January Med/Long Range Disco

[mitchnick]

Does the 12z EURO show any CAD at 96 hrs?  I would think it would show some with that 1046 H in the Northern Plains

850's a couple above 0

by day 5, Euro blows the cold front through so it's well below 0C but dry

[paulythegun]

Possibly, but GGEM has been proposing an ice storm for our area for I believe a few straight runs now

Here's the heaviest period of precip if anyone wants to see it. Ice storm for the NW, marginal around DC: 

 

[ravensrule]

Surface is a uniform 30-31 at hr96. Light ice before it get scoured out. With hp like that it could end up a few degrees colder of course.

What is the total QPF?.

[stormtracker]

Not very encouraging runs today.  But I have faith that trends will be colder with these sprawling highs around.

[nflwxman]

The euro suppresses the midweek storm to be an exclusively NC ice/light snow event.  The cold is certainly wedged in there per the Euro in that time frame.  

[Bob Chill]

What is the total QPF?.

Not much. Like .05. More would fall after 7am but looks like a non event on this particular run.

[H2O]

After the last couple events there is no way anyone should take what the Euro is showing for this 12z run as gospel.  Temps wont be resolved for days as HP placement and depth of a stale air mass have yet to be worked out

[yoda]

Light snow Day 8 for our area?  Or is that SLP too far east?

[AlaskaETC]

I agree that those sprawling highs could do us some favors. It would be nice to have a bit more variety beyond cold rain with these borderline events, which is nice, but somewhat unexciting.

 

I think the next few runs could see more variety.

[ravensrule]

Not much. Like .05. More would fall after 7am but looks like a non event on this particular run.

Thanks Bob.

[Bob Chill]

Dr. Cohen is now chasing February

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

 

 

January 8, 2015 Summary

• A positive to strongly positive AO will continue for the next week along with a positive North Atlantic Oscillation (NAO). Meanwhile, higher in the atmosphere, a minor sudden stratospheric warming (SSW) event has occurred with a split in the stratospheric polar vortex into two distinct centers.
• Extreme cold over the Central and Eastern US in the near term should relax to more seasonable cold next week before milder weather takes hold at the end of week 2. Extreme cold across Eastern Europe will also moderate, and a more seasonable regime will take hold across the continent.
• The downward propagation of negative AO conditions in the stratosphere will be slow to influence the tropospheric circulation, particularly if vortex recovery is slow as forecasted to be. Therefore, we anticipate near-neutral AO conditions to persist for much of the second half of January. This will promote a progressive flow pattern and periods of warmth and seasonable coolness hemispherically for the remainder of the month.
• Prospects for a negative AO remain fairly high into early February given the recent minor SSW, though some uncertainty on timing and the eventual strength of the negative state still remains.

 

 

The Dec 30th post said that the current warming event was the real deal and we could expect the -ao to go negative in mid to late Jan. The mets on Amwx agreed (at the same time Cohen posted the update) that the warming event was not going to be nearly large enough to make a big difference in the overall state of the AO. And they got it right. Yes, the strat PV split but it is going to be quite brief and it re-consolidates until further notice. 

 

I'm not sure how the recent event can be connected to a -ao in Feb. I'll let someone who knows something about that to explain further. I don't see how at this point the SAI doesn't bust this year. Dec came in at +.413. The first half of Jan is going to make it very very hard to get a neg reading for the month. I suppose Feb could go -5 or something. 

[WEATHER53]

Lot of temperature equivalents to Jan 1970 and 1982, neither ever thawed in Jan., Feb was around average.

[AlaskaETC]

Dr. Cohen is now chasing February

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

 

 

The Dec 30th post said that the current warming event was the real deal and we could expect the -ao to go negative in mid to late Jan. The mets on Amwx agreed (at the same time Cohen posted the update) that the warming event was not going to be nearly large enough to make a big difference in the overall state of the AO. And they got it right. Yes, the strat PV split but it is going to be quite brief and it re-consolidates until further notice. 

 

I'm not sure how the recent event can be connected to a -ao in Feb. I'll let someone who knows something about that to explain further. I don't see how at this point the SAI doesn't bust this year. Dec came in at +.413. The first half of Jan is going to make it very very hard to get a neg reading for the month. I suppose Feb could go -5 or something. 

