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Pattern Jammin' January

For this Sunday storm system for my area which is Chattanooga, I think it a case of cold chasing out the rain with maybe some left over precip maybe in the form of light snow or snow flurries. I also think this is not the right set up for Chattanooga to get any big snow out of this system. Things can change and they always do. We need the low to stay along the gulf and swing up toward SE GA. for Chattanooga to anything big. Will watch and see what happens. Models are showing we are going into a colder pattern, but sometimes to much cold around here can be a bad thing making systems push farther south away from my area. Everyone have a good week.
 
deltadog03 said:
I’m not sure Larry. I think it’s more transient than a feature we are having to worry about ATM.
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With the projected strong -AO/-NAO by the last few days of the month combined with what by then should be a favorable MJO once again, I agree if transient means the next 12 days or so. Until then, the further west storm track could dominate.

By the way, it looks like the SSW may finally be showing its influence on the -AO.
 
GaWx said:
With the projected strong -AO/-NAO by the last few days of the month combined with what by then should be a favorable MJO once again, I agree if transient means the next 12 days or so.

By the way, it looks like the SSW may finally be showing its influence on the -AO.
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Based on what you have observed with the ensembles, have they been steady with the depiction you described above? In other words, has that projection been steady for the last few days of the month, or has the awesome pattern depiction been coming and going and remaining at the end of the run (i.e. getting pushed back)?

My observation of the operational models shows little consistency with the type of pattern they want to set up. We've seen short bursts of -NAOs and southward displaced PVs, mixed with central US-centered troughs, mixed with bursts of SE ridging. The western ridging seems to oscillate between setting up off or along the west coast or just inland. Yes, the pattern looks generally colder, but there is no consistent indication of a suppressed flow. What this has commonly evolved into (and which fits with the current pattern) is the propensity for low pressures tracking through TN or NC or reforming over or off the NC or VA coast, along with high pressure centers too far north up in Canada.

I know the ensembles continue to advertise great patterns, but my experience over the last few years tells me this may be fools gold until it starts working closer in time and the operational models start honing in on it. Have you noticed any trends in the ensembles that indicate we are advancing appreciably closer?

Again, for the optimists, I'm not trying to be a Debbie Downer. The pattern is changing to one that should feature at least bouts of cold in which really good timing can produce a winter storm for much of the SE. But I'm just wondering what the trends in the primary tools (operational models and ensembles) are showing in terms of things being on track, in line with the overall longer range tools (analogs, Weeklies, Seasonals, SSW projections, etc.) that suggest blocking and a more favorable pattern for SE winter storms developing?
 
Another comment re: the ensembles -- It seems like we've been seeing good depictions with the ensembles for a good while now. They only go out to 360 or whatever, so at some point very soon, I'd expect to start seeing things evolve favorably inside of 7-10 days. Looking at 240+ ensemble images of awesomeness is fine. But we need to see that work in at some point.
 
Rain Cold said:
Based on what you have observed with the ensembles, have they been steady with the depiction you described above? In other words, has that projection been steady for the last few days of the month, or has the awesome pattern depiction been coming and going and remaining at the end of the run (i.e. getting pushed back)?

My observation of the operational models shows little consistency with the type of pattern they want to set up. We've seen short bursts of -NAOs and southward displaced PVs, mixed with central US-centered troughs, mixed with bursts of SE ridging. The western ridging seems to oscillate between setting up off or along the west coast or just inland. Yes, the pattern looks generally colder, but there is no consistent indication of a suppressed flow. What this has commonly evolved into (and which fits with the current pattern) is the propensity for low pressures tracking through TN or NC or reforming over or off the NC or VA coast, along with high pressure centers too far north up in Canada.

I know the ensembles continue to advertise great patterns, but my experience over the last few years tells me this may be fools gold until it starts working closer in time and the operational models start honing in on it. Have you noticed any trends in the ensembles that indicate we are advancing appreciably closer?

Again, for the optimists, I'm not trying to be a Debbie Downer. The pattern is changing to one that should feature at least bouts of cold in which really good timing can produce a winter storm for much of the SE. But I'm just wondering what the trends in the primary tools (operational models and ensembles) are showing in terms of things being on track, in line with the overall longer range tools (analogs, Weeklies, Seasonals, SSW projections, etc.) that suggest blocking and a more favorable pattern for SE winter storms developing?
Click to expand...

I've noticed the GEFS the last couple days has advertised a much better pattern steadily around the 28th/29th. Still don't like that stinkin WAR, and would like it gone in February, but this would certainly get it done I think. But yeah, I'd love to see this look in under 300 hours. I'll be watching it this week for sure.

If it actually shows up and stays through February, I think it'll be well worth the wait. Especially if we get lower heights in SE Canada. So we wait.

