November Mid-Long Range Discussion

[usedtobe]

I see what you did there.

Sneaky meteorologist.

lol, you caught me. My article wasn't anti-snow so you should be semi happy. I sure hope we have some nice storms to track, after all, you need to re-earn you moniker. Last winter, you and I both failed.

[Yeoman]

lol, you caught me. My article wasn't anti-snow so you should be semi happy. I sure hope we have some nice storms to track, after all, you need to re-earn you moniker. Last winter, you and I both failed.

Excellent article, Wes.. thanks

[marked8]

I hope this is accurate:

http://www.accuweather.com/en/weather-blogs/anderson/signs-of-a-cold-start-to-december-in-the-east/1619732

[Bob Chill]

I hope this is accurate:

http://www.accuweather.com/en/weather-blogs/anderson/signs-of-a-cold-start-to-december-in-the-east/1619732

If it is it was by accident.

[Kevin Druff]

If it is it was by accident.

No, I think Brett Anderson does a pretty good job at "just the facts", especially when he's giving his read of the Euro weeklies, which he does on a regular basis.

[Bob Chill]

Latest GFS is continuing to make things interesting. The goa low weakens and moves north allowing heights to build in the sw. Flow starts to buckle and the vortex in canada moves to near hudson bay. The NAO is also on the way down but it doesn't look like ridging near gl is ideal. A bit east but who cares because it's a bit out there in d8+ range but still, this is pretty good to see.

ANYTHING but raging pac zonal with no prospects beats last year.

[mattie g]

Euro (mid 60s) and GFS (60) still on the warm train for Next wed-Fri/saturday

And warm down south.

Nice.

[Bob Chill]

Not much of a storm signal on the GFS in the LR (didn't expect one) but it's quite chilly. Highs in the 30's for days. Local ski areas would be able to start pasting the slopes. Midlo might get his first significant snow of the season in his front yard too.

[WxUSAF]

12z GFS takes away zwyts' Turkey Day shirtless football weather. Cold advecting with seasonable highs at best. Gets really close to unleashing the arctic hounds on us in the Day 11-15 range, but doesn't quite get there even though it looks quite cold.

[WxUSAF]

Pretty solid Day 11-15 GFS ensemble mean chart. That's a bit more of a N.Atlantic ridge than a true -NAO block, but the NAO will technically be negative in that pattern. Get the trough off the West Coast to weaken or retrograde out into the Pacific and that would be a good looking pattern for us.

[H2O]

12z GFS takes away zwyts' Turkey Day shirtless football weather. Cold advecting with seasonable highs at best. Gets really close to unleashing the arctic hounds on us in the Day 11-15 range, but doesn't quite get there even though it looks quite cold.

Good news.

[Ian]

I see Jay Hatem weather calling for a Dec 5 snowstorm.

I predict cold and dry.

[WxUSAF]

MOS is 59/60 for THU/FRI

Raleigh's 2m temp maps look colder. Just by interpolating distances between the 50F and 60F isotherms on the 18z maps and looking at the pattern (downsloping, but cold advecting winds on Thursday), I'd say low 50s for the burbs and maybe mid 50s for the downtown areas of DC/Balt on Thursday and 3-5F colder on Friday.

I'd love temps near 50 for those days. Warm enough to get the kiddies running around outside, but chilly enough to feel like late November.

[Yeoman]

I've upped my El Nino chances to 23.9%

[WxUSAF]

you mean 12Z?..

Sorry, that was confusing. 12z run, but 18z maps for those days (i.e., 11222012 1800z).

I want it to torch like 2003...wasting a cold pattern in late November sucks

I see that point. At this point, I'd say we have a 60/40 shot or better at finishing BN for this month and December certainly looks like it could start quite cold if we buy the pattern seen in the GFS and Euro weeklies. Hard to keep a cold/snowy pattern going for weeks or months on end. But, I don't think the pattern the next 2 weeks is really a cold one, just a seasonable one until at least the 27th-28th. The real cold pattern looks like it starts setting up around the beginning of the month. Hopefully we can get a stable cold pattern for much of December, a January thaw/reload early in the year, and then finish the winter out strong.

