November Mid-Long Range Discussion

[Ian]

Who knows. I never make guesses about temps for a individual day so far out there in time. Does look like a warmer than normal period, also drier than normal.

I haven't looked much myself and it probably doesn't matter but we're into a decent dry streak now.. any reason to think that rolls through winter?

[usedtobe]

good...Dec 1-15 is a bad time to waste a cold pattern

I'm not certain how long the above normal will last in the 2nd week. The CFS2 likes it but we do have a neg Ao which may exert some influence especially as we roll forward. Don Sutherland has nice seasonal snowfall stats for snowfall when the AO tanks like it is forecast to do. we average over 20 with a median of 17. Both about 5" more than a typical year.

[usedtobe]

I haven't looked much myself and it probably doesn't matter but we're into a decent dry streak now.. any reason to think that rolls through winter?

I don't think it will with the ao tanking that eventually should get the jet farther south giving us a few events where we tap the gulf. Of course that may have to wait until the pacific gets a little less hostile.

[Bob Chill]

12z Euro has a megatorch next Sunday-Wednesday.....highs in the 60s....near 70 at least 1 day

I haven't looked at the panels but it doesn't surprise me. The GFS totally had the look of pumping up a ridge (and possibly a big one) in the east half of the country next week before pushing a pretty big ec trough down. I think we all know how this would work out if that kind of ridge builds. Expect it to take longer than modeled to break down. And that's fine too. Just don't do it again during the second half of the month.

[WxUSAF]

Both GFS and Euro ensembles have a pattern that looks to be developing well for us in the long range, similar to what we're looking for/expecting. Bering straight ridge retrogrades just a bit toward Siberia, which allows a trough north of HI and then pumps the PNA ridge up along the west coast. AO looks quite negative and the NAO is also negative.

[nj2va]

WxUSAF, do you have those kind of maps for the setup for Snowmageddon or the Dec. '09 storm, or know where I can find them? I've got the model runs archived but I'm curious if there is a way to find those maps for those events to compare. Thanks.

[Bob Chill]

WxUSAF, do you have those kind of maps for the setup for Snowmageddon or the Dec. '09 storm, or know where I can find them? I've got the model runs archived but I'm curious if there is a way to find those maps for those events to compare. Thanks.

I use this site all the time. It's shows actual conditions and not progs though. Is that what you are looking for or are you looking for the various solutions leading up to the events? I don't think there is a site for pulling old runs.

http://www.esrl.noaa.gov/psd/data/composites/day/

[nj2va]

I use this site all the time. It's shows actual conditions and not progs though. Is that what you are looking for or are you looking for the various solutions leading up to the events? I don't think there is a site for pulling old runs.

http://www.esrl.noaa...composites/day/

Yeah, this is awesome! Thanks, exactly what I was looking for.

[Bob Chill]

Yeah, this is awesome! Thanks, exactly what I was looking for.

Excellent. I love that site. I've wasted plenty of hours pulling maps. Data is available for as recent as a couple of days ago can be accessed. Another great feature.

[mitchnick]

I use this site all the time. It's shows actual conditions and not progs though. Is that what you are looking for or are you looking for the various solutions leading up to the events? I don't think there is a site for pulling old runs.

http://www.esrl.noaa...composites/day/

yes there is Bob, but it only goes back to April, 2011

NAM

http://charlie.wxcas...odelArchive.cgi

GFS

http://charlie.wxcas...odelArchive.cgi

[usedtobe]

WxUSAF, do you have those kind of maps for the setup for Snowmageddon or the Dec. '09 storm, or know where I can find them? I've got the model runs archived but I'm curious if there is a way to find those maps for those events to compare. Thanks.

The pattern is still quite a bit different in where the anomlaies are located. Here's teh anomlaies for Dec 19th using a 72 hr GFS ens mean (left) and a composite of a number of 8 inch or greater events at dca. Note that the progs for the upcoming pattern do not have the negative quite in the right place with respect to the Greenland positive anomaly and also do not have teh nice southern stream shortwave vicinity of the tn or MS valley region.

[Bob Chill]

yes there is Bob, but it only goes back to April, 2011

NAM

http://charlie.wxcas...odelArchive.cgi

GFS

http://charlie.wxcas...odelArchive.cgi

Great, just what I need. Another pile of data to screw around with and waste more of my remaining precious hours on this planet. lol

Thanks Mitch!