Agreed, the SAI was a huge disappointment. February could be huge, of course.

[Bob Chill]

Agreed, the SAI was a huge disappointment. February could be huge, of course.

 

It could be but I'll never be convinced that it is connected to SAI if it happens. We're going to have a +AO for at least the first 7 weeks of met winter. There's no way to sugar coat that. We've had plenty of -AO winter months when there was nothing special about Oct snow stuff in eurasia. 

[Isotherm]

Dr. Cohen is now chasing February

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

 

 

The Dec 30th post said that the current warming event was the real deal and we could expect the -ao to go negative in mid to late Jan. The mets on Amwx agreed (at the same time Cohen posted the update) that the warming event was not going to be nearly large enough to make a big difference in the overall state of the AO. And they got it right. Yes, the strat PV split but it is going to be quite brief and it re-consolidates until further notice. 

 

I'm not sure how the recent event can be connected to a -ao in Feb. I'll let someone who knows something about that to explain further. I don't see how at this point the SAI doesn't bust this year. Dec came in at +.413. The first half of Jan is going to make it very very hard to get a neg reading for the month. I suppose Feb could go -5 or something. 

 

 

 

I think what the past couple years have proven is that the SAI (and might as well throw the OPI in there as well) is simply one tool that must be utilized in concert with all the other correlations and forcing mechanisms we examine for the creation of longer term outlooks. Last autumn, it was apparent by late November / early December that the EPO would be negative overall for the winter and thus aid in significantly muting the +AO / warm signal for the CONUS. The AO did finish positive as forecasted (Slightly so) but the resultant weather resembled a -AO winter due to the strong north pacific / -EPO ridging. This month will be colder than normal for most of the CONUS, but it again will be due largely to the -EPO forcing rather than Arctic or Atlantic help.

 

Regarding the AO, there are indications that we begin to trend negative by / post the 20th on both GFS and ECMWF guidance now. However, these model changes are probably due in part to improving tropical forcing over the next week-10 days as convection begins to propagate further ewd toward the dateline region. Minor SSW events (and this was a fairly impressive warming event at 10mb as shown below) do aid in tropospheric perturbation and increased tendency for the negative AO state 2-3 weeks following its occurrence. So if a negative AO does initiate in the last week or so of January, I think it's probably a combination of the stratospheric warming and improving tropical Pacific-forcing. The mean DJF AO number could still verify depending upon the outcome of the February AO state, but it would certainly need to be quite / very negative, especially to justify such a strong SAI signal from the preceding autumn. At this point, in order for the SAI to NOT be considered a bust this year, the AO needs to be slightly negative at MAXIMUM for the DJF average. Such an impressive SAI signal really suggested a strongly negative AO for DJF, but as said, February probably needs to be < -1.5 or or < -1.75 for such a verification.

 

Ultimately I think the AO average will end up negative for DJF, but I'm not sure of the magnitude. This winter thus far, to me, has been negatively impacted by heightened solar flux / geomagnetic activity, negating the effects of a -QBO and tightening the stratospheric vortex, as well as poor / Nina-like tropical forcing which has induced a strong +NAO regime to date.

 

Thankfully for many of our long range forecasts, I still believe the DJF period will be colder than normal for much of the East due to a combined very cold January/February. We'll see.

 

 

 

[AlaskaETC]

I think what the past couple years have proven is that the SAI (and might as well throw the OPI in there as well) is simply one tool that must be utilized in concert with all the other correlations and forcing mechanisms we examine for the creation of longer term outlooks. Last autumn, it was apparent by late November / early December that the EPO would be negative overall for the winter and thus aid in significantly muting the +AO / warm signal for the CONUS. The AO did finish positive as forecasted (Slightly so) but the resultant weather resembled a -AO winter due to the strong north pacific / -EPO ridging. This month will be colder than normal for most of the CONUS, but it again will be due largely to the -EPO forcing rather than Arctic or Atlantic help.

