SE Ridge May Not Be A Factor For DJF 2010-2011 On Average

[bluewave]

So far we are seeing much below normal to record breaking cold temperatures to start off the month of December over the SE US.

The model forecasts are indicating that this unusually cold pattern will persist well into the month.

7day running mean temperature departures from the GFS.

I found 16 Decembers where at least some portion of the SE US averaged 5 degrees below normal or more for the entire month, which I believe

this pattern can produce when all is said and done.I am mainly using the composites for the SE temperatures as the forecasts

this year are indicating warmer temperatures departures out west and spots further to the north relative to the mean than the composites.

The DJF composite on average featured a below normal temperature signal for the East and not one that you would see with a prominent SE ridge.

That is not to say that there won't be intervals where the SE ridge emerges but it may not be a factor when DJF is averaged out.

[Amped]

Good Job,

Can you redow the last map for Just January and February. I think the cold decembers maybe skewing the numbers. It looks like January and February raise anomolies a lot even though they aren't quite positive.

[tacoman25]

I think it would be helpful to look at Ninas that have shown a similar pattern in Dec.

Followed by Jan-Mar.

If we eliminate the weak Ninas to account for 2010's strength....

[okie333]

I think it would be helpful to look at Ninas that have shown a similar pattern in Dec.

Followed by Jan-Mar.

If we eliminate the weak Ninas to account for 2010's strength....

ERROR!!!

Remember to use the same scale in all maps (I prefer -5 to 5 with 0.5 increments)

[NCSnowstorm]

What result would you get if you took SOIL MOISTURE into account? I don't see that included in your analysis...

So far we are seeing much below normal to record breaking cold temperatures to start off the month of December over the SE US.

The model forecasts are indicating that this unusually cold pattern will persist well into the month.

7day running mean temperature departures from the GFS.

I found 16 Decembers where at least some portion of the SE US averaged 5 degrees below normal or more for the entire month, which I believe

this pattern can produce when all is said and done.I am mainly using the composites for the SE temperatures as the forecasts

this year are indicating warmer temperatures departures out west and spots further to the north relative to the mean than the composites.

The DJF composite on average featured a below normal temperature signal for the East and not one that you would see with a prominent SE ridge.

That is not to say that there won't be intervals where the SE ridge emerges but it may not be a factor when DJF is averaged out.

[okie333]

ERROR!!!

Remember to use the same scale in all maps (I prefer -5 to 5 with 0.5 increments)

Here are the three pictures corrected:

[tacoman25]

ERROR!!!

Remember to use the same scale in all maps (I prefer -5 to 5 with 0.5 increments)

Lol sorry, just used the scales automatically assigned by the site. Overall picture is basically the same.

[JBG]

Good Job,

Can you redow the last map for Just January and February. I think the cold decembers maybe skewing the numbers. It looks like January and February raise anomolies a lot even though they aren't quite positive.

I think its very common for December to be cold and then January and February quite variable. Examples are Decembers of 1970, 1988, 1995, 2000, 2005 and 2007. In all cases the remaining winter months were either quite variable (think Januaries and Februaries 1971, 1989, 1996, 2001, 2006, and 2008). 1973-4 was fickle throughout, and 1999-2000 had its cold weather in the heart of January.

[bluewave]

Good Job,

Can you redow the last map for Just January and February. I think the cold decembers maybe skewing the numbers. It looks like January and February raise anomolies a lot even though they aren't quite positive.

Thanks,that's right.There's more variability over JAN/FEB with a weaker overall signal than just DEC by itself.

[bluewave]

What result would you get if you took SOIL MOISTURE into account? I don't see that included in your analysis...

With this thread I am just looking at the unusually cold pattern for the SE US.

[bluewave]

I think it would be helpful to look at Ninas that have shown a similar pattern in Dec.

Followed by Jan-Mar.

If we eliminate the weak Ninas to account for 2010's strength....

Right,thank's for adding those composites.

The composites from the major -PDO/-NAO era has the same look as we are seeing now.

[okie333]

Right,thank's for adding those composites.

The composite form the major -PDO/-NAO era has the same look as we are seeing now.

Try using an Interval of 0.5 next time... it has much less white space, which is important when dealing with averages of many members.

[Lee]

Try using an Interval of 0.5 next time... it has much less white space, which is important when dealing with averages of many members.

True,this would be the more refined, definitive maps to use but, at the same time it makes it appear that the shaded areas were much more < > than average to many that are accustomed to using the other maps. Of which, as you know, are quite a few.

[Lee]

I think it would be helpful to look at Ninas that have shown a similar pattern in Dec.

Followed by Jan-Mar.

