Why I think Long Range Winter Forecasts are inaccurate in the Northeast U.S

[blizzard1024]

As a professional meteorologist in the northeast for over 20 years and watching long range patterns, for the northeast U.S, you can NOT predict the winter unless you can get the phase of the NAO correct. La Nina and El Nino have less effect on our weather up here. Since no one has yet been able to accurately predict this oscillation more than 2-3 weeks in advance, all this winter long range forecasting in my opinion...just my opinion...is a joke. Analogs don't work....they are worthless, unless you can predict the NAO. Since the last time we were seeing many La Ninas and more negative NAOs was the 60s and 70s, analogs often are spitting out the tremendous winters of these times. The climate has warmed in the winter in the northeast by 2-3F since the 1960s. That is a fact. I am not one of those "warmistas" or whatever they are called. But it is true that winters are somewhat milder now. The reason could be natural variability (PDO-AMO-Volcanic) or man-made (CO2) or a combo. But the warmer winters on average make any analogs using the 60s or 70s in general, erroneous.

I still find them entertaining. Do any of you verify your predictions? It would be interesting to see who is doing the best over the long run and post it on this board.

My theory on the NAO/AO is related to the radiation balance in the high arctic regions. When enough excess cold air develops, baroclinicity increases which increases storminess over the high latitudes which in turn develops surface highs which follow the land masses southward which in turn increases baroclincity at the middle latitudes and allows the heights to fall in the middle latitudes. The arctic highs don't stay at the high latitudes so they migrate southward to the middle latitudes due to the increased baroclinicity and storminess. This leaves higher heights at the high latitudes and a negative NAO/AO.

When the NAO/AO is positive you have low heights at high latitudes at mid and upper levels, but the colder air is higher up and there is no surface highs forming hence the wind blows...there are clouds and the really cold surface air can't develop and form many large high pressures which come south. When there are no big arctic highs over Canada... it seems that more storms from the Pacific can make it into western Canada and then we get mild westerly downsloping off the rockies which come east.

So it in my opinion it is the radiation balance in the high latitudes that drives the NAO/AO...maybe that is why snowcover anomalies in Eurasia in the fall correlate to the NAO phase? Since you can't forecast future radiation balances in the Arctic...I don't see much hope in being able to forecast this oscillation. But we have to keep trying...without trying...we will never be able to do it.

[okie333]

As a professional meteorologist in the northeast for over 20 years and watching long range patterns, for the northeast U.S, you can NOT predict the winter unless you can get the phase of the NAO correct. La Nina and El Nino have less effect on our weather up here. Since no one has yet been able to accurately predict this oscillation more than 2-3 weeks in advance, all this winter long range forecasting in my opinion...just my opinion...is a joke. Analogs don't work....they are worthless, unless you can predict the NAO. Since the last time we were seeing many La Ninas and more negative NAOs was the 60s and 70s, analogs often are spitting out the tremendous winters of these times. The climate has warmed in the winter in the northeast by 2-3F since the 1960s. That is a fact. I am not one of those "warmistas" or whatever they are called. But it is true that winters are somewhat milder now. The reason could be natural variability (PDO-AMO-Volcanic) or man-made (CO2) or a combo. But the warmer winters on average make any analogs using the 60s or 70s in general, erroneous.

I still find them entertaining. Do any of you verify your predictions? It would be interesting to see who is doing the best over the long run and post it on this board.

My theory on the NAO/AO is related to the radiation balance in the high arctic regions. When enough excess cold air develops, baroclinicity increases which increases storminess over the high latitudes which in turn develops surface highs which follow the land masses southward which in turn increases baroclincity at the middle latitudes and allows the heights to fall in the middle latitudes. The arctic highs don't stay at the high latitudes so they migrate southward to the middle latitudes due to the increased baroclinicity and storminess. This leaves higher heights at the high latitudes and a negative NAO/AO.

When the NAO/AO is positive you have low heights at high latitudes at mid and upper levels, but the colder air is higher up and there is no surface highs forming hence the wind blows...there are clouds and the really cold surface air can't develop and form many large high pressures which come south. When there are no big arctic highs over Canada... it seems that more storms from the Pacific can make it into western Canada and then we get mild westerly downsloping off the rockies which come east.

So it in my opinion it is the radiation balance in the high latitudes that drives the NAO/AO...maybe that is why snowcover anomalies in Eurasia in the fall correlate to the NAO phase? Since you can't forecast future radiation balances in the Arctic...I don't see much hope in being able to forecast this oscillation. But we have to keep trying...without trying...we will never be able to do it.

