The Weather Wire
August 2009 Volume 17 Number 08
Avg High -84.0
Avg Low - 56.5
Snow - 0.0"
Season Snow - 38.1"
Precipitation - 3.56"
Avg High - 86.0
Avg Low - 57.4
Avg Snow - 0.0"
Avg Precip - 1.82"
Wettest Years in Denver History
With all of the wet weather recently and the precipitation surplus of 4.71 at DIA so far this year I thought it would be interesting to look at the top 10 wettest years in Denver history and see if we even have a chance at the top 10. It is surprising that this topic even comes up as the year began very dry in January and February. It was not until the last couple weeks of March when the weather pattern became more active and continues currently. Here is a list of the 10 wettest years in Denver history.
1. 23.31 in 1967
2. 22.96 in 1909 and 1973
3. 21.87 in 1965
4. 21.58 in 1957
5. 21.52 in 1969
6. 21.43 in 1891
7. 21.42 in 1923
8. 20.95 in 1999
9. 20.36 in 1979
10. 20.32 in 1991
The most recent year to reach the top ten was in 1999 with 20.95 of precipitation. So far this year as of July 31st DIA has reported 13.94 of precipitation. To reach the top 10 DIA would need to record 6.38 of precipitation for the rest of the year. How probable is this? Well if we just have normal precipitation from August through December, 5.56 would be the total. This would leave 2009 just 0.82 shy of the 10 place or at 19.50 for the full year. Since normal to above normal precipitation is expected for the rest of this year lets look at what 25% above normal precipitation till the end of the year would look like. 25% would add on an additional 1.39 to the 5.56 of normal which would result in an additional 6.95 of precipitation for the year. If DIA receives 25% above normal precipitation for the year then that put the yearly total at 20.89 or in 9th place. Anything above 25% of normal is approaching the unrealistic but cannot be completely ruled out.
It appears that we have a legitimate shot at reaching the top ten wettest years in Denver history this year. All that needs to play out is slightly above normal precipitation from now until years end. Sounds easy enough, but the problem is that months get drier and drier from here on out and after August the threat for heavy thunderstorm rainfall really tapers off. It will take heavy wet snowfall during the fall and early part of the winter to make this year stand out as one of the wettest in Denver history.
With the widespread precipitation of the last several months, little areas of drought remain in Colorado.
The map below shows forecasted temperature deviances for August 2009. As can be seen, it is expected that much of Colorado to have normal temperatures for the month of August 2009, with far southwestern Colorado expected to have above normal temperatures.
The map below shows forecasted precipitation deviances for August 2009. Most of Colorado is expected to have above normal precipitation for August 2009.
Little in the way of drought remains in Colorado, with no changes expected.
Cooler and wetter than normal conditions this summer persisted through the month of July along the Front Range of Colorado. The average high for the month came in 4 degrees below normal and the mean temperature for the month was 3.2 degrees below normal, the same as June. More impressive is that the high for the month was only 93 degrees and there were only 7 days during the month with a temperature of 90 or more compared to 15 on average. Precipitation once again came in well above normal with 3.56 reported at DIA compared to 2.16 on average. This resulted in 1.40 above normal precipitation for the month and 4.71 above normal for the year. There were 15 days with measureable precipitation and 19 days with thunderstorms reported at DIA, both were well above normal. With all the rain and thunderstorm activity percent of possible sunshine was only 58% compared to 71% on average. A big change from last year at this time as July of 2008 was ranked in the top 5 driest and warmest Julys on record.
Summer slowly begins to lose its grip during the month of August as days become noticeably shorter towards the end of the month. The beginning of August can still be very hot though as the all time record high temperature for Denver of 105 was recorded during this month. Severe weather becomes less common as the ground begins to cool and slow moving thunderstorms producing heavy rainfall become the greatest thunderstorm threat. The average high temperature for August is 86 degrees with an average low of around 57. This month the Front Range will likely experience cooler than normal temperatures once again this month. Precipitation begins to fall off from previous months with around 1.82 on average. This should not be a surprise to anyone, but above normal precipitation is likely for the month. In fact we could be approaching a full years worth of precipitation by the end of the month! With cooler and wetter conditions expected the percent of possible sunshine will also be lower than the 71% of average.
Sunrise/Sunset (Jul - December Denver area)
May 2009 to October 2009