My Winter Outlook 2011-2012

[FoothillsNC]

One of the reasons some long range forecasts call for a "typical" climatogical forecast for Winter, such as playing the usual "el nino" or "la nina"

climatology forecast, is because in the past, those ENSO states have given a typical 30 year pattern. However, starting about 10 years ago, the various

multi-decadal indicies have been in a phase change, and as we've seen with many long range Winter Forecasts (and Summer),and if you don't account for the phase changes and overlappings, the outlooks have busted. Just last year, most every forecaster went with a traditional "la nina" temperature and precipitation pattern map forecast across the United States, but that

didnt' work out.(self included).

Even though short range weather forecast accuracy has increased tremendously through much better weather modeling and real-time data input, the long range

forecasts leave a lot to be desired. But, that is changing quickly I think. More and more is being learned quickly with using all the various indicies, such

as PDO (pacific-decadal oscillation), NAO (north atlantic oscillation), and a host of other oscillations and forcings around the globe, all of which tie in

with the main forcing from either "El Nino", "La Nina" or neutral state. We're still a ways off from getting long range forecasting accurate enough to be

truly viable to the average person, but some forecasters are really working hard at getting it right.

Aside from the main players, there's a few new pieces to add to the puzzle, but I won't get technical with the use of those, even though they may be just as important as those mentioned above. Things like Geo-magnetism, solar wind, and tropical forcing in the Pacific can alter the overall flow around the globe. At current, we are still in a relaxed period of sunspot activity and it's not rising as fast as once thought. It's believed the relative minimum sunspot activity that led to the Dalton and Maunder time frame cold periods in western Europe and the United States has some correlation in the basically cold period of the time around the 1600's and again in the late 1800's, then it rose during the 1900's, roughly speaking. The trend lately has been down, but there are spikes within decades so it's difficult to make an accurate, strategic year to year correlation.

A much better index to predict the overall temperature pattern in the Eastern United States especially, is the North Atlantic Oscillation. If you look at the graph, you can see that its state corresponds pretty nicely with what kind of temperatures occurred in the Eastern US, and fits almost perfectly to the year. In laymen's terms, a negative NAO simply means a strong high pressure has closed off and is a bubble of warmer air over Greenland or thereabouts (there are east and west based versions). A positive NAO means there is no high pressure there, and thus, the air in Canada moves more eastward, not southbound such that occurs during negative phases. Again, there are spikes within the phases, but overall, a negative phase of the NAO usually directly relates to "cold and stormy" in the eastern United States, and that has been exactly the case for each of the past three Winters. Once we can accurately forecast the long range state of the NAO, we can much more accurately forecast the temperature profiles. As of now, we can only forecast it several weeks in advance, but here's the caveat: I've been forecasting a much more negative state to the NAO for a couple of years now, and the long term 30 year trend is obvious...we're in for colder Winters. This index, in my opinion, trumps them all. The big snows and cold of the past several years in the MidAtlantic, Northeast and even Southern Appalachians and interior Southeast directly fall in line with the negative NAO states. The same can be said basically speaking for the 1960's, the late 1970's and the late 1800's...when the NAO goes negative, regardless of ENSO state, snowfall becomes above normal and temperature goes below normal. In the last few years, the NAO has been running negative for an unusually long time, and rivals the cold 1960's, late 1970's and late 1800's. The trend on the graph is pretty obvious, we're in a long term 30 year cycle of negative NAO. Much like the enhanced hurricane activity prediction that came out in the 1990's, there are just some signs we can see that point to a period in general, and this is one of those periods. Just like though we can't say for sure any one particular year won't be the exception , for example, not every year in the last 10 has been extremely hurricane active, overall, the trend can be seen with some certainty. And for the next 25 years roughly, the Eastern United States is in store for more unusually cold, and active weather, but there are those spikes within phases, that will be the exception to the rule. So the bottom line is there are phases within phases, those "spikes", and looking back at actual data regarding temps and precip, we can clearly see the overall graph points to enhanced NAO blocking, which means cold and stormy during Winter.

The NAO through time:

Typically during negative NAO, the flow is similar to the last 2 years:

So for this Winter, I'm predicting another year of generally below normal temperature and very active period in the Southeast, Tennessee, Valley and lower MidAtlantic/Interior Southeast, with a quiet Southwest and Southern Plains. The difference this year could be the enhanced shortwaves generating more storminess in the East as La Nina could weaken toward the first of the year. Already, the pattern this Fall has been increased shortwaves and there are signs of Greenland Blocking, with several strong damming episodes occurring, particularly in the Carolinas and Virginia. We can't predict damming months in advance, but the damming events have been lacking the last several years and the fact they've shown up lately is probably a clue that we're not done with those.

