The Weather Wire

 

October 2009                                                                                                            Volume 17 Number 10

 

Contents

 

 

 
·   Winter Weather
 

·   Drought Monitor

 

·   September

    Summary

 

·   September Stats

 

·   October Preview

 

·   Sunrise/Sunset

 

·   Rain Totals

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September

Avg High - 78.0

Avg Low - 48.9

Snow - 0.0"

Season Snow - 0.0"

Precipitation - 0.74"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

October

Avg High - 66.0

Avg Low - 35.9

Avg Snow -  4.1"

Avg Precip - 0.99"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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

Winter Weather Definitions... 

With winter looking like it will make a visit to Colorado this month it is time to review all the winter weather definitions since we will be seeing a lot of these over the coming winter months as higher than average snowfall is expected.

The National Weather Service issues many different types of watches and warnings during the winter months.  Here is what they mean:

WINTER STORM WATCH:

A winter storm watch is issued when winter storm conditions are possible within the next 12 to 36 hours, but the timing, intensity, or occurrence may still be uncertain.

WINTER STORM WARNING:

A winter storm warning is issued when heavy snow is occurring or will develop in the next 18 hours.  The heavy snow may be accompanied by wind and blowing snow. 

BLIZZARD WARNING:

A blizzard warning is issued when the following conditions are expected for at least 3 hours:     Sustained winds of 35mph or greater with considerable falling and/or drifting snow lowering visibilities to less than 1/4 mile.  Remember, snow does not necessarily need to be falling and dangerous wind chills are often observed during blizzard events.

WINTER WEATHER ADVISORY:

A winter weather advisory for snow is issued when these general snow accumulations are expected:     Between 4 and 8 inches in 12 hours in the mountains.  Between 3 and 6 inches in 12 hours at lower elevations, such as Denver Metro.

 

A winter weather advisory for snow and blowing snow is issued when falling snow is accompanied by blowing snow to cause travel problems due to lowered visibilities and drifting snow.

 

A winter weather advisory for blowing snow is issued when wind blown snow will occasionally reduce visibilities and create a hazard for travelers.

FROST/FREEZE WARNING:

Below freezing temperatures are expected and may cause significant damage to plants, crops, or fruit trees in areas unaccustomed to freezing temperatures.  Usually issued for first frost/freeze of season and again in spring for late frost/freezes.  

HIGH WIND WARNING:

A high wind warning is issued for the following conditions:     Sustained winds of 50mph for at least 1 hour, or gusts to 75mph for any duration in the mountains and foothills.  Sustained winds of 40mph for at least 1 hour, or gusts to 58mph for any duration at lower elevations away from the foothills. 
 

We as weather forecasters use different wording or terms when we describe a snow event.  Whether it is just some flurries or a large winter storm we use different words that best suit the snow event that is expected. 

Snow

FLURRIES - Light snow falling for short durations. No accumulation or light dusting is all that is expected.
SHOWERS - Snow falling at varying intensities for brief periods of time. Some accumulation is possible. You can best relate to these by thinking about a summer shower, but instead of rain you get snow.
SQUALLS - Brief, intense snow showers accompanied by strong, gusty winds. Accumulation may be significant. Snow squalls are best known in the Great Lakes region.
BLOWING SNOW - Wind-driven snow that reduces visibility and causes significant drifting. Blowing snow may be snow that is falling and/or loose snow on the ground picked up by the wind.
BLIZZARD - Winds over 35 mph with snow and blowing snow, reducing visibility to near zero.  

Sleet

Rain drops that freeze into ice pellets before reaching the ground. Sleet usually bounces when hitting a surface and does not stick to objects. However, it can accumulate like snow and cause a hazard to motorists.

Freezing Rain

Rain that falls onto a surface with a temperature below freezing. This causes it to freeze to surfaces, such as trees, cars, and roads, forming a coating or glaze of ice. Even small accumulations of ice can cause a significant hazard.

