December Forecast Discussion

[GaWx]

What about 3 consecutive...we could be due for a multi-year shutout if things continue next year, I need to dig up some numbers on central NC's longest drought with snowfall under say 2".

For those who may be curious, the record long string of winters going back to 1876-7 for Atlanta of under 2" of S/IP (i.e., under the longterm avg.) is nine, which was set twice:

1. 1942-3 through 1950-1 (highest 1.4" and avg. only 0.3") (four La Ninas out of nine winters)

2. 1969-70 through 1977-8 (highest 1.0" and avg. 0.6") (five La Ninas out of nine winters)

Third longest strong is five in a row, set three different times. Since 1978-9, the longest drought has been only four years followed by two three-year long droughts.

The longest drought of no measurable S/IP since 1890-91 is three years, which was set during the period 1948-9 through 1950-1 (two La Ninas out of three winters).

There have been only four winters without measurable S/IP over the last 30 years. There were six duing the prior 30 years, eleven the preceding 30 years, and six the 30 years before that.

Only one year since 1889-90 had no S/IP at all: 1924-5, which was as you might guess during La Nina.

[griteater]

Only one year since 1889-90 had no snow at all: 1924-5, which was as you might guess during La Nina.

But it had the April snow right?

[GaWx]

But it had the April snow right?

That would have been interesting. However, I'm already counting all months. That recently mentioned April snow was in 1910, not 1925.

[packbacker]

As for PDO forecasting, it can't be done until its flipped positions, atleast thats the study I read recently. It is roughly a 30 year cycle but we really don't have enough in the bank to say even that, since it's so new. Like the NAO, it takes spikes, but right now is negative. And slightly increasing toward positive but has a ways to go. You can see it clearly on SST maps. The readings last few years:

2010** 0.83 0.82 0.44 0.78 0.62 -0.22 -1.05 -1.27 -1.61 -1.06 -0.82 -1.21

2011** -0.92 -0.83 -0.69 -0.42 -0.37 -0.69 -1.86 -1.74 -1.79 -1.34 -2.33 -1.79

2012** -1.38 -0.85 -1.05 -0.27 -1.26 -0.87 -1.52 -1.93

Looks like we started another 30 year negative PDO cycle in 2010, so we have until 2040 of this crappy pacific to deal with :-). Great when I am 67 years old I can start sledding again!

[FoothillsNC]

Looks like we started another 30 year negative PDO cycle in 2010, so we have until 2040 of this crappy pacific to deal with :-). Great when I am 67 years old I can start sledding again!

Not so fast. There's other things to consider besides -PDO (plus theres a slew of good ones of those...look at 1950 to 1980). The NAO pattern trumps all , in my opinion, and back in 2009 I said there are good signs its on the way down. And it delivered. Immediately afterwards we saw back to back good Winters overall, then a "spike". There will always be spikes in any pattern, but the overall trend in the NAO is definitely downward and I stand by that trend a lot, but any one year (like last) can be totally different. Even with any index, a good or bad year can pop out of nowhere, so I don't think you'll necessarily have to wait until 2040 to see snow again.

[packbacker]

For those who may be curious, the record long string of winters going back to 1876-7 for Atlanta of under 2" of S/IP (i.e., under the longterm avg.) is nine, which was set twice:

1. 1942-3 through 1950-1 (highest 1.4" and avg. only 0.3") (four La Ninas out of nine winters)

2. 1969-70 through 1977-8 (highest 1.0" and avg. 0.6") (five La Ninas out of nine winters)

Third longest strong is five in a row, set three different times. Since 1978-9, the longest drought has been only four years followed by two three-year long droughts.

The longest drought of no measurable S/IP since 1890-91 is three years, which was set during the period 1948-9 through 1950-1 (two La Ninas out of three winters).

There have been only four winters without measurable S/IP over the last 30 years. There were six duing the prior 30 years, eleven the preceding 30 years, and six the 30 years before that.

Only one year since 1889-90 had no S/IP at all: 1924-5, which was as you might guess during La Nina.

