M
minet
Well-known member
http://johndee.com/
Seasonal Outlook: Winter 09/10
(Produced October 27, 2009)
Getting a late start this year due to all of my fun health issues this October, but better off late than never I guess.
I make this claim every year and this year is no different. If there is one item that you should keep in mind before, during and after reading this outlook it should be: There is no way to reliably predict the weather on a seasonal scale! Those of you who have been following my site know that I have always been pretty low key and skeptical of any seasonal forecast- even my own. In fact I like to use the work "outlook" as I feel "forecast" should be reserved for something that has a little more proven science behind it.
For those of you that are relatively new to the site, you might want to click here and read my "Soap Box Speech on Seasonal Forecasting". For those of you that have read it before, no need to again- it is the same as in years past.
Now with that said, lots of folks still want me to produce a winter forecast, so here it is:
Unlike the past two winters, there is concern for snow lovers this winter. The much dreaded El Nino has shown it’s face and looks to continue through the winter months. About a month ago I had mixed feelings as to if this El Nino was going to even have an impact on the northern US this winter, but things have occurred since then to convince me that the odds are strong that the current El Nino will play a role in the weather we see across the US this winter.
I am the eternal optimist in most things I do in my life and that includes a winter outlook, so I will be providing some glimmers of hope for this winter, but the reality of the situation is that the deck looks to be stacked against us snow lovers in the northern US this winter.
Figure 1 shows the typical weather anomalies seen across the US during moderate to strong El Nino and La Nina events. Note that these are the anomalies seen for moderate to strong ENSO events and not weak. That brings up my first glimmer of hope. That is we are currently only seeing a weak El Nino going on. So the chances of the El Nino anomalies occurring are much smaller than if the El Nino was moderate to strong. The current forecasts for this El Nino is for it to strengthen to a moderate one, but so far the models have been overstating how strong this event will get, so I believe the verdict is still out as to how strong this El Nino event will get..
So the strength of the El Nino will make a big difference in the weather seen across the US this winter.
It is also important to point out that there is really no precipitation anomaly seen across the snow belts of the northern US, just the large warm anomaly that runs from southern Alaska through western Canada and then the Pac. NW, the northern Rockies, northern Plains and northern Midwest. One might then think that snowfall could be OK, but the reality is the warmer than average temps does two things: First it increases the odds that a winter storm would bring something other than snow- especially the further south you go in the snow belts of the northern US and it also means that the snows that fall may not last as long due to the fact that thaws would be more frequent during an El Nino winter. Snow is obviously a crucial ingredient to winter sports, but so are temps. Not much fun to get a foot of snow and then have it completely melt off in just a few days. The past two winters have featured extended periods of cold weather that when combined with above average snowfall led to exceptionally long periods of significant snow depth in areas of the central Midwest and it is these same areas that I think will see the largest change in this winters snowpack when compared to the previous two years.
The other glimmer of hope is for the lake snow belts of the Midwest. While the warmer than average temps should seem to translate to less lake effect snow, only in the most severe El Nino’s does that seem to be the case. Otherwise it seems that temps do get cold enough to produce at least average LES amounts and the winter is yet mild enough to keep ice cover from getting too extensive by Feb and March, which allows the lakes to keep producing the LES into the late winter- unlike the previous two winters when significant ice cover- especially on Lake Superior pretty much shut down LES production by February.
One last "glimmer" is that much of the Northeast US does not partake in the warm anomaly. In fact there can sometimes be a cold anomaly that occurs from the Canadian Maritimes down into far northern New England during an El Nino. So I do not see the El Nino being too much of a worry for the NE US.
So in a nutshell, even though most of my talk above was optimistic, I do believe that there are greater than average chances that most of the northern US will see a warmer and less snowy winter than average and significantly less than the past 2 years. Not that I think it will be a disaster of a winter for snowlovers, but after two good ones, this winter will likely provide more disappointment than joy and snow lovers in the major metro areas of the Midwest will likely have to monitor the forecasts and be prepared to act quickly when a storm rolls through the northern Midwest- rather than being able to ride in their own back yard whenever they want for much of the winter like the past two winters.