Snow and or severe cold can be potentially life threatening and every year we see cold and snow related deaths.

Everyone is potentially at risk during winter storms. The actual threat to you depends on your specific situation. Recent observations indicate the following:

  • Related to ice and snow:
    • About 70% occur in automobiles.
    • About 25% are people caught out in the storm.
  • Related to exposure to cold:
    • 50% are people over 60 years old.
    • Over 75% are males.
    • About 20% occur in the home.

FROSTBITE

Frostbite is damage to body tissue caused by that tissue being frozen. Frostbite causes a loss of feeling and a white or pale appearance in extremities, such as fingers, toes, ear lobes, or the tip of the nose. If symptoms are detected, get medical help immediately! If you must wait for help, slowly re-warm affected areas. However, if the person is also showing signs of hypothermia, warm the body core before the extremities.

HYPOTHERMIA: LOW BODY TEMPERATURE

Warning signs - uncontrollable shivering, memory loss, disorientation, incoherence, slurred speech, drowsiness, and apparent exhaustion.

Detection - Take the person's temperature. If below 95F (35C), immediately seek medical care! If medical care is not available, begin warming the person slowly. Warm the body core first. If needed, use your own body heat to help. Get the person into dry clothing, and wrap them in a warm blanket covering the head and neck. Do not give the person alcohol, drugs, coffee, or any hot beverage or food; warm broth is better. Do not warm extremities (arms and legs) first! This drives the cold blood toward the heart and can lead to heart failure.

WIND CHILL

The wind chill is based on the rate of heat loss from exposed skin caused by combined effects of wind and cold. As the wind increases, heat is carried away from the body at an accelerated rate, driving down the body temperature. Animals are also affected by wind chill.

When CAUGHT in a Winter Storm...

OUTSIDE

Find shelter:

    • try to stay dry
    • cover all exposed parts of the body.

No shelter:

    • prepare a lean-to, wind-break, or snow cave for protection from the wind.
    • build a fire for heat and to attract attention.
    • place rocks around the fire to absorb and reflect heat.

Do not eat snow: It will lower your body temperature. Melt it first.

 

IN A CAR OR TRUCK

Stay in your car or truck. Disorientation occurs quickly in wind-driven snow and cold.
Run the motor about ten minutes each hour for heat:

    • open the window a little for fresh air to avoid carbon monoxide poisoning.
    • make sure the exhaust pipe is not blocked.

Make yourself visible to rescuers:

    • turn on the dome light at night when running engine.
    • tie a colored cloth (preferably red) to your antenna or door.
    • raise the hood indicating trouble after snow stops falling.

Exercise from time to time by vigorously moving arms, legs, fingers, and toes to keep blood circulating and to keep warm.

 

AT HOME OR IN A BUILDING

Stay inside. When using ALTERNATIVE HEAT from a fireplace, wood stove, space heater, etc.:

    • use fire safeguards.
    • properly ventilate.

No heat:

    • close off unneeded rooms.
    • stuff towels or rags in cracks under doors.
    • cover windows at night.

Eat and drink. Food provides the body with energy for producing its own heat. Keep the body replenished with fluids to prevent dehydration.
Wear layers of loose-fitting, lightweight, warm clothing. Remove layers to avoid overheating, perspiration, and subsequent chill.

 

Colorado sees it share of snow during the winter months.  The best time to prepare for the next snow is now while the weather is mild and dry.  Take an inventory of you winter supplies both for the car and the home and stock in items that you need.  Be prepared and the winter snows will be a lot less bothersome this year.  

Drought Update

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

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

The map below shows forecasted precipitation deviances for October 2009.  All of Colorado is expected to have above normal precipitation for October 2009.

Little in the way of drought remains in Colorado, with no changes expected.

