tag:blogger.com,1999:blog-6168620747792092240.post1031169627747946381..comments2024-03-27T15:09:59.039-06:00Comments on Wasatch Weather Weenies: Winter Speculation: Does a Dry October Mean a Dry Winter?Jim Shttp://www.blogger.com/profile/15799757451626876963noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-6168620747792092240.post-59234492160060112782014-11-12T19:46:20.658-07:002014-11-12T19:46:20.658-07:00I have correlated month-to-month snowfall for 27 N...I have correlated month-to-month snowfall for 27 North American ski locations over an average of 42 years. I do not have October data.<br />November to December +15%<br />December to January +10%<br />January to February +20%<br />February to March +6%<br />March to April +19%<br />These are consistent with jdm83's findings <br /><br />2 month correlations (November to January for example) are all in the +5% range, which is about as close to random as you can get.<br /><br />The one month correlations are weak also. If you look at the individual ski area one-month correlations, about 20% of them are negative. <br /><br />My conclusion is that current weather has trivial influence on future weather more than a month in advance.<br /><br />Tony Crockerhttp://bestsnow.netnoreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-69318145186765673912014-10-20T10:23:42.522-06:002014-10-20T10:23:42.522-06:00Well done post. It just supports the idea that lo...Well done post. It just supports the idea that long term seasonal forecasts are very hard to predict. Would have been nice to see this correlated to other snotel sites. As we know there is significant variation between sites even within <100 miles. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-57901921298057233942014-10-17T15:02:02.235-06:002014-10-17T15:02:02.235-06:00It seems to me that you may be looking for a multi...It seems to me that you may be looking for a multi-dimensional correlation. For example, best correlation may not be between time periods at the same location but any two time periods at perhaps different locations. In other words the best correlation for snowfall in Utah my be tied to average temperature in Tundrova Siberia in July. Bubbanoreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-65922250642142900252014-10-16T16:03:39.554-06:002014-10-16T16:03:39.554-06:00Good idea, David. My guess is that there would be...Good idea, David. My guess is that there would be some weak correlation between months, but perhaps not. I will try to run the numbers next weekjdm83https://www.blogger.com/profile/00769900107375781290noreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-3847138605358010362014-10-16T16:00:12.909-06:002014-10-16T16:00:12.909-06:00Good catch Lisa! Yes I meant to say the preceding...Good catch Lisa! Yes I meant to say the preceding Octoberjdm83https://www.blogger.com/profile/00769900107375781290noreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-52217830945175270872014-10-16T12:46:11.203-06:002014-10-16T12:46:11.203-06:00One way you could further investigate this is to d...One way you could further investigate this is to do a month-to-month correlation of monthly precipitation totals (not of existing snowpack or accumulated precip, obviously) to look for patterns. For example, first correlate October vs. November, then November vs. December, etc for the available period of record. If the correlation coefficients all turn out to be very small numbers or are quite variable (some positive and some negative, etc) then likely there is essentially zero predictability with regard to this. If the coefficients are more significantly non-zero, or show some sort of obvious trend as you go through the season, then this may have some significance in terms of guessing at future precipitation based on a given month. My guess is that for Utah these coefficients would be quite low and variable, implying essentially no statistical relationship between one month and the next. But maybe there is something there.Davidhttps://www.blogger.com/profile/02814313368731066590noreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-12917945263515227682014-10-16T10:41:10.155-06:002014-10-16T10:41:10.155-06:00On the scatter plot, is that really the preceding ...On the scatter plot, is that really the preceding Nov->April that is plotted against the following October? Or did you mean to say it's the preceding October plotted against the Nov->April that follows?Lisahttps://www.blogger.com/profile/15180331785357345922noreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-75209350921399387792014-10-15T21:54:16.197-06:002014-10-15T21:54:16.197-06:00Back of the envelope: Snow season is Oct-April, si...Back of the envelope: Snow season is Oct-April, six months, so Oct is 1/6 = 0.16 or 16% of the snow season. If there is statistical independence in the totals each month, then one would expect that the variance accounted for by any given month is roughly 10-18%. One would expect that Oct would account for less than Feb, say, but looking at the average snow total chart shows the Oct1 to Oct31 slope to only be slightly less than mid-season slope, which is surprising to me, but maybe I'm just in the mountains more in Feb so I don't really notice... Could you do the same analysis on Feb? I'm betting r-squared is no more than 0.2Anonymoushttps://www.blogger.com/profile/00232210409891278155noreply@blogger.com