28 July 2008

Another Hot and Dry Summer In Denver

So far in 2008, Denver has had 3.28 inches of precipitation. The normal amount of precipitation for the year to date is 9.97 inches. July has been particularly dry with just 0.24 inches to date, compared to a normal of 1.88 inches this far into the month.

The average yearly precipitation in Denver is 15.81 inches (40.2 cm). A desert is often defined as an area receiving less than ten inches of rain per year, and this year's dry first seven months could easily push Denver from merely being semi-arid, into being a true desert. Unless the spring brings above average precipitation, Denver will be a desert this year.

A good snowpack last winter is preventing us from suffering severe water shortages, but this isn't the first time Denver has set heat and drought records in the past few years. Colorado's ski resorts fear that global warming could cut their competitiveness vis-a-vis Canadian ski resorts soon, however, which is why they are some of the most ardent proponents of controlling greenhouse gases in the state.

We are also chasing the record for the longest number of ninety degree plus days in a row, eighteen, last seen in 1901 and tied a quarter decade earlier. With fourteen straight ninety degree days in a row (as of Sunday), we are already in fourth place for heat waves, and the forecast has us breaking the record on Thursday, and the forecast is for the heat to stay at least another several days. Wednesday is also forecast to be just short of a record high for that day; a slight shift in the weather cut set a new one.

The heat wave will surely break in August, at some point. With luck, the Democratic National Convention will have somewhat cooler weather in late August.

Global warming has gone far enough, and is irreversible enough at this point that summers like this one are what we have to look forward to in the decades to come. Moreover, one of the main big picture take away messages from a recently completed national drought atlas is that drought phenomena operate over very large geographical areas. A fair small number of areas capture a very large share of all dought phenomena in the United States.

In English, that means that dry summers in Denver mean bad news for wide swaths of the Front Range. Dare I say Dust Bowl II?

1 comment:

Anonymous said...

I think you should take that Dare, oh fearless one!