Winter forecast, part III: the Old Farmer's Almanac
Since 1792, the Old Farmer's Almanac has been issuing long-range seasonal weather forecasts. This year, the Almanac is predicting that winter will be colder than average for 3/4 of the U.S., and above average over just 1/8 of the country. Only the Pacific Northwest and the upper Midwest near Minnesota are predicted to be warmer than average. For the Appalachian region that includes the three woolly bear forecasts I discussed last week, the Old Farmer's Almanac is siding with Oil Valley Vick and Kelly the woolly bear, forecasting colder than average temperatures. The Hagerstown Woolly Bears and NOAA disagree, predicting warmer than average temperatures are more likely.
How accurate is the Old Farmer's Almanac?
The Old Farmer's Almanac claims to have a secret formula developed in 1792 based on sunspots and climatology, which gives their long-range predictions 80% accuracy. I've heard a number of anecdotal stories about how uncannily accurate their forecasts are, and have always felt a vague sort of anxiety that maybe I should be checking them out when someone asks me what the upcoming winter will be like. However, the Almanac does not post any verification statistics of their forecasts. It is not hard to do a simple check of their forecast accuracy, though. Unfortunately, the results of my check and those done by several others show that there is little reason to believe that the Old Farmer's Almanac forecasts are any better than flipping a coin.
Figure 1. Observed departure of temperature from average for the period Nov. 2004-Mar. 2005. Superimposed in bold text is the winter forecast made in the 2004 Old Farmer's Almanac for the same period. The Almanac got four regions correct and eight incorrect, with two too close to call.
For example, for the winter of 2004-2005 (Figure 1), the November 2004 version of the Old Farmer's Almanac made a simple prediction of "cold" or "mild" for sixteen separate regions of the U.S. The original forecast map they presented only labels the U.S. in fourteen places, and I've overlaid these predictions on a temperature anomaly map showing what actually happened during the winter of 2004-2005. If we assume that "mild" refers to an above average temperature forecast and "cold" refers to a below average temperature forecast, then the Almanac got four regions correct, eight wrong, with two too close to call. Admittedly, I've "eyeballed" this, and it is a subjective verification. Still, I don't see any way that this forecast could approach even 50% (chance) accuracy. Their precipitation forecast fared better, with seven correct regions, five incorrect, and two too close to call. I also looked at the Farmer's Almanac forecasts for the winter of 2006-2007. They did much worse that winter, with only three of sixteen temperature forecasts verifying, and five out of twelve precipitation forecasts verifying (four were too close to call). For these two winters, the Old Farmer's Almanac made a successful forecast just 37% of the time.
Studies by Jan Null
Jan Null, a meteorologist who founded the private weather consulting firm, Golden Gate Weather in California, has evaluated the Old Farmer's Almanac predictions for San Francisco for three separate years. His first study looked at the forecasts for 1999-2000. His conclusion: "Even trying to be objective and giving the benefit of the doubt to cases that were close, I found last year's forecast from the Old Farmer's 2000 Almanac for San Francisco to be laughable at best and abysmal at worst. The Old Farmer's Almanac was wrong on their monthly temperature forecast 8 out of the 12 months (67%) and wrong on their rainfall forecast 5 of the 8 months evaluated (63%)". His grade for the Old Farmer's Almanac winter forecast for San Francisco during 2006-2007 was a D+. He also evaluated the Old Farmer's Almanac for two separate summers and winters for all sixteen regions of the U.S., and found mostly poor results. For the summer of 2005, just one of the sixteen Old Farmer's Almanac regional forecasts got both the temperature and the precipitation correct. He plans to post a verification of their 2008 summer forecast sometime in the next week.
Weatherwise magazine study
In the October 1981 issue of Weatherwise magazine, pages 212-215, John E. Walsh and David Allen performed a check on the accuracy of 60 monthly forecasts of temperature and precipitation from the Old Farmer's Almanac at 32 stations in the U.S. They found that 50.7% of the monthly temperature forecasts and 51.9% of the precipitation forecasts verified with the correct sign. This compares with the 50% success rate expected by chance.
Old Farmer's Almanac climate forecast
It's also of interest to note that the Old Farmer's Almanac believes that sunspot cycles and other factors suggest that "a cold, not warm climate may be in our future". Their climate forecaster is Joeseph D'Aleo, who was the first Director of Meteorology at the Weather Channel. Mr. D'Aleo is now retired, and is often quoted for his skeptical opinions about climate change.
Conclusion
The results of my forecast verifications and those done by several others indicate that there is little reason to believe the Old Farmer's Almanac claim of 80% accuracy. These verifications attempted to be fair, but one can justifiably argue they were not objective nor complete. However, unless the Almanac posts some scientific evidence to the contrary, I won't believe their forecasts are any better than flipping a coin. One's best bet for the upcoming winter forecast is to use NOAA's prediction, which calls for an an above-average chance of a warm winter across the center portion of the U.S. If you live in Banner Elk, North Carolina, it might be wise to go with Kelly the Woolly worm's forecast of a cold winter, though, given the success of her predecessors!
Tropical disturbance near Costa Rica
An area of disturbed weather (96L) has developed in the extreme southern Caribbean, near the coast of Costa Rica. Wind shear is a hefty 20-30 knots over the disturbance, which will keep any development slow. The disturbance will bring heavy rains to Costa Rica and Nicaragua through Wednesday. If the center can stay off shore, this disturbance has the potential to develop into a tropical depression. NHC is giving a moderate (20-50% chance) that 96L will develop into a tropical depression by Wednesday morning. The GFDL model does develop 96L, but none of the other models do. I'll have an update on the system this afternoon if it gets more organized.
