• 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!

Ostrich December

Webberweather53 said:
Definitely looks like all systems go from now thru mid-December, and we'll probably have the coldest air of the season knocking on our door step later in week 2 & we definitely won't be torching for a little while. High-latitude North Pacific blocking regimes like this one deliver the coldest patterns possible around here and they typically morph into -WPOs/+EPO/-PNA a week or so after the -EPO peaks.

View attachment 55143

View attachment 55144





I think we'll eventually start to transition to a more canonical Nina regime w/ Aleutian ridge/-PNA/SE ridge by the Winter Solstice (Dec 21st) or so give or take a few days, but there's some considerable uncertainty in this idea & we could go off the beaten path in a big/dramatic way. My current expectation is the whole North Pacific wave pattern will continue retrograding beyond mid-month, leading to the development of a -WPO/+EPO/-PNA w/ the establishment of a big Aleutian ridge in week 3, SE Canada vortex that initially delivers big shots of cold air towards the east-central US & retrogrades towards the Canadian Rockies/central Canada, destroying whatever -NAO we've established in the process & replacing it w/ a stout +NAO as we close in on the 4th week of December (Dec 21-28). Furthermore, the return of Indian Ocean convection next week as shown on both the GEFS & EPS, would give us a positive lag of about 10 days or so for a +NAO to reappear (putting us at Dec 20th ish).

Now, when exactly the transition to a more canonical NINA/SE ridge regime begins is dependent in large part on what initial state the NAO is in imo in addition to the evolution of subseasonal tropical forcing. If we get a very strong, persistent Greenland block/-NAO in week 2, it would probably delay the flip to a warmer regime a little longer, say towards Christmas (or even after that) instead of the Winter Solstice.

As it stands now, (& as I've discussed for a week or more), we should see a legit -EPO come calling in week 2 and deliver some seriously cold air into east-central N America by mid-December. After that the question mark is how long that pattern holds, I believe it will probably terminate around the winter solstice (Dec 21), but it realistically could take until after Christmas for that happen, and that's the only major change I've had in my thinking the past few days. In this latter case, where the good pattern holds thru Christmas thanks largely to the initially intense -NAO, we could be setup for something good in time for the heart of the Holiday Season. Regardless, I think it's at least probable if not likely that we'll eventually see a legit, prolonged warm spell settle in prior to the New Years in the SE US.

Thereafter, it's almost anyone's guess and remains to be seen what could happen, but it's not unrealistic to think we might see a better pattern return around mid-January or so, but that's largely speculation on my end & trying to anticipate how fast the tropical convection in the Indian Ocean propagates into the western Pacific again (it usually takes longer than usual in La Ninas).
Click to expand...
Webb, great job as always, even if I dont completely understand everything you post, lol
 
We're definitely about to get some major blocking.
PNA - The good: it is currently strongly positive. The bad: looks to go to neutral (through individual run averages) in the LR.
NAO - The good: about to go strongly negative. The bad: nothing really, except maybe it doesn't stay strongly negative (by average) in the LR
AO - The good: about to go strongly negative. The bad: same as NAO
CPC - Climate Weather Linkage: Teleconnections (noaa.gov)
 
Webberweather53 said:
Definitely looks like all systems go from now thru mid-December, and we'll probably have the coldest air of the season knocking on our door step later in week 2 & we definitely won't be torching for a little while. High-latitude North Pacific blocking regimes like this one deliver the coldest patterns possible around here and they typically morph into -WPOs/+EPO/-PNA a week or so after the -EPO peaks.

View attachment 55143

View attachment 55144





I think we'll eventually start to transition to a more canonical Nina regime w/ Aleutian ridge/-PNA/SE ridge by the Winter Solstice (Dec 21st) or so give or take a few days, but there's some considerable uncertainty in this idea & we could go off the beaten path in a big/dramatic way. My current expectation is the whole North Pacific wave pattern will continue retrograding beyond mid-month, leading to the development of a -WPO/+EPO/-PNA w/ the establishment of a big Aleutian ridge in week 3, SE Canada vortex that initially delivers big shots of cold air towards the east-central US & retrogrades towards the Canadian Rockies/central Canada, destroying whatever -NAO we've established in the process & replacing it w/ a stout +NAO as we close in on the 4th week of December (Dec 21-28). Furthermore, the return of Indian Ocean convection next week as shown on both the GEFS & EPS, would give us a positive lag of about 10 days or so for a +NAO to reappear (putting us at Dec 20th ish).

