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TOP 6 DATES TO PICK  1. May 92. April 283. May 104. April 275. April 236. May 8 |
TOP 6 DATES TO AVOID 1. April 302. April 203. May 14. April 185. May 66. May 12 | ||||
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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. | |||||
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Last year equations were introduced to help you predict the ice-out date. So how did these formulas perform? Some Monday morning quarterbacking can be done since we know the weather conditions from last winter and the actual ice-out date. In general, the formulas predicted a later ice-out date by 2 to 8 days although the "February" (only) formula predicted the actual ice-out date. The main reason that many of the formulas missed the actual date is because weather conditions in Dec (2008) and Jan (2009) were far from normal. The temperatures were significantly lower than the 90-year average and the snowfall in December was three times the normal amount. The formulas are robust but they obviously have limits when the weather is significantly different than the normal. The other factor is the variability in the regression that produced the chances of predicting the ice-out date with a specific formula. The formulas, which had Dec. and Jan. weather in them, were more accurate in predicting the ice-out date when the formula also included some later months (Feb., Mar.). These later months reduced the impact of the extreme weather in Dec./Jan. but the formulas still predicted the ice-out date to be 2 or 3 days later than what actual happen. Since the ice went out in April, the two formulas with May data were not applicable. The month of May causes all kinds of problems in the regression because of the limited weather data that is available and the limited time that is available to meet the contest rules. For these reasons, the May (only) formula is dropped for 2010 and replaced by a March and April formula. Recall that the weather in these months has the greatest impact on the ice-out date. Clicking on 'Iceoutequations10' provides formulas for you to use to predict the ice out date. The equations were derived from the ice out database. The weather data in this database is from the DNR in Tower, MN. The monthly weather history is available from the DNR in Tower, MN and also though local newspaper outlets. Use the monthly weather data in the equations. Let's say you are trying to predict the ice out in April and it's now April 5th. In the equation use the average daily temperatures and snowfall totals (if any) in the equation for the first 5 days in April. This is true for May dates too. The point is that average daily temperatures will work in these months too. The chances of winning the ice out contest improve with late entries because you know more about the weather. But since the ice may go out after April 10th or so you need to watch your entry date. The 'Iceoutequations10' provide chances of winning the ice out contest by using different monthly weather data. The Iceman usually turns in his prediction around April 10th depending on March weather. If March is warm, then the entry goes in April 6 with the weather for the first five days of the month used in the equation. If it's real warm then the entry goes in April 1. The legend for the equations can be found by clicking on 'Iceoutdatabase10'. The Iceman has calculated the weather averages for 91 years of data in 'Iceoutdatabase10' so comparisons to the 2009-2010 winter weather conditions can easily be made in case you are missing some data points and want to make an educated estimate to use in the equations. Of course, the quoted chances of winning when this is done do not apply. An example equation is shown in 'Iceoutequations10' to help you with the application. Good Luck and we'll let you know how these revised formulas performed next year! An example equation is shown in Iceoutequations10 to help you with the application. Good Luck! © Iceman - January, 2010 | |||||