Winter forecast, part I: the woolley bear prediction

By: Dr. Jeff Masters , 1:48 PM GMT on November 20, 2008

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According to legend, the severity of the upcoming winter can be judged by examining the pattern of brown and black stripes on woolly bear caterpillars--the larvae of Isabella tiger moths. If the brown stripe between the two black stripes on either end of the caterpillar is thick, the winter will be a mild one. A narrow brown stripe portends a long, cold winter. Some traditional forecasters say that the 13 segments on the caterpillar's body correspond to the 13 weeks of winter.

The Hagerstown, Maryland woolley bear forecast
The Hagerstown, Maryland Town and Country Almanack has been publishing weather forecasts and weather lore for 211 years. The Almanack sponsors an annual woolly bear caterpillar event, where local school children in Hagerstown collect woolly bears. A panel of judges examines the collected specimens and issues a woolly bear forecast for the upcoming winter. The results of this year's contest, which ended October 31: "From the small number of woolly bears, the consensus is that the winter will be very mild. The woolly bears predicted this by their three (3) bands of which the front band (representing the first half of winter and black in color) was shorter in length and normal. The back band (representing the second half of winter) was very small, thus indicating the mild winter prediction. As a result of those markings, which were similar in all woolly bears, the sponsors were able to make the predictions."

Oil Valley Vick
Naturally, this forecast only applies to the Hagerstown, Maryland area, so other locales will need to do their own woolly bear work to gauge the local winter forecast. In Oil City, Pennsylvania, just 150 miles northwest of Hagerstown, organizers of the Pumkin Bumkin Festival have located the lair of "Oil Valley Vick", a woolly bear caterpillar of unknown forecasting ability, but great potential. In his inaugural forecast on October 23 this year, Oil Valley Vick wowed the crowd at the Pumkin Bumkin Festival when he crawled out of his log. The black stripes covering fully 2/3 of Oil Valley Vick's body left no doubt that he expected a cold, severe winter for northwestern Pennsylvania.


Figure 1. Kelly the woolly bear caterpillar with her owner, six-year-old Kurstin Hartsell of Ansonville, NC. Image credit: Jim Morton, Avery County Chamber of Commerce.

The Banner Elk, North Carolina Woolly Bear forecast
In Banner Elk, NC it's the fastest woolly bear caterpillar which is judged to be the best forecaster. After successfully out-sprinting hundreds of other woolly bears, this year's winner of the 31st Annual Woolly Worm Festival race was Kelly the Woolly Worm, raced by six-year-old Kurstin Hartsell of Ansonville, NC. Kelly the Woolly Worm's official forecast for the winter of 2008-2009 calls for the first four weeks to be cold and snowy, followed by three weeks of seasonably cold weather, followed by six weeks of snowy and cold weather (severely cold in week 11, March 1-7). A study of the predictions of the Banner Elk woolly bears between 1978 and 2000 revealed that "woolly worm winter predictions were exactly on target eight times out of 23, or 34.8%. Woolly worm predictions were close (4.0-4.9) another five times (21.7%). Woolly worm predictions were right in some areas, wrong in others (3.0-3.9) six times (26.1%). Woolly worm predictions were wrong more than they were right (2.0-2.9) four times (17.4%). Put another way, the woolly worms were close or completely right 57% of the time, and more than half right 82.6% of the time".

Other studies of woolly bear forecast accuracy
Several scientific studies have been done on woolly bear caterpillar forecasts, including one by the American Museum of Natural History. None of these studies has shown any correlation between woolly bear markings and the severity of the upcoming winter. According to the Old Farmer's Almanac, Dr. Charles Curran, curator of insects at the American Museum of Natural History in New York City, studied woolly bear markings between 1948-1956 in Bear Mountain State Park, 40 miles north of New York City. He found some preliminary results that seemed to indicate that the thickness of the bands might indicate the severity of the upcoming winter. However, Dr. Curran gave up the study in 1955 after finding two groups of caterpillars living near each other that had vastly different predictions for the upcoming winter, according to science writer Ned Rozell.

So, two out of three woolley bear forecasts point to a colder than average winter for the Appalachian region of the U.S. In upcoming blog posts, I'll analyze what NOAA's computer models and the Old Farmer's Almanac have to say about the upcoming winter.

Portlight making keynote presentation at charity funding conference today
The Portlight.org charity is making the keynote presenation at a funding conference hosted by a coalition of state and federal agencies which work in the area of post-disaster relief involving people with disabilities. The presentation is this morning, November 20, at 9:15 am EST. You can follow the proceedings via the portlight webcam at stormjunkie.com. At the conference, they plan to discuss the Hurricane Ike relief efforts made possible by the Weather Underground community. Thanks for everyone's support for making all this possible!

Jeff Masters

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WIND WARNING: Greater Victoria, Issued at 4:37 AM PST FRIDAY 21 NOVEMBER 2008

STRONG WINDS UP TO 90 TO 110 KM/H ARE EXPECTED TO DEVELOP NORTH AND WEST OF VANCOUVER ISLAND. STRONG WINDS 60 GUSTING TO 90 KM/H ARE EXPECTED TO DEVELOP LATER THIS MORNING OVER THE SOUTH COAST. THIS IS A WARNING THAT POTENTIALLY DAMAGING WINDS ARE EXPECTED OR OCCURRING IN THESE REGIONS. MONITOR WEATHER CONDITIONS..LISTEN FOR UPDATED STATEMENTS
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419. GeneW
I told you. Those caterpillars warned us it was going to snow. It is from Asheville to Camp Lejeune, NC.