 

Regarding the AO, there are indications that we begin to trend negative by / post the 20th on both GFS and ECMWF guidance now. However, these model changes are probably due in part to improving tropical forcing over the next week-10 days as convection begins to propagate further ewd toward the dateline region. Minor SSW events (and this was a fairly impressive warming event at 10mb as shown below) do aid in tropospheric perturbation and increased tendency for the negative AO state 2-3 weeks following its occurrence. So if a negative AO does initiate in the last week or so of January, I think it's probably a combination of the stratospheric warming and improving tropical Pacific-forcing. The mean DJF AO number could still verify depending upon the outcome of the February AO state, but it would certainly need to be quite / very negative, especially to justify such a strong SAI signal from the preceding autumn. At this point, in order for the SAI to NOT be considered a bust this year, the AO needs to be slightly negative at MAXIMUM for the DJF average. Such an impressive SAI signal really suggested a strongly negative AO for DJF, but as said, February probably needs to be < -1.5 or or < -1.75 for such a verification.

 

Ultimately I think the AO average will end up negative for DJF, but I'm not sure of the magnitude. This winter thus far, to me, has been negatively impacted by heightened solar flux / geomagnetic activity, negating the effects of a -QBO and tightening the stratospheric vortex, as well as poor / Nina-like tropical forcing which has induced a strong +NAO regime to date.

 

Thankfully for many of our long range forecasts, I still believe the DJF period will be colder than normal for much of the East due to a combined very cold January/February. We'll see.

 

 

 

Good to hear about tropical forcing possibly improving. That was a concern of mine.

[Bob Chill]

Nice post, Isotherm. I'm a QBO skeptic. Seems to be the scapegoat this year but when I see December AO's like 2005 and JF AO's like 1966 I think it becomes way too muddy to say it was too negative this year or that was the real reason things went awry. I don't doubt that the sun/qbo etc impacts weather but I often hear most about them when things aren't going as planned. 

[CoastalWx]

Dr. Cohen is now chasing February

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

 

 

The Dec 30th post said that the current warming event was the real deal and we could expect the -ao to go negative in mid to late Jan. The mets on Amwx agreed (at the same time Cohen posted the update) that the warming event was not going to be nearly large enough to make a big difference in the overall state of the AO. And they got it right. Yes, the strat PV split but it is going to be quite brief and it re-consolidates until further notice. 

 

I'm not sure how the recent event can be connected to a -ao in Feb. I'll let someone who knows something about that to explain further. I don't see how at this point the SAI doesn't bust this year. Dec came in at +.413. The first half of Jan is going to make it very very hard to get a neg reading for the month. I suppose Feb could go -5 or something. 

 

It wasn't hard to see. I mean, I don't need a PhD to know that when the vortex bounces back and consolidates, it's not going to be easy to get a -NAO. Sometimes people need to take a step back and not be so literal with what is supposed to happen. Look at the data in front of you. We'll see what happens later this month. I don't see anything really until at least Feb in the -NAO dept. But that's just me. Maybe we get a bootleg earlier -NAO from any storm blowing up near Labrador.

[tnweathernut]

Nice post, Isotherm. I'm a QBO skeptic. Seems to be the scapegoat this year but when I see December AO's like 2005 and JF AO's like 1966 I think it becomes way too muddy to say it was too negative this year or that was the real reason things went awry. I don't doubt that the sun/qbo etc impacts weather but I often hear most about them when things aren't going as planned. 

I agree.  I have been a hobbyist for 20+ years and until this year hadn't heard much about it.

 

It seemed all the stars were in proper alignment heading into winter and when it didn't go the way it was supposed to, the heavily negative QBO was trotted out as the reason.  Not saying there isn't anything to this, but for some to speak about it like they are positive it's the culprit seems a stretch to me.  

 

There are just so many things we simply don't know enough about.

[mitchnick]

Cohen's forecast of warmer than normal temps last year busted, his AO - SHMAO dance he's doing now is with the hope that things some how change for him to save face. He doesn't have one scientific fact that he can rely on for the AO to go negative in FEB, unless you count a wing and a prayer as mass and electromagnetic energy. Sorry bub, step aside for the next, newest sealing wax salesman to appear (sorry Mick/Keith).

[snowfan]

Possibly, but GGEM has been proposing an ice storm for our area for I believe a few straight runs now

That 12Z run looked to have roughly 15mm (.6") of FZRA for DC. Extreme and not likely, but certainly enough to keep an eye on. 