Alright, here is RDU's numbers....Going back to 1887 we have gotten 2" or below of snowfall in back to back seasons 5 times. Once we have had 3 years in a row and once we have had 4 years in a row. The 4 years in a row happened 2005-2008. Last year we had 0.9" of snow and I think this year we stay below 2" for the 6th time of back to back winters of under 2" in the past 125 years.

1948-1949 0 1949-1950 0 1950-1951 1.2

2004-2005 0.9 2005-2006 0 2006-2007 1.6 2007-2008 0.5

[dsaur]

For those who may be curious, the record long string of winters going back to 1876-7 for Atlanta of under 2" of S/IP (i.e., under the longterm avg.) is nine, which was set twice:

1. 1942-3 through 1950-1 (highest 1.4" and avg. only 0.3") (four La Ninas out of nine winters)

2. 1969-70 through 1977-8 (highest 1.0" and avg. 0.6") (five La Ninas out of nine winters)

Third longest strong is five in a row, set three different times. Since 1978-9, the longest drought has been only four years followed by two three-year long droughts.

The longest drought of no measurable S/IP since 1890-91 is three years, which was set during the period 1948-9 through 1950-1 (two La Ninas out of three winters).

There have been only four winters without measurable S/IP over the last 30 years. There were six duing the prior 30 years, eleven the preceding 30 years, and six the 30 years before that.

Only one year since 1889-90 had no S/IP at all: 1924-5, which was as you might guess during La Nina.

Yeah, but I've seen a lot of those episodes that "count" as something frozen falling, and you had to squint a lot, or drive around trying to catch a cloud...or if it actuall got to the ground, after Marietta got most of it, it was gone before you could do a movie double take, lol. If I can't sled on it, it hardly counts to me And, anyway, earlier, I thought I read you preparing folks for a maybe not much Dec., then next, things might be better in the Pac. after all...hmmm...might be ice cream Pdo brain freeze, lol.

I can always count on you to tell me it has been far better than I remember, but remember a lot of winters where I got 10 minutes of sleet in Dec. and nada for the rest of the winter. All that is is a blue ba@@ tease! The thing I'm focused on like a laser is that rain out in Goofyland. I'll take a normal cold, heavy on the wet, winter in a heartbeat. T

[nchighcountrywx]

The hilarious part is that the person he agrees with basically said this would be a normal winter for the east with above average snowfall...not sure how that decimates winter forecasts.

If you were referring to the other individual in the other thread, he was pretty clear the primary track would be across the Ohio valley into the NE. Those tracks unfortunately don't bode very well for winter precip in NC except some upslope on the backside.

As usual, it will be a big challenge south of I-40 in Western NC this year to get something of significance.

We all like snow and I hope we all get at least one good event for all areas in the Western and Central part of NC.

In the High County, the ski slopes will take a whipping the next few weeks. Hopefully they can ramp back up around December 21st.

[Snowless in Carrollton]

For those who may be curious, the record long string of winters going back to 1876-7 for Atlanta of under 2" of S/IP (i.e., under the longterm avg.) is nine, which was set twice:

1. 1942-3 through 1950-1 (highest 1.4" and avg. only 0.3") (four La Ninas out of nine winters)

2. 1969-70 through 1977-8 (highest 1.0" and avg. 0.6") (five La Ninas out of nine winters)

Third longest strong is five in a row, set three different times. Since 1978-9, the longest drought has been only four years followed by two three-year long droughts.

The longest drought of no measurable S/IP since 1890-91 is three years, which was set during the period 1948-9 through 1950-1 (two La Ninas out of three winters).

There have been only four winters without measurable S/IP over the last 30 years. There were six duing the prior 30 years, eleven the preceding 30 years, and six the 30 years before that.

Only one year since 1889-90 had no S/IP at all: 1924-5, which was as you might guess during La Nina.

I'm surprised Atlanta didn't get any snow during the Great Appalachian storm on 11-25-1950. I know Atlanta set its all time record Nov low of 3 degrees during that storm.