I'm not forecasting above normal precipitation in the Southeast states, but only Florida and the immediate surrounding region should be below normal...the rest should be around normal thanks to an active stream with more embedded shortwaves than last season. Most precip events will still be rain, but I'm expecting enough cold air for there to be above normal snow in the southern Apps and Tennessee Valley, and the odds of one significant ice storm in the damming regions is fairly high this year, thanks to the precedent damming already seen,the fact that temperatures will likely be below normal, and the fact storm tracks are supressed, plus odds favor one anytime since it's been a while. I'd actually be pretty suprised to NOT have a major ice event from northeast Georgia to the central Carolinas and southern Virginia this Winter.

For the Southeast/Tenn Valley region, all it takes is around 2 significant widespread Winter events to deliver above normal snowfall outside the higher mountains, and with the prevailing storm track, negative NAO at times and enhanced shortwaves embedded in the flow compared to last season, I easily see another year of above normal snowfall in the deep south, where places like Huntsville, Atlanta, Athens and Greenville-Spartanburg are possibly equivalent or even surpass the Midatlantic like Roanoke and DC again this season. Re-development in the Gulf and overrunning into the Cold Air could be equal to that of last year. During periods the NAO relaxes the midwest will endure severe snowstorms that track through the Midwest.

[andyhb]

Any possible correlations for the SE severe season next spring? Particularly considering the violence of this April.

[FoothillsNC]

Any possible correlations for the SE severe season next spring? Particularly considering the violence of this April.

I just read a study showing -PDO and cold out west is a strong indicator of increased tornadoes. This due to more troughing, airmass collision that generates shear, exactly what we saw this year in the Plains and Southeast. Hard to say if the nina is gone by then, if its not, then I'd say we'd see increase over normal in tornadoes, once again.

[andyhb]

Also asking because I'm considering flying down to Birmingham/Jackson/Atlanta/etc. to give SE chasing a shot, if a big outbreak becomes evident.

[LithiaWx]

This forecast was very pleasant to read and very understandable to the layman. Thank you for your thoughts Robert, they are always appreciated. If all this comes true then...

[andyhb]

I just read a study showing -PDO and cold out west is a strong indicator of increased tornadoes. This due to more troughing, airmass collision that generates shear, exactly what we saw this year in the Plains and Southeast. Hard to say if the nina is gone by then, if its not, then I'd say we'd see increase over normal in tornadoes, once again.

Quite a few outlooks that I have checked out have been predicting a potentially late peak to the upcoming Nina, so that proposition could come into fruition.

[NCSNOW]

Excellent job as usual. If this laymen has leaned anything over the past few years , its that the NAO trumps all other cards/signals in the seasonal forecast for our region, espeacilly winter. I honestly beleive most of us will have no problem reaching and exceeding our seasonal averages this winter. Not hard to do outside of the apps, But I'm sure we will have our occasional 33 degree and rain got burned by the models/weenish moments this year as well. In my unprofesional opinion it's harder to get those phased bombs when the nortthern stream is more dominant. Meaning we are more likely to get at or above our seasonal averages taking baby steps as oppossed to getting walloped with 5-6 plus inch snow storms. 2 years ago you had the -Nao working along with an el-nino hence why DC got walloped with 3 big whoppers. Last year we had -Nao working with La-Nina meaning not as many blockbuster events, but still more than all of us could ask for climo wise.

[FoothillsNC]

Excellent job as usual. If this laymen has leaned anything over the past few years , its that the NAO trumps all other cards/signals in the seasonal forecast for our region, espeacilly winter. I honestly beleive most of us will have no problem reaching and exceeding our seasonal averages this winter. Not hard to do outside of the apps, But I'm sure we will have our occasional 33 degree and rain got burned by the models/weenish moments this year as well. In my unprofesional opinion it's harder to get those phased bombs when the nortthern stream is more dominant. Meaning we are more likely to get at or above our seasonal averages taking baby steps as oppossed to getting walloped with 5-6 plus inch snow storms. 2 years ago you had the -Nao working along with an el-nino hence why DC got walloped with 3 big whoppers. Last year we had -Nao working with La-Nina meaning not as many blockbuster events, but still more than all of us could ask for climo wise.

exactly, usually I'm more likeing the el nino side of things if hoping for snow, but thats only because of split flow and more gulf lows in general, even though that usually means marginal temps (usually too warm actually here). The fact we're looking at below normal temps is the first ingredient, and even though thats not a given, its looking more and more likely, and if blocking develops in Dec and Jan like it looks like is more than likely, we in NC could watch Ms, Al, SC and GA get more snow than here, but this year I think a couple shortwaves will be further north than last year. Depends on the strength of La Nina. The long term trend in NAO is what's crucial, and even though not every year will be cold and stormy, with the return of that feature in general you have to like our chances in the Southeast, compare to the 80s and 90's when it was mostly absent. We're living in a new paradigm now, who's to say we're not going to repeat the 1960s and 1970's or <gulp> late 1800's. We're in that kind of overall pattern. Or headed that way, imo.