Now, when exactly the transition to a more canonical NINA/SE ridge regime begins is dependent in large part on what initial state the NAO is in imo in addition to the evolution of subseasonal tropical forcing. If we get a very strong, persistent Greenland block/-NAO in week 2, it would probably delay the flip to a warmer regime a little longer, say towards Christmas (or even after that) instead of the Winter Solstice.

As it stands now, (& as I've discussed for a week or more), we should see a legit -EPO come calling in week 2 and deliver some seriously cold air into east-central N America by mid-December. After that the question mark is how long that pattern holds, I believe it will probably terminate around the winter solstice (Dec 21), but it realistically could take until after Christmas for that happen, and that's the only major change I've had in my thinking the past few days. In this latter case, where the good pattern holds thru Christmas thanks largely to the initially intense -NAO, we could be setup for something good in time for the heart of the Holiday Season. Regardless, I think it's at least probable if not likely that we'll eventually see a legit, prolonged warm spell settle in prior to the New Years in the SE US.

Thereafter, it's almost anyone's guess and remains to be seen what could happen, but it's not unrealistic to think we might see a better pattern return around mid-January or so, but that's largely speculation on my end & trying to anticipate how fast the tropical convection in the Indian Ocean propagates into the western Pacific again (it usually takes longer than usual in La Ninas).
Click to expand...
Very well summarized, sir. The prolonged chill in the SE throughout the 7 day forecast (and beyond) has certainly gotten my hopes up, but as we all know, the cold air and the storm have to line up. At least we have a chance for everybody (EDIT: at least most) on this board to see something by Christmas if this all turns out like you've said.
 
Last edited:
Will Rossman said:
Very well summarized, sir. The prolonged chill in the SE throughout the 7 day forecast (and beyond) has certainly gotten my hopes up, but as we all know, the cold air and the storm have to line up. At least we have a chance for everybody on this board to see something by Christmas if this all turns out like you've said.
Click to expand...

It's going to snow in Miami? Lets go!!!!!!!!!!!!!
 
Will Rossman said:
Now that would be a miracle. Hasn't south FL seen flurries before? I feel like that happened during the winter of 09-10, unless I'm mistaken.
Click to expand...

It's happened twice. Flurries were widespread in the Miami area in the late morning hours of January, 19th, 1977 and isolated here during the pre-dawn hours of January, 10, 2010.
 
accu35 said:
Webb, great job as always, even if I dont completely understand everything you post, lol
Click to expand...

Np. What I'm basically saying here is that I think we have a decently good handle on the pattern the next 10 days or so, this giant +PNA regime progressively gives way to a -EPO by mid-month and truly arctic air starts to enter the pattern, giving us an opportunity or two for something wintry perhaps but that's heavily dependent on details atm and consider any snow/ice even in mid-Dec unlikely for now even w/ the favorable +TNH/-EPO look because we have drained Canada of cold air this week w/ the extreme +PNA/+EPO & it'll take some time to restore it.

There's a potential fork in the road around Dec 15th or so, where 2 scenarios could emerge. I'll explain the two extremes as I see them:

#1 (more likely): The -EPO/+TNH pattern gives way to a more classic La Nina look and the SE ridge comes back by or before the winter solstice (Dec 21), thus we warm up right before the Holidays.

#2 (less likely, but possible): We still get the favorable -EPO/+TNH mid-month (Alaskan ridge/SE Canada vortex >>> very cold), but the -NAO is much stronger late next week. Stronger -NAOs usually persist longer & are harder to get rid of than weaker ones which means we are more likely to delay the return of the SE US ridge & big warm up until after Christmas.

In summary, we're not gonna see a prolonged warm up the next few weeks, we might see a really big shot or two of arctic air near mid-month and perhaps an outside chance for snow/ice. After we hit Dec 15th, do warm-up by the Winter Solstice (Dec 21) or do we put the warm pattern on hold until even later in December & give ourselves a chance for snow/ice around Christmas? The answer to this question is largely dependent on what the NAO does in my opinion. A bigger -NAO next week and we may stand a chance for snow/ice even around Christmas (scenario 2), a weaker, transient -NAO and we are more likely to warm up before Christmas and possibly remain that way on into early January (scenario 1).

Hope this helps.
 
Last edited:
Webberweather53 said:
Definitely looks like all systems go from now thru mid-December, and we'll probably have the coldest air of the season knocking on our door step later in week 2 & we definitely won't be torching for a little while. High-latitude North Pacific blocking regimes like this one deliver the coldest patterns possible around here and they typically morph into -WPOs/+EPO/-PNA a week or so after the -EPO peaks.

