Pattern Marvelous March

[Webberweather53]

No blocking. what is keeping this suppressed besides the ridging and confluence and general s/w evolution? Nothing... this was my concern from the get go, we really need the cold and high to not trend the other direction. This is why I mentioned I wrote off March 1-5 (even though the models actually differ on the second wave and make it March 5), the second wave on March 5-6 looks much better to me and has the most potential for N.C. at least. But I think the first wave has the most potential for the SE as a whole so I see why people aren’t necessarily excited for wave 2. I just feel like we are lacking the substantial deep cold needed for wave 1 to work...but there’s still time for models to change so I wouldn’t give up yet..


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No, blocking actually isn't the problem.

It's pretty clear blocking isn't the issue when there's more of it on recent EPS runs over the NW Territories and Alaska and the +NAO is weaker, it's really the strength of the SE Canada/Lakes vortex and the interaction w/ the trailing s/w over the midwest that's caused recent runs to trend NW. Weaker Lakes vortex = weaker high descent east of the Rockies and the stronger trough over the midwest allows heights to rise over the SE US.

As crazy as this sounds to some, the problem (at least locally) is more blocking over the NW Territories and the equatorward propagating wavetrain associated w/ it.

In the end we may get a bigger dose of cold air out of this w/ stronger blocking over NW Canada but it definitely hurts our chances specifically w/ this first storm.

0z EPS from 2 days ago



Last night's 0z EPS

 

[mrdaddyman]

Not even close on the UKMET either. UKMET and EURO are in lockstep on the first system. Very hard to beat that combo.

 

[Jon]

No, blocking actually isn't the problem.

It's pretty clear blocking isn't the issue when there's more of it on recent EPS runs over the NW Territories and Alaska and the +NAO is weaker, it's really the strength of the SE Canada/Lakes vortex and the interaction w/ the trailing s/w over the midwest that's caused recent runs to trend NW. Weaker Lakes vortex = weaker high descent east of the Rockies and the stronger trough over the midwest allows heights to rise over the SE US.

As crazy as this sounds to some. the problem at least locally is more blocking over the NW Territories and the equatorward propagating wavetrain associated w/ it.

0z EPS from 2 days ago
View attachment 16630


Last night's 0z EPS
View attachment 16631

Just because there’s more blocking doesn’t mean blocking isn’t the problem. You’re telling me if we had a substantial -NAO we would have the same issue we have now? I have doubt, given that would be a very cold look with the current -EPO. When I mention blocking, I’m not talking about faux blocking, I’m talking about a real, deep, west based -NAO which is stout on basically any analog you find for deep SE snow or NC snow. If you’re talking about blocking in any sense of the word, then yeah it’s not worst case and technically it’s there but it’s not what I meant


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[Brick Tamland]

I don't think its all that crazy to say the euro could come back south at 12z. Unless I'm horribly mistaken, that's what it did from 0z to 12z yesterday

I think we went through this same thing with the December storm, too. It went north and came back south again with the snow. Just depends on where the cold temps set up. It was cold enough for me, but southern Wake didn't get hardly anything. This one looks to be more expansive in coverage. Instead of big totals, this might be more of a widespread 2 to 3 inches.

 

[Webberweather53]

Just because there’s more blocking doesn’t mean blocking isn’t the problem. You’re telling me if we had a substantial -NAO we would have the same issue we have now? I have doubt, given that would be a very cold look with the current -EPO. When I mention blocking, I’m not talking about faux blocking, I’m talking about a real, deep, west based -NAO which is stout on basically any analog you find for deep SE snow or NC snow. If you’re talking about blocking in any sense of the word, then yeah it’s not worst case and technically it’s there but it’s not what I meant


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Your argument doesn't hold up here because the NAO is both less positive and we have a stronger -EPO in later NWP runs but we don't have a storm in this timeframe, I think you're clearly missing the mark w/ what's actually the problem here. You also have to keep in mind how a -NAO gets there in the first place. It's from synoptic-scale planetary wave breaking, in particular big vortices breaking over SE Canada and off the eastern seaboard do that and that usually happens before the -NAO shows up.