[jburns]

Excellent job as usual.

I agree, but I'm most impressed with the 400 years of sunspot obs chart. Just how the hell old is he?

[weathertree4u]

exactly, usually I'm more likeing the el nino side of things if hoping for snow, but thats only because of split flow and more gulf lows in general, even though that usually means marginal temps (usually too warm actually here). The fact we're looking at below normal temps is the first ingredient, and even though thats not a given, its looking more and more likely, and if blocking develops in Dec and Jan like it looks like is more than likely, we in NC could watch Ms, Al, SC and GA get more snow than here, but this year I think a couple shortwaves will be further north than last year. Depends on the strength of La Nina. The long term trend in NAO is what's crucial, and even though not every year will be cold and stormy, with the return of that feature in general you have to like our chances in the Southeast, compare to the 80s and 90's when it was mostly absent. We're living in a new paradigm now, who's to say we're not going to repeat the 1960s and 1970's or <gulp> late 1800's. We're in that kind of overall pattern. Or headed that way, imo.

Four of the twenty snowiest Winter Seasons in Nasvhille's history occurred before 1900, in fact, the largest snowfall in Middle TN History occured before 1900...

March 17 1892- Nashville records its greatest one-day snowfall ever, measuring 17". The snow starts after midnight, and continues until noon. Members of the Ancient Order of Hibernians in America cancel their annual parade. No street cars are running. Morning trains are delayed. And the "arteries of trade" are clogged. Suburban workers have to walk to town. Mailmen don't leave the post office on their rounds until 10:00 a.m. A freight train from Chattanooga slides off the track at the Winton community, near Murfreesboro, and a passenger train from Memphis due at 7:00 a.m. doesn't arrives until 2:00 p.m. Riddleton, a few miles northwest of Carthage, receives 18.7" in what is believed to be the greatest single-day snowfall in Middle Tennessee's history.

http://www.srh.noaa.gov/ohx/?n=calendar

[BIG FROSTY]

Great read as always Robert! Just what I was hoping for, good solid reasoning for a cold and stormy southeast!!! Thanks for sharing and here's to hoping it verifies

[wx n of atl]

Thank you Robert! That was a very understandable read for me. All the best to everyone this Winter!

[Carvers Gap]

Linked your website to my Facebook page. It's great to have forecasters in this part of the world that know their stuff. GFS sure has a similar look over the next few weeks - not a a winter pattern but has cold sliding SE from the northern plains. Should put an end to above normal temps here. It will be interesting to see if the winter pattern mirrors the upcoming pattern. The negative PDO sure seems to be influencing the pattern and has since it flipped.

[Psalm 148:8]

Awesome job, Robert!! Thanks for the time and energy you spent in making this prediction. I really thought you just colored those pretty maps to make me happy! Sooooo hoping you are right! Sounds like a repeat of last year with maybe a few ice storms thrown in.....man....fantasy football and another year like last winter....My computer is DEFINITELY going to blow up Might as well go on down to Best Buy and pick one out I can however do WITHOUT another tornado season like last year....I'll be glad if I NEVER see that again in my lifetime!

[november rain]

You made my day thats for sure

[ncjoaquin]

Awesome write-up Robert. Right or wrong, I greatly appreciate your contribution to this board.

[buckeyefan1]

Awesome write-up Robert. Right or wrong, I greatly appreciate your contribution to this board.

+1

[FallsLake]

I love the outlook and agree. I think we're in a new climate pattern (i.e. solar, NAO cycle, etc. --as Robert said) that most climatologists will have problems making predictions. One shift south in the predominant pattern gives our area the sweet spot for many winter storms.

I don't think the mid-Atlantic and NE folks like this possibility.

[NYsnowlover]

I love the outlook and agree. I think we're in a new climate pattern (i.e. solar, NAO cycle, etc. --as Robert said) that most climatologists will have problems making predictions. One shift south in the predominant pattern gives our area the sweet spot for many winter storms.

I don't think the mid-Atlantic and NE folks like this possibility.