Below are the details to the forecast for the different regions of the northern US:
REGION 1 – The Northwest Midwest: This is sort of "Ground Zero" for the warm anomaly created by El Nino. Keep in mind that the stronger the El Nino, the better the chances for this warm anomaly to occur as well as it’s intensity. Right now we are at a weak El Nino and if it stays that way through the winter, then the warm anomaly may not end up being too much of a problem. If the El Nino intensifies to a moderate or strong one, then all bets are off and things could be rather crappy in these areas for snowplay. I also believe that while the lake snow belts of the UP may not have a banner year, they will still see enough LES fall to minimize the effect of the El Nino and may be the place to go for the best snow conditions this winter. I suspect that many folks in this region will have to watch the weather closely and keep their trip plans as flexible as possible to "catch" the storms as they roll through and have access to the freshest snow.
REGION 2 – The Southeast Midwest: Portions of this region (eastern IA, the southern 1/2 of WI and sections of northern IL) saw another year of record or near record setting seasonal snowfall last winter. This combined with the extended periods of cold air allowed for some unusually good and long lasting snow cover. It is these same areas that I think will notice the biggest changes this winter compared to the previous two. Not that I think no snow will fall, but I do believe less than average will fall due to the fact that there will be precip other than snow that falls during the heart of winter. The better chances for warmer than average temps will also cause lead to more frequent thaws and thus the snow that does fall will not last as long as it did in the past two winters. So the amount of local snowplay will be much lower this winter than in the past two winters and like region 1, persons living in this region will need to monitor the weather closely and remain as flexible as possible in their plans to play in the snow so that they can get out as the storm(s) hit.
REGION 3 – The Northeast US: This is the only region in the northern US that does not have increased chances for warmer than average temps due to El Nino. That should not be taken to mean I believe they are in store for a great winter, but I really do not see any reason why it should be anything less than an average one. I also believe that the further north you go in this region as well as into the Canadian Maritimes, the better the chances you will have of seeing a cooler than average winter. I think the LES belts of this region should do pretty good snowfall wise this winter.
REGION 4 – The Northern Rockies: Like the northern Plains and northern Midwest, this region also stands pretty good chances to see warmer than average temps occur. The good news is most of the snowplay in this region is done in the higher terrain of the mountains and even with warmer than average temps, most of the precip would fall as snow and temps would remain cold enough that the snow that falls would not melt any more than would be seen in an average winter. The bad news is that the same thing that causes temps to be warmer also causes less storm activity in this region and that means less snow. So while it may not be a disaster of a winter, I do think that the northern Rockies will see less than average snowfall occur this winter and winter sports folks will have to keep an eye on the forecast to catch the storms and thus the freshest snow.
REGION 5 – The Central Rockies: This region does not see the warm anomaly like the northern Rockies sees with El Nino, but would share in the less storm activity and thus is likely to see less than average snowfall this winter. The exceptions could be in the far south. El Nino's tend to produce a more active southerly branch of the jetstream, which brings about more storms and thus more snowfall in the mountains. The best chances for the heavier than average snowfall would be areas like AZ, NM and far southern UT and CO.
REGION 6 – The Pacific NW and Sierra Range: This region is likely to be a tale of two regions, rather than one. The further north you go the less storm activity that will occur and thus the less snowfall that will occur this winter. The further south you go, the more storm activity that is likely to occur and thus the more snow that will fall in the mountains. The demarcation line is likely to be somewhere in the Tahoe region. Meaning from Tahoe south above average snowfall and then north of that less than average snowfall.
REGION 7 – Eastern Canada: I should really break this region into two separate regions as it is big enough. In any case, I expect the western sections of this region (Ontario mainly) to see below average snowfall and warmer than average temps, with close to average snowfall and average to below average temps in Quebec.