The last several years have clearly shown (as have prior historical examples) that the -NAO is often not the answer to getting a winter storm in general around here. I'd hardly call North Pacific blocking faux" and is the one that's usually associated with deep-very deep south overrunning events. To get the best, board-wide event you need something to suppress the storm track and provide cold air into the mix, a vortex over SE Canada is almost always the answer to that in some way shape or form, the -NAO can certainly foster one but the EPO/WPO are present more often in those cases.

I've also shown previously what the pattern looked like for the biggest winter storms in central NC during the month of March and a west based -NAO is certainly there but there's a stronger signal for North Pacific blocking. It's no coincidence that once the big vortex over Atlantic Canada and New England faded in the models so did the threat for a storm in March 3-4, the blocking upstream over the NP and in the Atlantic actually trended favorably.

The problem is obvious, the vortex over New England & SE Canada is virtually gone and lifting out in recent NWP runs, the blocking encapsulating it has less to do w/ it and actually has trended to keep the vortex around longer & dig equatorward.

 

[ForsythSnow]

Definitely not the trends you want to see from overnight. More non snow members and as mentioned because of the ongoing change in the GL high and other features. If mentioned continues we might as well throw this last hope in the trash can and move on.

 

[Brick Tamland]

Definitely not the trends you want to see from overnight. More non snow members and as mentioned because of the ongoing change in the GL high and other features. If mentioned continues we might as well throw this last hope in the trash can and move on.

Well, we went from the Euro not showing anything Sunday to a big hit for NC just yesterday afternoon, to looking less impressive overnight. We know how these storms can go back and forth on the models in less than 24 hours.

 

[Jon]

Your argument doesn't hold up here because the NAO is both less positive and we have a stronger -EPO in later NWP runs but we don't have a storm in this timeframe, I think you're clearly missing the mark w/ what's actually the problem here. You also have to keep in mind how a -NAO gets there in the first place. It's from synoptic-scale planetary wave breaking, in particular big vortices breaking over SE Canada and off the eastern seaboard do that and that usually happens before the -NAO shows up.

The last several years have clearly shown (as have prior historical examples) that the -NAO is often not the answer to getting a winter storm in general around here. I'd hardly call North Pacific blocking faux" and is the one that's usually associated with deep-very deep south overrunning events. To get the best, board-wide event you need something to suppress the storm track and provide cold air into the mix, a vortex over SE Canada is almost always the answer to that in some way shape or form, the -NAO can certainly foster one but the EPO/WPO are present more often in those cases.

I've also shown previously what the pattern looked like for the biggest winter storms in central NC during the month of March and a west based -NAO is certainly there but there's a stronger signal for North Pacific blocking. It's no coincidence that once the big vortex over Atlantic Canada and New England faded in the models so did the threat for a storm in March 3-4, the blocking upstream over the NP and in the Atlantic actually trended favorably.

The problem is obvious, the vortex over New England & SE Canada is virtually gone and lifting out in recent NWP runs, the blocking encapsulating it has less to do w/ it and actually has trended to keep the vortex around longer & dig equatorward.
View attachment 16634

Would a traditional -NAO not keep a 50/50 low in place? What is keeping the vortex from staying? Isn’t it a true -NAO or at least blocking more east than depicted? I get what you’re saying just trying to wrap my brain around why a true -NAO and 50/50 wouldn’t be better and the NW territory block would be better


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[ForsythSnow]

Well, we went from the Euro not showing anything Sunday to a big hit for NC just yesterday afternoon, to looking less impressive overnight. We know how these storms can go back and forth on the models in less than 24 hours.

If you read any of what Webber said you would know what is causing this. We had grown in chance because of a better setup with the GL high and now that it is looking less likely due to other factors around the world it is on the negative trend. Sure it could in theory come back but it's losing likelihood.

 

[Brick Tamland]

If you read any of what Webber said you would know what is causing this. We had grown in chance because of a better setup with the GL high and now that it is looking less likely due to other factors around the world it is on the negative trend. Sure it could in theory come back but it's losing likelihood.

It's losing likelihood because the runs look different in less than 24 hours from yesterday? If they can change that way in less than 24 hours, then they could change back, too.

