The Weather Wire
March 2010 Volume 17 Number 03
Avg High - 39.7
Avg Low - 18.5
Snow - 5.8"
Season Snow - 46.0"
Precipitation - 0.30"
Avg High - 53.7
Avg Low - 25.4
Avg Snow - 11.7"
Avg Precip - 1.28"
Now that spring on the horizon and there are only a few more months of accumulating snow in the mountains let’s see how our major river drainages are doing in the snowpack department. Since most of our water here in Colorado comes from the high country in the form of spring runoff it is important that snow falls where it supposed to, “in the mountains”. This year along the Front Range at lower elevations from the Palmer Divide northward snowfall has been abundant with near normal to above normal snowfall currently for an entire winter season. The mountains on the other hand vary from above normal in southern and southwestern Colorado and below normal in northern areas of the state including the South Platte River drainage. Below is a map of current snowpack as of March 1st compared to normal.
Parts of the North and South Platte River systems have the lowest snowpack with generally 70-80% of normal at this time. The active southern jet due to the El Nino cycle this winter has resulted in near normal to above normal snow in the southern mountains.
With the relatively warm weather the first 5 days of the month along the I-25 corridor much of the snow on the ground that has persisted for a good part of the winter has melted with just a few lingering patches in heavily shaded areas. Below is a snow cover map that shows the snow depths and another map below that shows the snow water equivalent.
This map shows the heaviest snow concentrated in the San Juan Mountains with over 100” of snow currently in areas such as Wolf Creek Pass.
This map shows the snow water equivalent which is more important than the actual snowfall depth when it comes to spring runoff. There is a lot of water trapped in the mountains with some rivers like the Arkansas River peaking sometime in late June or July as it is fed from the highest peaks in the state.
There is still plenty of time to make up for the below normal snow in the South Platte River drainage as March and April can deliver some heavy, wet snows with high water content which can quickly add to snow totals. But this year the northwest region may have some difficulty catching up as the storm track has been favoring southern and eastern areas. Since March has come in like a lamb here in the Denver area one would think it will go out like a lion!
With the widespread precipitation of the last several months few areas of drought remain over Colorado, though some dry areas have developed in western Colorado.
The map below shows forecasted temperature deviances for March 2010. As can be seen, normal temperatures are expected for much of the state, though the southeastern areas of the state are expected to have below normal temperatures.
The map below shows forecasted precipitation deviances for March 2010. Virtually all of Colorado is expected to have above normal precipitation for the month..
Little in the way of drought remains in Colorado.
Our unseasonably cold winter continues through February with average highs more than 7 degrees below normal and 8 days during the month where the maximum temperature remained below freezing. Monthly low temperatures were near normal resulting in a monthly mean temperature of 29.1 degrees which is 4.1 degrees below normal. There was not any heavy snowfall during the month but there were 9 days with measurable snowfall totaling 5.8" at DIA which is 0.5" below normal. This snow amount does not represent the Denver Metro area very well as many other locations received between 7-17" for the month. Total precipitation was also low at DIA with 0.30" for the month, 0.19" below normal and now 0.63" below normal for the year.
The snowy month of March is finally upon us, but will it live up to its reputation as Colorado's snowiest month? As of March 8th we have had a near miss with a powerful spring storm, but no meaningful snow has fallen so far for most locations. The month is not over though and if you remember last year March of 2009 there was some active weather towards the end of the month into April which basically saved our winter season as far as snow and precipitation went. Some heavy spring snow is still forecast for this month, but it will likely have to wait for the last couple weeks as the current weather pattern will bring weather disturbances through, but they are relatively fast moving and the "big" snows require a slow moving low pressure system, sometimes cut off from the northern jet stream. One thing is for certain and that is that March will bring frequent weather changes with rain, wind, snow, sun and blizzards. There is even some lightning possible during the month of March as the warmth of spring and the cold of winter battle it out.
Sunrise/Sunset (Jan - June Denver area)
Sept 2009 to Apr 2010