SE Mid-Long Range Discussion II

[POWERSTROKE]

Just read a blocking study by Carrera that stated ecmwf wasn't as good in blocking episodes, so take that fwiw. They specifically mentioned the Bering Strait/Alaskan blocking episodes. Either way, both models have a pretty good southern stream developing and cold pressing south. And both have double blocking, the other being at Scandinavia, which is a preferred site and very climo when it happens in Nina Winters.

The rest of the run shows impressive double blocking. Extremely impressive. Here's day 9 , notice the 576dm ridge near Uk/Scandinavia, and its counterpart north of Alaska. This run brings the colder further south by day 9 and much further south on day 10 than yesterday's run. So the models are seeing what usually happens when you get high Lat blocking---->>>cold air seeps or screams south, depends on the flow, and the heart land of the north american continent is ground zero for the coldest air. Not only that, a generally sinking storm track emerges from the Pacific. It's only a matter of time before models hone in on the individual s/w that will produce the overrunning ice and snow across the lower Plains and Southeast in this pattern, but eventually they likely will. Just pure pattern recognition and climo here, snow shovels and ice scrapers will be handy devices in the Mid-South's future , not too far from now.

I like the way you talk

[packbacker]

We have -10 to -20 2m temps over the lakes, the cold is here. Very cool looping thr temps and seeing a big wall of cold cover Canada.

[tnweathernut]

I agree but so long as its hinting at something it's better than nothing

I still think we have a good period of winter weather to go through with several opportunities. That said, this year will certainly go down as one where a full boatload of patience was needed.

[lilj4425]

I think the big picture is key long term. The models are consistently showing the intrusion of colder air in the East. The details will get ironed out as we get closer to precip events.

Sorry but i'm still not feeling the mojo with this.

[FoothillsNC]

It happens almost every time, and I don't remember the last time we had double blocking. I can , however think of one good year we did have DB, but that doesn't look the same as this. All models will continue to shift their storm tracks south, so long as the blocking develops, and its looking more and more each day that it will. This evacuates the cold in Polar regions (like hurricanes evacuate heat from tropics), this will force 2 main lobes of cold, one in Russia, one in Canada and the US, and our side is so far looking like the bigger chunk of cold. The ECMWF only goes to 10 days, what happens beyond this is a guess of course, but GFS shows blocking continuing for a while, and it handles blocks better in both short and long term, so that has to be encouraging for winter lovers. We shouldn't be looking for small scale systems yet (but they're already showing up inPineapple Express form). Using general synoptics, we'll have several southern systems that are supressed south of the strong high pressure in Canada, and could have extreme surface ridging of High Pressure from said source (unusual...but not unusual in blocks). The trend lately is for colder pressing further south, and any southeast ridging to be squelched severely. That means less amplified storms, but more of them, in the form of overrunning possibly, However any system can amplify quite a bit in this past season so far proves that. But we're entering a new paradigm, so one day at a time. Overall it's hard to imagine some part of the Southern half of the country coming out of the next 2 to 4 weeks without feeling some significant winter precipitation.

[Southern Track]

Sorry but i'm still not feeling the mojo with this.

I'm sorry you aren't. I'm definitely not an expert but Robert has been saying for several days is consistency on the models is needed and we are getting that within a reasonable time frame. The little details on storm track, precip events, etc. are never ironed out until around 72 hours and within. Always with weather we will just have to see.

[POWERSTROKE]

I'm sorry you aren't. I'm definitely not an expert but Robert has been saying for several days is consistency on the models is needed and we are getting that within a reasonable time frame. The little details on storm track, precip events, etc. are never ironed out until around 72 hours and within. Always with weather we will just have to see.

yep but either way it is just a matter of time now

[Gastonwxman]

It's going to be a long week but once we get through this week it appears to be game on for some wintry shenanigans down the road. I dare say I'm almost completely excited about this potential. We can only hope to keep it up over the next several days so long as the blocking signals remain. Any system we get assuming that kicks into place will have to be watched carefully. It's been quite a wait to see this finally showing up in the long term since December. As my avatar title says: Let's get the winter train rolling!

http://gwxmanblog.blogspot.com/2012/01/wet-weather-shaping-up-for-early-this.html (typed as of early this morning)

[packfan98]

Did anybody look at the latest Canadian or UK Met runs and want to give a quick post about what they are showing?

[LithiaWx]

Did anybody look at the latest Canadian or UK Met runs and want to give a quick post about what they are showing?

CMC shows a good rain with the ULL early-mid next week, cold settles on in, then by hour 144 the cold is retreating and another system with non-frozen precip moves on in. No frozen precip on the CMC not even a threat.

UKMET does not show a wintery threat either.

[griteater]

Did anybody look at the latest Canadian or UK Met runs and want to give a quick post about what they are showing?