Seasonal Outlook: Winter 09/10
(Produced October 27, 2009)
Getting a late start this year due to all of my fun health issues this October, but better off late than never I guess.
I make this claim every year and this year is no different. If there is one item that you should keep in mind before, during and after reading this outlook it should be: There is no way to reliably predict the weather on a seasonal scale! Those of you who have been following my site know that I have always been pretty low key and skeptical of any seasonal forecast- even my own. In fact I like to use the work "outlook" as I feel "forecast" should be reserved for something that has a little more proven science behind it.
For those of you that are relatively new to the site, you might want to click here and read my "Soap Box Speech on Seasonal Forecasting". For those of you that have read it before, no need to again- it is the same as in years past.
Now with that said, lots of folks still want me to produce a winter forecast, so here it is:
Unlike the past two winters, there is concern for snow lovers this winter. The much dreaded El Nino has shown it’s face and looks to continue through the winter months. About a month ago I had mixed feelings as to if this El Nino was going to even have an impact on the northern US this winter, but things have occurred since then to convince me that the odds are strong that the current El Nino will play a role in the weather we see across the US this winter.
I am the eternal optimist in most things I do in my life and that includes a winter outlook, so I will be providing some glimmers of hope for this winter, but the reality of the situation is that the deck looks to be stacked against us snow lovers in the northern US this winter.
Figure 1 shows the typical weather anomalies seen across the US during moderate to strong El Nino and La Nina events. Note that these are the anomalies seen for moderate to strong ENSO events and not weak. That brings up my first glimmer of hope. That is we are currently only seeing a weak El Nino going on. So the chances of the El Nino anomalies occurring are much smaller than if the El Nino was moderate to strong. The current forecasts for this El Nino is for it to strengthen to a moderate one, but so far the models have been overstating how strong this event will get, so I believe the verdict is still out as to how strong this El Nino event will get..
So the strength of the El Nino will make a big difference in the weather seen across the US this winter.
It is also important to point out that there is really no precipitation anomaly seen across the snow belts of the northern US, just the large warm anomaly that runs from southern Alaska through western Canada and then the Pac. NW, the northern Rockies, northern Plains and northern Midwest. One might then think that snowfall could be OK, but the reality is the warmer than average temps does two things: First it increases the odds that a winter storm would bring something other than snow- especially the further south you go in the snow belts of the northern US and it also means that the snows that fall may not last as long due to the fact that thaws would be more frequent during an El Nino winter. Snow is obviously a crucial ingredient to winter sports, but so are temps. Not much fun to get a foot of snow and then have it completely melt off in just a few days. The past two winters have featured extended periods of cold weather that when combined with above average snowfall led to exceptionally long periods of significant snow depth in areas of the central Midwest and it is these same areas that I think will see the largest change in this winters snowpack when compared to the previous two years.
The other glimmer of hope is for the lake snow belts of the Midwest. While the warmer than average temps should seem to translate to less lake effect snow, only in the most severe El Nino’s does that seem to be the case. Otherwise it seems that temps do get cold enough to produce at least average LES amounts and the winter is yet mild enough to keep ice cover from getting too extensive by Feb and March, which allows the lakes to keep producing the LES into the late winter- unlike the previous two winters when significant ice cover- especially on Lake Superior pretty much shut down LES production by February.
One last "glimmer" is that much of the Northeast US does not partake in the warm anomaly. In fact there can sometimes be a cold anomaly that occurs from the Canadian Maritimes down into far northern New England during an El Nino. So I do not see the El Nino being too much of a worry for the NE US.
So in a nutshell, even though most of my talk above was optimistic, I do believe that there are greater than average chances that most of the northern US will see a warmer and less snowy winter than average and significantly less than the past 2 years. Not that I think it will be a disaster of a winter for snowlovers, but after two good ones, this winter will likely provide more disappointment than joy and snow lovers in the major metro areas of the Midwest will likely have to monitor the forecasts and be prepared to act quickly when a storm rolls through the northern Midwest- rather than being able to ride in their own back yard whenever they want for much of the winter like the past two winters.