 

[jackendrickwx]

It's losing likelihood because the runs look different in less than 24 hours from yesterday? If they can change that way in less than 24 hours, then they could change back, too.

Yes, it is losing likelihood now because the runs are looking bad. If they come back, the chances increase

 

[ForsythSnow]

It's losing likelihood because the runs look different in less than 24 hours from yesterday? If they can change that way in less than 24 hours, then they could change back, too.

At a lower likelihood as we approach verification. And if it trends worse today it'll only make it less likely.

On the other hand, we now have this. Drag this west more and there would be a nice Miller A potential I would say. Not beneficial for you, but for others to the west.

 

[ajr]

No, blocking actually isn't the problem.

It's pretty clear blocking isn't the issue when there's more of it on recent EPS runs over the NW Territories and Alaska and the +NAO is weaker, it's really the strength of the SE Canada/Lakes vortex and the interaction w/ the trailing s/w over the midwest that's caused recent runs to trend NW. Weaker Lakes vortex = weaker high descent east of the Rockies and the stronger trough over the midwest allows heights to rise over the SE US.

As crazy as this sounds to some, the problem (at least locally) is more blocking over the NW Territories and the equatorward propagating wavetrain associated w/ it.

In the end we may get a bigger dose of cold air out of this w/ stronger blocking over NW Canada but it definitely hurts our chances specifically w/ this first storm.

0z EPS from 2 days ago
View attachment 16630


Last night's 0z EPS
View attachment 16631

This could be a misinterpretation of the pattern, but it seems like as the PV is weakening that more blocking from the NW is amplifying the cold drive... so at the surface, while we're losing our NE cold source, the NE cold source is (more slowly) able to build in. Thoughts?

 

[Brick Tamland]

At a lower likelihood as we approach verification. And if it trends worse today it'll only make it less likely.

On the other hand, we now have this. Drag this west more and there would be a nice Miller A potential I would say. Not beneficial for you, but for others to the west.

Okay, but if we are looking at one storm around the 6th, we still have 7 days to go. We've seen storms go away and then come back 3 days out before. I just think a change on the models in less than 24 hours is not that big of a deal this far out.

 

[jackendrickwx]

Okay, but if we are looking at one storm around the 6th, we still have 7 days to go. We've seen storms go away and then come back 3 days out before. I just think a change on the models in less than 24 hours is not that big of a deal this far out.

While I agree (to a degree) I think we are way too close for comfort to this storm being a non-event as of right now. But I would agree we do have time. We're just running out of it

 

[snowlover91]

The 12z runs today will be important to see if the first system holds with the track or if models shift back south and colder some, especially the Euro. This is a fairly sensitive 5h setup but we are getting to the point where we need this to shift back favorably for the first wave in the next 36-48 hours. If not we will have to hope it can set the stage for the second wave.

 

[Webberweather53]

Would a traditional -NAO not keep a 50/50 low in place? What is keeping the vortex from staying? Isn’t it a true -NAO or at least blocking more east than depicted? I get what you’re saying just trying to wrap my brain around why a true -NAO and 50/50 wouldn’t be better and the NW territory block would be better


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A traditional -NAO lowers heights off the eastern seaboard and favors Miller A/coastal cyclones w/ any vortex displaced near or just east of Atlantic Canada. The airmasses are usually modified over the continent relative to a -EPO/WPO because North Pacific blocking generates cross-polar flow that deposits arctic and Siberian air into North America, the problem usually is that the airmasses struggle to reach the SE US, but when they do, the chances of scoring are really high. Contrarily, those during a -NAO often reach the SE US w/ ease but are increasingly marginal even when the strongest anomalies are centered overhead because they're typically weaker cP air masses that are formed in-situ in north-central Canada.

Well, that's the interesting part, the vortex actually is in fact staying around longer here because we have stronger blocking overall, the upstream wavetrain in the North Pac is stronger which also means the wavelengths associated w/ it shorten & therefore bigger piece of our vortex is taking its sweet time to leave the Rockies instead of already sliding off towards New England in front of the March 3-4 storm like it was forecast to do a few days ago. Also notice the heights are rising over the Baffin Bay w/ successive runs of the EPS.