Would definitely make sense, given how SSW's tend to push the cold air downward and eventually southward

BTW, AO goes neg within 3 weeks... mark it.

[blizzard1024]

Would definitely make sense, given how SSW's tend to push the cold air downward and eventually southward

BTW, AO goes neg within 3 weeks... mark it.

I HOPE you are right!!!!!!!!

[JTA66]

As a professional meteorologist in the northeast for over 20 years and watching long range patterns, for the northeast U.S, you can NOT predict the winter unless you can get the phase of the NAO correct. La Nina and El Nino have less effect on our weather up here. Since no one has yet been able to accurately predict this oscillation more than 2-3 weeks in advance, all this winter long range forecasting in my opinion...just my opinion...is a joke. Analogs don't work....they are worthless, unless you can predict the NAO. Since the last time we were seeing many La Ninas and more negative NAOs was the 60s and 70s, analogs often are spitting out the tremendous winters of these times. The climate has warmed in the winter in the northeast by 2-3F since the 1960s. That is a fact. I am not one of those "warmistas" or whatever they are called. But it is true that winters are somewhat milder now. The reason could be natural variability (PDO-AMO-Volcanic) or man-made (CO2) or a combo. But the warmer winters on average make any analogs using the 60s or 70s in general, erroneous.

I still find them entertaining. Do any of you verify your predictions? It would be interesting to see who is doing the best over the long run and post it on this board.

My theory on the NAO/AO is related to the radiation balance in the high arctic regions. When enough excess cold air develops, baroclinicity increases which increases storminess over the high latitudes which in turn develops surface highs which follow the land masses southward which in turn increases baroclincity at the middle latitudes and allows the heights to fall in the middle latitudes. The arctic highs don't stay at the high latitudes so they migrate southward to the middle latitudes due to the increased baroclinicity and storminess. This leaves higher heights at the high latitudes and a negative NAO/AO.

When the NAO/AO is positive you have low heights at high latitudes at mid and upper levels, but the colder air is higher up and there is no surface highs forming hence the wind blows...there are clouds and the really cold surface air can't develop and form many large high pressures which come south. When there are no big arctic highs over Canada... it seems that more storms from the Pacific can make it into western Canada and then we get mild westerly downsloping off the rockies which come east.

So it in my opinion it is the radiation balance in the high latitudes that drives the NAO/AO...maybe that is why snowcover anomalies in Eurasia in the fall correlate to the NAO phase? Since you can't forecast future radiation balances in the Arctic...I don't see much hope in being able to forecast this oscillation. But we have to keep trying...without trying...we will never be able to do it.

I've also wondered what role the Mt. Redoubt and Eyjafjallajokull erupts of 2009 and 2010 played in the -AO and -NAO states during the past two winters. But you're right, we have a ways to go before accurately predicting the NAO two+ weeks out.

[Bob Chill]

Last year was interesting because iirc the persistent -ao/nao we had during dec/jan wasn't predicted in many of the lr forcasts. Nina aside, we had a persistent cold pattern in the east early on.

This year is the opposite. I agree that it is very hard to predict the ao/nao 3+ weeks in advance with a few exceptions. I'm starting to see a connection with strong early signals with the indexes.

There are 15 occurances since 1950 when the AO has a strong to fairly strong positive index early on and 13 of the years had an overall neutral to +AO for the remainder of the season. 79-80 was the only outright flip to persistent negative. 82-83 had a decent flip too but it came later.

I haven't dug in too deep with strong early -AO signals yet. I did do a brief review of monthly temp anoms for djfm and it looked like a similar connection but I haven't looked too hard at the data yet.

NAO is much more volitile than the AO but the general trend appeared similar. I plan on digging in a bit with those stats too.

Predicting winter behavior with the ao/nao in September is probably very difficult but I'm starting to think it may be easier in the Nov-Dec timeframe if the signal is strong.

[okie333]

Last year was interesting because iirc the persistent -ao/nao we had during dec/jan wasn't predicted in many of the lr forcasts. Nina aside, we had a persistent cold pattern in the east early on.

This year is the opposite. I agree that it is very hard to predict the ao/nao 3+ weeks in advance with a few exceptions. I'm starting to see a connection with strong early signals with the indexes.

