December Forecast Discussion

[CAD_Wedge_NC]

If we don't watch every run we will never know when it's within five days! Come on man, we see you here after every model run... Lol the cold is just 10 days out!!!

OK, here's my 2 cents worth....... We see this time and time again. The models have a hard time with any pattern change. You will see one run that will be cold and the next one is somewhat modified. I agree with a previous poster in the fact that we will not have stability in the models until the first push comes down. I believe a lot will depend on the strength of the lakes cutter and how the first trough sets up after that. The change is occurring and it will not be like last winter. Let's see how it all shakes out before getting too excited. I can see that folks are getting discouraged and rightfully so, but don't get too wrapped up in the run to run changes. I know.... easier said, than done.

[beanskip]

GaWx has been all over this pattern. Of course, these days on this board if you are forecasting something other than snow for everybody, you are called a cynic, but the fact is that the models are woefully overhyping instrusions of cold, mainly because of "false positives" when it comes to the Pacific.

"Bet the streak" is the oldest Vegas adage, and right now, unfortunately, our streak is number of consecutive days in a snowless pattern and it stretches all the way back to the latter part of the 2010/2011 winter.

The 0Z Euro is already coming in warmer early in the 6-10 vs. the 12Z Euro. Also, I can already tell from upstream (including Canada) that the rest of the 6-10 is going to come in MUCH warmer than the 12Z Euro. These are facts, not a figment of my imagination. Don't shoot the messenger. I'm already wounded from earlier today lol. So, there is STILL no clearcut model support for when an actual steady cold pattern will start as it keeps getting delayed.

Edit:

- coldest 850 for RDU on 12Z Sat. Euro: -13 C

- coldest 850 for RDU on 0Z Sun. Euro: -6 C

[IWC]

Well with today being the 16th I waiting for the 20th to see what MIGHT be falling on Christmas+- a day. the models are always back and forth. I thought everyone waited till we were 48 to 72 hours before they accepted what the models said? I'm hoping ( not expecting ) a white Christmas.

[IWC]

I heard it around 2:45. Really surprised me. It'll be interesting to see what happens 10 days later, and that is the timeframe that everyone is looking at right now for possible winter weather here.

16th today

10 days of folklore

26th day of December

And we have been coaxing a storm for that time frame.. Lets see what happens!!!

[burgertime]

12z GFS doesn't look too bad in the medium range. Out to the 23rd cold air is making it's way towards the Southeast. Maybe this one might give us some real hope.

[metalicwx366]

I heard it around 2:45. Really surprised me. It'll be interesting to see what happens 10 days later, and that is the timeframe that everyone is looking at right now for possible winter weather here.

Is this a NC thing or something? Thunderstorms = snow 10days later in winter? lol

[toxictwister00]

Is this a NC thing or something? Thunderstorms = snow 10days later in winter? lol

No, it's a Southern thing and strangely it does happen sometimes. One example I can think of is back on January 6, 2008 we had severe weather here and 10 days later we saw half an inch of snow and three from that we got about an inch.

[burgertime]

Well this run of the GFS now has our storm for Christmas week as a CAD event at 264 with a 1028 high sitting around northern PA and the low heading up the Apps. Hard to tell if there would be enough cold air to work with but someone would probably get a bad ice storm out of this in VA. Either way this is not the run we want as there isn't really any cold air coming south of VA out to 300....on to the Euro.

[HKY_WX]

I think there's a chance around the 27th if we can just get the 50/50 low to setup. I like the PNA setup and I like the HP i see up in Canada, but we need a mechanism to pull it down in time and lock it in over southern Canada. If we can see some trends in that direction, i think a big dog is likely.

[packbacker]

Yuck...GaWx is right...,

[burgertime]

GFS in the LR doesn't look pretty for the SE...mainly seasonal temps leaning towards the warm side with a possible CAD events and that's about it. No major cold in the SE the entire run. All the cold air just sits to our north.

[Wow]

Yuck...GaWx is right...,

Lack of a 50/50 low bombing out and pulling a ridge over Greenland. Pac setup which has been GaWx's meteorological argument all along looks much better with a Rex block forming over AK. Here it is the Atlantic setup which needs to buck up in order to achieve a sizable and longer lasting cold shot.

[mackerel_sky]

To debunk that myth,we had a good many tstorms last winter,and we know how that turned out!

No, it's a Southern thing and strangely it does happen sometimes. One example I can think of is back on January 6, 2008 we had severe weather here and 10 days later we saw half an inch of snow and three from that we got about an inch.

[Southern Track]

Lack of a 50/50 low bombing out and pulling a ridge over Greenland. Pac setup which has been GaWx's meteorological argument all along looks much better with a Rex block forming over AK. Here it is the Atlantic setup which needs to buck up in order to achieve a sizable and longer lasting cold shot.

Is this due to the relaxing of the NAO to a more neutral state? The Pacific looks to be cooperating more.

[Wow]

Is this due to the relaxing of the NAO to a more neutral state? The Pacific looks to be cooperating more.

