The Weather Wire
October 2010 Volume 17 Number 10
Avg High - 84.8
Avg Low - 49.1
Snow - 0.0"
Season Snow - 0.0"
Precipitation - 0.06"
Avg High - 66.0
Avg Low - 35.9
Avg Snow - 4.1"
Avg Precip - 0.99"
The word drought has not been thrown around for awhile as last year precipitation totals were well above normal for many Front Range communities. Even this year up until last month precipitation amounts were near normal for the year but with a very dry September precipitation totals are currently below normal. September of 2010 was the 5th driest September on record with only 0.06 reported at DIA and there were many locations along the Front Range that only reported a trace during the month. As of the end of September Denver is 1.60 below normal with 10.61 so far this year compared to 12.21 on average which is about 13% below normal. If one month is dry that is ok, but with a strong La Nina expected through at least the first half of this winter chances are quite high to continue the below normal precipitation trend. This will likely result in the yearly precipitation deficit to increase to 20% or more below normal by the New Year. Below is an up close look at the Drought Monitor for the state of Colorado showing percent of normal precipitation observed last month:
Notice how most locations in eastern and especially northeastern Colorado received less than 5% of normal precipitation for the month. It should be no surprise then that a moderate drought is already developing in these areas as can be seen on the map below:
Abnormally dry conditions persist over much of Colorado except the SW region and extreme SE Colorado. Moderate drought has already developed over most of the highly populated areas of the state from Colorado Springs through Fort Collins. Drought conditions may become severe over the winter as below normal snowfall is projected. In the previous newsletter normal to below normal temperatures were expected this winter but looking at the pattern now above normal temperatures are becoming more likely. The combination of warmer temperatures and below normal snowfall may lead to a more severe drought and watering restrictions next spring if this pattern is not broken by March or April of next year.
Images above can be found at:
Dry conditions since mid August have brought areas of drought to much of Colorado again.
The map below shows forecasted temperature deviances for October 2010. As can be seen, above normal temperatures are expected statewide for the month.
The map below shows forecasted precipitation deviances for October 2010. Below normal precipitation is expected across most of Colorado.
Some areas of drought have returned and are likely to persist across north central Colorado.
With only 0.06" reported at DIA for the month, September of 2010 will go down as the 5th driest September on record. Normal precipitation for the month is 1.14" and now puts our yearly precipitation deficit at 1.60" below normal. Temperatures were also incredibly warm with average highs of 84.8 and lows of 49.1 resulting in a monthly mean temperature of 67.0 which is 4.6 degrees above normal. 67.0 degrees is warm enough to rank 7th all time for the warmest September ever! This may not come as much of a surprise as there were 4 high temperature records broken or tied and the 96 degrees on the 19th was the warmest it has ever been this late in the season.
The unseasonably warm dry weather of September is carrying into the first part of October. Despite the beautiful fall weather currently October will bring the seasons first freeze and more than likely the first snowfall. The first freeze usually occurs by the 7th of the month but looks like we will be waiting a little longer this year. The first snow typically occurs by the 15th with 4.1" on average for the entire month. Temperatures can be quite extreme with a record high of 90 and a record low of -2 which results in an incredible temperatures spread of 92 degrees. October can be one of the more pleasant months of the year with a high percentage of sunshine and warm days with cool nights. Most of the locals will tell you there is typically some sort of weather to deal with around Halloween and with a dry start to the month it will likely end up a little unsettled at the end so there should be no surprise if Halloween features some acitve weather this year.
Sunrise/Sunset (July - Dec Denver area)
May 2010 to Sept 2010