Silence on those models runs can't be good

UKMet looks a lot like the Euro to 144...it may even have the weak clipper rolling through TN/NC. The Canadian finally abandoned the deep MS Valley trough and Miller A storm threat, but it's chilly Thurs through Sat before warming up.

[ams30721us]

12z Euro paints a strip of Snow across the Tenn. Valley region. All of Tennessee, Nrn Miss, Nrn Alabama, Nrn GA into the Carolinas.

[WilkesboroDude]

It's going to be a long week but once we get through this week it appears to be game on for some wintry shenanigans down the road. I dare say I'm almost completely excited about this potential. We can only hope to keep it up over the next several days so long as the blocking signals remain. Any system we get assuming that kicks into place will have to be watched carefully. It's been quite a wait to see this finally showing up in the long term since December. As my avatar title says: Let's get the winter train rolling!

http://gwxmanblog.bl...early-this.html (typed as of early this morning)

Not so fast. We live in the south-east so we are due a washout before any more cold dry air comes around. This week may be exciting if we get storms on Wednesday!

[jburns]

I think what is being said with his statement is more in pattern recognition than in actual model output with individual storms. If you look at it that way, the pattern could become ripe in a hurry.

True. I can't remember a winter that smelled as ripe as this one has so far.

[weatherheels]

It happens almost every time, and I don't remember the last time we had double blocking. I can , however think of one good year we did have DB, but that doesn't look the same as this. All models will continue to shift their storm tracks south, so long as the blocking develops, and its looking more and more each day that it will. This evacuates the cold in Polar regions (like hurricanes evacuate heat from tropics), this will force 2 main lobes of cold, one in Russia, one in Canada and the US, and our side is so far looking like the bigger chunk of cold. The ECMWF only goes to 10 days, what happens beyond this is a guess of course, but GFS shows blocking continuing for a while, and it handles blocks better in both short and long term, so that has to be encouraging for winter lovers. We shouldn't be looking for small scale systems yet (but they're already showing up inPineapple Express form). Using general synoptics, we'll have several southern systems that are supressed south of the strong high pressure in Canada, and could have extreme surface ridging of High Pressure from said source (unusual...but not unusual in blocks). The trend lately is for colder pressing further south, and any southeast ridging to be squelched severely. That means less amplified storms, but more of them, in the form of overrunning possibly, However any system can amplify quite a bit in this past season so far proves that. But we're entering a new paradigm, so one day at a time. Overall it's hard to imagine some part of the Southern half of the country coming out of the next 2 to 4 weeks without feeling some significant winter precipitation.

Great breakdown as usual. It's very rare I read one of your posts, and don't learn anything. Seeing the double blocking that is progged gets me excited. With that set up the cold is just gonna funnel right down onto us. We're due for some fun, and that set up, if it happens, would probably give us some fun.

[griteater]

It happens almost every time, and I don't remember the last time we had double blocking. I can , however think of one good year we did have DB, but that doesn't look the same as this. All models will continue to shift their storm tracks south, so long as the blocking develops, and its looking more and more each day that it will. This evacuates the cold in Polar regions (like hurricanes evacuate heat from tropics), this will force 2 main lobes of cold, one in Russia, one in Canada and the US, and our side is so far looking like the bigger chunk of cold. The ECMWF only goes to 10 days, what happens beyond this is a guess of course, but GFS shows blocking continuing for a while, and it handles blocks better in both short and long term, so that has to be encouraging for winter lovers. We shouldn't be looking for small scale systems yet (but they're already showing up inPineapple Express form). Using general synoptics, we'll have several southern systems that are supressed south of the strong high pressure in Canada, and could have extreme surface ridging of High Pressure from said source (unusual...but not unusual in blocks). The trend lately is for colder pressing further south, and any southeast ridging to be squelched severely. That means less amplified storms, but more of them, in the form of overrunning possibly, However any system can amplify quite a bit in this past season so far proves that. But we're entering a new paradigm, so one day at a time. Overall it's hard to imagine some part of the Southern half of the country coming out of the next 2 to 4 weeks without feeling some significant winter precipitation.

Good write-up Foothills. A lot of potential here if the dual blocking materializes. The ridging going up west of Alaska has been modeled very consistently for the last 5 days, maybe more. I would feel a lot better about this if the ridge was going up thru Alaska, or even better in E AK / far west Canada....and if the blocking on the other side of the pole was going up in at least an east based -NAO fashion. If the blocking occurs as modeled, we could see the cold get tucked under the west AK ridge/closed low such that the cold air hangs to the north across all of Canada and doesn't get thrusted south far enough. Good point about how the modeling is showing the larger chunk of cold on this side of the pole vs. Asia. We don't have any evidence that we are going to get good blocking in the north atlantic. So, we need this dual blocking configuration to materialize so that the big polar vortex that sets up in northern Canada (north of Hudson Bay) is forced south. The GFS and GFS Ensembles show this occurring to some extent, and they show lobes of the vortex rotating through SE Canada which is what we need to keep the cold air flowing south, with a supressed storm track.