[GaWx]

I'm surprised Atlanta didn't get any snow during the Great Appalachian storm on 11-25-1950. I know Atlanta set its all time record Nov low of 3 degrees during that storm.

Actually, they did get a trace on both 11/24 and 11/25. That storm's cold was an anomaly of anomalies!!

[burgertime]

If you were referring to the other individual in the other thread, he was pretty clear the primary track would be across the Ohio valley into the NE. Those tracks unfortunately don't bode very well for winter precip in NC except some upslope on the backside.

As usual, it will be a big challenge south of I-40 in Western NC this year to get something of significance.

We all like snow and I hope we all get at least one good event for all areas in the Western and Central part of NC.

In the High County, the ski slopes will take a whipping the next few weeks. Hopefully they can ramp back up around December 21st.

Well number one his analog of 1969 showed that the winter temp was normal/colder than normal with improved snow. He specifically says that that analog is the WORST case....and he specifically even says that before with the --PDO it resulted in non winters for the southeast but not this one. He even circles parts of SC and all of NC for above normal snowfall. So again please explain how this decimates winter forecasts? I'm not saying you're wrong but I just don't see how you took what he said and equated that to it being a terrible winter again this year.

[nchighcountrywx]

Well number one his analog of 1969 showed that the winter temp was normal/colder than normal with improved snow. He specifically says that that analog is the WORST case....and he specifically even says that before with the --PDO it resulted in non winters for the southeast but not this one. He even circles parts of SC and all of NC for above normal snowfall. So again please explain how this decimates winter forecasts? I'm not saying you're wrong but I just don't see how you took what he said and equated that to it being a terrible winter again this year.

Certainly not a cold lock in the East this winter, but expect much variability with primary storm track north of us in Ohio valley dragging down bouts of cold air on the backside. Not the best of NC winters but certainly not the train wreck of last year.

His thoughts did seem to generally agree with the CPC outlook.

[Cold Rain]

Certainly not a cold lock in the East this winter, but expect much variability with primary storm track north of us in Ohio valley dragging down bouts of cold air on the backside. Not the best of NC winters but certainly not the train wreck of last year.

His thoughts did seem to generally agree with the CPC outlook.

Are you basing all of your expectations off of this one winter forecast? If so, it's certainly your right to do that. But I think you should at least consider that for this area, you don't need a primary snowstorm track all winter to get snow, unless you expectation is for record, Arctic tundra conditions in the SE. You can have a primary storm track up or west of the Apps and get one or two favorable tracks and still wind up with well above normal snow.

I don't think it's reasonable to expect solid cold all winter down here. Variability is much, much more likely and much, much more usual. So if anyone is discouraged by that fact, they're probably living in the wrong place.

On another note, the overnight model runs must not have been good since nobody posted about them. I won't be able to look until I get to work.

[calculus1]

From what I've heard,the model runs last night were horrific! Not much cold showing up

06Z GFS didn't look horrible to me. No massive shots of cold air to the SE, but there were lots of systems taking the southern route from day 7 onward. In fact, there was quite a bit of welcome precipitation shown during that time period and some cold air was close. All it take is one lucky break and wintery precip might be present. If nothing else, the SE did look incredibly wet which would be a welcome change from the recent dryness.

[burgertime]

06Z GFS didn't look horrible to me. No massive shots of cold air to the SE, but there were lots of systems taking the southern route from day 7 onward. In fact, there was quite a bit of welcome precipitation shown during that time period and some cold air was close. All it take is one lucky break and wintery precip might be present. If nothing else, the SE did look incredibly wet which would be a welcome change from the recent dryness.

Yep I was about to say the same thing. It is the 6z of course, but it basically had the train of wet weather come towards us after 200 hours....just one system after the other hitting drought effected areas.....now if the Euro weeklies are right and we are in that sort of patter we could really be in business. Just have a storm coming on the heels of the cold air getting here.

[franklin NCwx]

The cold comes first to the plains and the pattern is a step down process. There is no snow pack in the plains and that has to happen first. I know most folks hate cutter but they are badly needed now. The Ensembles continue to dump the cold into the northern plain states with a more active southern jet.

