skin, known as frostbite.  Now I did say apparent temperature.  With a temperatures of 20 degrees and a wind of 30mph the ‘wind chill’ drops below zero, but the actual air temperature is still 20 degrees. 

QPF – On some of our forecasts you will see QPF.  This stands for Quantitative Precipitation Forecast.  Rather fancy sounding, but simply we quantify the amount of precipitation we are expecting for a particular storm situation.  We use it more during the summer months in regard to the potential for flooding.   Let’s say that a particular creek can handle only 2.00 inches of rain in a one hour period.  Anything more than that would cause the stream to come out of its banks.  So a forecast QPF of 0.25 inch wouldn’t cause concern, while a forecast of 3.00 inches would raise red flags that this stream would need to be watched closely.

Min RH/Max RH – You see these on your daily forecast sheets that we send out.  While it is pretty straight forward not everyone uses these.  Basically it is the humidity range we expect every 12 hour period.  Our fire clients find this quite useful as the drier that range the higher the fire danger to drying vegetation becomes.  A forecast for high humidity would indicate that vegetation would now dry as quickly, or on a working fire would help slow the fire down due to the higher water content of the air.

Watch/Warning - Always good to go over these two.  They come in a variety of flavors depending on the season.  During the summer; severe weather, flash flood, tornado.  During the winter; winter storm, high wind, heavy snow.  To keep it simple a ‘Watch’ means that conditions are present that could produce those events, but those events are not currently happening.  Warning on the other hand means that those conditions are now occurring or will be a very short period of time.  For example: Tornado Watch - the weather conditions exist where tornadoes might form during the time period indicated in the watch, but these is no tornado currently being seen. Tornado Warning – A tornado has been spotted on the ground or radar indicates a tornado.  The threat is imminent and those in the warning area should take the proper precautions.

If you have a term or two of your own that you are hazy on, send an email to Paul@skyview-wx.com or Tim@skyview-wx.com, and we will cover it in a future news letters.

Online Forecasts Available Again

Skyview Weather is happy to announce that online forecasts and snow reports are again available on our sister www.anythingweather.com website.  Forecasts and snow reports are password protected, but an email to Tim@Skyview-WX.com requesting your forecast and/or snow reports be available online will result in an account being setup for you.  As always, forecasts and snow reports are for client use only, but with the online access, forecasts and snow reports are just a click away from any computer with an internet connection!

Drought Update

Little change in drought conditions across most of Colorado, with few areas of drought remaining..

The map below shows forecasted temperature deviances for August 2005. As can be seen, normal  temperatures are expected for  Colorado for August 2005.

The map below shows forecasted precipitation deviances for August 2005.  Normal or near normal precipitation is expected for Colorado for August 2005.

As can be seen in the below map, most of the state has come out of the widespread drought conditions of a year ago.

July Summary

Denver’s  July 2005 is now the 2nd hottest and 3rd driest in Denver weather history since 1872.

July 2005 has been a record heat setting month.  Six record high temperatures were set, all in the 100s.  In fact on July 20th, the mercury soared to 105 degrees tying the all time Denver high temperature set on August 8th 1878 and breaking the 102 record for July 20th.  Other records were 102 on the 16th, 101 on the 19th, 105 on the 20th, 104 on the 21st, 102 on the 22nd, 102 on the 23rd and 101 degrees on the 30th.  On the 8th, a record high minimum 70 degrees was set.  On the 29th, the record high of 99 was tied.  There were no low temperatures set or tied during the month.  July 2005 became the second hottest month in Denver weather history, since 1872.  Temperatures ranged from the record setting 105 degrees down to a low of 50 degrees.  There were 25 days registering 90 degrees or higher, which ties for the 3rd most days ever with 1963.  The most ever 90 degree days or higher occurred in 1964 with a total of 27.  The year 2000 recorded 26 90 degree days and n 2003 there were twenty four 90 degree days.

Up through July 22nd, July 2005 was the driest July ever with a mere trace recorded.  Then there were 4 consecutive days of measurable precipitation resulting in the month’s total rainfall of 0.27 inch.  This makes July 2005 the 3rd driest July in Denver weather history.  The driest July remains 0.01 inch recorded in 1901.  To show you how fast things can turn around in our weather patterns, June was the 4th wettest on record and now follow that with July being the 3rd driest, and the turn in around again with many areas reporting over 2 inches of rain through just the fist 4 days of August.

July Stats

TEMPERATURE (IN DEGREES F)

 

 

 

 

 

 

AVERAGE MAX

94.5

NORMAL

88.0

DEPARTURE

6.5

AVERAGE MIN

60.9

NORMAL

58.7

DEPARTURE

2.2

MONTHLY MEAN

77.7

NORMAL

73.4

DEPARTURE

4.3

HIGHEST

105 on the 20th

LOWEST

50 on the 4th

 

 

 

 

 

 

DAYS WITH MAX 90 OR ABOVE

25

NORMAL

15

DAYS WITH MAX 32 OR BELOW

0

NORMAL

0

DAYS WITH MIN 32 OR BELOW

0

NORMAL

0

DAYS WITH MIN ZERO OR BELOW

0

NORMAL

0

 

 

 

 

 

 

TEMPERATURE RECORDS

 

Record High 102 on 7-16 Record High 101 on 7-19
Record High 105 on 7-20 Record High 104 on 7-21
Record High 102 on 7-22 Record High 102 on 7-23
Record High 101 on 7-30  

 

 

 

 

 

 