Gene
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GM,all from frigid new england,amazing to see everyone in the south shivering also,but wait until this weekend,possibly below freezing as far south as the Florida panhandle.
Member Since: September 6, 2007 Posts: 875 Comments: 15621
Hmmmm the RTL & Rob show.. hows it going :)

Complete Blog Refresh
Mirror Site (New Format)
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We had big snow flakes here in Sanford, NC this morning. Crazy weather!
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414. RTLSNK

Yum indeed, hoping I can start taking some long weekends this winter. Friends and family up and down both coast with boats and secret spots. Standing invitations to fish or dive, but so busy the last few years that I haven't done much of either.
Member Since: September 2, 2008 Posts: 96 Comments: 31776
411 - Rob - That sounds good! Wife and I spent a wild week in Islamorada once, right off the sea wall on the Gulf side, 30 min before sunset, the red snapper come in close to feed, live shrimp, only had two dozen of them the first night, caught 15 snappers, nice filets, rolled in cornmeal, YUM.
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Expecting lows in the mid thirties tonight in Houston. Brrrrr we don't choose live here for the cold. Have to cover the tropicals tonight and getting out to volunteer at the bird sanctuary in the morning just won't be fun.
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Good Morning everybody :0)

Man is it "COLD" down here in South Alabama....


Taco :0)
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Morning Rattler,

Much warmer here, will be in the low 70's maybe even mid. but will get a tad windy.

Sure you don't want to fish the keys this week?
Member Since: September 2, 2008 Posts: 96 Comments: 31776
Dr.Masters,
What is the price in Michigan for oil? I wonder if the winter is very warm oil drops furthers. Good Evening by the way.
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Geoffrey,
Thank you for the Butterball update on turkeys.
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Morning all, temp in Macon only hit 36*F this morning, high today 48, low Sat morn = 22*F for Sun also 22.
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waves looked waist to chest high in my area yesterday evening
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Mornin WxLogic!

Not paying much attention, trying to get a crew started on a job this morning...think their brains froze this week!
Member Since: September 2, 2008 Posts: 96 Comments: 31776
Good morning...
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Workin on the Coffee right now, but will try some tea later today. With your weather of late, you should know.
Member Since: September 2, 2008 Posts: 96 Comments: 31776
Quoting RobDaHood:
398. surfmom

I miss my tropic weather -- my skin is screaming for humidity and my bones ache from

Yeah, shoulder, elbow, wrists, feel 20 yrs older this week.

Floridians, you need some tea down ya. Revitalises and takes away the cold like no other. :)
Member Since: August 23, 2008 Posts: 7 Comments: 5300
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Member Since: September 2, 2008 Posts: 96 Comments: 31776
398. surfmom

I miss my tropic weather -- my skin is screaming for humidity and my bones ache from being cold

Yeah, shoulder, elbow, wrists, feel 20 yrs older this week.
Member Since: September 2, 2008 Posts: 96 Comments: 31776
Under a blizzard advisory for this weekend now, yippee. Seems we'll have widespread snow. :P
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Brrr! just back from walking the dog -- couldn't believe in this cold she had such a mission today -- just did not want to go back in ---ughhh 20 minutes in the cold & I forgot my coffee LOL.... Futuremet, when is this going to turn around -- I miss my tropic weather -- my skin is screaming for humidity and my bones ache from being cold
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Quoting StSimonsIslandGAGuy:
It appears that November here will be the coldest since 1976.


It has been cold for 3 days straight
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Anyone know how SJ fared?
Member Since: August 23, 2008 Posts: 7 Comments: 5300
I imagine that the NOAA's computer models will be about as accurate as the wooly bears in predicting this winter's severity!
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don't think it'll go down that low,probably bottom out around $1.70 IMO
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avg. gas prices in 2001.....1.31
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with so many complaints about the stock market,anyone notice how cheap your gas is a gallon now???,oh,yea in the next 3 months watch all the food prices re-adjust to "normal prices" annnnnd my local power company here in FL is actually going to be lowering rates to adjust for lower fuel prices...in my opinion all this market action in the last yr is just the market correcting itself...prices in the stockmarket were all way to high to start with...JMO
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thanks keeper..hypocricy is funny to me...but when challenged to video truth..it is just funny to me.
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dont worry wpb its not worth it nobody here got nothing to prove
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for those of us supporting families and writing on this blog..please respond mr. keywest.
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mr. keywest?
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i have three jobs sir...and yourself?
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stupid is as stupid does
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this is not at all being politcal...i mean this is just stupid...
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gobble gobble
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Time for me to stoke the wood stove and carry my banned behind to da loft....
Member Since: September 11, 2008 Posts: 9 Comments: 10077
Quoting RobDaHood:
How could anyone ignore you sugar?

Probably time to get out of here. More pics tomorrow or sat sugar! My desk is a wreck and I don't want to wake up to that in the am...Been fun folks!
Nite

G'nite, Rob!! I think I need to be police again for the XBOX offender. Nite all!
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http://www.youtube.com/watch?v=k8DTSPzU0RI
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How could anyone ignore you sugar?

Probably time to get out of here. More pics tomorrow or sat sugar! My desk is a wreck and I don't want to wake up to that in the am...Been fun folks!
Nite
Member Since: September 2, 2008 Posts: 96 Comments: 31776
Sarah Palin Pardons Alaskan Turkey..

http://www.youtube.com/watch?v=k8DTSPzU0RI
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good nite everyone......
Member Since: September 2, 2007 Posts: 178 Comments: 20439
347 - Pottery - great story! I really have a live and let live attitude about trants, scorps, and snakes, have been in areas of the world where some of the serious predators lived and as long as they didn't invade what I considered my personal space they would survive the encounter. But when they come in my house its terminate with extreme prejudice time. LOL, Had three wolf spiders get into my garage in the last week, and they are fast runners and they jump like jack-rabbits, don't even try to "catch" them. hahaha
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.