January 11th-12th 2025 East Coast Snow Storm Potential

Morning Folks.  Lets go ahead and start posting Mondays discussing over in the Jan Obv thread, and focus on the Jan 11th/12th potential here.  Who knows maybe it will change the ju ju and bring Monday a tad N by doing so, but Im not holding my breath IMBY.  If I get a C- to half inch Ill take it.  

My apologies but this is going to be a long one.  Get the coffee pot ready.  

Ok let me start by reiterating a few facts about the 6th system, because its important to understand why I believe the 11th12th system will have a different out come; one that most and potentially the entire board can benefit from.  And let me also state that Mondays system's ceiling was always approx 5-10".  That said I believe the 11th/12th system ceiling is this....




For those of you who dont have your reading glasses on or dont quite know what you're looking at, let me introduce you to FRANKZILLA.  This was a classification given to a storm system that puts down 2-3 feet or higher amounts of snow in someone's backyard.  I believe I created this image after NEMO in 2014 when 30" fell IMBY.  

Now please dont get panties in a bunch.  Im not calling for this to happen yet at all.  I am merely pointing out that I dont think this is hyperbole in that IF ALL the ingredients come together this is the actual potential for this system.  Lets talk about it

Im going to start with some graphs.  Below you will see the graphic forecast for the European ensemble for 3 of our teleconnections.  Take notice the WPO, AO, and NAO are all either moderately or strongly negative.  Its this trifecta that is suppressing our Monday system to the south.  But pay attention to the second set of circles farther along the graph.  What it shows is a relaxation of all three teleconnections.  In general it is very well known that some of the most memorable storms to have occurred in the NE did so as the entrenched pattern was relaxing.  





To me the two to focus on here are the -AO and -NAO for the 11th/12th set up.  Graphically you can see the AO, while drastically weakening between now and next weekend, remains in the -0.5 to -1 state.  This keeps the cold air in NA.  Combine that with our -NAO which only goes from a -2 to a -1 to -1.5 status.  This is critical.

Now graphs are nice but lets take a look at this on a map to see how this applies to our set up.

Below is this am's 06z GFS run northern hemisphere view 500mb map at time 0 hrs to out line the current -WPO, -AO, -NAO.  Pay attention to their position and strength.



Because of this combination, and how strong they are you can clearly see how they pin the Tropospheric Polar Vortex (TPV) to our north.  There is no where for it to go due to this blocking Trio of teleconnections; therefore, our 6th system is forced to take the more southern route giving the S mid Atlantic region the bulk of this system.  Not much to do about that.  But again remember what was mentioned above graphically about these teles relaxing.  This will hold the key for our storm track for 11th/12th to be very different I believe.  

Next image is the same 06z initialization, time 00hrs.  The energy that will become our potential system is outlined as 1 and 2.  




The second image above is valid for approx 7am Wednesday morning where you can now see 1 has dropped into the SW CONUS and 2 is entering onto and fully sampled on the WC of Canada.  (Keep this in mind as we head through the early part of the week).  Now the next bit is where things get critical for this system.  

The main difference between yesterday's 12z GFS and Frankzilla soln, and yesterdays 12z Euro OTS soln is whether or now energy gets left behind in the SW associated with 1 on my map.  It's that simple.  Below I will use last nights 00z GFS and this mornings 06z GFS to illustrate this, but keep in mind the Euro, as well as the cmc, has been holding back that energy.   Also keep in mind IF the final soln involves holding all of that energy back, some of the energy, back, or all of it comes out and "joins forces" with 2, will all lead to different solns.  Also keep in mind that there are other factors that will ultimately bee the determining factors into how much or if any of 1 ends up holding back or not.  

Next image below is the same time stamp as the vorticity map I showed above. Approx 7am Wed morning.  Notice how we lose our -WPO, and our AO and -NAO begin to back off a little.  We also have a ridge going up along the WC of NA.   


Now next set of images is from last nights 00z GFS.  Hr 114, 132, & 162.  Notice 2 digs in but 1 misses the trough.  The result is 1 holds back and 2 swings through our area as a weak progressive system that stays suppressed to the south.  If we went further in time you'd see 1 gets picked up by the next trough and finally ejects out.  








Now lets examine 06z images.  timestamps are the same as 00z but hrs 108, 126, & 156.  In this case 2 digs in and 1 ends up being picked up by the trough and coming out together with time.  The result is a fully negatively tilted trough that matures right as it hits the coast by closing off which gives up the strongest possible system.  