[Gastonwxman]

Not so fast. We live in the south-east so we are due a washout before any more cold dry air comes around. This week may be exciting if we get storms on Wednesday!

By long week I was referring to eventually reaching the period of the expected change but yes we have a nice system to keep watch for the mid-week period while we wait. Looks like plenty of folks could benefit nicely with sufficient rainfall and as I posted in the blog, we could also be dealing with strong, maybe severe thunderstorm activity in spots as it slides across the Southeast should it materialize. At least that should keep us entertained for the time being. Hopefully for some of you out there who has been pleading for such will get soaked this go around.

[dsaur]

Not so fast. We live in the south-east so we are due a washout before any more cold dry air comes around. This week may be exciting if we get storms on Wednesday!

Lol, yeah, I'm with you! We may be standing at the virge of historic winter weather in the later part of Jan. and into Feb. but my eyes are focused on tomorrow and the next few days after. Right now my winter time is all about ending this drought I'm in. I know everyone else wants cold air, but I know I can't get any sleet without moisture If I can get some rain this week, then Tinkerbell can live on a while longer... because then I'll believe. T

[NCMET]

Strongly agree with this assessment. I would like to see the eastern block extend a little further to the west to connect with the poleward blocking such that the polar vortex has NO choice but to move south. Good post

Good write-up Foothills. A lot of potential here if the dual blocking materializes. The ridging going up west of Alaska has been modeled very consistently for the last 5 days, maybe more. I would feel a lot better about this if the ridge was going up thru Alaska, or even better in E AK / far west Canada....and if the blocking on the other side of the pole was going up in at least an east based -NAO fashion. If the blocking occurs as modeled, we could see the cold get tucked under the west AK ridge/closed low such that the cold air hangs to the north across all of Canada and doesn't get thrusted south far enough. Good point about how the modeling is showing the larger chunk of cold on this side of the pole vs. Asia. We don't have any evidence that we are going to get good blocking in the north atlantic. So, we need this dual blocking configuration to materialize so that the big polar vortex that sets up in northern Canada (north of Hudson Bay) is forced south. The GFS and GFS Ensembles show this occurring to some extent, and they show lobes of the vortex rotating through SE Canada which is what we need to keep the cold air flowing south, with a supressed storm track.

[NGaWxNerd]

Can someone be so kind as to update me on the thunder/snow farmer tale? is it kind of like if the cows are laying down its going to rain? BTW we had a good thunderstorm here over the lake (Lanier) last night.

[Psalm 148:8]

Can someone be so kind as to update me on the thunder/snow farmer tale? is it kind of like if the cows are laying down its going to rain? BTW we had a good thunderstorm here over the lake (Lanier) last night.

If it thunders in winter, then in 10 days or so it will snow. Old farmers tale. Most weather lore has some elements of truth as to why they are observed....not sure on this one but somehow there is a connection....It may be a stretch though.

[NCStateMMY]

Can someone be so kind as to update me on the thunder/snow farmer tale? is it kind of like if the cows are laying down its going to rain? BTW we had a good thunderstorm here over the lake (Lanier) last night.

The tale goes that in the winter, if you experience thunder, 10 days later, you will see snow.

[FoothillsNC]

Strongly agree with this assessment. I would like to see the eastern block extend a little further to the west to connect with the poleward blocking such that the polar vortex has NO choice but to move south. Good post

I don't think you'd want that, unless you like over powering high pressure. So far I like how the models sag the jetstream south , so that the westerlies are far displaced, and we have high pressure ridging down from Canada a lot. If the arctic motherlode came down totally (which is possible) then most likely the southern stream would be too depressed. Southern Texas, the Gulf coast and Ga to Carolina coasts would be watching carefully for frozen precip chances.

[NCSNOW]

The 12 z GFS ensembles and the 12z Euro ensembles(only goes out to 240) never show the northern half of NC getting it's 850' above 0 the entire run starting late this week after the apps runner/rainmaker gets past us. Hang in their folks, by Thursday/Friday things won't be quite as foggy run to run in model world with regards to sensible/local weather. Pay attention to Robert and some of the others on here about recognizing the pattern and working from the outside-in.

[NGaWxNerd]

The tale goes that in the winter, if you experience thunder, 10 days later, you will see snow.

Awesome! So everyone come see the big snow storm at my house on the 17th. Problem solved no more discussion needed.

