December Forecast Discussion

[burgertime]

A wide array of scenarios between the ensemble members. Not much agreement yet. This is still 8+ days away people.

Of course, of course. Just funny looking at that map. Usually you don't see that big of a spread having such an impact....I mean it literally heads south jumps due north than practically goes due east.

[franklin NCwx]

Of course, of course. Just funny looking at that map. Usually you don't see that big of a spread having such an impact....I mean it literally heads south jumps due north than practically goes due east.

FWIW here is the CMC. It's out to 180 hours so this is all a huge grain of salt.

[Cold Rain]

The system is going to have a tendency to go north at some point. Where it starts to do that and how far north it gets before reforming is going to be directly related to the strength and positioning of the block/50-50.

My feeling is that the 50/50 pulls out soon enough to allow the system to cut and then reform over the coastal plain of Va or north. I have yet to see a graphical depiction of a major winter storm setup for a large portion of the SE.

Several have suggested that the models are struggling and will eventually come around to such a setup, but I think the more likely scenario is what I described above. In fact, there may actually be more of a severe threat for portions of the SE than a winter storm threat.

[SnowNiner]

The system is going to have a tendency to go north at some point. Where it starts to do that and how far north it gets before reforming is going to be directly related to the strength and positioning of the block/50-50.

My feeling is that the 50/50 pulls out soon enough to allow the system to cut and then reform over the coastal plain of Va or north. I have yet to see a graphical depiction of a major winter storm setup for a large portion of the SE.

Several have suggested that the models are struggling and will eventually come around to such a setup, but I think the more likely scenario is what I described above. In fact, there may actually be more of a severe threat for portions of the SE than a winter storm threat.

That was has me confused as well. There's lots of optimism about what the models "should" be showing due to the pattern but I haven't seen any actual winter storms on any of the models. Just a big low going to the Northwest of us which never does anything but give us a glorified cold front. I'm listening though...

[Wow]

Euro taking a more ho-hum approach to this system.. less blocking, less digging. It's a Plains storm.

[mackerel_sky]

It may not be a widespread snow storm for the SE,but could still be icy for CAD regions depending on placement of the high,regardless of the low track

[burgertime]

Euro appears quicker with the energy and further north than last nights run. Has light qpf in NC on Christmas.

[Poimen]

Day 7 EURO is not a wintry scene for these parts

[Wow]

Euro appears quicker with the energy and further north than last nights run. Has light qpf in NC on Christmas.

It's in Illinois on Christmas Day. The ULL barely makes it into MO. Not a good scenario.

[burgertime]

No real CAD to speak of showing up on this run either.

[burgertime]

NEXT please...as others have noted not a good run for winter weather lovers in the southeast...heck even for those in the MA and NE...some major cold is coming in behind though so this run might have some fun and games at the end.

[packbacker]

It's in Illinois on Christmas Day. The ULL barely makes it into MO. Not a good scenario.

Nice and warm on Xmas day....Looks like Dec will be full blown torch. Right now RDU is at +11F for the month. I believe 90/91, 91/92 had record warmth for December and we know how those two years turned out. Hopefully the LR forecasts will verify for Jan.

[tnweathernut]

I mentioned it earlier today and I think it could very well hold true that this storm just after Christmas could set the table for us heading into the period around New Years. It wouldn't surprise me in the least to see an actual threat as there appears to be a fairly potent trailing shortwave.

[burgertime]

850 line almost down into Orlando on this run of the Euro @222.....storm or not it's looking more likely major cold is coming to the SE after Christmas.

[burgertime]

Major cold coming into the heart land with sfc temps in the negatives for MN and IA NC looks to have a low for most around 20.

[GaWx]

850 line almost down into Orlando on this run of the Euro @222.....storm or not it's looking more likely major cold is coming to the SE after Christmas.

Taking with a huge grain, but, if the 12Z Euro were to somehow verify, wow, this would be some pretty serious cold for 12/27-8! (Cold would be coming in on 12/26.) -13C at 850 at KATL as of 6Z Fri 12/28 fwiw! Teen low(s) and near or below freeezing high(s) would almost be guaranteed if the 850's were to get that cold. But we're talking IF on a late 6-10 day map. So, we can only hope this is going to verify!!

Edit: Brick had better not look as he hates dry cold. So, nobody tell him.

[calculus1]

Nice and warm on Xmas day....Looks like Dec will be full blown torch. Right now RDU is at +11F for the month. I believe 90/91, 91/92 had record warmth for December and we know how those two years turned out. Hopefully the LR forecasts will verify for Jan.

Can you provide a link to get this data? I'm interested in similar data for other cities. Where do you go to find this number?

[calculus1]

Can you provide a link to get this data? I'm interested in similar data for other cities. Where do you go to find this number?

Never mind. I found this link to access requested data:

http://www.nws.noaa.gov/climate/xmacis.php?wfo=gsp

[packbacker]

Can you provide a link to get this data? I'm interested in similar data for other cities. Where do you go to find this number?