1547477966496.png
 
Rain Cold said:
Based on what you have observed with the ensembles, have they been steady with the depiction you described above? In other words, has that projection been steady for the last few days of the month, or has the awesome pattern depiction been coming and going and remaining at the end of the run (i.e. getting pushed back)?

My observation of the operational models shows little consistency with the type of pattern they want to set up. We've seen short bursts of -NAOs and southward displaced PVs, mixed with central US-centered troughs, mixed with bursts of SE ridging. The western ridging seems to oscillate between setting up off or along the west coast or just inland. Yes, the pattern looks generally colder, but there is no consistent indication of a suppressed flow. What this has commonly evolved into (and which fits with the current pattern) is the propensity for low pressures tracking through TN or NC or reforming over or off the NC or VA coast, along with high pressure centers too far north up in Canada.

I know the ensembles continue to advertise great patterns, but my experience over the last few years tells me this may be fools gold until it starts working closer in time and the operational models start honing in on it. Have you noticed any trends in the ensembles that indicate we are advancing appreciably closer?

Again, for the optimists, I'm not trying to be a Debbie Downer. The pattern is changing to one that should feature at least bouts of cold in which really good timing can produce a winter storm for much of the SE. But I'm just wondering what the trends in the primary tools (operational models and ensembles) are showing in terms of things being on track, in line with the overall longer range tools (analogs, Weeklies, Seasonals, SSW projections, etc.) that suggest blocking and a more favorable pattern for SE winter storms developing?
Click to expand...

Well, the AO/NAO blocking on today’s GEFS looks the best yet for very late month. The GEFS MJO forecast is looking good for then as of yesterday/has been progressing nicely. Unlike the very frustrating mid to late Dec GEFS runs with the cold mirages that kept showing up after 10 days, we’re progressing way better and we just had a cold few days. The only fly in the ointment has recently been what I’ll somewhat agree with Delta on is a transient stubborn SE ridge/further west storm track that has recently been holding off the cold from deeply penetrating the SE vs earlier runs that were covering more of the SE with very cold. Now it has backtracked to cold more in and out between storms and strong cold further west. I’m guessing this is right side MJO influenced. I expect we’ll all be in the more solid cold pattern by 1/26-8 or so and then going forward.
 
I'm seeing more and more talk of the SSW actually starting to slowing propagate downwards, which is great news. End of January will be right about 30 days from the start of the SSW, and right about time we should start feeling the effects of the SSW with blocking up top. Ensembles show much blocking at the pole and in -EPO/-NAO regions at that time. Is the SSW doing work, or is that just a coincidence?

1547480263616.png
 
SnowNiner said:
I've noticed the GEFS the last couple days has advertised a much better pattern steadily around the 28th/29th. Still don't like that stinkin WAR, and would like it gone in February, but this would certainly get it done I think. But yeah, I'd love to see this look in under 300 hours. I'll be watching it this week for sure.

If it actually shows up and stays through February, I think it'll be well worth the wait. Especially if we get lower heights in SE Canada. So we wait.

View attachment 11051
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Won’t have to worry about cutters with that look. Y'all will be begging for a cutter or apps rubber if this verifies and holds but until then we shall keep complaining about the rain. On a side note, what makes you guys think those heights over Greenland will verify this time vs the last 10,000 times it showed up at the end of the run?
 
Jimmy Hypocracy said:
Won’t have to worry about cutters with that look. Y'all will be begging for a cutter or apps rubber if this verifies and holds but until then we shall keep complaining about the rain. On a side note, what makes you guys think those heights over Greenland will verify this time vs the last 10,000 times it showed up at the end of the run?
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Well to me, it makes alot of sense. The models are consistent with it around that time (the last couple days at least), the WAR retrogrades up to it, and it's right around the time the SSW is supposed to take effect in the troposphere, and it jives with the EURO weeklies which has been adamant about it, and pretty accurate I think in the long range. The weeklies actually predicted the "ridge sandwich" pattern with the WAR and the western ridge which seem to want to verify in the shorter range ensembles. Everything seems to point to the end of the month becoming blocky and having a greenland block that could work. It could vanish sure, but to me it looks like a consistent element of the forecast that's logical.
 
Jimmy Hypocracy said:
Won’t have to worry about cutters with that look. Y'all will be begging for a cutter or apps rubber if this verifies and holds but until then we shall keep complaining about the rain. On a side note, what makes you guys think those heights over Greenland will verify this time vs the last 10,000 times it showed up at the end of the run?
Click to expand...
Personally, I don't think they will verify. I mean, I could see a transitory block up there, but nothing lasting. This isn't based in any sort of meteorology. In fact, I have no idea why a sustained pattern of blocking up there doesn't happen anymore, even when it looks like it should. It just doesn't, for reasons nobody can identify. Until that changes and it shows us that we can get a true sustained west-based -NAO in the heart of winter, I don't think we should count on it, even if longer range stuff and analogs say it should happen. That's not a good forecasting methodology, generally, but it may end up working well in this area. We'll see.
 
