Posted by Bert Cregg
Yesterday afternoon I did a little fall garage clean-up and listened to former MSU Extension colleague Dean Krauskopf’s call-in gardening show on the radio. A couple callers in a man phoned the show worried about his Japanese maple tree, which had a near-death experience from this past winter’s severe cold. The man had heard this coming winter was supposed to be just as bad as last winter and he wanted to know how best to protect his struggling tree from further calamity. Dean quizzed the caller for details about the tree and the site and gave some reasonable advice to try to modify the micro-environment around the tree to limit exposure to winter wind and cold. But I wondered where the caller got his information that winter 2015 was going to be as bad as 2014. As if anyone around here needs a reminder; January-March 2014in Michigan was the coldest since 1978 and the 4th coldest on record, with most locations reporting snowfall totals well above average. Many surrounding states has similar winter weather issues.
To get some insights on predictions for the upcoming winter, I consulted with the two most trusted sources of such information: The NOAA Climate Prediction Center and the Old Farmer’s Almanac.
The Climate Prediction Center maps present probabilities of colder or warmer than average weather for a given three month period. The most recent NOAA projections available on-line are predicting near-normal temperatures for January-March 2015 for most of the eastern half of the country, above average temps for the Northwest and below average for Texas and Florida. NOAA predicts below average precipitation for the lower Great Lakes and Northwest and above average precip for much of the South.
Apparently, however, Dean’s caller is dismissing NOAA and all of their satellites and computer models and is relying on the Old Farmer’s Almanac instead for his long-term weather outlook. The Old Farmer’s Almanac is currently predicting colder and drier than normal for most of this upcoming winter for the lower Great Lakes.
So, how much stock should we place in these predictions? Let’s step inside the Wayback Machine for a moment and see what each source was saying a year ago about the then-upcoming winter of 2014. NOAA and the computers are up first.
For most of the eastern U.S., NOAA predicted a warmer than average Jan-March 2014 with normal precip. Ooh, sorry about that NOAA but we thank you for playing ‘Guess that Winter’! Please be sure to pick up your parting gifts on your way to our Loser’s Lounge.
Next up is the Old Farmer’s Almanac, which predicts winter weather based on… well, no one’s quite sure. In any event, this time last year the Almanac predicted Jan-March 2014 would be mostly warmer and drier than normal for the lower Great Lakes. Oh no, bummer Almanac. Looks like you and NOAA can commiserate in our Loser’s Lounge. And that means Old Man Winter repeats once again as our champion!
So, what does all this mean for Winter 2015? Even with huge datasets and sophisticated models, long term weather projections are an iffy proposition. And, as much as everyone loves to say, “See, the Old Farmer’s Almanac was the only one to get it right”, there is little evidence that it does better than chance alone. Beyond that all we can say with certainty is that NOAA and the Computers would make a really cool name for a rock band.
It continues to amaze me that people would put any faith in the weather predictions of a publication (Farmer’s Almanac) that continues to deny the existence of global climate change/global warming. I was particularly flabbergasted by their showpiece denialist article in last year’s edition (they have at least one every year) that, if I remember correctly, said we were in for a round of global cooling because of an invisible film of asteroid dust that surrounds the planet, but because it is so special, it cannot be detected by any technology currently in existence.
Interesting post!
I am a research meteorologist, not involved in forecasting. Do you know that there are people who do verification studies on forecasts issued by various parts of NOAA (e.g. the National Weather Service (NWS), National Hurricane Center (NHC), Climate Prediction Center (CPC), etc.) as well as some private forecasts (e.g. broadcast meteorologists in a particular market)? I don’t do this type of research myself, but I’m aware of its existence.
Inspired by your post, I went to CPC hoping to find some sort of forecast verification for the JFM2014 seasonal forecast issued in September 2013 (that’s considered a 4.5month lead). I discovered an interactive web tool that I think let me gather that information. I saved the results as a PDF but don’t know how to include it here. Here’s the gist, quotations from the output:
• The results are given as a “Heidke Skill Score (HSS) …. [whose] values range from -50 to 100. A score of 100 indicates a perfect forecast and a score of -50 indicates a perfectly incorrect forecast. Scores greater than 0 indicate improvement compared to a random forecast and indicate skill.” They are presented for regional climate divisions; Michigan has 3 (upper peninsula, north-central, and southern).
• All the values are either -50, 0, or 100; I think that’s because there was only 1 forecast I was trying to verify.
• The HSS = 0 (no skill) in WA, OR, CA, ID, MT, and northern WY, and in VA, NC/SC, southern AL & GA, and FL.
• The HSS = 100 (skill) in AZ, NM, and much of NV/UT/CO, as well as in western NY and southern New England.
• The HSS = -50 (perfectly incorrect) everywhere else.
The forecast map above showed a 33-40% probability that Michigan’s temperatures would be warmer than normal in JFM2014; they were not. I have no idea what the predicted or actual temperatures were, but one might be able to extract them from this tool.
If you do the same exercise for the 3.5month lead forecast (issued Oct 2013), there was no skill in the eastern third of the country, skill in many parts of the western half, and perfect incorrectness throughout the Great Plains and much of the northwest.
Finally, the tool allows you to verify the JFM forecast issued in September (4.5 months lead) for “all [verification] years” 1995-2014. Under these conditions the lowest skill scores, in the -20 to -10 range, are in the central ID mountains, northwest CO, southeast MN, southern WI, the Upper Penninsula, and southern MI. The forecasts for Central MI had very little skill (2.63). The best skill (scores 42 to 58) are in southeast AZ, southern NM, and the west TX panhandle.
Sorry, I was too literal and didn’t put in the “end http” tag. Would fix if I could!
Thanks for the thoughtful follow up Leslie!
Very welcome. Thanks for fixing my html error!
For those that are curious here is the link that to the Climate Prediction Verification tool that Leslie referenced.
http://www.vwt.ncep.noaa.gov/
I rely on the wooly bear caterpillar … 🙂
http://franklincountymgs.blogspot.com/2012/10/wooly-bear-caterpillars.html
Science is great…but nature is still very much a mystery to us in many ways. First of all, I would never want to be a forecaster…if you think about it, you are really no different than a fortune teller…
Second, even if there is some evidence of accuracy in weather reports, we just have to be prepared for the unexpected anyway. It’s a part of sensible living; think of how our ancestors survived without forecasts, smart phones, satellites, electricity, furnaces etc. They prepared for each season, based on worse-case scenarios experienced by them or others they knew. We just need to use common sense and take the information given as guidance-by looking at weather maps and radar, the average person can learn to track systems and make preparations long before the emergency alerts come out. Signing up for severe weather alerts on your phone takes care of sudden incidents.
Check out weather bell.com
Joe Bastardi (WxBell) has been adamant since March that the coming winter will be a repeat for the mid-West/Plains/Great Lakes, with one additional twist: the mid-Atlantic will get in on the action, with snowfall totals similar to the “snowmageddon” winter of 2009-10. Should be interesting to see who verifies.
Hey Alan, here we are on March 7, 2015 after two months of the worst cold ever recorded in some areas of the Great Lakes, not to mention the incredible amounts of snow + cold witnessed in the mid-Atlantic up to Boston and Atlantic Canada. Sounds like this Joe fellow really predicted accurately!