View attachment 55143

View attachment 55144





I think we'll eventually start to transition to a more canonical Nina regime w/ Aleutian ridge/-PNA/SE ridge by the Winter Solstice (Dec 21st) or so give or take a few days, but there's some considerable uncertainty in this idea & we could go off the beaten path in a big/dramatic way. My current expectation is the whole North Pacific wave pattern will continue retrograding beyond mid-month, leading to the development of a -WPO/+EPO/-PNA w/ the establishment of a big Aleutian ridge in week 3, SE Canada vortex that initially delivers big shots of cold air towards the east-central US & retrogrades towards the Canadian Rockies/central Canada, destroying whatever -NAO we've established in the process & replacing it w/ a stout +NAO as we close in on the 4th week of December (Dec 21-28). Furthermore, the return of Indian Ocean convection next week as shown on both the GEFS & EPS, would give us a positive lag of about 10 days or so for a +NAO to reappear (putting us at Dec 20th ish).

Now, when exactly the transition to a more canonical NINA/SE ridge regime begins is dependent in large part on what initial state the NAO is in imo in addition to the evolution of subseasonal tropical forcing. If we get a very strong, persistent Greenland block/-NAO in week 2, it would probably delay the flip to a warmer regime a little longer, say towards Christmas (or even after that) instead of the Winter Solstice.

As it stands now, (& as I've discussed for a week or more), we should see a legit -EPO come calling in week 2 and deliver some seriously cold air into east-central N America by mid-December. After that the question mark is how long that pattern holds, I believe it will probably terminate around the winter solstice (Dec 21), but it realistically could take until after Christmas for that happen, and that's the only major change I've had in my thinking the past few days. In this latter case, where the good pattern holds thru Christmas thanks largely to the initially intense -NAO, we could be setup for something good in time for the heart of the Holiday Season. Regardless, I think it's at least probable if not likely that we'll eventually see a legit, prolonged warm spell settle in prior to the New Years in the SE US.

Thereafter, it's almost anyone's guess and remains to be seen what could happen, but it's not unrealistic to think we might see a better pattern return around mid-January or so, but that's largely speculation on my end & trying to anticipate how fast the tropical convection in the Indian Ocean propagates into the western Pacific again (it usually takes longer than usual in La Ninas).
Click to expand...
How would you say the possible weakening of the PV could set us up later in winter? I’ve been seeing posts that some models are really trying to mix the PV up .. will this help us by mid December or later down the line in January? I know there is a lag time between a weakened PV or even a split of the PV to how is translates cold air around the world.. obviously a weak PV gives anyone a shot at seeing that cold air so I suppose it’s more of a coin flip right now as to whether we can get those effects to help counter act the Nina pattern .. but interested in your thoughts on the topic.
 
Nick_boynton_ said:
How would you say the possible weakening of the PV could set us up later in winter? I’ve been seeing posts that some models are really trying to mix the PV up .. will this help us by mid December or later down the line in January? I know there is a lag time between a weakened PV or even a split of the PV to how is translates cold air around the world.. obviously a weak PV gives anyone a shot at seeing that cold air so I suppose it’s more of a coin flip right now as to whether we can get those effects to help counter act the Nina pattern .. but interested in your thoughts on the topic.
Click to expand...
The 0z canadian ensembles were super aggressive with the squeezing of the pv on their 0z rungem-ens_Tz10_nhem_33 (5).png
 
metwannabe said:
So are we still Ostriches here as it relates to a cold December? Asking for a friend.....
Click to expand...

4f1117065e4faeffbe55a8523525e33a.gif



Sent from my iPhone using Tapatalk
 
metwannabe said:
So are we still Ostriches here as it relates to a cold December? Asking for a friend..... ?
Click to expand...

Don't count your roosters and hens before they hatch. Don't count your goats before they're born. ;) Although I'd love for it to verify, I'm a realist who realizes that we're still far from getting a cold overall December. With the fantastic for cold +PNA looking to say bye bye (see below), the SE will per GEFS at least not have the support of the #1 index for most of the SE that is correlated to cold once we get to midmonth. So, mid to late month is way up in the air (no pun intended) as the SER is always lurking as a possibility when the +PNA goes away, especially with a mod to strong La Nina, and very warm W Pac. If we can manage to stay inside the MJO circle and go into the left side late month, that could save us and allow the cold to remain/return or at least keep it from warming to AN but we'll have to see:

1606928033005.png
 
You must log in or register to reply here.
Back
Top