THIS. Its hour 240 on the 6z FV3 but exactly what I think we'll see this weekend behind the front (except for central MS) before moisture outruns the cold. Tupelo, MS to Florence AL, to Crossville TN is the cutoff 90% of the time with artic fronts, and reason for ice instead of snow is due to the initial shallowness of artic air masses post-fropa.

In the snow department, the old GFS 6z looks very reasonable IMO. Jonesboro AR to Clarksville TN to Bowling Green KY line for 1" cutoff, with dusting to 1/2" south of there for northern middle and west TN and northern AR.

fv3p_mslp_pcpn_frzn_us_40.png

snku_acc.conus.png
 
cyclogent said:
THIS. Its hour 240 on the 6z FV3 but exactly what I think we'll see this weekend behind the front (except for central MS) before moisture outruns the cold. Tupelo, MS to Florence AL, to Crossville TN is the cutoff 90% of the time with artic fronts, and reason for ice instead of snow is due to the initial shallowness of artic air masses post-fropa.

In the snow department, the old GFS 6z looks very reasonable IMO. Jonesboro AR to Clarksville TN to Bowling Green KY line for 1" cutoff, with dusting to 1/2" south of there for northern middle and west TN and northern AR.

fv3p_mslp_pcpn_frzn_us_40.png

snku_acc.conus.png
Click to expand...
Yep, and if you look at the upper air depiction, you can see a couple of things that stand out, which support your point:

fv3p_z500_mslp_namer_41.jpg

The big red area shows where the PV is. Right up in the wrong place. Short waves rotate around it, with areas of subsequent high pressure after the wave moves by. As you can see in the smaller red circle, that high is too far north. Looks like this past weekend. Plus, there's no way it will be that strong. So we have to look elsewhere for help. Maybe the western ridge? Nope. Unfortunately, it's too far west for much of the SE. And what do you get? A storm that cuts inland with what will be marginal cold air on the north west side.

Even if we get a slight change, and you get some sort of northern wave out ahead of the southern wave, the air still looks to be quite marginal for much of the SE, given where the core of the cold sits. All that said, we're still 10 days out, so it's almost senseless to analyze in this kind of detail. But we're going to need to see some fairly big changes with the PV placement if we want to see a better cold air feed. Otherwise, we need a perfectly timed phase, which would likely only work out for the western and northern portions of the SE for this particular threat.

My number one rule for being enthusiastic for a genuine SE winter storm is a legitimate cold air feed where legitimate cold air is available. I don't see a way for that to turn up here, based on what this model is showing. I'm not poo pooing the chance for wintry weather. Not at all. But the odds are not all that great, given what we see now. Maybe that changes in the next few minutes, though. We will see.
 
Rain Cold said:
Yep, and if you look at the upper air depiction, you can see a couple of things that stand out, which support your point:

View attachment 11059

The big red area shows where the PV is. Right up in the wrong place. Short waves rotate around it, with areas of subsequent high pressure after the wave moves by. As you can see in the smaller red circle, that high is too far north. Looks like this past weekend. Plus, there's no way it will be that strong. So we have to look elsewhere for help. Maybe the western ridge? Nope. Unfortunately, it's too far west for much of the SE. And what do you get? A storm that cuts inland with what will be marginal cold air on the north west side.

Even if we get a slight change, and you get some sort of northern wave out ahead of the southern wave, the air still looks to be quite marginal for much of the SE, given where the core of the cold sits. All that said, we're still 10 days out, so it's almost senseless to analyze in this kind of detail. But we're going to need to see some fairly big changes with the PV placement if we want to see a better cold air feed. Otherwise, we need a perfectly timed phase, which would likely only work out for the western and northern portions of the SE for this particular threat.

My number one rule for being enthusiastic for a genuine SE winter storm is a legitimate cold air feed where legitimate cold air is available. I don't see a way for that to turn up here, based on what this model is showing. I'm not poo pooing the chance for wintry weather. Not at all. But the odds are not all that great, given what we see now. Maybe that changes in the next few minutes, though. We will see.
Click to expand...

We are still at the point that a favorable pattern may establish day 10+. Yeah, the day 6-7 threat is a chance but a very low one for us. We are going to take another trip through the warm MJO phases.

Good news is that day 10+ cold does seem to dump into the southern plains. Until then we look to get cold from rainy fronts passing.

This may be a great pattern below for TX to AL so that would be great.

E2F71A9A-A518-48F5-8F19-2D0EB4A458CB.png
 
Good luck figuring out all this energy . Gonna be some wild op runs in the coming days
582fdada23b70807e99a7b502f86be12.jpg


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