[Amped]

Might as well have our warm pattern now. The MA rarely capitalizes on cold Decembers anyway. A warm December usually leads to cold January.

[Ian]

Might as well have our warm pattern now. The MA rarely capitalizes on cold Decembers anyway. A warm December usually leads to cold January.

Cold January seems to be dry of late. Feb will be rockin!

[WxUSAF]

Well, the good news is the 12z GFS ensemble mean AO doesn't even sniff positive for the next 15 days. Stays well negative. Bad news is, so does the PNA, although maybe it's getting near neutral by the end of the run. With the mean trough axis through the eastern Rockies in the 2nd week of December, that would suggest brief warm ups ahead of cutters, and then transient cold shots.

[usedtobe]

The Euro is awful...worst run in a while...the entire conus is flooded with warmth

It's timing fits better with the CFS2 models timing for any pattern change. At least it would start building highs in western Canada and Ak which could eventually get into the western u.s. and plains if you extrap it out which is usually a mistake. Wish I had seen it before sending Jason my post for today.

[H2O]

The Euro is awful...worst run in a while...the entire conus is flooded with warmth

like you said yesterday, it is better it torches in early Dec than going into the better part of our winter.

[WinterWxLuvr]

The Euro is awful...worst run in a while...the entire conus is flooded with warmth

It also had us cooking under a ridge today with 850's of about 8-10C today in its 10 day forecast 10 days ago.

But, I know what you're saying. 10 day forecasts of heat usually pan out, 10 day forecasts of cold usually don't.

[usedtobe]

looks like the GFS ens do this, but we aren't necessarily cold here even by mid dec....I don't want to jump the gun but I think I will be wrong about rushing any pattern change by 12/10 and we can punt the 1st half of December

I agree, that's still not a good pattern for us but would be for the plains. I think the cfs2 may be onto something, it pretty much kept the conus flooding with warmth through week 2 (at least yesterday's version did).

[Bob Chill]

I agree, that's still not a good pattern for us but would be for the plains. I think the cfs2 may be onto something, it pretty much kept the conus flooding with warmth through week 2 (at least yesterday's version did).

I'm not thrilled with the euro in days 7-10 at all. I know it's just a model run but I really don't like seeing the vortex spinning around the aluetians. It really pumps up the heights in the npac/goa area. Those are the kinds of things that can cost us a couple weeks. Absolutely not saying it will this time. I just don't like it. I know that a -nao can totally change the the way a pattern like that in the pac affects us here on the EC. But a big +nao with a config like that will have us in shorts and tees.

If it were to happen like the euro is thinking I just hope it's very temporary. And it probably is but still.

[Ian]

It also had us cooking under a ridge today with 850's of about 8-10C today in its 10 day forecast 10 days ago.

But, I know what you're saying. 10 day forecasts of heat usually pan out, 10 day forecasts of cold usually don't.

it was pretty close

https://twitter.com/FakeGFS/status/269913263733624832/photo/1

[mitchnick]

idk, starting with October 29, BWI has only had 7 days with an AN daily temp (2 of which were only +1), one normal day and the rest have been below normal

that is a pretty darn impressive stretch of BN temps

I say d@mn the computers, it may not stay BN (or snow for that matter) but I don't believe we torch for more than a day or 2 (OK, maybe 3) during any stretch regardless of what the models may suggest

EDIT: I know some may misinterpret what I'm trying to say if we get a strong of AN days so my point is really intended to be more a general statement that I don't believe we will get way above normal and will probably stay cooler than what the MR progs suggest now, that's all

[mdsnowlover]

Just saw the cfvs2 projected cold around xmas time , and projected snow cover in mid atlantic on twitter. Rather amazing if it comes true. Our area was in 14-18 in snow cover. Hard to believe. That snow cover was from Md south. Guess its predicting a major snow storm in th xmas time frame. New England doesnt get the heaviest snow.

[usedtobe]

Just saw the cfvs2 projected cold around xmas time , and projected snow cover in mid atlantic on twitter. Rather amazing if it comes true. Our area was in 14-18 in snow cover. Hard to believe. That snow cover was from Md south. Guess its predicting a major snow storm in th xmas time frame. New England doesnt get the heaviest snow.