If we eliminate the weak Ninas to account for 2010's strength....

How do those look when you put the pre-1950 strong Nina's as bluewave had back in there though?

[JBG]

Thanks,that's right.There's more variability over JAN/FEB with a weaker overall signal than just DEC by itself.

Of course one of the things I keep on forgetting is that it's far easier to have a large negative anomoly in December or late February on than in January through early February. With the exception of some outlier temperature readings such as the -15 on February 9, 1934 or the -10s to -14s during December 28 or so, 1917 to January 4 or so, 1918, at least KNYC is effectively "maxed out" in terms of coldness with a low of say -4 and a high of +12. It just very rarely gets colder, so the lowest mean would be +4, and that's for a day or two every 10 year. That's a negative anomaly of 27 against a normal mean of 31. So as a practical matter the biggest anomolies most winters are, say, 15 degrees below normal.

By contrast it's far more common to torch to 65 or so, which happens even during the coldest winters (with some exceptions like 1969 which was consistently but not severely cold throughout). On such "torch days" the low will be, say, 45, with a mean of 55, or 24 above normal. Or combinations, on drizzly, boring days like a high of 50 and a low of 40,or 16 degrees above normal. In terms of being common that's far more frequent than the cold direction. In other words, a typical "cold" winter day would be a high of say 25 and a low of 14, which would result in a mean of about 20, or 11 below normal.

When the "means" start to rise, getting big negative anomolies is a lot easier.

During the summers, similarly, the maximum high for KNYC is 106, against a normal max of 85 (and 84 for the day we hit that high, July 9, 1936). That's a mere 22 above normal, so during the summer we max out on positive anomolies.

[tacoman25]

How do those look when you put the pre-1950 strong Nina's as bluewave had back in there though?

I believe the only pre-1950s Ninas bluewave included in the original post were 1917 and 1903. 1917 was included in my composite...didn't mean to leave out 1903-04, Dec 1903 actually looks like it might end up a good match to this Dec as well.

Here's Jan-Mar 1904. Not sure how strong a Nina it was.

[bluewave]

Try using an Interval of 0.5 next time... it has much less white space, which is important when dealing with averages of many members.

Yeah,I usually use that scale and edited the images in the above posts to reflect the change.

It was easier in the first post for the purpose of finding the original analogs.

[BlizzardWx]

This is a nice thread, good job! I still feel the SE ridge will emerge, especially in January or Feb. BUT this is pretty compelling that it may not be a huge factor. Certainly a great learning experience for future reference.

[SnoSki14]

The GOA low will probably be the biggest factor although I bet the SE ridge will emerge in Jan and Feb, but it may be weaker than expected. If so, there could be more opportunities available for snow than previously expected. I'll take the GOA low over the SE ridge because we'll have a greater chance at an overrunning or Miller B like event.

[bluewave]

Several stations in the SE coming in around a remarkable -13 degree temperature departure for the first 15 days of the month.

[Nikolai]

Several stations in the SE coming in around a remarkable -13 degree temperature departure for the first 15 days of the month.

I'm sure you'll hear differently, but not one meteorologist predicted this December's evolution--not one! I am not met, and I did go cold for the NE, but who would have ever guessed the SE would be so absolutely frigid? These kind of anomalies are just incredible, and I don't think they'll be muted over the next two weeks, either.

How anyone can justify the rest of their winter forecast after what has transpired (if they did not go for a cold December, in particular) is beyond me. I think that we've seen the calls for 'no winter because of Nina' bust already very thoroughly--we may not have tons of snow (yet!), but we have been well below normal. I originally called for a somewhat cold January (-1 in DC, -2 or -3 in NYC), and I think I'll still stick with that. Blocking has been extreme and persistent, and I don't see any period of length this winter where we lose the -NAO until late January at the earliest. Even then, I'm beginning to doubt my warm February call...

[Ellinwood]

I'm sure you'll hear differently, but not one meteorologist predicted this December's evolution--not one! I am not met, and I did go cold for the NE, but who would have ever guessed the SE would be so absolutely frigid? These kind of anomalies are just incredible, and I don't think they'll be muted over the next two weeks, either.

How anyone can justify the rest of their winter forecast after what has transpired (if they did not go for a cold December, in particular) is beyond me. I think that we've seen the calls for 'no winter because of Nina' bust already very thoroughly--we may not have tons of snow (yet!), but we have been well below normal. I originally called for a somewhat cold January (-1 in DC, -2 or -3 in NYC), and I think I'll still stick with that. Blocking has been extreme and persistent, and I don't see any period of length this winter where we lose the -NAO until late January at the earliest. Even then, I'm beginning to doubt my warm February call...

lol @ paragraph 1... you weren't looking hard enough for mets with the cold east in Dec. Also, you don't think the Southeast will erode some of those big negative anomalies by the end of the month? The Southeast has probably seen the biggest cold anomalies they'll get this month... they'll still be well into the negative, but not at the level they're at now.