If you take a composite of the biggest 20-25 overrunning events in the southern US, you end up w/ this:
Our March 3-4 storm trended away from that w/ a weaker New England/SE Canada vortex and one that's displaced closer to the Rockies, but the same can not be said w/ the next storm.



Not surprisingly, it's very close to the March composite I've shown multiple times here.

Furthermore, if you project the -EPO pattern onto this composite, you'll get a much larger signal than w/ the -NAO, but both are present to some extent.

In fact the EPO explains almost all of the large-scale variability in the above composite and is also correlated w/ + height anomalies in the Baffin Bay.



This clearly shows that lack of blocking is not the problem, it's actually because we have more of it that recent runs have trended away from a SE US storm on March 3-4. In the long run, it's not hurting our chances w/ the March 5-6 storm & we'll end up w/ a bigger cold shot at the end if we continue along this path.

 

[snowlover91]

There is still a pretty significant degree of variability among ensemble members and global model timing. The Euro/UK are a bit faster with the system than the GFS/GEFS is, by about roughly 24 hours. Even among GEFS members you can clearly see there is a significant amount of variance in timing, amount of cold and precip to work with.

 

[Jon]

A traditional -NAO lowers heights off the eastern seaboard and favors Miller A/coastal cyclones w/ any vortex displaced near or just east of Atlantic Canada. The airmasses are usually modified over the continent relative to a -EPO/WPO because North Pacific blocking generates cross-polar flow that deposits arctic and Siberian air into North America, the problem usually is that the airmasses struggle to reach the SE US, but when they do, the chances of scoring are really high. Contrarily, those during a -NAO often reach the SE US w/ ease but are increasingly marginal even when the strongest anomalies are centered overhead because they're typically weaker cP air masses that are formed in-situ in north-central Canada.

Well, that's the interesting part, the vortex actually is in fact staying around longer here because we have stronger blocking overall, the upstream wavetrain in the North Pac is stronger which also means the wavelengths associated w/ it shorten & therefore bigger piece of our vortex is taking its sweet time to leave the Rockies instead of already sliding off towards New England in front of the March 3-4 storm like it was forecast to do a few days ago. Also notice the heights are rising over the Baffin Bay w/ successive runs of the EPS.

View attachment 16636

If you take a composite of the biggest 20-25 overrunning events in the southern US, you end up w/ this:
Our March 3-4 storm trended away from that w/ a weaker New England/SE Canada vortex and one that's displaced closer to the Rockies, but the same can not be said w/ the next storm.

View attachment 16637

Not surprisingly, it's very close to the March composite I've shown multiple times here.

Furthermore, if you project the -EPO pattern onto this composite, you'll get a much larger signal than w/ the -NAO, but both are present to some extent.

In fact the EPO explains almost all of the large-scale variability in the above composite and is also correlated w/ + height anomalies in the Baffin Bay.
View attachment 16638


This clearly shows that lack of blocking is not the problem, it's actually because we have more of it that recent runs have trended away from a SE US storm on March 3-4. In the long run, it's not hurting our chances w/ the March 5-6 storm & we'll end up w/ a bigger cold shot at the end if we continue along this path.

Thanks for the explanation. Makes some sense for the 3-4 storm although you do lose me in some aspects, just goes to show we always have more to learn. This is largely why I wrote of 3-4 early and has my focus on 5-6, even though it’s from a basic standpoint

This was the look I’d like to have that we clearly don’t have and what I like to see when tracking literally any storm. But your argument goes to show yet another reason why there’s always exceptions to the rule. Science is wild

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[BHS1975]

Yeap looks more like a colder more powdery snow on March 5-6 after the cold rain.


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[KyloG]

Haven't really looked at models until now, was expecting worse than this though. I am sure this has been said already but a slightly slower wave on Monday would help too.

 

[mrdaddyman]

Well that's an understatement.