September Summary

September of 2009 was fairly quiet weather wise with most of the monthly precipitation falling between the 21st and 23rd of the month as a slow moving storm system brought rain and snow to the Front Range.  DIA did not report any snow from this fall like system, but many foothill and Palmer Divide locations received the seasons first snow, generally an inch or less with higher amounts in the Jefferson, Boulder and Larimer County foothills.  Precipitation fell short of normal for the second month in a row with only 0.74" reported at DIA with 1.14" on average.  For the month ending in September the yearly precipitation now stands at 15.82" which is 3.63" above normal and assures that this year will feature above "normal " precipitation.  Even with the stretch of cool weather towards the end of the month temperatures were above normal with an average high of 78 compared to 77.4 on average.  Low temperatures averaged 48.9 compared to 47.3 degrees normally.  The warmer overnight temperatures may have been held up by above normal cloud cover acting like a blanket and not allowing the daytime heat to escape overnight.  The percent of possible sunshine was only 61% compared to 74% on average which is quite significant and indicates much more cloudiness than normal.     

September Stats

TEMPERATURE (IN DEGREES F)

 

 

 

 

 

 

AVERAGE MAX

78.0

NORMAL

77.4

DEPARTURE

0.6

AVERAGE MIN

48.9

NORMAL

47.3

DEPARTURE

1.6

MONTHLY MEAN

63.5

NORMAL

62.4

DEPARTURE

1.1

HIGHEST

91 on the 1st

LOWEST

36 on the 28th

 

 

 

 

 

 

DAYS WITH MAX 90 OR ABOVE

1

NORMAL

2.2

DAYS WITH MAX 32 OR BELOW

0

NORMAL

0.2

DAYS WITH MIN 32 OR BELOW

0

NORMAL

0.8

DAYS WITH MIN ZERO OR BELOW

0

NORMAL

0

 

 

 

 

 

 

TEMPERATURE RECORDS

 

No records tied or broken

 

 

 

 

 

 

 

HEATING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

117

NORMAL

136

DEPARTURE

-19

SEASONAL TOTAL

139

NORMAL

146

DEPARTURE

-7

 

 

 

 

 

 

COOLING DEGREE DAYS

 

 

 

 

 

 

MONTHLY TOTAL

78

NORMAL

57

DEPARTURE

21

YEARLY TOTAL

533

NORMAL

696

DEPARTURE

-163

 

 

 

 

 

 

PRECIPITATION (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

0.74

NORMAL

1.14

DEPARTURE

-0.40

YEARLY TOTAL

15.82

NORMAL

12.19

DEPARTURE

3.63

GREATEST IN 24 HOURS

0.42" from 9/22 to 9/23

DAYS WITH MEASURABLE PRECIPITATION

5

 

 

 

 

 

SNOWFALL (IN INCHES)

 

 

 

 

 

 

MONTHLY TOTAL

0

NORMAL

2.1

DEPARTURE

-2.1

SEASONAL TOTAL

0

NORMAL

3.4

DEPARTURE

-3.4

GREATEST IN 24 HOURS

NA

GREATEST DEPTH

NA

 

 

 

 

 

 

WIND (IN MILES PER HOUR)

 

 

 

 

 

 

AVERAGE SPEED

9.2 mph

PEAK WIND GUST

45mph from the west

 

 

 

 

 

 

MISCELLANEOUS WEATHER

 

 

 

 

 

 

NUMBER OF DAYS WITH THUNDERSTORMS

6

NORMAL

4

NUMBER OF DAYS WITH HEAVY FOG

1

NORMAL

1

NUMBER OF DAYS WITH HAIL

0

 

 

PERCENT OF SUNSHINE

61%

NORMAL

74%

October Preview

October of 2009 will likely bring the seasons first meaningful snowfall to many Front Range locations as the onset of fall has occurred.  Already this month DIA has reported record low temperatures in the middle 20s and the trees sure seem to be changing early this year, especially the scrub oak and they are "typically" one of the last trees to change.  Daylight loss becomes very noticeable in October especially after the time change and temperatures respond accordingly dropping 12 degrees from the average high of September.  Overnight temperatures are frequently at or below freezing with 9 days on average per month.  There can certainly be some beautiful fall weather in October with 72% of possible sunshine which makes October one of the sunniest months of the year.  Large variations in temperatures and weather conditions are common in October with thunderstorms and blizzards both possible just days or hours apart.  Skyview Weather believes that this October will feature colder than normal temperatures and above normal precipitation with a couple bouts of snow likely.