HEATING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

3

NORMAL

1

DEPARTURE

2

SEASONAL TOTAL

3

NORMAL

1

DEPARTURE

2

 

 

 

 

 

 

COOLING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

405

NORMAL

261

DEPARTURE

144

YEARLY TOTAL

558

NORMAL

422

DEPARTURE

136

 

 

 

 

 

 

PRECIPITATION (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

0.27

NORMAL

2.16

DEPARTURE

-1.89

YEARLY TOTAL

8.40

NORMAL

10.25

DEPARTURE

-1.85

GREATEST IN 24 HOURS

0.14 on the 25yh

DAYS WITH MEASURABLE PRECIPITATION

4

 

 

 

 

SNOWFALL (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

0.0

NORMAL

0.0

DEPARTURE

0.0

SEASONAL TOTAL

39.3

NORMAL

61.7

DEPARTURE

-22.4

GREATEST IN 24 HOURS

0.0

GREATEST DEPTH

0.0

 

 

 

 

 

 

WIND (IN MILES PER HOUR)

 

 

 

 

 

 

AVERAGE SPEED

10.4

       

PEAK WIND GUST

54mph from East on the 9th

 

 

 

 

 

 

MISCELLANEOUS WEATHER

 

 

 

 

 

 

NUMBER OF DAYS WITH THUNDERSTORMS

7

NORMAL

 11

NUMBER OF DAYS WITH HEAVY FOG

3

NORMAL

 LT 1

NUMBER OF DAYS WITH HAIL

0

 

 

PERCENT OF SUNSHINE

81

NORMAL

71

 

 

 

August Preview

The weather pattern in August is similar to the rest of the summer months, but the severe weather decreases significantly.  Temperatures also toward the end of the month begin to decline.  Skies are generally clear between midnight and noon, but during the afternoon showers and thunderstorms develop along the foothills during the afternoon and then move eastward across the urban corridor.

The occurrence of severe weather decreases considerably during August compared to the severe weather months of June and July.  The typical air mass aloft over Denver is nearly as warm as earlier in the summer, however, the air mass is usually a bit cooler near the surface.  As a result, the air mass is more stable and therefore thunderstorms are less intense.  Tornadoes and large damaging hail are fairly rare, especially after the middle of August.  Because of slow movement, thunderstorms in August are more likely to produce heavy rain then large hail.

By late August, the days become noticeably shorter and an occasional cold front slips across Denver and brings a nip to the air.  A reminder that summer is really winding down.  There has never been any snowfall recorded in Denver during August.  August still brings in some hot days.  In fact, the highest temperature ever recorded in Denver was recorded during the month of August, 105 degrees on August 8, 1878.  This record was just tied last month on the 20th.

DENVER'S AUGUST CLIMATOLOGICALLY NORMAL

(NORMAL PERIOD 1971-2000)

 

 

TEMPERATURE

 

 

 

AVERAGE HIGH

86.0

AVERAGE LOW

57.4

MONTHLY MEAN

71.7

DAYS WITH HIGH 90 OR ABOVE

9

DAYS WITH HIGH 32 OR BELOW

0

DAYS WITH LOW 32 OR BELOW

0

DAYS WITH LOWS ZERO OR BELOW

0

 

 

PRECIPITATION

 

 

 

MONTHLY MEAN

1.82"

DAYS WITH MEASURABLE PRECIPITATION

9

AVERAGE SNOWFALL IN INCHES

0

DAYS WITH 1.0 INCH OF SNOW OR MORE

0

 

 

MISCELLANEOUS AUGUST AVERAGES

 

 

 

HEATING DEGREE DAYS

38

COOLING DEGREE DAYS

217

WIND SPEED (MPH)

8.0

WIND DIRECTION

SOUTH

DAYS WITH THUNDERSTORMS

8

DAYS WITH DENSE FOG

1

PERCENT OF SUNSHINE POSSIBLE

71

 

 

AUGUST EXTREMES

 

 

 

RECORD HIGH

105 DEGREES ON 8/8/1878

RECORD LOW

40 DEGREES ON 8/26/1910

WARMEST

76.8 DEGREES IN 1937

COLDEST

66.5 DEGREES IN 1915

WETTEST

5.85 INCHES IN 1979

DRIEST

0.02 INCHES 1924

SNOWIEST

None Ever Recorded

LEAST SNOWIEST

None Ever Recorded

Sunrise/Sunset (Denver area)

     Date

Sunrise

Sunset

     August 1  

05:59

20:13

     August 5

06:02

20:09

     August 10

06:07

20:03

     August 15

06:12

19:57

     August 20

06:15

19:50

     August 25

06:21

19:42

     August 30

06:26

19:35

 Rainfall

May - July 2005

City

May

June

July

August Sept

Seasonal Totals

Aurora (Central)

0.83 3.35 0.63     4.81

Castle Rock 4 NE

0.73 1.48 1.16     3.37

Colorado Springs

0.73 2.10 1.94     4.77
Denver DIA 0.71 3.99 0.27     4.97

Denver Downtown

0.83 2.25 0.16     3.24

Golden

2.01 2.99 0.71     5.71

Highlands Ranch

0.75 1.38 1.06     3.19

Lakewood

0.95 2.01 0.99     3.95

Littleton

0.63 2.48 0.51     3.62

Louisville

1.38 1.62 0.71     3.71

Parker

0.83 1.58 0.24     2.65

Sedalia

0.75 1.69 0.20     2.64

Thornton

0.63 3.59 0.16     4.38

Westminster

0.63 1.54 0.24     2.41

Wheatridge

0.75 2.01 0.47     3.23