I am from the NYC area, and I like this, less mixing events!!!!

[NEGa]

thanks robert - i hope its right my biggest fear is nothing scientific, but more statistically...three awesome back to back winters in the se? if we are shifting back to the pattern in the 70s/80s maybe we can be. i sure hope so on interesting note on the cads so far, the one thing missing the last 6 years has been with the last one or two hear....the noticeable ne winds (that continued the duration of the event until it went to drizzle). get that set up again in dec and we may finally break out no-ice streak

[pcbjr]

Wish that colder than normal blue were about 100 miles further south !!!

Great analysis. Thanks for the thoughts and insights!

[POWERSTROKE]

exactly, usually I'm more likeing the el nino side of things if hoping for snow, but thats only because of split flow and more gulf lows in general, even though that usually means marginal temps (usually too warm actually here). The fact we're looking at below normal temps is the first ingredient, and even though thats not a given, its looking more and more likely, and if blocking develops in Dec and Jan like it looks like is more than likely, we in NC could watch Ms, Al, SC and GA get more snow than here, but this year I think a couple shortwaves will be further north than last year. Depends on the strength of La Nina. The long term trend in NAO is what's crucial, and even though not every year will be cold and stormy, with the return of that feature in general you have to like our chances in the Southeast, compare to the 80s and 90's when it was mostly absent. We're living in a new paradigm now, who's to say we're not going to repeat the 1960s and 1970's or <gulp> late 1800's. We're in that kind of overall pattern. Or headed that way, imo.

like the way you talk Robert!!! Just bought another truck and a salter, Bring it on!!

[Pathfinder]

Robert, thanks for a well-written and easy to understand post, as always appreciate all your efforts and contributions.

[pcbjr]

This is my dream (yes, I know, IMBY and "my dream"), but ....

[NYsnowlover]

This is my dream (yes, I know, IMBY and "my dream"), but ....

[pcbjr]

Concur

[FallsLake]

This is my dream (yes, I know, IMBY and "my dream"), but ....

All it takes is one low to traverse way to the south. I lived in Florida as a kid back in the mid 70s. I remeber the snow in Orlando and the flurries we had at Patric AFB. It can happen...

[NC_hailstorm]

Nice read Foothills when the AO/NAO goes negative the winter precip picks up,that's what's happened over the last 3 years

Just don't know how much precip we get from the SW though with La Nina but the SOI isn't raging like last year when it was 19-21.So far it's been around 6-8 which looks like a weak La Nina.

[pcbjr]

All it takes is one low to traverse way to the south. I lived in Florida as a kid back in the mid 70s. I remeber the snow in Orlando and the flurries we had at Patric AFB. It can happen...

Lived here all my life (except 6 years in South Bend, Indiana from 1973 - 1979 - talk about SNOW); I remember some flakes and sleet being not uncommon in my younger days; but since that blast of 1983 and the "snow" of 1989, 1986 - 2009 have been pretty much nondescript (although 2004 and 2005 Feb's had pretty good sleet and we had a 15 minute snow shower last late December). Anyway - here's hoping ....

[gracetoyou]

One of the reasons some long range forecasts call for a "typical" climatogical forecast for Winter, such as playing the usual "el nino" or "la nina"

climatology forecast, is because in the past, those ENSO states have given a typical 30 year pattern. However, starting about 10 years ago, the various

multi-decadal indicies have been in a phase change, and as we've seen with many long range Winter Forecasts (and Summer),and if you don't account for the phase changes and overlappings, the outlooks have busted. Just last year, most every forecaster went with a traditional "la nina" temperature and precipitation pattern map forecast across the United States, but that

didnt' work out.(self included).

Even though short range weather forecast accuracy has increased tremendously through much better weather modeling and real-time data input, the long range

forecasts leave a lot to be desired. But, that is changing quickly I think. More and more is being learned quickly with using all the various indicies, such

as PDO (pacific-decadal oscillation), NAO (north atlantic oscillation), and a host of other oscillations and forcings around the globe, all of which tie in

with the main forcing from either "El Nino", "La Nina" or neutral state. We're still a ways off from getting long range forecasting accurate enough to be

truly viable to the average person, but some forecasters are really working hard at getting it right.

Aside from the main players, there's a few new pieces to add to the puzzle, but I won't get technical with the use of those, even though they may be just as important as those mentioned above. Things like Geo-magnetism, solar wind, and tropical forcing in the Pacific can alter the overall flow around the globe. At current, we are still in a relaxed period of sunspot activity and it's not rising as fast as once thought. It's believed the relative minimum sunspot activity that led to the Dalton and Maunder time frame cold periods in western Europe and the United States has some correlation in the basically cold period of the time around the 1600's and again in the late 1800's, then it rose during the 1900's, roughly speaking. The trend lately has been down, but there are spikes within decades so it's difficult to make an accurate, strategic year to year correlation.