[Bob Chill]

I see that point. At this point, I'd say we have a 60/40 shot or better at finishing BN for this month and December certainly looks like it could start quite cold if we buy the pattern seen in the GFS and Euro weeklies. Hard to keep a cold/snowy pattern going for weeks or months on end. But, I don't think the pattern the next 2 weeks is really a cold one, just a seasonable one until at least the 27th-28th. The real cold pattern looks like it starts setting up around the beginning of the month. Hopefully we can get a stable cold pattern for much of December, a January thaw/reload early in the year, and then finish the winter out strong.

I like the way you think. And to be honest, my only hope/wish is that we don't get stuck in a tough to break crappy pattern. Normal swings are fine. Winter in these parts isn't supposed to be cold start to finish. Just please don't let the AO go through the roof, the SE ridge build, or let that weenie hope killing vortex set up shop near AK. That's all. Just don't let a 4+ week pattern set up and steal 1/3 of our winter with zero prospects. That's not too much to ask is it?

Can someone post or pm me a list of 6"+ storms in DCA since 1960 or so? Will posted a sweet h5 anom map for all the big storms in NE and KU's. It was really cool to see. I want to do the same for DC but I want to do it for the day of, 3 days prior, and 1 week prior to the storms. I'll post the maps after I'm done. Should be a decent tool to use when things get interesting.

[MillzPirate]

El Nino is smoking right now

[Bob Chill]

we are OK for now....There will likely be a Bering Sea ridge/block...That isn't great for us, but way better than a vortex..I think that is a fairly stable/repetitive feature, but I could be wrong

Can't help but to get paranoid right? I've never really paid that much attention to a feature like that until last year. I had no idea it could be so damaging to us downstream.

And I agree, the ridging in some form or another is probably stable enough to not worry about everything going to he!! again. I don't know the odds or anything but I would have to guess that it would be very unusual to have that same feature 2 years in a row. We'll find a new and different way to get screwed instead.

[ORH_wxman]

well...we don't look like this...I think the die was cast by this time in the years with bad decembers (2001,2006,2011)..I think if Wes and Orh were around today 11 years ago, they would cancel December....yet a lot of people went cold that winter....

The AK/Bering ridge is quite stable on the Euro weeklies for several runs now including last night's runs FWIW. Euro SIPS seasonal model also liked the idea. The stratosphere isn't the greatest but its not like last year either. The siberian snow cover probably is helping out.

Last year there were some hideous signs around this time...the hope was that we were going to break out of it by New Years and into January, but we never did. The Euro weeklies last year (and then the ensembles followed shortly after in late November) showed a Dec 2001 pattern. That AK vortex basically didn't move for 17 months....it weakened a bit in fall of 2011, but when it restrengthened late, it was goodnight. I think in retrospect, hoping for a January turn-around was not very feesible. We did get some good blocking late that month into Feb but it was wrong for us. Hindsight is always 20/20 of course.

The huge wildcard is going to be the NAO going into December...there are a lot of mixed signals on that. The Bering ridge I think is extremely likely to be there in the means.

[Bob Chill]

Always appreciate the pop in Will. Please visit often (except when you think we're screwed. lol).

Wes and I went back and forth with AO data last year. When it comes to temps and snow (at least down here) the AO seems to be king and the nao is queen. I wouldn't mind your opinion of how you think the AO shapes up in Dec. It's a strong signal when it's anomalous. Much moreso than the NAO.

Big +AO's in Dec seem to almost always trail into Jan and even Feb. Same goes for big -AO's. I only know the basics but it seems like it can become quite stable when it's anomalous. The NAO seems to bounce around quite a bit more. I'm hoping at the very least that the AO stays close to neutral in Dec. Any signs of it tanking is really good news for us down here in the MA.