 

[Webberweather53]

Thanks for the explanation. Makes some sense for the 3-4 storm although you do lose me in some aspects, just goes to show we always have more to learn. This is largely why I wrote of 3-4 early and has my focus on 5-6, even though it’s from a basic standpoint

This was the look I’d like to have that we clearly don’t have and what I like to see when tracking literally any storm. But your argument goes to show yet another reason why there’s always exceptions to the rule. Science is wild

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If you think about in a basic sense, heights at 500mb are related to the mean temperature in the column (cold air more dense and takes up less space), so you have to ask yourself which pattern is going to produce the lowest possible heights and coldest potential air masses over SE Canada and the Great Lakes? North Pacific blocking because it injects the coldest possible air masses over the N Hem into North America.

That's not to say a North Atlantic block can't produce a similar pattern, but again because the air masses are typically more marginal, that feature will usually be weaker.

-NAOs really just tend to increase the frequency of coastal cyclone/Miller A events here in NC.

If you look elsewhere on this board to areas like SC, GA, AL, MS, LA, etc. the evolutionary stage of most of their biggest winter storms is anafrontal or a weak frontal wave. Having a -NAO doesn't really hurt them (or even us) because the storm is usually not mature enough yet for the downstream -NAO to matter, but NC is at the peculiar inflection point on the eastern seaboard where coastal lows consume enough of our snowfall climatology that it actually matters to us somewhat but a large proportion of our biggest storms are also overrunning/anafronts. The further north you go towards the Mid-Atlantic & New England, the biggest storms are almost exclusively Miller A cyclones, with overrunning playing second or third fiddle which is largely why having a -NAO is so critical from around northern VA & Maryland and points north.

 

[snowlover91]

I'm not sure why people are giving up already over one set of runs that wasn't as favorable. Sure the Euro and UK 00z runs weren't that great and neither was the 00z GEFS. It showed very light totals from most members with the first wave.


Yet the 6z run bounced back and as I posted previously there is a lot of internal variability between models in regards to timing, 5h setup and amount of cold to work with for this first wave. The 6z GEFS was a noticeable increase compared with it's previous run. Also keep in mind these maps on COD are pure snow maps and filter out any ice, some of the members have some mixing in NC


We need to realize that with this being 6-7 days out, depending on the timing, there is still going to be some fairly significant changes with regards to the timing and 5h setup. Today and tomorrow are the critical days imo, if you live in NC you want to see this trend better especially the Euro/UK. I think for this first storm NC has the best shot at some wintry weather of anyone in the SE. The second wave could bring more people in the game but it's still 8-10 days out depending on the model and timing.

 

[Webberweather53]

I'm not sure why people are giving up already over one set of runs that wasn't as favorable. Sure the Euro and UK 00z runs weren't that great and neither was the 00z GEFS. It showed very light totals from most members with the first wave.
View attachment 16643

Yet the 6z run bounced back and as I posted previously there is a lot of internal variability between models in regards to timing, 5h setup and amount of cold to work with for this first wave. The 6z GEFS was a noticeable increase compared with it's previous run. Also keep in mind these maps on COD are pure snow maps and filter out any ice, some of the members have some mixing in NC
View attachment 16644

We need to realize that with this being 6-7 days out, depending on the timing, there is still going to be some fairly significant changes with regards to the timing and 5h setup. Today and tomorrow are the critical days imo, if you live in NC you want to see this trend better especially the Euro/UK. I think for this first storm NC has the best shot at some wintry weather of anyone in the SE. The second wave could bring more people in the game but it's still 8-10 days out depending on the model and timing.

The reason I'm backing off on the first wave has more to do w/ the large-scale changes in the pattern that are clearly leading us to a much warmer solution w/ the vortex holding back towards the Rockies instead of Atlantic Canada. This isn't just random, model internal variability like you're assuming it to be, it's pretty obvious why the solutions look different now. If this feature goes back to where it was a few days ago then it might be worth watching again for something substantial east of the Apps w/ the first storm.

