Recently the Chief of the met office went on UK TV to say:
“OUR SHORT TERM FORECASTS ARE AMONG THE BEST IN THE WORLD.” (see video here)
Yesterday, the UK Met Office had to make a rare mea culpa, saying they had botched their own recent snow forecast, it is useful to point out that they aren’t the only one with egg on their faces.
In early October, the Arctic Oscillation (AO) took an unexpected dip into deeply negative territory, which led to the sixth snowiest October on record in the Northern Hemisphere and the snowiest on record in the US. If you look at the 14 day forecast at the bottom of the graph below, you can see that the dip caught NOAA forecasters off guard.
According to Rutgers University Snow Lab, October, 2009 was the snowiest on record in the US.
|Contiguous United States|
The director of NCAR captured the moment perfectly in this East Anglia Email – dated October 12.
From: Kevin Trenberth <email@example.com>To: Michael Mann <firstname.lastname@example.org>
Subject: Re: BBC U-turn on climate
Date: Mon, 12 Oct 2009 08:57:37 -0600
Cc: Stephen H Schneider <email@example.com>, Myles Allen <firstname.lastname@example.org>, peter stott <email@example.com>, “Philip D. Jones” <firstname.lastname@example.org>, Benjamin Santer <email@example.com>, Tom Wigley <firstname.lastname@example.org>, Thomas R Karl <Thomas.R.Karl@xxxxxxxxx.xxx>, Gavin Schmidt <email@example.com>, James Hansen <firstname.lastname@example.org>, Michael Oppenheimer <email@example.com>
Well I have my own article on where the heck is global warming? We are asking that here in Boulder where we have broken records the past two days for the coldest days on record. We had 4 inches of snow. The high the last 2 days was below 30F and the normal is 69F, and it smashed the previous records for these days by 10F. The low was about 18F and also a record low, well below the previous record low. This is January weather (see the Rockies baseball playoff game was canceled on saturday and then played last night in below freezing weather).
Trenberth, K. E., 2009: An imperative for climate change planning: tracking Earth’s global
energy. Current Opinion in Environmental Sustainability, 1, 19-27,
doi:10.1016/j.cosust.2009.06.001. [PDF] (A PDF of the published version can be obtained
from the author.)
The fact is that we can’t account for the lack of warming at the moment and it is a
travesty that we can’t.
Once again, this begs the question – if the GCMs can’t forecast the AO two weeks in advance, how can they possible forecast snow and cold 70 years in advance? University of Colorado professor Mark Williams used climate models in 2008 to come up with a remarkable prediction (below) in a year when Aspen broke their snowfall record.
Study: Climate change may force skiers uphill
From the From the Associated Press
Tuesday, December 16, 2008
DENVER — A study of two Rocky Mountain ski resorts says climate change will mean shorter seasons and less snow on lower slopes.
The study by two Colorado researchers says Aspen Mountain in Colorado and Park City in Utah will see dramatic changes even with a reduction in carbon emissions, which fuel climate change.
University of Colorado-Boulder geography professor Mark Williams said Monday that the resorts should be in fairly good shape the next 25 years, but after that there will be less snowpack — or no snow at all — at the base areas, and the season will be shorter because snow will accumulate later and melt earlier.
If carbon emissions increase, the average temperature at Park City will be 10.4 degrees warmer by 2100, and there likely will be no snowpack, according to the study. Skiing at Aspen, with an average temperature 8.6 degrees higher than now, will be marginal.
Since the first of October, Colorado is averaging two to eight degrees below normal, as is most of the US:
In December 2009, Colorado averaged three to fifteen degrees below normal, once again correlating with a strongly negative Arctic Oscillation
Climate models are iterative through time, which means once they go off in the weeds they can not recover. If AO trends can not be forecast more than a few days in advance, it would seem problematic to make any sort of meaningful long-term climate projections using GCMs.