[midatlanticweather]

So Early consensus -

NAO looks negative in early December but Not ideal.

AO also going negative

PNA? - not convinced one way or the other

MJO - Not looking the best for EC storms?

[ORH_wxman]

Always appreciate the pop in Will. Please visit often (except when you think we're screwed. lol).

Wes and I went back and forth with AO data last year. When it comes to temps and snow (at least down here) the AO seems to be king and the nao is queen. I wouldn't mind your opinion of how you think the AO shapes up in Dec. It's a strong signal when it's anomalous. Much moreso than the NAO.

Big +AO's in Dec seem to almost always trail into Jan and even Feb. Same goes for big -AO's. I only know the basics but it seems like it can become quite stable when it's anomalous. The NAO seems to bounce around quite a bit more. I'm hoping at the very least that the AO stays close to neutral in Dec. Any signs of it tanking is really good news for us down here in the MA.

The AO has a better correlation than the NAO in DCA by a bit...mostly because the AO includes a lot of the NAO domain but also other important areas such as the EPO region. So when the AO is strongly negative, you are likely to have both the EPO and NAO negative which is a huge cold signal versus just the -NAO where a positive EPO would essentially offset it. The NAO is probably a bit more important for a specific synoptic snow setup versus a generalized AO...but when talking about the overall winter temps, the AO will usually do a little bit better.

[Bob Chill]

The AO has a better correlation than the NAO in DCA by a bit...mostly because the AO includes a lot of the NAO domain but also other important areas such as the EPO region. So when the AO is strongly negative, you are likely to have both the EPO and NAO negative which is a huge cold signal versus just the -NAO where a positive EPO would essentially offset it. The NAO is probably a bit more important for a specific synoptic snow setup versus a generalized AO...but when talking about the overall winter temps, the AO will usually do a little bit better.

Makes complete sense. Bottom line is that we need help with temps down here much more than you guys. Majority of marginal temp setups don't usually go our way so the AO is something I started paying a lot more attention to. Neg nao's can do ok pushing canadian air down here but that's not always enough. Especially when areas like Quebec are running above normal.

I'm just praying that we don't get an AO on steroids again this Dec. That can be a kiss of death in itself. If you see anything interesting with the AO please share your thoughts. We're a paranoid bunch down here (and rightfully so).

[usedtobe]

The AO has a better correlation than the NAO in DCA by a bit...mostly because the AO includes a lot of the NAO domain but also other important areas such as the EPO region. So when the AO is strongly negative, you are likely to have both the EPO and NAO negative which is a huge cold signal versus just the -NAO where a positive EPO would essentially offset it. The NAO is probably a bit more important for a specific synoptic snow setup versus a generalized AO...but when talking about the overall winter temps, the AO will usually do a little bit better.

Even for 4 inch or greater snowstorms, the ao correlates a little better for dc. I think becuase the nao allows the blocking to be pretty far east since the index uses iceland in the calculation and we really want the blocking over greenland and canada with below normal heights to the south of the block.

[usedtobe]

It is torching, but Wes thinks it is temporary

But I may be totally wrong. Forecasting ENSO is not my strength. It looked like the warming was due to the Kelvin Wave but it has been impressive. Looks like I may be able to use on of my tables that I prepared earlier this summer in an article later next week or more likely the week after turkey day.

[MillzPirate]

But I may be totally wrong. Forecasting ENSO is not my strength. It looked like the warming was due to the Kelvin Wave but it has been impressive. Looks like I may be able to use on of my tables that I prepared earlier this summer in an article later next week or more likely the week after turkey day.

How much does your winter forecast change/or at all if the warming continues and we're able to get solidly into weak Nino territory?