 

DENVER'S NOVEMBER CLIMATOLOGICALLY NORMAL

(NORMAL PERIOD 1971-2000)

 

 

TEMPERATURE

 

 

 

AVERAGE HIGH

66.0

AVERAGE LOW

35.9

MONTHLY MEAN

51.0

DAYS WITH HIGH 90 OR ABOVE

0

DAYS WITH HIGH 32 OR BELOW

Less than 1

DAYS WITH LOW 32 OR BELOW

9

DAYS WITH LOWS ZERO OR BELOW

0

 

 

PRECIPITATION

 

 

 

MONTHLY MEAN

0.99"

DAYS WITH MEASURABLE PRECIPITATION

5

AVERAGE SNOWFALL IN INCHES

4.1"

DAYS WITH 1.0 INCH OF SNOW OR MORE

1

 

 

MISCELLANEOUS AVERAGES

 

 

 

HEATING DEGREE DAYS

436

COOLING DEGREE DAYS

0

WIND SPEED (MPH)

7.8 mph

WIND DIRECTION

South

DAYS WITH THUNDERSTORMS

1

DAYS WITH DENSE FOG

1

PERCENT OF SUNSHINE POSSIBLE

72%

 

 

EXTREMES

 

 

 

RECORD HIGH

90 on 10/1/1892

RECORD LOW

-2 on 10/29/1917

WARMEST

59.9 degrees in 1950

COLDEST

39.0 degrees in 1969

WETTEST

4.17" in 1969

DRIEST

Trace in 1934

SNOWIEST

31.2" in 1969

LEAST SNOWIEST

0.0" 14 years on record
 

Sunrise/Sunset (Jul - December Denver area)

              JUL                AUG                SEP            OCT               NOV            DEC
______________________________________________________________________________
            sr - ss            sr - ss             sr - ss          sr - ss             sr - ss           sr - ss
 01  0535-0831 | 0559-0813 | 0628-0732 | 0656-0643 | 0629-0457 | 0702-0436  01
 02  0536-0831 | 0600-0812 | 0629-0730 | 0657-0641 | 0630-0456 | 0703-0435  02
 03  0536-0831 | 0601-0811 | 0630-0729 | 0658-0640 | 0631-0455 | 0704-0435  03
 04  0537-0831 | 0601-0810 | 0630-0727 | 0659-0638 | 0632-0454 | 0705-0435  04

 05  0538-0831 | 0602-0809 | 0631-0725 | 0700-0637 | 0633-0453 | 0706-0435  05
 06  0538-0830 | 0603-0808 | 0632-0724 | 0701-0635 | 0634-0452 | 0706-0435  06
 07  0539-0830 | 0604-0807 | 0633-0722 | 0702-0634 | 0635-0451 | 0707-0435  07
 08  0539-0830 | 0605-0805 | 0634-0721 | 0703-0632 | 0637-0450 | 0708-0435  08

 09  0540-0830 | 0606-0804 | 0635-0719 | 0704-0630 | 0638-0449 | 0709-0435  09
 10  0541-0829 | 0607-0803 | 0636-0717 | 0705-0629 | 0639-0448 | 0710-0435  10
 11  0541-0829 | 0608-0802 | 0637-0716 | 0706-0627 | 0640-0447 | 0711-0435  11
 12  0542-0828 | 0609-0800 | 0638-0714 | 0707-0626 | 0641-0446 | 0711-0435  12