Go back to hr 180 on this run and you can see how the 50/50 low fails to adequately build enough ridging into Greenland and so it is already on the move out. This feature needs to wrap up and establish itself in this position to keep the southern system from cutting up inland.

The lack of a stronger NAO signal is more of an effect than a cause to this scenario.

[packbacker]

Go back to hr 180 on this run and you can see how the 50/50 low fails to adequately build enough ridging into Greenland and so it is already on the move out. This feature needs to wrap up and establish itself in this position to keep the southern system from cutting up inland.

The lack of a stronger NAO signal is more of an effect than a cause to this scenario.

Which isn't good as this is a day 7 model prog...which indicates to me the models are catching on to moving the 50/50 low out.

[GaWx]

GaWx has been all over this pattern. Of course, these days on this board if you are forecasting something other than snow for everybody, you are called a cynic, but the fact is that the models are woefully overhyping instrusions of cold, mainly because of "false positives" when it comes to the Pacific.

"Bet the streak" is the oldest Vegas adage, and right now, unfortunately, our streak is number of consecutive days in a snowless pattern and it stretches all the way back to the latter part of the 2010/2011 winter.

beanskip,

Thanks for your support. Yep, many people just seem to not want to hear about it if snow is not a good possibility anyime soon. I prefer being objective to try to maintain credibility regarding wx forecasting topics

Folks,

The 12Z GFS continues the recent string of unimpressive runs regarding SE US cold. (I'm not talking about other regions like the Mid-Atlantic.) Do the complaining readers (about my posts) even recall those many GFS runs from last week showing the blocking produced Arctic air being forced pretty deep down into the SE US for the period near 12/22-25? Now, it isn't coming down that far and is, therefore, largely missing the SE. In case you have forgotten, check this out:

GFS run, Coldest 850 KATL 12/22-5, Coldest 850 entire run

0912 -5, -5

0918 -7, -7

1000 +4, -4

1006 +6, +1

1012 -13, -13

1018 +8, -5

1100 -12, -12

1106 +4, -11

1112 -8, -8

1118 -4, -4

1200 -3, -3

1206 -6, -6

1212 -11, -11

1218 -8, -8

1300 -2, -2

1306 -6, -6

1312 -9, -9

1318 -12, -12

1400 -1, -1

1406 +3, -2

1412 -5, -6

1418 -8, -8

1500 +3, -1

1506 -3, -4

1512 +3, +1

1518 +4, -5

1600 +4, -3

1606 +4, -5

1612 +3, -4

-For 12/22-5 coldest: 1st 22 GFS runs avg. -4.1 C; Last seven GFS runs avg. +2.6 C or 6.7C/12.1 F warmer

-For entire run coldest: 1st 22 GFS runs avg. -6.5 C; Last seven GFS runs avg. -3.0 C or 3.5C/6.3 F warmer

So, the last seven runs have actually been warmer on avg. than the preceding 22 runs on avg. That's not a good sign for getting a cold dominated pattern to actually finally start in the SE. The delaying tendencies continue.

[dsaur]

GFS in the LR doesn't look pretty for the SE...mainly seasonal temps leaning towards the warm side with a possible CAD events and that's about it. No major cold in the SE the entire run. All the cold air just sits to our north.

Burger..Burger! Unless you Carolina folks have somehow managed to get a surfeit of rain while the rest of us lanquish in drought, then the long range is a thing of beauty! Rain galore, and temps near the borderline. Cads showing. It is a cup half full, lol. You have to learn to enjoy the little things If Larry's is correct, and he usually is, then instead of rain falling into temps below freezing, it may fall into temps at, or near, freezing, lol. Chances still, and if not, then lots of wonderful rain!! Do not dispair, be happy! The cold bomb is out there..somewherre... but the rain is on our doorsteps. T

[Wow]

Which isn't good as this is a day 7 model prog...which indicates to me the models are catching on to moving the 50/50 low out.

Possibly.. This morning's European kept the 50/50 in place but held the PAC energy back too much. If the 12z run follows the GFS regarding a weakening trend of the 50/50 low then I would agree.

[burgertime]

Burger..Burger! Unless you Carolina folks have somehow managed to get a surfeit of rain while the rest of us lanquish in drought, then the long range is a thing of beauty! Rain galore, and temps near the borderline. Cads showing. It is a cup half full, lol. You have to learn to enjoy the little things If Larry's is correct, and he usually is, then instead of rain falling into temps below freezing, it may fall into temps at, or near, freezing, lol. Chances still, and if not, then lots of wonderful rain!! Do not dispair, be happy! The cold bomb is out there..somewherre... but the rain is on our doorsteps. T

What is this rain you speak of? I've only heard of snow! Actually I'll believe those big flooding rains in the LR when I look out the window to see puddles forming in the backyard. GFS seems to want to fool us on all ends.

[packbacker]

Possibly.. This morning's European kept the 50/50 in place but held the PAC energy back too much. If the 12z run follows the GFS regarding a weakening trend of the 50/50 low then I would agree.