 

[Brick Tamland]

I'm not sure why people are giving up already over one set of runs that wasn't as favorable. Sure the Euro and UK 00z runs weren't that great and neither was the 00z GEFS. It showed very light totals from most members with the first wave.
View attachment 16643

Yet the 6z run bounced back and as I posted previously there is a lot of internal variability between models in regards to timing, 5h setup and amount of cold to work with for this first wave. The 6z GEFS was a noticeable increase compared with it's previous run. Also keep in mind these maps on COD are pure snow maps and filter out any ice, some of the members have some mixing in NC
View attachment 16644

We need to realize that with this being 6-7 days out, depending on the timing, there is still going to be some fairly significant changes with regards to the timing and 5h setup. Today and tomorrow are the critical days imo, if you live in NC you want to see this trend better especially the Euro/UK. I think for this first storm NC has the best shot at some wintry weather of anyone in the SE. The second wave could bring more people in the game but it's still 8-10 days out depending on the model and timing.

That is what I have been trying to say, too. I think the 6th is really the time we should be looking at. The first wave just might be more noise than anything, and like you said we are still a week out if we really only get one storm on the 6th.

 

[snowlover91]

The reason I'm backing off on the first wave has more to do w/ the large-scale changes in the pattern that are clearly leading us to a much warmer solution w/ the vortex holding back towards the Rockies instead of Atlantic Canada. This isn't just random, model internal variability like you're assuming it to be, it's pretty obvious why the solutions look different now. If this feature goes back to where it was a few days ago then it might be worth watching again for something substantial east of the Apps w/ the first storm.

There is considerable internal variability among ensemble members at this stage that effects their 5h setup, timing, etc. I'm well aware of the synoptics behind why we have a different setup and how that effects what the models show. I'm pointing out that there is still a considerable degree of variance among the globals and their ensemble members at this time and things could easily shift back or to a warmer solution as well.

 

[Webberweather53]

There is considerable internal variability among ensemble members at this stage that effects their 5h setup, timing, etc. I'm well aware of the synoptics behind why we have a different setup and how that effects what the models show. I'm pointing out that there is still a considerable degree of variance among the globals and their ensemble members at this time and things could easily shift back or to a warmer solution as well.

It could be internal variability that's forcing the warmer solutions, but that seems unlikely because the stronger North Pac/NW Territories block that's leading to a NW/less snowy trend for us w/ the March 3-4 storm has been consistently getting more intense in the models for the past several runs and that's forcing our big vortex to hang back longer towards the Rockies, pumping the heights over the SE US and western Atlantic... It's far less likely to be random if said signal that's forcing changes in the observed response is happening run after run.

 

[NickyBGuarantee]

I think if you live in NC I don’t think you could have asked for a better set up than this. We might be able to squeak out two events. Unfortunate for the real Deep South east states is that they usually never really get a whole bunch of winter weather regardless.. sorry guys ... time for NC to rob y’all again (maybe if you stop being so negative all the time the models may trend ur way someday)

 

[NickyBGuarantee]

Models are tools ... they aren’t going to show u the right answer 5 DAYS OUT let alone 7!

 

[snowlover91]

It could be internal variability that's forcing the warmer solutions, but that seems unlikely because the stronger North Pac/NW Territories block that's leading to a NW/less snowy trend for us w/ the March 3-4 storm has been consistently getting more intense in the models for the past several runs and that's forcing our big vortex to hang back longer towards the Rockies, pumping the heights over the SE US and western Atlantic... It's far less likely to be random if said signal that's forcing changes in the observed response is happening run after run.

I haven't seen the 6z panels come out but there are some significant differences between the various GEFS members at the 5h level in both the NW PAC blocking as well as the position and strength of our vortex from the 00z suite. Members 6 and 14 were both snowy members on the it.

 

[GaWx]

From Radiant this morning: their forecast for March 3-7 is for the 2nd coldest on a national energy usage based weighted heating degree day basis since 1950 at 182.45 HDD. This is only 6 HDD warmer than the great 1960! The next coldest, 1978, is way back at 167 HDD!

This is the reason I think there is so much more SE wintry potential in this year’s early March than almost any other one in our lifetime. This doesn’t at all mean the SE will definitely get the goods as some model runs have shown, but it does up the ante way higher than normal because the right H5 setup could result in rare early March major wintry in the SE thanks to that very cold air to the NW . I think the fact that the very intense cold is not plunging into the SE and is instead meeting resistance and putting the SE near the bottom of the cold actually raises the SE’s chances (WSW H5 flow with a weak south enough Gulf surface low as opposed to dry WNW flow), but we still obviously need enough of the cold air to get into the SE.