I use accuweather, but I bet other people have a lot better resources, which hopefully they share. I am really curious on how the other top 10 warmest Decembers worked out for the rest of the winter (Jan/Feb)....

http://www.accuweather.com/en/us/apex-nc/27502/december-weather/11323_pc?monyr=12/1/2012&view=table

[DaculaWeather]

Got some of that here

http://www.daculawea...at_a_glance.php

http://www.daculaweather.com/4_climate_temp_precip_plots.php

[packbacker]

Got some of that here

http://www.daculawea...at_a_glance.php

http://www.daculawea...recip_plots.php

Perfect! So far RDU is on target is for the 3rd warmest December in the last 50+ years. I didn't go back any farther, what's the point...

[Brick Tamland]

I mentioned it earlier today and I think it could very well hold true that this storm just after Christmas could set the table for us heading into the period around New Years. It wouldn't surprise me in the least to see an actual threat as there appears to be a fairly potent trailing shortwave.

It looks like that is our only hope. Maybe we can get something big to happen if the timing is right. That's the way things seem to be with the winters around here lately. It's either one extreme or the other, all or nothing. It might be cold around Christmas, but dry. And when we do get moisture, it's too warm. But maybe the systems coming through this week and next week will set the way for something good.

[beanskip]

Just to recap, the non-storm for the SE that was being modeled to cut toward the Lakes is still being modeled to cut toward the lakes and is still a non-storm for the SE.

[nrgjeff]

Though the CONUS experienced a major pattern change already, I don't see much winter precipitation in the Southeast the rest of December. Meanwhile the central Plains and Upper Midwest are having fun. Colder weather patterns take a long time to build. In cased like this where it starts out West, guess who is last. That's us in the Southeast.

The next couple storm systems this week and next week will likely track into the Ohio Valley. That puts the Southeast in the mild rainy conveyor belt. Cold fronts should be stout, so we'll get cold dry air behind each system. However there is virtually no chance of winter precipitation to the south and east of the storm track. Cold air cannot get into place at the same time precipitation moves through. A subtle flat upper level ridge has been stubborn over the Southeast, which explains the storm track. You really see that ridge when systems eject north and the ridge sharpens up a bit.

For winter precip that subtle ridge must depart the Southeast. It is forecast to remain through December. However January long-term guidance shows it being replaced by lower than normal heights over the Southeast while eastern Canada heights stay above normal. Throw in some blocking at even higher latitudes, including Alaska, and January could be a whole new ball game.

[Cold Rain]

Here is some decent meteorology from the New England forum:

What you have here is above normal heights to begin with across Canada so that when you get some ridge from a Mid Latitude Wave, the anomaly charts appear to look amazing. This is a case where you actually have to look at the means and the anomalies. If you just look at the h5 anomalies, you'd think 2009 or 2010 was on the way or something. In reality, the Arctic Heights took a hike back to Asia and we are left with generally above normal heights throughout Canada, so any small ridge will appear like a huge block on anomaly charts.

The thing about "models not realizing the strength of the 50-50 low and block" is usually when there is a strong cold air source / suppressive high / polar vortex. The situation after Christmas is another hybrid, bootleg scenario that could possibly benefit the interior and portions of New England. Even we could see a snow to rain but I'm about 50, 50 myself on that one. This is NOT a classic 50-50 low / -NAO setup; otherwise, I'd be on board with DT.

[dsaur]

Of course, of course. Just funny looking at that map. Usually you don't see that big of a spread having such an impact....I mean it literally heads south jumps due north than practically goes due east.

ONe of the maps I was looking at yesterday had a low in La./Miss. then jumped back in Texas, then next up in your neck of the woods, lol. I can't get excited except by general trends out more than a few days with Goofy being goofy. I'm getting more rain in two days, and I believe that. How much, remains to be seen And around XMas a whole bunch of probably rain, but maybe some "Who Knows", but that far off it could be a sunny 50, just as easy, though trends would say no. T

[GaStorm]

Taking with a huge grain, but, if the 12Z Euro were to somehow verify, wow, this would be some pretty serious cold for 12/27-8! (Cold would be coming in on 12/26.) -13C at 850 at KATL as of 6Z Fri 12/28 fwiw! Teen low(s) and near or below freeezing high(s) would almost be guaranteed if the 850's were to get that cold. But we're talking IF on a late 6-10 day map. So, we can only hope this is going to verify!!

Edit: Brick had better not look as he hates dry cold. So, nobody tell him.

It won't be long before there is a significant storm to track in January. What percentage of winter storms occur in January for the Southeast? I think you had some info on that before and the numbers were pretty good.

[GaStorm]

Not sure if anyone posted this but here is the CFS temp forecast for January.

[HKY_WX]

Euro ensembles are quite a bit different than the operation on the 26th storm. They bring 5h low much further south and HP is in much better position(1040mb sitting over north dakota at hour 168). The models have backed off a bit w/ the 50/50 low today, so hopefully that trends back towards a stronger scenario.

[SN_Lover]

Euro ensembles are quite a bit different than the operation on the 26th storm. They bring 5h low much further south and HP is in much better position(1040mb sitting over north dakota at hour 168). The models have backed off a bit w/ the 50/50 low today, so hopefully that trends back towards a stronger scenario.

Question: How would a high pressure over North Dakota enhance winter precip for the southeast? I dont think that would enhance a CAD event if the high is that far west.