Well the 12z GEFS is slower to move the 50/50 out, so there must be several members that keep it in a fairly good position, the GEFS does look better than the OP. There is a glob of moisture over the SE states on days 10-11 which indicates several members are not cutting.

I agree, not ready to throw in the towel just yet, but I am reaching for it....

[Wow]

What is this rain you speak of? I've only heard of snow! Actually I'll believe those big flooding rains in the LR when I look out the window to see puddles forming in the backyard. GFS seems to want to fool us on all ends.

The SOI tanking last week will get things going with some meaningful precip for our region for the next couple of weeks. Don't rely on the models.

[Wow]

Well the 12z GEFS is slower to move the 50/50 out, so there must be several members that keep it in a fairly good position, the GEFS does look better than the OP. There is a glob of moisture over the SE states on days 10-11 which indicates several members are not cutting.

I agree, not ready to throw in the towel just yet, but I am reaching for it....

It is 10 days out.. I would suggest not even picking it up in the first place LOL!

[burgertime]

Great PDF here for those wanting to learn more about -NAO signatures and 50/50 low

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CDcQFjAA&url=http%3A%2F%2Fwww.abington.k12.pa.us%2Fteachers%2Fhurmms%2FMajorsnowstormchecklist_files%2FStormchecklist.ppt&ei=6gPOUL2_N4es8QTon4CQDg&usg=AFQjCNGF986-hz6PsTW577uhW-WAv3oqNg&sig2=R2t0IKsqOwA7cljUyuPIfQ&bvm=bv.1355325884,d.eWU

[HKY_WX]

I don't see any vodka cold this month. The AO is negative, which has and will continue to make the pattern much more interesting and also give us some snow/ice chances the last 10 days of the month. But in order to get the big cold, you need the pacific to setup more favorably. There are signs that this will happen. With the -AO trend and with the likelihood it will be negative on average the entire winter, I wouldn't be arguing about it at this point. I am betting Jan/Feb will bring plenty of chances. You just can't stress enough the importance of this anomalous -AO when referencing winter on the whole.

[Wow]

beanskip,

Thanks for your support. Yep, many people just seem to not want to hear about it if snow is not a good possibility anyime soon. I prefer being objective to try to maintain credibility regarding wx forecasting topics

Folks,

The 12Z GFS continues the recent string of unimpressive runs regarding SE US cold. (I'm not talking about other regions like the Mid-Atlantic.) Do the complaining readers (about my posts) even recall those many GFS runs from last week showing the blocking produced Arctic air being forced pretty deep down into the SE US for the period near 12/22-25? Now, it isn't coming down that far and is, therefore, largely missing the SE. In case you have forgotten, check this out:

GFS run, Coldest 850 KATL 12/22-5, Coldest 850 entire run

-For 12/22-5 coldest: 1st 22 GFS runs avg. -4.1 C; Last seven GFS runs avg. +2.6 C or 6.7C/12.1 F warmer

-For entire run coldest: 1st 22 GFS runs avg. -6.5 C; Last seven GFS runs avg. -3.0 C or 3.5C/6.3 F warmer

So, the last seven runs have actually been warmer on avg. than the preceding 22 runs on avg. That's not a good sign for getting a cold dominated pattern to actually finally start in the SE. The delaying tendencies continue.

First, a little bit of apples and oranges here. This is sustained cold pattern vs. opportunity for wintry weather for parts of our region. The GFS having a cold bias at times in the long range is always expected. The Euro has thrown them into the mix as well. I'm not buying a major cold outbreak either in the near term, but the wintry wx could occur.

Regardless, there really isn't any forecasting going on at all here.. this is all based on statistical history of verbatim long range GFS numbers, and arguing this would spiral right back down to the ENSO debacle.

Let's try this approach... a sustained -AO, a recent tanking of the SOI, and an MJO consistently being forecast to trail into Phase 1 territory.. given our climatology, what would you forecast to occur over the next couple of weeks and into January? By the way, this isn't really a rebuff to your model statistic, just taking this on a meteorological point of view rather than statistical data of the GFS.

[burgertime]

Euro isn't nearly as ugly as the 00z run last night....not fantastic but @216 it could have some fun and games in store for around the 27th or so...thought it's like the storm could cut up the apps.

[packbacker]

Euro isn't nearly as ugly as the 00z run last night....not fantastic but @216 it could have some fun and games in store for around the 27th or so...thought it's like the storm could cut up the apps.

Completely different from 0z, nice block with 50/50, HP over the lakes.

I guess the 50/50 is more like a 45/60 but it should help suppress.

[burgertime]

Completely different from 0z, nice block with 50/50, HP over the lakes.

I guess the 50/50 is more like a 45/60 but it should help suppress.

Possible CAD event near the end of the run with big cold sweeping east. As Brandon alluded to it could still trend our way.

[Wow]

Euro looks good. No bitter arctic air but air from Canadian origin is good enough.