COUCH POTATO TECHNIQUES
The easiest technique to choose an ice-out date is to open a calendar to April/May and
throw a dart. However, if you want to improve your chances of winning you might review
the ice-out facts and throw a dart at a smaller number of dates.
Or you can review the same ice-out data and look at the dates to pick/avoid (shown above)
and choose a date based on the theory that the actual ice-out percentages will, over time,
match the normal (Bell) curve. This is happening with each passing year but it's certainly
not foolproof for any given year, although the above dates improve your chances over the
dart technique. Are you wondering why May 8, 9 and 10th are in the top picks?
Answer: Over 10% of the ice-outs have occurred after May 10th. There is only 1 ice-out
date for May 8,9,10th combined, around 1%. This creates a hole in the distribution. There
should be 3-4 "ice-outs" on these dates to fill in the hole and match the Bell curve shape.
The ice went out on May 17th, 2013. We were in striking distance of another record since the latest ice-out is May 23rd. In 2010 a record was set for the earliest ice out and then in 2012 that record was broken and the earliest ice-out on April 2nd was recorded. Why are ice-out records being set? Is it climate change? Good questions.
Last year I stated that I would, in 2013-2014, provide some weather characteristics to look for that drive an early ice-out. Last year's Ice Chatter discussed some weather clues that drive late ice-outs. I am going to defer the weather characteristics that drive early ice-outs for another year and revisit the clues from last year's discussion.
How did the weather clues do in predicting a May 17th ice-out in 2013?
So what were the first clues from the weather characteristics that the ice-out was going to be late?
- Average High Temperatures - when the average high temperatures for the months of December to May are colder than the normal temperatures for each of these months, there is an excellent chance that the ice-out will be on or later than May 7th. December and January, 2013 were warmer than the normal temperatures so the average high temperatures did not provide any clues on a late ice-out. However, months of February and March, had average high temperatures much colder than average by 1.62 and 3.35 degrees. By April the average high temperature was much colder than average by 9.55 degrees and May was over 3 degrees colder.
- Average Low Temperatures - when the average low temperatures for the months of December to May are colder than the normal temperatures for each of these months, there is an excellent chance that the ice-out will be on or later than May 7th. December and January, 2013 had warmer low temperatures so the average low temperatures did not provide any clues on a late ice-out. February was slightly warmer too, so no clues where provided. March, April, and May had significant colder low temperatures than average.
- Snow - There was more snow every month from December to May than the averages. March had almost 10 inches more and April had over 26 inches more.
Recall my message from last year. If the weather in March is bad, followed by cold temps and snow early in April pick a May ice-out date. The weather in March of 2013 provided the first clues that a late ice-out was coming. The temps and snow fall totals from December to February were traps that enticed ice-out forecasters to predict an early ice-out.
- December? No, the temps were warmer than average and the snow, while more, was not that significant.
- January? No, the temps were warmer than average and the snow, while more, was not that significant.
- February? Hard to tell. The temps were mixed and the snow was 6 inches more than average.
- March? Yes, the temps were colder than average and the snow fall by March significantly exceeded the average.
- April? Definitely yes. The temps were really cold and there was a lot of snow on the ground.
We now have 14 years of data when the ice-out happened on or after May 7th. Confidence in predicting any variable is enhanced when a minimum of 32 data points are available. The Iceman, who actually likes to fish (early), prefers that we do not ever achieve that number.
Meanwhile, keep looking at the weather profiles in December through February but key in on the weather profiles for March and you will be in the hunt to win the ice-out contest!
© Iceman - January 2014