[Carvers Gap]

I'm just not seeing it. Take Greensboro for example. This run of the GFS has only 7 of the next 16 days with below normal temperatures. Only two of those days, next Friday and Saturday, are well below normal, with the highs projected to be around 38 both days. The other five days are only a couple of degrees below normal (Mid 40's). The coldest temperature projected during the entire period is one morning when the model projects a low of 20. This is normally the coldest period of the season we are entering into, and these numbers are just not very impressive for the middle of January. It just looks like the cycle we have been in this entire season looks to continue. The synopsis may not be the same, but the end results are. I know this has been said before, but this is one of those years where the Southeast will have to rely on perfect timing which rarely works out. I'm sure that at some point everything will come together to bring a decent event to some in the Southeast, but overall I'm thinking this Winter season is going to go in the books as a disappointment to most.

Are you out of country...if so you know I'll be looking for a major winter storm in the SE. LOL. I've pretty much, over the past few weeks, stated my opinion about the upcoming pattern. I don't look at raw temp output, just the pattern. With the coldest air at the pole sliding to this hemisphere, odds are in favor of an Arctic outbreak for the continental US w/ high latitude blocking in place. The 12GFS is flat out cold here in NE TN w/ the pattern it is showing. The pattern from the past 6 weeks is going to completely relax or leave during the 1-3 week time frame at least. It may return w/ La Nina in place though the ENSO state may trend towards neutral. Definitely not the same pattern on the 12z runs. If you don't see it, I probably won't convince you. Now, I'm not saying above normal snow/ice - yet. Until the new pattern "stabilizes" the details of each piece of energy will have great variability w/each run. I do think the winter will be above normal w/ temps and below for snow @ KTRI. I don't think we will erase +5 F from December. La Ninas can have great temp swings as you know and this will be one of them IMO.

[NCMET]

Here's what I am worried about...seen the EURO ensembles yet? Look at how far west that Alaskan block retrogrades at the end of the run and where the polar vortex is positioned (WELL to the north). Without a block over the far Northern Atlantic, how are you going to lodge the cold south?

I don't think you'd want that, unless you like over powering high pressure. So far I like how the models sag the jetstream south , so that the westerlies are far displaced, and we have high pressure ridging down from Canada a lot. If the arctic motherlode came down totally (which is possible) then most likely the southern stream would be too depressed. Southern Texas, the Gulf coast and Ga to Carolina coasts would be watching carefully for frozen precip chances.

[POWERSTROKE]

I don't think you'd want that, unless you like over powering high pressure. So far I like how the models sag the jetstream south , so that the westerlies are far displaced, and we have high pressure ridging down from Canada a lot. If the arctic motherlode came down totally (which is possible) then most likely the southern stream would be too depressed. Southern Texas, the Gulf coast and Ga to Carolina coasts would be watching carefully for frozen precip chances.

check email

[iceman]

The 12 z GFS ensembles and the 12z Euro ensembles(only goes out to 240) never show the northern half of NC getting it's 850' above 0 the entire run starting late this week after the apps runner/rainmaker gets past us. Hang in their folks, by Thursday/Friday things won't be quite as foggy run to run in model world with regards to sensible/local weather. Pay attention to Robert and some of the others on here about recognizing the pattern and working from the outside-in.

How's it going over in Jackson Creek?

[FoothillsNC]

Here's what I am worried about...seen the EURO ensembles yet? Look at how far west that Alaskan block retrogrades at the end of the run and where the polar vortex is positioned (WELL to the north). Without a block over the far Northern Atlantic, how are you going to lodge the cold south?

Have you seen the ensembles last few days? Or been following them this Season? They change daily, even though they only run out to day 10. Also, its proven in several blocking studies I just finished (and know from 20 + years of forecasting) that ecmwf doesn't handle the pre-block or mature block or decaying block period well, and this blocking will go well beyond its short range. Most likely what happens is when the block cuts off in west or north Canada it stays in that general area and that will leave a weak vortex under it just offshor the Pac NW. South of there will be the other branch of the westerlies, aka split flow. With western Greenland and the Northeast US still under a cold vortex that stretches the flow east to west across the country but what the models wont see are the ejected shortwaves in either the polar flow or stj flow, which will likely amplify. And with the coldest part of the vortex right in the middle of Hudson's Bay region and High Pressure all throughout western and central and northern Canada, the cold will literally stretch thousands of miles south of the polar jet. I've seen that quite a few times, even under warmer than normal heights. Its common in cold airmasses of this -30 to -40 nature. Any system will pull cold air further south and east as the sytem goes by , toward Greenland. Now eventually the block will decay or re-form elsewhere but thats too far out to really speculate. I'm basing my forecast and reasoning on climo and past analogs similar. But you're right if the block heads too far north, then things would change in the flow in a hurry, but so far the GFS and ECMWF don't show that early on, and GFS never really does through the run. I guess its still possible all the cold dumps totally down into the western part of the trough, but with Greenland and the northeast 50/50 vortex that would still argue for significant cold to remain in the east a lot.