Its the fact that the AO and NAO are relaxing, but not completely that ultimately leads to a smaller TPV that sets up in perfect 50/50 position to allow heights to rise along the coast, provides a cold air source, and slows down the flow which allows the storm to mature. BECAUSE the -NAO is still negative but instead of -2 sigma centered around southern Greenland, it has eased up a little and set up centered in the N Atlantic/Scandinavia location.  



Again this apparent relaxation to key teleconnections is ultimately what should allow this system to come up the coast and not be suppressed.  All models forecast this to one extent or another.  We obviously still have a long long way to go with this so refrain, if possible, from getting to high or tow low, because models will continue to show Franzilla to oogatz, and everything in between.  All energy comes aboard by overnight Tuesday into Wednesday morning.

WE TRACK!!

Another telling sign… the EURO Ensembles trended favorably for an east coast storm. Check out the individual members 12z vs 00z. Look how many more show a formidable storm off the coast while 12z members were scattered and disorganized.

12z -



00z -

heehaw453 wrote:Nice write up and now we know who to blame or praise

Ill take that burden and put it on my back and hopefully have enough stamina to take it across the finish line. In all seriousness though this one feels little different. I mean the timing of a legit solid cold pattern is in place, and the described teleconnections relaxing, but not completely, makes this really feel legit. Of course nothing ius set in stone. We are still far enough out where what appears to be the "tele" forecast may evolve differently, but again this feels diff in my mind.

And for the record...Ray if you're out there Buddy, and I know you are, you outlined this particular time frame first so IF IF IF this comes to fruition with any gusto Ray (Rb) gets full credit.

Detailed post...Like it....First post on the site, and looking forward to this one....Monday is a teaser...now off to tune up my 6 year old blower that I have used once.

rb924119 wrote:by rb924119 Wed Dec 25, 2024 11:08 pm

Next storm threat that really stands out to me is between about January 8th-12th. An argument could also be made for the 4th-6th, but I think that’s more of a Central-Southern Mid-Atlantic threat because there won’t be enough wave spacing. We’ll see, but the December 30th-January 2nd window is reminding me VERY MUCH of the November storm. That requires further digging on my end, though. How/when? Lord only knows lol but I’ll try, darn it! Haha

I feel good about this one, but 6-7 days out going to keep my optimism in-check to avoid being Charlie Brown with the football again. lol

Interestingly though, if this comes to fruition, there will be NFL playoff games next weekend in Baltimore, Philadelphia and Buffalo so could create some good visuals for those games.

Unofficially I call 10-12 inch storms a “Scotty”.  What else?  I have show tickets at 3 pm on Sunday. I hope our pending storm hits Sat. Having said this, I will be watching and learning from this storm thread.

Great write up SROC and the synoptic pattern is ripe, also the weekend rule!!

The 12z suite says what storm next weekend?

12z suite says what storm becaus it holds that energy back in the SW.  Here is your fly in the ointment.  

If you only focus on the ridge out west you quickly notice there is a wave break.  Put another way the ridge axis is such that the north half gets out ahead of the southern half so it tilts from SW to NE or positively tilted.  The reason for this is the large potent trough in the NE Pacific is on its heals keeping the northern half of the mean patter moving faster relative to the southern half.  Imagine a wave approaching the shore.  As the depth of water decreases it raises the wave height until the top half of the wave begins to topple over.  However if you are floating on the surface of the water as the wave approaches there is a good chance it ends up pushing you along with, and you end up traveling along with the wave as is moves in closer to shore; however, if you go under water towards the bottom as the wave aproaches, there is a good chance the wave passes over the top of you and you remain behind.  As the wave passes over you you can still feel the tug as it passes over, so if you werent a solid individual, but rather more of a fluid structure like our energy hanging back in the SW, you might imagine some of you getting pulled into the wave and moving along with it and the rest hangs back.  Perhaps ven getting stung out.  In the images below the straight black line is the surface of the water.  The further south the energy is, aka the deeper below the wave break, the more the energy misses the wave.  





This is obv an over simplification, and Im hoping it made at least some sense.  We have been plagued by our WC ridge being knocked down affecting the result here on the EC for years now.  Despite the positives out lined in my earlier discussion this is a real possibility as to how this can fail up.  And quickly in the third image above notice the two circles aree essentially the same thing about to happen. energy drops into the SW, ridge goes up, more energy on its heals in the N Pac

Here comes the beating of the dead horse when I say timing of all of this both N S E & W of us means everything.  We days away still from sorting this all out so as I said earlier refrain, if possible, from getting to high or too low, because models will continue to show Frankzilla to oogatz, and everything in between for a bit.  