Jeff Masters
Reader Comments
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They had a big debate on whether or not Fay would.
The reason why Dr. Lyons picked it was because it caused over 1 billion $ in damage and 36+ deaths.
Sure...flip a coin.
Floridians want that "witch" retired. As in adios, don't call us ,we'll call you. LOL
I've not read any reports saying it caused that much damage. Could you direct me to any?
Yup, it's a looong time away. We've got Thanksgiving and Christmas to go through yet. Even this season isn't officially done and dusted.
However, I hope you'll forgive me for presenting the first taste of what is to come. CSU usually presents its long-term prediction in the early part of December. Why, I've no idea. What will they say?
This year they predicted 13-7-3, and while it wasn't as close as the April revision, it wasn't too bad. (16-8-5.)
2007 their initial shot was the closest they ever got. 14-7-3. Actual activity was 15-6-2. Not bad, considering they were 7-8 months behind the season's start. 'Course, it just got more out from there.
Perhaps that is making up for badly getting 06 wrong, with 17-9-5... ending up with 10-5-2. Never mind.
So, what will they say this time?
A lot of December's forecast appears to be based on what is to come in terms of ENSO (A major factor in tropical activity) and the previous season. Yes, there are other things involved, but they are more refined come April. Current forecasts seem to show a strengthening of La Nina, to keep neutrality or even to a weak La Nina. Coming off this season, I would not be surprised to see a 'safe bet' 15-8-4 mooted. (The 95-07 average.)
So, expect a re-run? Perhaps not. History tells us that no two seasons are the same. So, don't take this next comparison too literally, but it's interesting regardless.
Let's look at the bastion of the current AMO, 2005. Compare it to the previous active phase of the oscillation's most active season, 1933. What do we see?
Well, the season before 1933, like 05, was deadly. While Florida wasn't adorned with Perfume de Huracan like it was in 04, Cuba and the Bahamas amongst others were hit hard. Texas also got its fair share.
Continuing with this line of inquiry, the following year. 2006 was 'surprisingly' inactive (Though El Nino has a lot to do with that.), how about 1934? Lo and behold, was not much to right home about either. While it did have 11 storms, no majors to speak of. 1935 (2007 in another dimension) has the Labor Day Hurricane, and a couple of other majors. Could that have been the Felix or Dean of the year? Although the era of pre-satellite comes with a warning of 'Expect at least 2 more storms', it wasn't particularly active, whereas 2007 had 15 storms. Though most stayed relatively weak.
1936? Well, this is the most compelling of all. 16 storms were mentioned (Possibly more), the exact same as this year. However, this season was far more intense, with 4 extra majors.
1937? Just 9 storms, no major. Though the links are tenuous, it makes for an interesting read. However, the previous '2005' to 1933, 1887, doesn't fit the pattern so well. 1886 was pretty intense (Including that Indianola Hurricane...), 1888 wasn't too bad... but 1889/1890 don't fit the pattern at all.
Any names grab you for 2009?
Ana
Bill
Claudette
Danny
Erika
Fred
Grace
Henri
Ida
Joaquin
Kate
Larry
Mindy
Nicholas
Odette
Peter
Rose
Sam
Teresa
Victor
Wanda
As CybrTeddy has pointed out, this decade seems to be the time of the I's... Isabel, Isidore, Ivan, Iris have been retired this decade alone, with Ike set to join them. Will Ida be one of these, or will it pass harmlessly?
What do you think may occur?
Bill - Atlantic
Billy - Australia
Fred - Atlantic
Freddy - Australia
A people don't panic when the name jogs memories
B so that historical or record breaking storms are not confused (ie if there was another Katrina that hit New Orleans in 2035 that would get very confusing )
danny
grace
ida
nicolas
sam
In my opinion, this list is way off...especially if it is based off of every year in recorded history. The only year I can agree with is 2005. But, why do you have 2003 and 1999 but not 1992, 1950, or even 1933?
Also, I don't think this year is as bad as 2004, as the main storms of that year (Charley, Ivan, Frances, Jeanne) caused much more destruction/deaths of people in the caribbean and the United States than this year without a doubt.
What Hurricane season is the worst is a very subjective thing...I would say 2004 since that is the only one that has ever had a significant effect on me and it also had a major effect on my entire state...TX or LA would probably disagree...Folks in Miami area that experienced Andrew would have a different opinion...
410. stormpetrol- I understand completely, and am sure folks in the Panhandle would agree.
slips back out...
Now it's 7C at near midnight.
How weird.
wow that is wierd did you really stay up till midnight just to find that out lol
Just a casual observation.
Anyway, have a good night all. -signing off-.
Having lived 58 years on the "Florida dartboard" and seeing science evolve first hand, I have zero interest or confidence in preseason forecasts. LOL...Don't get me wrong, I love your passion...LOL... "BUT", I remember Physics 101 and the characteristics of "meander". Dr Masters (a conservative steward) covered the shortcomings of short term dynamics quite well. It's the meander factor that prompts the flip of a coin. I see these predictions as well meaning , but it has a bit of a face of oneupmanship to me.
Just my two cents, but I think Omar should be retired for the interplay, at one brief moment, of three internal COVs that kept popping up and jockying for dominance and for the nebulous meander. Dollar value doesn't have to be the only factor.
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