Below are the details to the forecast for the different regions of the northern US:
REGION 1 – The Northwest Midwest: This is sort of "Ground Zero" for the warm anomaly created by El Nino. Keep in mind that the stronger the El Nino, the better the chances for this warm anomaly to occur as well as it’s intensity. Right now we are at a weak El Nino and if it stays that way through the winter, then the warm anomaly may not end up being too much of a problem. If the El Nino intensifies to a moderate or strong one, then all bets are off and things could be rather crappy in these areas for snowplay. I also believe that while the lake snow belts of the UP may not have a banner year, they will still see enough LES fall to minimize the effect of the El Nino and may be the place to go for the best snow conditions this winter. I suspect that many folks in this region will have to watch the weather closely and keep their trip plans as flexible as possible to "catch" the storms as they roll through and have access to the freshest snow.
REGION 2 – The Southeast Midwest: Portions of this region (eastern IA, the southern 1/2 of WI and sections of northern IL) saw another year of record or near record setting seasonal snowfall last winter. This combined with the extended periods of cold air allowed for some unusually good and long lasting snow cover. It is these same areas that I think will notice the biggest changes this winter compared to the previous two. Not that I think no snow will fall, but I do believe less than average will fall due to the fact that there will be precip other than snow that falls during the heart of winter. The better chances for warmer than average temps will also cause lead to more frequent thaws and thus the snow that does fall will not last as long as it did in the past two winters. So the amount of local snowplay will be much lower this winter than in the past two winters and like region 1, persons living in this region will need to monitor the weather closely and remain as flexible as possible in their plans to play in the snow so that they can get out as the storm(s) hit.
REGION 3 – The Northeast US: This is the only region in the northern US that does not have increased chances for warmer than average temps due to El Nino. That should not be taken to mean I believe they are in store for a great winter, but I really do not see any reason why it should be anything less than an average one. I also believe that the further north you go in this region as well as into the Canadian Maritimes, the better the chances you will have of seeing a cooler than average winter. I think the LES belts of this region should do pretty good snowfall wise this winter.
REGION 4 – The Northern Rockies: Like the northern Plains and northern Midwest, this region also stands pretty good chances to see warmer than average temps occur. The good news is most of the snowplay in this region is done in the higher terrain of the mountains and even with warmer than average temps, most of the precip would fall as snow and temps would remain cold enough that the snow that falls would not melt any more than would be seen in an average winter. The bad news is that the same thing that causes temps to be warmer also causes less storm activity in this region and that means less snow. So while it may not be a disaster of a winter, I do think that the northern Rockies will see less than average snowfall occur this winter and winter sports folks will have to keep an eye on the forecast to catch the storms and thus the freshest snow.
REGION 5 – The Central Rockies: This region does not see the warm anomaly like the northern Rockies sees with El Nino, but would share in the less storm activity and thus is likely to see less than average snowfall this winter. The exceptions could be in the far south. El Nino's tend to produce a more active southerly branch of the jetstream, which brings about more storms and thus more snowfall in the mountains. The best chances for the heavier than average snowfall would be areas like AZ, NM and far southern UT and CO.
REGION 6 – The Pacific NW and Sierra Range: This region is likely to be a tale of two regions, rather than one. The further north you go the less storm activity that will occur and thus the less snowfall that will occur this winter. The further south you go, the more storm activity that is likely to occur and thus the more snow that will fall in the mountains. The demarcation line is likely to be somewhere in the Tahoe region. Meaning from Tahoe south above average snowfall and then north of that less than average snowfall.
REGION 7 – Eastern Canada: I should really break this region into two separate regions as it is big enough. In any case, I expect the western sections of this region (Ontario mainly) to see below average snowfall and warmer than average temps, with close to average snowfall and average to below average temps in Quebec.
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