The latest run actually now shows it being warmer than normal through the period, a flip from yesterday so I wouldn't give the cold and snow too much credence. Last night's euro makes the 1st two weeks of Dec looks warmer than normal.

[easternsnowman]

With the temperatures being above normal for the last couple of years it will be very difficult to have 2 months in a row below normal. With the exception of deccember 2009 and dec 2010 the month has trended above normal the last 10 years or so.

[psuhoffman]

For me the two most significant factors that seem to correlate to a favorable pattern for snowfall in our area seem to be the PNA and the AO/NAO combo. The problem for our area, is it really does take a fairly favorable combo of the two to get a good pattern. If one of them is in a horrible phase we really are screwed. I doubt we get much help from the PNA this winter but at times perhaps it becomes less awful then it is now, and during those periods a favorable NAO/AO could take over the pattern. The other possibility is the pattern never times up well...and when we have a favorable NAO the PNA is not cooperative, and vise versa. Either way, I see no sign yet of the Pacific and Atlantic cooperating in a way that helps our area in the range that the guidance can be trusted. There are signs in the day 10+ range that things could be starting to move towards a more favorable pattern but again... it seems these changes are still stuck in the "fiction" range and until I see favorable changes making their way inside the day 10 period on guidance I am in a "believe it when I see it attitude".

[Bob Chill]

It's interesting that even when the models retrograde the vortex in the goa and replace it with ridging they still show a tendency for pushing higher height into GL. This is important for obvious reasons because it can fight a crap pac and even a -pna. When I say fight I don't mean snow I just mean that we won't melt and get stuck in the worst case scenario.

It sure is looking that this winter is going to be a battle of these 2 general looks.

First 7 days in Nov:

240 hr gfs from last night (just using for reference. Euro and other lr models like the similar idea with different placement of the features):

Just like many have pointed out. The first half of winter may feature 2 week stretches of potential followed by something similar to what the GFS and Euro are showing. The good thing is doesn't look like we get screwed with a long term crap pattern and the tendency for a -nao/ao so far is pretty obvious and probably not going to flip like a switch (famous last words. lol).

[WinterWxLuvr]

It's interesting that even when the models retrograde the vortex in the goa and replace it with ridging they still show a tendency for pushing higher height into GL. This is important for obvious reasons because it can fight a crap pac and even a -pna. When I say fight I don't mean snow I just mean that we won't melt and get stuck in the worst case scenario.

It sure is looking that this winter is going to be a battle of these 2 general looks.

First 7 days in Nov:

240 hr gfs from last night (just using for reference. Euro and other lr models like the similar idea with different placement of the features):

Just like many have pointed out. The first half of winter may feature 2 week stretches of potential followed by something similar to what the GFS and Euro are showing. The good thing is doesn't look like we get screwed with a long term crap pattern and the tendency for a -nao/ao so far is pretty obvious and probably not going to flip like a switch (famous last words. lol).

Bob, I didn't feel that the Euro ens at 10 days was that bad of a pattern (as bad as that GFS map you posted), and the 6z GFS ens looks nothing like the pic you posted. There just doesn't seem to be a lot of consistency wrt these 10 day progs.

I think we rely on tried and true, so, with the AO and NAO progs looking OK for us, I think what really happens is that the pattern, and the weather, slowly start to turn in our favor.

That's my story, and I'm sticking to it.

[usedtobe]

If you roll over/extrapolate the pattern the 2nd half of DEC looks decent....We are seeing more and more that the plains are going to get cold in 10 days or so...of course as Wes pointed out, rolling over the pattern is kind of a futile exercise

But fun to do and probably no worse than any other method at that time range. The CFS2 went from cold on week 4 to warm from one day to the next so the models aren't very good either. I'm on he warm 1st half of Dec bandwagon despite my wishy washy week 2 forecast in yesterday's piece.

[Bob Chill]

And of course the GFS looking much better in the lr. Not great but a pretty big improvement. Especially in the west. Not very conducive but definitely not warm.

Edit: Want add that gfs still pointing towards some pretty cold stuff in the n plains during the first half of dec. 850's flirting with -20 at near the border. The overall pattern on the gfs is totally fine too. The ridge off the ca coast isn't nearly as sharp allowing for the pattern to stay fluid and the cold air intrusion easily moves east over time. No idea if it's right but it's reasonable at the very least.