[WinterWxLuvr]

I went back to 1948...all events over 5.5"

1/23-24/48 - 6.0"

1/31/49 - 5.7"

11/6-7/53 - 6.6"

1/22/54 - 6.4"

12/3-4/57 - 11.4"

2/15-16/58 - 14.4"

2/13-14/60 - 6.2"

3/2-3/60 - 7.9"

3/9-10/60 - 5.8"

12/11-12/60 - 8.5"

1/19-20/61 - 7.8"

1/26/61 - 5.9"

2/3-4/61 - 8.3"

2/8/61 - 8.4"

12/23/63 - 5.6"

1/12-13/64 - 8.5"

2/10-11/64 - 8.2"

3/30-4/1/64 - 6.2"

1/26-27/66 - 7.5"

1/29-30/66 - 13.8"

12/13/66 - 6.7"

12/23-24/66 - 7.0"

2/6-7/67 - 10.3"

2/17-18/67 - 6.7"

11/30/67 - 6.9"

12/31/70 - 1/1/71 - 9.3"

2/19/72 - 5.5"

12/16-17/73 - 10.2"

2/7/79 - 5.6"

2/12/79 - 5.6"

2/18-19/79 - 18.7"

1/4-5/80 - 6.9"

1/13-14/82 - 7.1"

12/12/82 - 6.6"

2/10-11/83 - 16.6"

1/22/87 - 10.8"

1/25-26/87 - 9.2"

2/22-23/87 - 10.3"

11/11/87 - 11.5"

1/7-8/88 - 8.0"

3/12-13/93 - 6.6"

1/6-8/96 - 17.1"

2/2-3/96 - 8.4"

2/16/96 - 6.8"

3/9/99 - 8.4"

1/25/00 - 9.3"

12/5/02 - 6.1"

2/6-7/03 - 6.6"

2/15-18/03 - 16.7"

1/25-27/04 - 5.7"

2/11-12/06 - 8.8"

3/1-2/09 - 5.5"

12/18-19/09 - 16.4"

1/30/10 - 6.4"

2/5-6/10 - 17.8"

2/9-10/10 - 10.8"

What was the total in the Jan 2011 storm? I thought it was a good one down there??

[Fozz]

What was the total in the Jan 2011 storm? I thought it was a good one down there??

5" at DCA. It was much better in the colder burbs (8-12"+).

[Bob Chill]

I went back to 1948...all events over 5.5"

Oh man, thank you! I'm going to have some fun this weekend for sure. Look for a long post full of diced and sliced data coming up. I'll probably toss in daily pna/nao/ao stuff as well. I have the daily data downloaded in excel so it will be easy to put together.

I'm interested in the week prior data. Hopefully I find a decent signal a week out. I want to get better at not buying big (but flawed) solutions with the models when the threat is 7+ days. Wes is really good at keeping us under control when obvious pieces are missing even though were getting pasted with virtual snow.

Works both ways too. Sometimes the models tease us with whiffs before locking in to something decent @ day 4 on in. It would be nice to have some data on hand when the upper air and indices are pointing at more potential than what is being shown.

[ORH_wxman]

Oh man, thank you! I'm going to have some fun this weekend for sure. Look for a long post full of diced and sliced data coming up. I'll probably toss in daily pna/nao/ao stuff as well. I have the daily data downloaded in excel so it will be easy to put together.

I'm interested in the week prior data. Hopefully I find a decent signal a week out. I want to get better at not buying big (but flawed) solutions with the models when the threat is 7+ days. Wes is really good at keeping us under control when obvious pieces are missing even though were getting pasted with virtual snow.

Works both ways too. Sometimes the models tease us with whiffs before locking in to something decent @ day 4 on in. It would be nice to have some data on hand when the upper air and indices are pointing at more potential than what is being shown.

I imagine 1 week out will not provide a ton of answers...you can probably create a composite for what it looked like 1 week out, but it might not be predictive since probably countless other times had similar setups 1 week out but the key synoptic players didn't solidify until a couple days before. Sometimes 1 week out you can see the writing on the wall with very stable features...ala Feb 5-6, 2010. That was about as much a slam dunk as you can have in the world of forecasting 6-7 days out for DC snow...the question was merely how much snow would there be. Those are usually the exception rather than the rule.