Here's a met that called for the cold Dec:

Jan was a complete torch after this... but it looks like I'll have to make some cool changes to the north and east.

[Nikolai]

lol @ paragraph 1... you weren't looking hard enough for mets with the cold east in Dec. Also, you don't think the Southeast will erode some of those big negative anomalies by the end of the month? The Southeast has probably seen the biggest cold anomalies they'll get this month... they'll still be well into the negative, but not at the level they're at now.

Here's a met that called for the cold Dec:

Jan was a complete torch after this... but it looks like I'll have to make some cool changes to the north and east.

I actually had your forecast in mind while writing this post, and I didn't think you had been quite so cold over the entire Southeast (I remembered the greatest anomalies being over the OV/NE). But yes, good job!

& I don't think the SE will see their departures reduced that significantly, with the current pattern persisting for at least the next two weeks. Could we get another cutter in that time frame? Sure, but that didn't dent anomalies for the first half of the month in any meaningful way.

[Christopher]

I actually had your forecast in mind while writing this post, and I didn't think you had been quite so cold over the entire Southeast (I remembered the greatest anomalies being over the OV/NE). But yes, good job!

& I don't think the SE will see their departures reduced that significantly, with the current pattern persisting for at least the next two weeks. Could we get another cutter in that time frame? Sure, but that didn't dent anomalies for the first half of the month in any meaningful way.

Yes another cold air mass coming down the pipe for christmas weekend...

[bluewave]

With the really strong -AO/NAO blocking pattern in effect,you can compare the SE cold so far this month relative to the means to a

a very cold half month period like last JAN 1-15.

DEC 1-15 ,2010

JAN 1-15,2010

[varicweather]

Thanks for the analysis and info. Its looking like the SE. ridge may not be a factor this Winter as it has been in previous years especially last decade.

It looks like a stubborn ridge axis may be setting up in the Arklatex region and the Southern plains. Hopefully these regions will

not be suffering devastating drought this Spring and Summer as often happens in La Nina years.

http://drought.unl.edu/dm/monitor.html

[bluewave]

Thanks for the analysis and info. Its looking like the SE. ridge may not be a factor this Winter as it has been in previous years especially last decade.

It looks like a stubborn ridge axis may be setting up in the Arklatex region and the Southern plains. Hopefully these regions will

not be suffering devastating drought this Spring and Summer as often happens in La Nina years.

http://drought.unl.edu/dm/monitor.html

Sure,it's a big switch from the great STJ that we had with the El Nino last winter.

[HM]

I'm sure you'll hear differently, but not one meteorologist predicted this December's evolution--not one! I am not met, and I did go cold for the NE, but who would have ever guessed the SE would be so absolutely frigid? These kind of anomalies are just incredible, and I don't think they'll be muted over the next two weeks, either.

How anyone can justify the rest of their winter forecast after what has transpired (if they did not go for a cold December, in particular) is beyond me. I think that we've seen the calls for 'no winter because of Nina' bust already very thoroughly--we may not have tons of snow (yet!), but we have been well below normal. I originally called for a somewhat cold January (-1 in DC, -2 or -3 in NYC), and I think I'll still stick with that. Blocking has been extreme and persistent, and I don't see any period of length this winter where we lose the -NAO until late January at the earliest. Even then, I'm beginning to doubt my warm February call...

I know you are going to call me a liar but I warned several times over the summer/autumn that December's temp anomalies would look odd for a La Niña and that the coldest anomalies would be in the Southeast. You're right that no one can forecast -10 to -15 anomalies but that is why you leave it ambiguous and just say "less than 4" or something like that to account for the potential of extremes.

[WVclimo]

I know you are going to call me a liar but I warned several times over the summer/autumn that December's temp anomalies would look odd for a La Niña and that the coldest anomalies would be in the Southeast. You're right that no one can forecast -10 to -15 anomalies but that is why you leave it ambiguous and just say "less than 4" or something like that to account for the potential of extremes.

I recall these comments about Dec. Nice job, HM. Now can we stick with the variable outlook with some big swings from cold to warm through Jan and Feb as i believe you had also mentioned, and avoid consistent AN boredom ?

[donsutherland1]

With the really strong -AO/NAO blocking pattern in effect...

FWIW, here is the composite temperature anomaly for December La Niña cases when the monthly AO averaged -0.5 or lower: