Ending out December with a Potential Pattern Change

[JC-CT]

This is literally all going to plan. I know you have been saying that Scott, but it is worth repeating.

[CT Valley Snowman]

nice write up. for thosewho don't want a big storm around Christmas, particularly if it is rain or think the pattern doesn't support it this is a good explanation for why it will probably happen. like I wrote several days ago if the trade off is a more favorable pattern with weeks of winter it is worth it. my concern like most weenies is that we could transition from warm and wet or cold and dry but you always have to take your chances with the cold

[CT Valley Snowman]

is there a met in here who could possibly explain why after a pattern transition takes place we will still likely be in an active stormy pattern versus cold and dry.

[J Paul Gordon]

Thanks for the write up, Mike. The question for us in SNE will be cold and dry versus cold and wet. We're certainly going to get mild and wet!

[Damage In Tolland]

Thanks for the write up, Mike. The question for us in SNE will be cold and dry versus cold and wet. We're certainly going to get mild and wet!

Don't count on that

[Baroclinic Zone]

is there a met in here who could possibly explain why after a pattern transition takes place we will still likely be in an active stormy pattern versus cold and dry.

In my non-scientific head, it's a re-shuffling of all the players on the field.   

[CoastalWx]

nice write up. for thosewho don't want a big storm around Christmas, particularly if it is rain or think the pattern doesn't support it this is a good explanation for why it will probably happen. like I wrote several days ago if the trade off is a more favorable pattern with weeks of winter it is worth it. my concern like most weenies is that we could transition from warm and wet or cold and dry but you always have to take your chances with the cold

 

That's what I posted in the beginning of this thread. That deep trough  in the second image, is what will carve a big storm out, but it likely won't be snowy. This is a fairly typical response to a pattern like this.  It's also a good way to try and ignite a -NAO when the atmosphere is in a state that would allow it to happen.

[CoastalWx]

is there a met in here who could possibly explain why after a pattern transition takes place we will still likely be in an active stormy pattern versus cold and dry.

 

Forecasting temps is difficult enough and forecasting snow is almost twice as hard given the variances that go into it. With ridging in AK, weak -NAO at the least, and the possibility of weak SE ridging...the storm track could be close by. That's usually a good recipe for snow, but the details to specifically say how snowy it will be a nearly impossible to see at this point.

[40/70 Benchmark]

I guess if you look at 50 degrees and rain vs 35 degrees and rain as somewhat of a moral victory then that is great but otherwise it is still disappointing

I'd rather lose out to Chicago, than ORH, Dendrite, moneyb*tch mike, and Tolland.

[CoastalWx]

I'd rather lose out to Chicago, than ORH, Dendrite, moneyb*tch mike, and Tolland.

 

This is also a good pattern for some OES CJ!

[TauntonBlizzard2013]

We've had some pretty big storms already this year. I think the pattern is fine for a cutter on Christmas. I actually think the 12/21 storm missing is the exception to this point.

We need something to transition thigs, and the Christmas storm may do it

[Ginx snewx]

Pretty much as planned from my 8 week forecast issued 11-3 , Grinch then entire country cold was my call, just need a big snowstorm to end the year as I also called for that.

[CT Valley Snowman]

yes taking a look at the weather bell telleconnections forecasts, I see the AO and NAO going negative EPO going negative the PNA negative but trending positive. The CFS v2 looks cold throughout January. With El Nino and an active subtropical jet I don't see any reason why we can't deliver. Can anyone explain perhaps what effect if any the MJO will have on the January pattern ?

[40/70 Benchmark]

Pretty much as planned from my 8 week forecast issued 11-3 , Grinch then entire country cold was my call, just need a big snowstorm to end the year as I also called for that.

I thought the pattern would have evolved enough by Xmas to allow for a wintrier outcome than the ugly cutter that is currently modeled, but at least the holiday tempest looks to alter the playing field, as expected.

[CoastalWx]

So lets go over this again. This is a classic response to the pattern reshuffle. 

 

Cold trough digs into the Plains, heights rise in the east and we have no blocking. Not a great outcome for those who want snow near Christmas, but the details are yet to be determined. Expectations probably should be low, regardless.

 

Hr 144.

 

 

 

Two days later. Notice heat flux pushing north into the Davis Straits.

 

 

 

 

 

Another two days later, at hr 240, the pattern is in place. Note this -NAO ridge is just a ridge and not a block. This means the longevity of this feature is in question, but it may be there in some shape or form through hr 360. It seems like the stratosphere is trying to relinquish its cyclonic stranglehold it has had for a couple of years now, but we'll see if it can truly split.

 

 

[J Paul Gordon]

Don't get the snowstorm envy thing...those who have a little envying those who have a lot... but then again, I'm not Freud (another thing to be happy about).

 

So this pattern change looks like a highly likely event, or is it just one of many potentials right now? There has been a lot of proclaiming, "its coming, its coming" on this board (often at the end of  the Euro ten day prognostics). What can screw this up in terms of real meteorology? HOW likely is it? Are we looking at a March 2014 situation in SNE with lots of cold but not much precip (at least frozen). 

 

I do understand that predicting storms at any distance out is just about impossible (look at the 12/21 non event and the annual Grinch storm--both of which had many potentials at one point). Is predicting cold/warm scenarios much more reliable?

In other words, how much is just plain roll of the dice?

[Ginx snewx]

I thought the pattern would have evolved enough by Xmas to allow for a wintrier outcome than the ugly cutter that is currently modeled, but at least the holiday tempest looks to alter the playing field, as expected.

actually not unhappy the 21st is a fail as losing that cover would really be Grinch like. Once that's over it will be patience grass hoppers. I fully expect the cold and dry then rainer crowd to be out in full force. Pattern is primed. I hate chasing patterns,some here love it, I would much rather chase snowstorms but for the next ten days it's snooze worthy. Time for a long winters nap, wake me up Christmas night.

[alex]

At least GYX gives *some* hope for Xmas... but doesn't give me a lot of comfort. I have a whole family coming up from Italy to ski, a big rainstorm would really really really suck:

 

FINALLY THE EURO AND GFS ARE STILL SHOWING A LARGE STORM FOR
CHRISTMAS EVE AND/OR CHRISTMAS DAY...HOWEVER WHERE IT WILL BE AND
TRACK TO IS STILL ANYONES GUESS. WE WILL CONTINUE TO MONITOR THE
POTENTIAL OVER THE NEXT SEVERAL DAYS. THERE IS ALREADY A LOT OF
RUN TO RUN DISCONTINUITY COMING WITH THE LOCATION OF THE LOW AND
THIS FAR OUT THAT IS EXPECTED...AS BOTH MODELS JUST WENT FROM A
COASTAL LOW WITH THE 12Z RUNS TO A WARM CUTTER WITH THE 00Z RUNS.
SO ALL WE CAN DO AT THIS TIME IS SEE HOW IT EVOLVES AS WE HEAD
INTO NEXT WEEK...AS THE ENERGY TO DEVELOP THIS STORM WILL NOT EVEN
BE SAMPLED WITH REAL DATA FOR SEVERAL DAYS YET.

[PivotPoint]

Scott,

 

You'd be the one to answer a question like this -- just out of curiosity, what features could change/evolve to bring the xmas storm along a track more conducive for snow in NNE? I figure a costal snow event is pretty much off the table, but so I can keep learning here, can you give a hypothetical scenario just for fun?

 

Thanks man!

[J Paul Gordon]

Love how the board goes dead when the news is not "good". Thanks CoastalWx for posting. I hit my post just as yours came up. Are the 360 hour maps up or does that not happen? Does the heat flux (hope I'm not using the wrong term) over the pole usually mean the PV will split and be pushed down over Hudson Bay or something like that? 

Want to know how the process works and how reliable these predictions are? Is this just more of "at the end of ten days" or are we looking at a highly likely set up after the big Christmas cutter?

[CoastalWx]

Scott,

 

You'd be the one to answer a question like this -- just out of curiosity, what features could change/evolve to bring the xmas storm along a track more conducive for snow in NNE? I figure a costal snow event is pretty much off the table, but so I can keep learning here, can you give a hypothetical scenario just for fun?

 

Thanks man!

 

If it can somehow move underneath SNE like the euro op had yesterday, than NNE would clean up and even down into interior high elevated areas of Mass. It still could happen like that and we are very far out so I wouldn't get too worked up. For SNE, we need a lot more help. Maybe it can slide underneath and bring more frozen for the far interior or something. Just seems like a situation where I wouldn't expect much.

[CoastalWx]

Love how the board goes dead when the news is not "good". Thanks CoastalWx for posting. I hit my post just as yours came up. Are the 360 hour maps up or does that not happen? Does the heat flux (hope I'm not using the wrong term) over the pole usually mean the PV will split and be pushed down over Hudson Bay or something like that? 