A much better index to predict the overall temperature pattern in the Eastern United States especially, is the North Atlantic Oscillation. If you look at the graph, you can see that its state corresponds pretty nicely with what kind of temperatures occurred in the Eastern US, and fits almost perfectly to the year. In laymen's terms, a negative NAO simply means a strong high pressure has closed off and is a bubble of warmer air over Greenland or thereabouts (there are east and west based versions). A positive NAO means there is no high pressure there, and thus, the air in Canada moves more eastward, not southbound such that occurs during negative phases. Again, there are spikes within the phases, but overall, a negative phase of the NAO usually directly relates to "cold and stormy" in the eastern United States, and that has been exactly the case for each of the past three Winters. Once we can accurately forecast the long range state of the NAO, we can much more accurately forecast the temperature profiles. As of now, we can only forecast it several weeks in advance, but here's the caveat: I've been forecasting a much more negative state to the NAO for a couple of years now, and the long term 30 year trend is obvious...we're in for colder Winters. This index, in my opinion, trumps them all. The big snows and cold of the past several years in the MidAtlantic, Northeast and even Southern Appalachians and interior Southeast directly fall in line with the negative NAO states. The same can be said basically speaking for the 1960's, the late 1970's and the late 1800's...when the NAO goes negative, regardless of ENSO state, snowfall becomes above normal and temperature goes below normal. In the last few years, the NAO has been running negative for an unusually long time, and rivals the cold 1960's, late 1970's and late 1800's. The trend on the graph is pretty obvious, we're in a long term 30 year cycle of negative NAO. Much like the enhanced hurricane activity prediction that came out in the 1990's, there are just some signs we can see that point to a period in general, and this is one of those periods. Just like though we can't say for sure any one particular year won't be the exception , for example, not every year in the last 10 has been extremely hurricane active, overall, the trend can be seen with some certainty. And for the next 25 years roughly, the Eastern United States is in store for more unusually cold, and active weather, but there are those spikes within phases, that will be the exception to the rule. So the bottom line is there are phases within phases, those "spikes", and looking back at actual data regarding temps and precip, we can clearly see the overall graph points to enhanced NAO blocking, which means cold and stormy during Winter.

The NAO through time:

Typically during negative NAO, the flow is similar to the last 2 years:

So for this Winter, I'm predicting another year of generally below normal temperature and very active period in the Southeast, Tennessee, Valley and lower MidAtlantic/Interior Southeast, with a quiet Southwest and Southern Plains. The difference this year could be the enhanced shortwaves generating more storminess in the East as La Nina could weaken toward the first of the year. Already, the pattern this Fall has been increased shortwaves and there are signs of Greenland Blocking, with several strong damming episodes occurring, particularly in the Carolinas and Virginia. We can't predict damming months in advance, but the damming events have been lacking the last several years and the fact they've shown up lately is probably a clue that we're not done with those.

I'm not forecasting above normal precipitation in the Southeast states, but only Florida and the immediate surrounding region should be below normal...the rest should be around normal thanks to an active stream with more embedded shortwaves than last season. Most precip events will still be rain, but I'm expecting enough cold air for there to be above normal snow in the southern Apps and Tennessee Valley, and the odds of one significant ice storm in the damming regions is fairly high this year, thanks to the precedent damming already seen,the fact that temperatures will likely be below normal, and the fact storm tracks are supressed, plus odds favor one anytime since it's been a while. I'd actually be pretty suprised to NOT have a major ice event from northeast Georgia to the central Carolinas and southern Virginia this Winter.

For the Southeast/Tenn Valley region, all it takes is around 2 significant widespread Winter events to deliver above normal snowfall outside the higher mountains, and with the prevailing storm track, negative NAO at times and enhanced shortwaves embedded in the flow compared to last season, I easily see another year of above normal snowfall in the deep south, where places like Huntsville, Atlanta, Athens and Greenville-Spartanburg are possibly equivalent or even surpass the Midatlantic like Roanoke and DC again this season. Re-development in the Gulf and overrunning into the Cold Air could be equal to that of last year. During periods the NAO relaxes the midwest will endure severe snowstorms that track through the Midwest.

Very well done sir! I also agree with your thinking & forecast. I've read way too many typical climatology forecasts for La Nina winters so far this year.