There are 15 occurances since 1950 when the AO has a strong to fairly strong positive index early on and 13 of the years had an overall neutral to +AO for the remainder of the season. 79-80 was the only outright flip to persistent negative. 82-83 had a decent flip too but it came later.

I haven't dug in too deep with strong early -AO signals yet. I did do a brief review of monthly temp anoms for djfm and it looked like a similar connection but I haven't looked too hard at the data yet.

NAO is much more volitile than the AO but the general trend appeared similar. I plan on digging in a bit with those stats too.

Predicting winter behavior with the ao/nao in September is probably very difficult but I'm starting to think it may be easier in the Nov-Dec timeframe if the signal is strong.

How many of those had a +AO in all of S/O/N?

[BethesdaWX]

A few opinions.

1) Just because the NE US climate had warmed 2-3F means nothing in terms of the ability to reproduce a great pattern, ansd it could be related to long term changes in the AO/NAO as well when you think about it. Look what happened in the Mid Atlantic in 2009/10, one of the warmest years ever yet we broke the all time snowfall record at DCA, even in the bad location+UHI today. NE US snowfall depends more on synoptic setups than temperature of the globe, as it does everywhere, espeically such a minute difference (2-3F will show almost zero correlation to snowfall since the signal is lost in natural variability in snowstorm #). Also note summer circulation patterns do not operate in the same manner during winter, and winters have been cooling this decade in the east. I think it's completely irrelavent.

2) I agree with your theory somewhat on the AO/NAO however I find it's more about balance/stability in the overall state. There is one perfect correlation to the NAO state, which is the difference between two solar cycles. A solar cycle that is similar in strength to it's predecessor always features a +NAO average. Meanwhile a solar cycle significantly different in strength to it's predecessor always features a -NAO average. This works in either direction (stronger or weaker).

[Ottawa Blizzard]

As a professional meteorologist in the northeast for over 20 years and watching long range patterns, for the northeast U.S, you can NOT predict the winter unless you can get the phase of the NAO correct. La Nina and El Nino have less effect on our weather up here. Since no one has yet been able to accurately predict this oscillation more than 2-3 weeks in advance, all this winter long range forecasting in my opinion...just my opinion...is a joke. Analogs don't work....they are worthless, unless you can predict the NAO. Since the last time we were seeing many La Ninas and more negative NAOs was the 60s and 70s, analogs often are spitting out the tremendous winters of these times. The climate has warmed in the winter in the northeast by 2-3F since the 1960s. That is a fact. I am not one of those "warmistas" or whatever they are called. But it is true that winters are somewhat milder now. The reason could be natural variability (PDO-AMO-Volcanic) or man-made (CO2) or a combo. But the warmer winters on average make any analogs using the 60s or 70s in general, erroneous.

I still find them entertaining. Do any of you verify your predictions? It would be interesting to see who is doing the best over the long run and post it on this board.

My theory on the NAO/AO is related to the radiation balance in the high arctic regions. When enough excess cold air develops, baroclinicity increases which increases storminess over the high latitudes which in turn develops surface highs which follow the land masses southward which in turn increases baroclincity at the middle latitudes and allows the heights to fall in the middle latitudes. The arctic highs don't stay at the high latitudes so they migrate southward to the middle latitudes due to the increased baroclinicity and storminess. This leaves higher heights at the high latitudes and a negative NAO/AO.

When the NAO/AO is positive you have low heights at high latitudes at mid and upper levels, but the colder air is higher up and there is no surface highs forming hence the wind blows...there are clouds and the really cold surface air can't develop and form many large high pressures which come south. When there are no big arctic highs over Canada... it seems that more storms from the Pacific can make it into western Canada and then we get mild westerly downsloping off the rockies which come east.

So it in my opinion it is the radiation balance in the high latitudes that drives the NAO/AO...maybe that is why snowcover anomalies in Eurasia in the fall correlate to the NAO phase? Since you can't forecast future radiation balances in the Arctic...I don't see much hope in being able to forecast this oscillation. But we have to keep trying...without trying...we will never be able to do it.

I agree with this completely. Regardless of the reason, the climate HAS warmed since the 60s and 70s. Back then, an abnormally warm winter really stuck out like a sore thumb, while in the past 10 years, the opposite is true. Last year I did an analysis of Decembers, Januaries and Februaries and they have warmed signifgicantly in Ottawa and Toronto since the early 60s, with a noticable spike beginning in 1998 and another in 2006. It used to be very common to see a mean temperature in the single digets in january in Ottawa while today that would make someone go "wow! it's cold" as happened in January 2003 and 2004. I'm not saying this is man made but the fact is it has been warmer in Ontario. I've been reading a book called "The Little Ice Age" by Brian Fagan and apparently even during those times, the NAO would go through a ten or fifteen year period of positive, followed by another few years of negative. I think right now Ontario is going through a phase where 8 out of 10 winters will be milder than average.