 13  0543-0828 | 0610-0759 | 0639-0712 | 0708-0624 | 0642-0445 | 0712-0436  13
 14  0544-0827 | 0611-0758 | 0640-0711 | 0709-0623 | 0643-0444 | 0713-0436  14
 15  0544-0827 | 0612-0757 | 0641-0709 | 0710-0621 | 0644-0444 | 0714-0436  15
 16  0545-0826 | 0613-0755 | 0642-0708 | 0711-0620 | 0646-0443 | 0714-0436  16

 17  0546-0826 | 0614-0754 | 0643-0706 | 0712-0618 | 0647-0442 | 0715-0437  17
 18  0547-0825 | 0615-0752 | 0644-0704 | 0713-0617 | 0648-0442 | 0715-0437  18
 19  0547-0824 | 0616-0751 | 0644-0703 | 0714-0615 | 0649-0441 | 0716-0438  19
 20  0548-0824 | 0616-0750 | 0645-0701 | 0715-0614 | 0650-0440 | 0717-0438  20

 21  0549-0823 | 0617-0748 | 0646-0659 | 0716-0613 | 0651-0440 | 0717-0439  21
 22  0550-0822 | 0618-0747 | 0647-0658 | 0717-0611 | 0652-0439 | 0718-0439  22
 23  0551-0821 | 0619-0745 | 0648-0656 | 0719-0610 | 0653-0439 | 0718-0440  23
 24  0552-0821 | 0620-0744 | 0649-0654 | 0720-0609 | 0654-0438 | 0718-0440  24

 25  0552-0820 | 0621-0742 | 0650-0653 | 0721-0607 | 0656-0438 | 0719-0441  25
 26  0553-0819 | 0622-0741 | 0651-0651 | 0722-0606 | 0657-0437 | 0719-0441  26
 27  0554-0818 | 0623-0739 | 0652-0650 | 0723-0605 | 0658-0437 | 0720-0442  27
 28  0555-0817 | 0624-0738 | 0653-0648 | 0724-0603 | 0659-0436 | 0720-0443  28

 29  0556-0816 | 0625-0736 | 0654-0646 | 0725-0602 | 0700-0436 | 0720-0444  29
 30  0557-0815 | 0626-0735 | 0655-0645 | 0726-0600 | 0701-0436 | 0720-0444  30
 31  0558-0814 | 0627-0733 |                      | 0727-0558 |                      | 0720-0445  31

 

 Rainfall

May 2009 to October 2009

City

May

June

July

Aug Sept

Seasonal Totals

Aurora (Central)

2.99 4.06 4.25 1.65 1.14 14.09
Brighton 2.13 4.02 3.07 0.51 0.94 10.67
Broomfield 1.38 1.69 1.34 0.35 0.71 5.47

Castle Rock 4 NE

2.20 2.09 2.87 0.98 1.73 9.87

Colorado Sprgs Airport

1.17 2.91 3.82 0.71 1.20 9.81
Denver DIA 1.30 4.86 3.56 1.14 0.74 11.60

Denver Downtown

3.15 3.07 2.56 0.83 0.87 10.48

Golden

2.68 3.15 2.62 0.79 0.79 10.03

Fort Collins

2.24 4.85 4.04 0.23 0.82 12.18

Highlands Ranch

3.23 2.28 3.07 1.50 1.10 11.18

Lakewood

3.90 3.90 3.07 1.06 0.59 12.52

Littleton

3.15 3.19 2.48 1.10 1.02 10.94

Parker

1.81 4.33 3.66 0.59 1.89 12.28

Sedalia - Hwy 67

2.40 3.54 4.09 0.79 1.61 12.43

Thornton

2.17 2.64 1.89 0.39 0.55 7.64

Westminster

2.77 3.92 2.55 0.85 0.72 10.81

Wheatridge

2.44 3.19 2.44 0.67 0.59 9.34