Saturday, February 22, 2014

U.S. Government Forecasters Last Fall Said This Winter Would Be Kind Of Warm. Oops

Last fall, I was a bit relieved when the National Oceanic and Atmospheric Administration Climate Prediction Center said the upcoming winter would be sort of on the warm side.    
This long range forecast for the winter, issued by
U.S. government forecasters in November
did not capture how cold the winter would be
in the eastern half of the nation.  

If that came true, maybe my fuel heating bill wouldn't be as high and nasty as it otherwise might have been.

Well, as you all know, that forecast was pretty much wrong

Much of the nation east of the Rockies has had a good old fashioned cold winter. Not the coldest ever, not the most extreme, but pretty darn cold.

The entire winter wasn't exactly one Big Fat Giant January thaw.

The not-so-great forecast from the Cimate Prediction Center is more evidence that mid-range forecasts, weeks and months out are lousy. A lot more research needs to be done to make them better.

It would be extremely helpful to have reliable forecasts for weeks and months down the road. Yeah, the accurate forecast for tomorrow can tell us whether to bring an overcoat or an umbrella, but in the grand scheme of things that's not totally crucial for the greater good of society.

What if long range forecasts for weeks or months down the road were reliable and accurate?  Water managers in California, for instance, would be able to tell how stringent water regulations should be because they'd know whether the drought there was going to get worse or not.

Midwest farmers would have a good idea about what kind of rainfall and heat the summer would bring, which would inform them as to what crops to plant, when to plant them, which pests will most need controlling and when to harvest.

Less important but still crucial, here in Vermont, ski resorts would know in advance if an upcoming winter would bring lots of snow or not, which would influence their long term plans on snowmaking and how much staff to hire to serve skiers and riders.

And yes, if long range forecasters were accurate, I would have been better able to predict how much cash I would have had to fork over to keep my house warm all winter.

The reason long range forecasts weeks or months down the road are so lame is scientists don't have a great understanding as to why large scale weather patterns set up the way they do, and when they do. 
For instance, forecasters didn't count on a persistent ridge of high pressure along the West Coast of the United States this winter.

That ridge worsened the California drought, and re-arranged the jet stream so that it delivered repeated Arctic blasts of frigid air to the eastern half of the nation this winter.

Scientists want to better understand why things like the western ridge developed. It has to do with a complex web of changing ocean currents and temperatures, poorly understood weather phenomenon on one side of the globe that affect much of the rest of the planet, and probably atmospheric mysteries that scientists don't even realize exist yet.

The Climate Prediction Center does implicitly acknowledge their long range forecasts are iffy. Back in the fall, they did have vast swaths of the country in an "equal chances" catagory when the December-February forecast came out, reflecting the inherent uncertainty of predictions two or three months out.

There were bits and pieces of the forecast that were accurate, so it's not all bad. The prediction called for below normal temperatures in the northern Plains, which was right. It also said New England would probably be on the warm side.

This winter, New England wasn't warm, necessarily, but the region wasn't as far below normal temperature wise as the Midwest, Middle Atlantic States and South. Vermont, New Hampshire and Maine, for instance, are only slightly cooler than average for this winter.

Given the unreliability of long range forecasts, don't ask me what kind of spring and summer we're going to have.  All I can tell you is we will have bright days and dark nights, most afternoons will be warmer than most nights, and if the wind blows, the breeze will come out of a direction.

That's about as good as anybody can do.

No comments:

Post a Comment