[WidreMann]

A few opinions.

1) Just because the NE US climate had warmed 2-3F means nothing in terms of the ability to reproduce a great pattern, ansd it could be related to long term changes in the AO/NAO as well when you think about it. Look what happened in the Mid Atlantic in 2009/10, one of the warmest years ever yet we broke the all time snowfall record at DCA, even in the bad location+UHI today. NE US snowfall depends more on synoptic setups than temperature of the globe, as it does everywhere, espeically such a minute difference (2-3F will show almost zero correlation to snowfall since the signal is lost in natural variability in snowstorm #). Also note summer circulation patterns do not operate in the same manner during winter, and winters have been cooling this decade in the east. I think it's completely irrelavent.

2) I agree with your theory somewhat on the AO/NAO however I find it's more about balance/stability in the overall state. There is one perfect correlation to the NAO state, which is the difference between two solar cycles. A solar cycle that is similar in strength to it's predecessor always features a +NAO average. Meanwhile a solar cycle significantly different in strength to it's predecessor always features a -NAO average. This works in either direction (stronger or weaker).

Please stop posting that bottom graph because it is bull**** and you should know better. Look at where you draw the trendline for the first 30-year trend. Notice how you could easily extend it back to the 30s and forward into the 80s. You have a five year period of +NAO in the middle of the 70s that does not count as a flip, but you go ahead and flip it for a mixed period in the early 80s. Certainly the late 80s through the 90s is pretty clearly positive, but it's not 30 years. Come up with a good metric for demarcating these periods (if there is, indeed, such a metric) and then we can talk.

[SN_Lover]

A few opinions.

1) Just because the NE US climate had warmed 2-3F means nothing in terms of the ability to reproduce a great pattern, ansd it could be related to long term changes in the AO/NAO as well when you think about it. Look what happened in the Mid Atlantic in 2009/10, one of the warmest years ever yet we broke the all time snowfall record at DCA, even in the bad location+UHI today. NE US snowfall depends more on synoptic setups than temperature of the globe, as it does everywhere, espeically such a minute difference (2-3F will show almost zero correlation to snowfall since the signal is lost in natural variability in snowstorm #). Also note summer circulation patterns do not operate in the same manner during winter, and winters have been cooling this decade in the east. I think it's completely irrelavent.

2) I agree with your theory somewhat on the AO/NAO however I find it's more about balance/stability in the overall state. There is one perfect correlation to the NAO state, which is the difference between two solar cycles. A solar cycle that is similar in strength to it's predecessor always features a +NAO average. Meanwhile a solar cycle significantly different in strength to it's predecessor always features a -NAO average. This works in either direction (stronger or weaker).

Your solar cycle map is out of date. We are now in solar cycle 24.

If you want cold and stormy weather, then you want the solar cycle to hit another minimum like the Maunder or Dalton. There was talk about hitting another minimum in 2008, but since then SC 24 has sparked back to life. So my prediction is that we might not have the potential to hit a minimum for another couple decades. This means that the NE and SE US might not have mega snow storms equivalent to the last 3 years for some time. What I don't get is that the rate of change of SC is positive, yet the East United States is in a active stormy pattern. I would think that it would be the opposite with less cosmic rays hitting Earth.

[Isotherm]

As a professional meteorologist in the northeast for over 20 years and watching long range patterns, for the northeast U.S, you can NOT predict the winter unless you can get the phase of the NAO correct. La Nina and El Nino have less effect on our weather up here. Since no one has yet been able to accurately predict this oscillation more than 2-3 weeks in advance, all this winter long range forecasting in my opinion...just my opinion...is a joke. Analogs don't work....they are worthless, unless you can predict the NAO. Since the last time we were seeing many La Ninas and more negative NAOs was the 60s and 70s, analogs often are spitting out the tremendous winters of these times. The climate has warmed in the winter in the northeast by 2-3F since the 1960s. That is a fact. I am not one of those "warmistas" or whatever they are called. But it is true that winters are somewhat milder now. The reason could be natural variability (PDO-AMO-Volcanic) or man-made (CO2) or a combo. But the warmer winters on average make any analogs using the 60s or 70s in general, erroneous.