[Ian]

Cohen's forecast of warmer than normal temps last year busted, his AO - SHMAO dance he's doing now is with the hope that things some how change for him to save face. He doesn't have one scientific fact that he can rely on for the AO to go negative in FEB, unless you count a wing and a prayer as mass and electromagnetic energy. Sorry bub, step aside for the next, newest sealing wax salesman to appear (sorry Mick/Keith).

 

Gotta kinda suck to put so much effort into a PhD and still be wrong all the time.

[Bob Chill]

It wasn't hard to see. I mean, I don't need a PhD to know that when the vortex bounces back and consolidates, it's not going to be easy to get a -NAO. Sometimes people need to take a step back and not be so literal with what is supposed to happen. Look at the data in front of you. We'll see what happens later this month. I don't see anything really until at least Feb in the -NAO dept. But that's just me. Maybe we get a bootleg earlier -NAO from any storm blowing up near Labrador.

 

I started getting the uneasy feeling during the first half of December. I made a few posts in Dec that things weren't going as planned (some in jest and others with true concern) but the consensus was that Dec was a toss month and it didn't matter. Most good -AO winters show their hand at some point in Dec. It was a pretty big flag that Dec did nothing except get worse in the blocking department all month. And the spiral has continued so far this month with pretty much a stout +AO. 

 

I think I can speak for almost everyone on the board....oh please let us get a solid AO for a month and actually have some real storms instead of these fast moving and flawed small messy events. 

[dallen7908]

...  but he's not wrong all of the time just half of the time. 

 

was ambushed by my son last night asking about next week's 6+ inch storm ... where does this come from? 

[MN Transplant]

GFS says it is raining at 15z Monday, but there is a hint of a leftover wedge in the dew points.

 

[Isotherm]

 

Nice post, Isotherm. I'm a QBO skeptic. Seems to be the scapegoat this year but when I see December AO's like 2005 and JF AO's like 1966 I think it becomes way too muddy to say it was too negative this year or that was the real reason things went awry. I don't doubt that the sun/qbo etc impacts weather but I often hear most about them when things aren't going as planned. 

 

 

 

Completely agree Bob about the strongly negative QBO. Some have been touting that it's the primary reason for the failure of AO blocking so far, but as you noted too, we've seen cases with good tropospheric blocking and a raging -QBO (2005, etc). The sample size is just too small to draw any conclusions about a severe -QBO signal.

 

The fact that this El Nino really hasn't acted like a Nino tropical forcing wise has been a major problem IMO. And I do believe the solar spike has played a role in preventing an earlier / more effective stratospheric event.

 

As coastalwx said, we'll see how the rest of the month ends up. NAO reversal by late January seems less likely than AO to me, the latter of which I think will begin to trend negative later this month due to more conducive tropospheric tropical forcing.

[usedtobe]

Nice post, Isotherm. I'm a QBO skeptic. Seems to be the scapegoat this year but when I see December AO's like 2005 and JF AO's like 1966 I think it becomes way too muddy to say it was too negative this year or that was the real reason things went awry. I don't doubt that the sun/qbo etc impacts weather but I often hear most about them when things aren't going as planned. 

I'm also a qbo skeptic and have noted that there have been big negative QBO years with a strongly negative AO. Also, I've actually seen papers that tout a negative QBO as being conducive to a negative AO.  There is too small a data set to know it's impact. 

[mitchnick]

our beloved HM's latest tweet      :-\

https://twitter.com/antmasiello

[HM]

This is why the QBO and sun must be used together: http://nldr.library.ucar.edu/repository/assets/osgc/OSGC-000-000-019-675.pdf

 

 

[SnowGoose69]

I agree.  I have been a hobbyist for 20+ years and until this year hadn't heard much about it.

 

It seemed all the stars were in proper alignment heading into winter and when it didn't go the way it was supposed to, the heavily negative QBO was trotted out as the reason.  Not saying there isn't anything to this, but for some to speak about it like they are positive it's the culprit seems a stretch to me.  

 

There are just so many things we simply don't know enough about.

 

There are probably some really small dumb ass things that control the AO and NAO that we don't realize, it may be even be something related to what occurs in the summer and fall weather.  Who knows, for all we know its possible the typhoon botched this winter, its entirely possible the whole chain of events that set off something mucked with the PV and AO.

forcing.