Storms (and the power of observations)

As someone who loves powder skiing, I am somewhat obsessed with weather forecasts. If it is my day to be hanging out at the ACES front desk, you can bet that there are probably multiple weather forecasts up on my computer.

However, while reading weather forecasts is great, experiencing weather is even better. This winter I have been lucky enough to get to spend a lot of time experiencing weather, particularly up at the Wapiti Wildlife Center (and warming hut!) at the top of the Elk Camp chairlift in Snowmass. The Wapiti is at 11,325 feet above sea level, and sits on an exposed open area near the top of Burnt Mountain. The weather down in Base Village at Snowmass is often very different from up at the Wapiti!

At the Wildlife Center we have a small weather station, which includes a Taylor Thermograph.

Thanks to Winding Way Weather for the picture. A thermograph does exactly what it sounds like; it makes a graph of the temperature over a week long period (or multiple weeks if you forget to change the paper!). This lets us look at the temperature over the whole winter. By doing this, we can analyze the weather far more than just saying 'it's really cold out today!'.

Here is a scan of one of my favorite thermograph sheets from this winter. I went over the red ink that the thermograph uses with a black permanent marker, so that it is more visible (click on the image to view it in a larger format!).

The first weekend of April (Friday and Saturday, April 1st and 2nd) were classic spring skiing days. Temperatures got into the low 40s up at 11,000 feet! For reference, there tends to be a difference of 3 degrees Fahrenheit for every 1,000 feet of elevation change, so back in town the temperatures were in the low 50s. However, on Sunday a cold front came in. Looking at the thermograph, the temperature dropped ten degrees in about an hour! While we may remember this storm and this temperature change, it is striking to see it recorded on the graph.

Here's one last way of looking at the storm, from one of my favorite weather forecasters, Joel Gratz and his Colorado Powder Forecast.

Right now we're enjoying a mid April blizzard here in Aspen-- hope you are all enjoying it!

Frost-free Days - Why Give a Hoot?

Living in Aspen has more than enough perks, from the incredible skiing in the winter to endless backpacking in the summer. The amazing snow and the beautiful sunny days makes you grow accustomed to the weather patterns and the climate of the area.

As a Naturalist and avid outdoor lover I couldn’t help but wonder, how is the warming of our planet affecting the Aspen area? A few naturalists and I dug into some data, provided by NOAA and Colorado Basin River Forecast Center, for the Independence Pass Snotel Site and found a noticeable change in frost-free days in the recent past. There are a lot of climate change numbers, from temperature increases to carbon emissions, it’s hard to keep up with all of the numbers. Focusing on the Aspen region we looked at the number of frost-free days recorded at the Independence Pass Snotel Site. Now, you maybe asking yourself: what exactly are frost-free days? Well, frost-free days are the number of days in a year with minimum temperatures above freezing (0° Celsius). 

This data was collected by the Natural Resource Conservation Service of the USDA.

The above record shows a linear increase in the number of frost-free days at the Independence Snotel site from 1986 to 2010. Starting with only 27 frost-free days in 1986 it has been hiking up to 53 days in 1992, 84 in 2000 and onward to 106 frost-free days last winter in 2010. It is hard to look at this data and not think, how does this impact our seasonal snowpack? How will more forst-free days affect our forests? Our rivers? Weltands? Fishing? White water rafting? Agriculture? And, what will this graph look like in twenty years?