I still find them entertaining. Do any of you verify your predictions? It would be interesting to see who is doing the best over the long run and post it on this board.

My theory on the NAO/AO is related to the radiation balance in the high arctic regions. When enough excess cold air develops, baroclinicity increases which increases storminess over the high latitudes which in turn develops surface highs which follow the land masses southward which in turn increases baroclincity at the middle latitudes and allows the heights to fall in the middle latitudes. The arctic highs don't stay at the high latitudes so they migrate southward to the middle latitudes due to the increased baroclinicity and storminess. This leaves higher heights at the high latitudes and a negative NAO/AO.

When the NAO/AO is positive you have low heights at high latitudes at mid and upper levels, but the colder air is higher up and there is no surface highs forming hence the wind blows...there are clouds and the really cold surface air can't develop and form many large high pressures which come south. When there are no big arctic highs over Canada... it seems that more storms from the Pacific can make it into western Canada and then we get mild westerly downsloping off the rockies which come east.

So it in my opinion it is the radiation balance in the high latitudes that drives the NAO/AO...maybe that is why snowcover anomalies in Eurasia in the fall correlate to the NAO phase? Since you can't forecast future radiation balances in the Arctic...I don't see much hope in being able to forecast this oscillation. But we have to keep trying...without trying...we will never be able to do it.

I verify my predictions , all of my long range outlooks for both summer and winter since 06-07 I have on my site here..you look through if you want.

http://www.lightinthestorm.com/

It also depends upon your definition/view of verifying. The majority of my outlooks I've done well for the overall/seasonal departures, but monthly timing is almost always a headache.

In terms of the NAO/AO, there are some theories/correlations I've been using the past couple winters which have had moderate success thus far, still waiting to see how this winter turns out. If the NAO and AO average positive for this winter DJF then I may try to look into other possible forcing mechanisms.

I disagree on analogs being worthless; they are a good tool, but shouldn't be used verbatim. They provide an idea as to the possible overall H5 pattern, but the temp/precip anomaly distribution can be quite different depending upon where the baroclinic zone/storm tracks set up.

I agree that the NAO and AO are the two most important factors in terms of the Northeast US sensible weather, and as we've seen the past couple winters - reversed ENSO states, a strong nino and a strong nina, both yielded a historic snow year for much of the NE corridor, due to that common denominator of high latitude blocking.

[BethesdaWX]

Please stop posting that bottom graph because it is bull**** and you should know better. Look at where you draw the trendline for the first 30-year trend. Notice how you could easily extend it back to the 30s and forward into the 80s. You have a five year period of +NAO in the middle of the 70s that does not count as a flip, but you go ahead and flip it for a mixed period in the early 80s. Certainly the late 80s through the 90s is pretty clearly positive, but it's not 30 years. Come up with a good metric for demarcating these periods (if there is, indeed, such a metric) and then we can talk.

What on earth are you talking about? The line drawn in the below graph is irrelevant to my point. Maybe read my post again? I just pulled that graph off google for the NAO data back to 1900.

[BethesdaWX]

Your solar cycle map is out of date. We are now in solar cycle 24.

If you want cold and stormy weather, then you want the solar cycle to hit another minimum like the Maunder or Dalton. There was talk about hitting another minimum in 2008, but since then SC 24 has sparked back to life. So my prediction is that we might not have the potential to hit a minimum for another couple decades. This means that the NE and SE US might not have mega snow storms equivalent to the last 3 years for some time. What I don't get is that the rate of change of SC is positive, yet the East United States is in a active stormy pattern. I would think that it would be the opposite with less cosmic rays hitting Earth.

I don't know much about cosmic rays and storminess in the east so I'm not the guy to ask there, but there has been research done that suggests cycle 24 may be the last legit cycle in awhile since the belt for cycle 25 still has not showed up in the Sun's interior.

[donsutherland1]

FYI, when one calculates the annual or winter NAO, one does not get flat trend lines for the 1950-80 and 1980-2010 periods.As this graph came from online, you were probably not aware of that. A number of online sources take a "lazy" approach and merely draw trendlines rather than plot calculated ones. Those drawn trendlines are incorrect.

The 1950-80 annual trendline is slightly positive (upsloping). The 1980-2010 annual trendline is negative (downsloping). The 1950-80 winter trendline (Dec.-Feb.) is negative. The 1980-2010 winter trendline is even more negative.