Here are the top 10 coldest March 3-7 nationally since 1950 with 2019’s Radiant forecast in comparison:

“Below are the GWHDD rankings for the period from March 3-7. Historical data dates back to 1950.

Rank
Period
Sum
1
Mar-3 1960 - Mar-7 1960
188.91
6-10 Day Forecast
182.45
2
Mar-3 1978 - Mar-7 1978
167.27
3
Mar-3 2014 - Mar-7 2014
157.13
4
Mar-3 1962 - Mar-7 1962
154.07
5
Mar-3 2015 - Mar-7 2015
151.79
6
Mar-3 1954 - Mar-7 1954
149.51
7
Mar-3 2003 - Mar-7 2003
148.42
8
Mar-3 1952 - Mar-7 1952
148.36
9
Mar-3 1989 - Mar-7 1989
146.88
10
Mar-3 1982 - Mar-7 1982
146.86

 

[BHS1975]

Yeap if it’s timed right we can get that nice powder which I would gladly trade in for that slop we had in December.


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[tonysc]

Yeap if it’s timed right we can get that nice powder which I would gladly trade in for that slop we had in December.


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Amen and hallelujah to that.

 

[Six Mile Wx]

The icon definitely has the 850 cold air in place for the second potential

 

[Tarheel1]

From Radiant this morning: their forecast for March 3-7 is for the 2nd coldest on a national energy usage based weighted heating degree day basis since 1950 at 182.45 HDD. This is only 6 HDD warmer than the great 1960! The next coldest, 1978, is way back at 167 HDD!

This is the reason I think there is so much more SE wintry potential in this year’s early March than almost any other one in our lifetime. This doesn’t at all mean the SE will definitely get the goods as some model runs have shown, but it does up the ante way higher than normal because the right H5 setup could result in rare early March major wintry in the SE thanks to that very cold air to the NW . I think the fact that the very intense cold is not plunging into the SE and is instead meeting resistance and putting the SE near the bottom of the cold actually raises the SE’s chances (WSW H5 flow with a weak south enough Gulf surface low as opposed to dry WNW flow), but we still obviously need enough of the cold air to get into the SE.

Here are the top 10 coldest March 3-7 nationally since 1950 with 2019’s Radiant forecast in comparison:

“Below are the GWHDD rankings for the period from March 3-7. Historical data dates back to 1950.

Rank
Period
Sum
1
Mar-3 1960 - Mar-7 1960
188.91
6-10 Day Forecast
182.45
2
Mar-3 1978 - Mar-7 1978
167.27
3
Mar-3 2014 - Mar-7 2014
157.13
4
Mar-3 1962 - Mar-7 1962
154.07
5
Mar-3 2015 - Mar-7 2015
151.79
6
Mar-3 1954 - Mar-7 1954
149.51
7
Mar-3 2003 - Mar-7 2003
148.42
8
Mar-3 1952 - Mar-7 1952
148.36
9
Mar-3 1989 - Mar-7 1989
146.88
10
Mar-3 1982 - Mar-7 1982
146.86

Even if the brutal cold air gets into the Plains, we’ve still got to find a way to get it to the SE! Remember the last cold outbreak where Chicago set all time records, and we were barely below norma!?

 

[Rain Cold]

A PV residing in south central Canada is not going to do the trick. Webber showed how one model had it trending from SE Canada to SC Canada. No good. It needs to be east. It will allow high pressure to build in and will help to squash the SER.

 

[Jimmy Hypocracy]

No this system won’t we modeled correctly 7 days out but the bleeding has to stop here at 12z. That big vortex needs to improve

 

[jackendrickwx]

ICON has that first system south of euro.

 

[Jimmy Hypocracy]

A PV residing in south central Canada is not going to do the trick. Webber showed how one model had it trending from SE Canada to SC Canada. No good. It needs to be east. It will allow high pressure to build in and will help to squash the SER.

Yep that big PV centered in eastern Candada US a week ago isn’t aging well atm