Want to know how the process works and how reliable these predictions are? Is this just more of "at the end of ten days" or are we looking at a highly likely set up after the big Christmas cutter?

 

I cannot post the hr 360 maps from the EC ensemble. The models were trying to split the 50mb vortex, but I've seen that already this season to no avail, so I am not sold yet.  The pattern "is not always 10 days away." It's here and transitioning. It will happen. 

 

As far as snow which is what everyone cares about, the pattern looks pretty good for the setup a few days after Christmas and into January, but remember nuances that dictate snowstorm vs no snowstorms simply cannot be seen this far out. All you can do, is look at the pattern and see if it is favorable or not.

[J Paul Gordon]

I cannot post the hr 360 maps from the EC ensemble. The models were trying to split the 50mb vortex, but I've seen that already this season to no avail, so I am not sold yet.  The pattern "is not always 10 days away." It's here and transitioning. It will happen. 

 

As far as snow which is what everyone cares about, the pattern looks pretty good for the setup a few days after Christmas and into January, but remember nuances that dictate snowstorm vs no snowstorms simply cannot be seen this far out. All you can do, is look at the pattern and see if it is favorable or not.

Thanks for the clear response. I understand the snowstorm thing. Of course, like most here, I'd love to see it, but I'm more interested in understanding "how" things happen. What I'm getting is that the pattern is in the transition mode already (or so close that its pretty well locked. Things are going to start to get interesting--which is what makes weather fun. Thanks again for your response.

[thunderbolt]

So lets go over this again. This is a classic response to the pattern reshuffle.

Cold trough digs into the Plains, heights rise in the east and we have no blocking. Not a great outcome for those who want snow near Christmas, but the details are yet to be determined. Expectations probably should be low, regardless.

Hr 144.

ecmwf-ens_z500a_nhem_144.png

Two days later. Notice heat flux pushing north into the Davis Straits.

ecmwf-ens_z500a_nhem_192.png

Another two days later, at hr 240, the pattern is in place. Note this -NAO ridge is just a ridge and not a block. This means the longevity of this feature is in question, but it may be there in some shape or form through hr 360. It seems like the stratosphere is trying to relinquish its cyclonic stranglehold it has had for a couple of years now, but we'll see if it can truly split.

ecmwf-ens_z500a_nhem_240.png

[thunderbolt]

Do you have any concerns with the Japanese monthly outlook for For January and looks like average temperature at best

[CoastalWx]

Can't say I've seen it. To be honest, those monthly srfc temp forecasts are so horrifically biased warm it's not even funny. I'd rather see H5 since I would have a better way to visualize how it works out. That's a good thing to remember. Seasonal models are usually biased warm where you would expect much colder conditions.

[moneypitmike]

I'd rather lose out to Chicago, than ORH, Dendrite, moneyb*tch mike, and Tolland.

 

I understand the sentiment.  If you're going to miss, miss big.

[weathafella]

I also don't get the sentiment of wanting others not to have snow if I can't. I think Mike Ventrice reeled a few weenies in from the edge with his nice writeup today.

[mahk_webstah]

Forecasting temps is difficult enough and forecasting snow is almost twice as hard given the variances that go into it. With ridging in AK, weak -NAO at the least, and the possibility of weak SE ridging...the storm track could be close by. That's usually a good recipe for snow, but the details to specifically say how snowy it will be a nearly impossible to see at this point.

in other words, it might not be a trough the overwhelms via a southward sinking strong PV?  The PNA will provide diving shortwaves into a trough, the NAO will slow things down a bit and help provide cold air and the SE ridge will help to get storms to come north.  I would add that an active southern storm will provide the chance for phases and Miller A storms so we don't have to depend on clippers and Miller Bs.  Is this right?

[SR Airglow]

ORH has had 5 winters greater than 105"

1. 1995-1996...132.9"

2. 1992-1993...120.1"

3. 2002-2003...117.3"

4. 2004-2005...114.3"

5. 2012-2013...108.9"

1960-1961 was close at 104.3"

But I agree I'd consider 105" a blockbuster at ORH.

My bad, guess the data set I was looking at was wonky given that I just checked again and it has ~85" for 95-96 and below 100 for those other 2 as well. Anyone have a better source for seasonal records so that this doesn't happen again?