DENVER — While spring temperatures in the Denver metro have been tracking well above average, rain and snow for March and April have been at their lowest since records have been kept.

According to the National Weather Service, the combined March and April snowfall was only 1.0”.  This has been the lowest since records were kept starting in 1882.

The previous low was 1.1” in 1887.  The average is normally 20.5” based on this period of record.  What’s more, for the last two years, the combined March-April snowfall has been below 5”.  Dating back to 1882 there has never been two consecutive years where the combined total for these two months was less than 5 years.

Much of this has to do with the weather patterns over the western U.S.

For the last few years, the Pacific Ocean temperatures have been relatively cool, which is known as the La Nina ocean circulation.  During La Nina years, weather systems tend to drop generous amounts of snowfall over the northern mountains near the Flat Tops, and northwest Plateau, while eastern Colorado sits under slightly above average temperatures and dry windy conditions.  Because of this, many reservoirs are still running at near or slightly above average capacity, but forecasters and water utility managers are concerned that if this dry situation continues, water usage may have to be curtailed in 2013.

As for the long term outlook, La Nina seems to be fading into what forecasters call a neutral phase, and this phase could easily return to La Nina by fall.  That could mean another round of mild and windy weather along the Front Range of eastern Colorado, another season of high fire danger, and another entry of unusually dry weather for the record books.