[griteater]

There is no snow pack in the plains

Yep, the U.S. is behind on the snowpack with the trough that has been parked off the west coast, and resulting mild Pacific Flow.

[MillerA]

Allan Huffman latest tweet about December outlook.

http://www.examiner.com/article/warm-december-looking-likely

[eyewall]

Allan Huffman latest tweet about December outlook.

http://www.examiner....-looking-likely

He stops just short of saying the failboat has arrived.

[griteater]

He stops just short of saying the failboat has arrived.

Indeed. It's funny though because a couple weeks back he was mentioning Dec 1989/2010.

[Cold Rain]

We've been in the -PDO phase. That's not a surprise. The prospects of an El Nino have been waning for weeks. That's not a surprise. The models have been oscillating between warm and cold in the LR, like the always do. That's not a surprise. But now it's going to be a warm winter and failboat and such. Ok.

[Mr Bob]

I haven't read anything that said this pattern will be changing. I've heard about alot of "mays" and "coulds" but nothing substantial. I'm not giving up completely, but let's just say I've started to prepare myself for another warm winter.

Excellent analysis....

Pattern is going to change....weather to become more seasonal. Supported by all NWP...No one has cliff dove on this. It is strictly a function of math...it is so warm right now and for the next week that there is no way the back half of the month can be cold enough given the look of the upcoming pattern to change that. So those that had a cold December are likely to have missed by a little bit.

[BullCityWx]

There is simply going to be no way to get us even close to normal here. If you go strictly by MOS, Columbia will be at average monthly temp of 60º by December 11th.

[Carvers Gap]

Our biggest plus right now is that Canada is cold. As many have stated December will be on the plus side for temps. The mechanism for sustained cold is not present yet. Until the pattern over Alaska changes, it will be unseasonably warm in the East. I do think the pattern will break when another blocking episode begins. The only haunting thing at this point is the blizzard in October. I am wary of big early snowstorms being the harbinger of warm winters.

[dsaur]

While I hate to dump on the pity party, I have to say to Cptn. Desiccated here, the long range the last few days has been a thing of fantasy beauty. If the gulf opens up like that, the cold will follow. Just let the middle of Dec. be for the rains, and I'll go out on a limb and say Christmas day in the 40's or 50's, then New Years Eve night down into the teens, or lower. Get me some slow gulf lows and I can at least guarantee you some 33 and rain scenarios during the winter:) Close enough for a winter disco, right? I'm looking at the long range as half full....of water!! You want a big time pattern change..then get some big time rains, and the rest will take care of itself. T

[SnowNiner]

Excellent analysis....

Why thank you!! It was not meant to be an analysis but simply a summation. And when I mean a pattern change, I mean to wintry cold in the east, not just a moderation to non-70 degree weather. Of course that's going to happen.

[BullCityWx]

If you go strictly by MOS temps, Charlotte's monthly average temperature will be at 56.54 by December 11th. That's nearly 2 full degrees warmer than the warmest previous December.

[BullCityWx]

Good god the doom and gloom. A few bad model runs and winter is over. Funny its only DECEMBER 4th. Some people need to relax. This is the south , if you want sustained cold with snow MOVE OUT OF THe SOUTh

That has no place in the forecast discussion thread. Please keep stuff like this to the banter thread.

[Bevo]

Our biggest plus right now is that Canada is cold. As many have stated December will be on the plus side for temps. The mechanism for sustained cold is not present yet. Until the pattern over Alaska changes, it will be unseasonably warm in the East. I do think the pattern will break when another blocking episode begins. The only haunting thing at this point is the blizzard in October. I am wary of big early snowstorms being the harbinger of warm winters.

I'll give you this - last fall was the first thing I thought of when the Sandy/Nor'easter burst in ringing a big bell. My jury is still out on this aspect for the coming winter though...

[burgertime]

One good thing to take note of on the 12z GFS is that it continues to seem to want to bring wet weather after day 7.