-
Hello, please take a minute to check out our awesome content, contributed by the wonderful members of our community. We hope you'll add your own thoughts and opinions by making a free account!
Pattern February 2024
- Thread starter SD
- Start date
griteater
Member
this is exactly what you want to see with this upcoming pattern dump some northern stream/energy from the TPV into that trof and boom you have a pretty legit cold feed 
GFS looks like it’s about to revert back to Garbo because it doesn’t effectively dig the S/W from the TPV, but the CMC just joined the train 
griteater
Member
If you are into the stratosphere stuff, Judah Cohen had a good post yesterday. Excerpt below.
Source: https://www.aer.com/science-research/climate-weather/arctic-oscillation/ (See "Impacts" section)
"...As I discussed back in November, Canadian warmings overwhelmingly transition to just two other PV phases - one is a larger sudden stratospheric warming but most commonly to a stretched PV. A Canadian warming can transition to other PV states (in the strong PV category) but it is significantly less likely. I don’t see another SSW anytime soon but the threshold for a stretched PV is much lower. I think in the time frame of the second week of February and even possibly mid-February a stretched PV is becoming more likely. This should help end the very mild pattern in place across North America. The intensity and duration of cold weather associated with the stretched PV is yet to be determined.
I want to end with one wild card. As usual I show the latest polar cap geopotential height anomalies (PCHs) plot in Figure 11, but occasionally I have also included the North Atlantic regional version of the plot, with the most recent in Figure iv. In Figure 11 one cannot observe the typical “drip” of warm/positive PCHs from the stratosphere to the troposphere often on a timescale of two weeks. Instead, the warm/positive PCHs in the stratosphere associated with last week’s major warming come to an abrupt end and independently warm/positive PCHs appear or emerge in the troposphere in early February. But looking at the North Atlantic regional PCHs (below) a different understanding is suggested. Warm/positive PCHs in the mid to upper stratosphere associated with last week’s major warming first “drip” or descend into the mid to lower stratosphere this week. This first leg down can be seen in Figure 13b with the polar stratospheric warming centered over Greenland. Then “drip” further into the troposphere in early February. Since this is only the North Atlantic regional plot, it is strongly suggestive of the return of Greenland blocking, though for now I don’t see much evidence of this in the weather model forecasts."
Source: https://www.aer.com/science-research/climate-weather/arctic-oscillation/ (See "Impacts" section)
"...As I discussed back in November, Canadian warmings overwhelmingly transition to just two other PV phases - one is a larger sudden stratospheric warming but most commonly to a stretched PV. A Canadian warming can transition to other PV states (in the strong PV category) but it is significantly less likely. I don’t see another SSW anytime soon but the threshold for a stretched PV is much lower. I think in the time frame of the second week of February and even possibly mid-February a stretched PV is becoming more likely. This should help end the very mild pattern in place across North America. The intensity and duration of cold weather associated with the stretched PV is yet to be determined.
I want to end with one wild card. As usual I show the latest polar cap geopotential height anomalies (PCHs) plot in Figure 11, but occasionally I have also included the North Atlantic regional version of the plot, with the most recent in Figure iv. In Figure 11 one cannot observe the typical “drip” of warm/positive PCHs from the stratosphere to the troposphere often on a timescale of two weeks. Instead, the warm/positive PCHs in the stratosphere associated with last week’s major warming come to an abrupt end and independently warm/positive PCHs appear or emerge in the troposphere in early February. But looking at the North Atlantic regional PCHs (below) a different understanding is suggested. Warm/positive PCHs in the mid to upper stratosphere associated with last week’s major warming first “drip” or descend into the mid to lower stratosphere this week. This first leg down can be seen in Figure 13b with the polar stratospheric warming centered over Greenland. Then “drip” further into the troposphere in early February. Since this is only the North Atlantic regional plot, it is strongly suggestive of the return of Greenland blocking, though for now I don’t see much evidence of this in the weather model forecasts."
Still the CMC is rather mid because it brings energy right back to the GLs afterwards 
Here’s the 4 run trend from the GFS… there is no trend, we either settle with a pacific origin wave that cuts off ots and we get WAA back in quicker and a ridge more rooted to the subtropics, or we inject a TPV ext into it, bring the can ridge more poleward and undercut quicker
Here’s the 4 run trend from the GFS… there is no trend, we either settle with a pacific origin wave that cuts off ots and we get WAA back in quicker and a ridge more rooted to the subtropics, or we inject a TPV ext into it, bring the can ridge more poleward and undercut quicker
rburrel2
Member
Yea, the verdict is still out on this timeframe. Seems like every piece is on a knife's edge from going one way or the other.
The 12z Icon looked great and hopefully the Euro has a similar look.
It's looking increasing likely we will get the mega wedge with a high pressure possibly rooted all the way in Northern Canada and knifing it's way through our area. I've seen those type CAD events overperform before on a few occasions. Problem is it won't matter if there no cold available. A piece of the TPV has to drop down and provide some cold dry air to tap in to for us to get wintery.
The 12z Icon looked great and hopefully the Euro has a similar look.
It's looking increasing likely we will get the mega wedge with a high pressure possibly rooted all the way in Northern Canada and knifing it's way through our area. I've seen those type CAD events overperform before on a few occasions. Problem is it won't matter if there no cold available. A piece of the TPV has to drop down and provide some cold dry air to tap in to for us to get wintery.
tonysc
Member
Me too Mitch, I'm over here in Greenwood and I would love to see something like that.
R2R trend on the GEFS. Would love to see that trough around Atlantic Canada dig more, but taking the right steps here 
You can see at 500mb the ridge going up through AK and the Aleutian Low establishing itself. The SW trough is in the process of pinching off and will allow the core of the cold to drop in farther east:
The 850s showing up in western Canada are cold. This is probably underdone, given the height of the ridge going up.
You can see at 250 mb the howling jet across the south and the split flow out in the Pacific....kind of an Omega block look:
It shows up really well on the 2 PVU pressure map too:
Add in the strat warm and it's impact on the NAO that the models aren't even picking up on yet, and by Valentine's day, we're going to be rocking. I'm thinking a major winter storm for the SE around 2/18. Let's go!!
The 850s showing up in western Canada are cold. This is probably underdone, given the height of the ridge going up.
You can see at 250 mb the howling jet across the south and the split flow out in the Pacific....kind of an Omega block look:
It shows up really well on the 2 PVU pressure map too:
Add in the strat warm and it's impact on the NAO that the models aren't even picking up on yet, and by Valentine's day, we're going to be rocking. I'm thinking a major winter storm for the SE around 2/18. Let's go!!
Broken024
Member
If he’s in I’m in. Let’s do this.
This is the most impressive analysis of 384 hr output I've ever seen. I can't think of even a single thing that could derail this
The 850 0 degree moved from *checks notes* New York City to just between 40 and the border in NC on the GEFS around day ten.
Last edited:
It's over man just ask a few here that make sure we know they think it is
Euro unloads a TPV into the NE US at day 7 ? just need a southern stream wave to eject from out west 
Here comes a wave entering the western US 
You got a little something down there over Mex. Seems like it would probably get squashed, but who knows.
Has wedgie written all over it.