I mean literally 06z showed Frankzilla numbers inland, and the very next 12z run showed oogatz.  Couldn't draw it up any better.  LOL.

heehaw453 wrote:I'd like to really start seeing more model support for something sig by 12Z 1/6 or 00Z 1/7 at latest regardless of where the s/w's are.

Agreed

It’s only an 18z run but GFs about to go nuclear I think

heehaw453 wrote:D6 time frame. Not fantasy land time period. If we get inside 100 hours with more support then that's the barometer IMO.

My Gawd that was one of the most beautiful runs for my backyard I’ve ever seen. Start to finish. Not bad for everyone else too.

Irish wrote:

sroc4 wrote:It’s only an 18z run but GFs about to go nuclear I think

You have my full attention.

That will be a Godzilla or Frankzilla if it comes to fruition and we are due for a storm for most of the state in a long time so maybe this will be the year

Brother Scott! I appreciate the shoutouts, though y’all have been doing yeoman’s work with the tracking too! Sorry for my absence, but work has just been flat out terrible, the holidays have kept me busy, and quite honestly I haven’t really had much to add in addition to what’s already been said. With that said, I do have a couple cents to add to this threat’s proverbial cookie jar lol

Synoptically and hemispherically speaking, I really don’t see much to dislike on the whole. As has been stated by multiple parties, the relaxation of some of our teleconnections, most notably in the Atlantic domain is a blessing because it will allow some resistance from the Atlantic ridge to re-orient the flow and allow a more southwesterly flow as opposed to what we are seeing over the next 24 hours, which is much more zonal (westerly). That said, there is a red flag flying high, and that is undoubtedly the possibility of the lead energy getting trapped in the Southwest either entirely, or enough so that it only comes out in a “dribble” rather than completely, and therefore leads to a sloppy broad trough, or misalignment with the second (third, too, perhaps? ) piece(s) of energy. As has been stated, this really has been a frustratingly persistent thorn in our side for several years, and is something that I think will end up rearing its ugly head yet again.

HOWEVER, it’s not all bad news and tears, because if at first we don’t succeed, we try and try again. It looks to me that we are going to have multiple* chances at this, at least two, maybe as many as FOUR between the 9th and 20th alone, and the fun doesn’t stop there. But, why so many? Well, quite honestly, this is an absolutely FASCINATING pattern to me, and the best way that I can think to describe it is “discontinuous retro-progression” lol completely scientific…..I know haha but, the pattern in the Pacific is in the process of turning progressive (temporarily) during the main window of interest (8th-12th), which means that large-scale features like long-wave ridges and troughs move as they normally would around the globe from west to east. This is what causes the wave breaks in the PNA domain (western North America) that have been mentioned already. The first one occurs on the 8th with a short-wave crashing into the ridge and toppling it over. Based on past tendencies, I say our lead energy in the Southwest misses the connection with that shortwave entirely* as the lead energy buries itself beneath the ridge and the short-waves scoots by to the north. But as that short-wave progresses, the ridge again temporarily rebuilds, only for the process to repeat a couple days later. The difference THIS TIME, though, is that the pattern in the Pacific is fully progressive, which means you’re also getting successive wave breaks UPSTREAM of our ridge. As a result, this leads to the development of a trough, which progressively strengthens as subsequent wave breaks occur and allow pieces of energy to keep piling in, near, and then eventually to the east of Hawaii. THIS IS KEY. Why? Because this results in a wave spacing scenario such that as that deepening trough drifts to the east of Hawaii, it should actively work to force our lead energy, which is still trapped in the Southwest, to eject. When that happens, and it will, THAT becomes our window of opportunity. But, the key is, HOW does it eject? Does it come out all at once? If so, our potential ceiling is very high. If it dribbles out, we could see multiple overrunning type events that are much more moderate (similar to a ‘93-‘94/‘95-‘96 setup), which repeat every couple-three days, or, they get completely shredded by the 50/50 vortex and we continue high and dry. Theoretically, the energy in the Southwest should fully eject as the second wave-break event occurs with our western North America ridge ~10th), but the progressiveness of the Pacific pattern leading to the positive tilt of the ridge axis and subsequent negative momentum flux beneath it combined with previous experience has me skeptical.

Remember, though, we are going to have repeated attempts at this, as the whole pattern - energy getting trapped in the Southwest, wave-breaking in western North America, etc. is going to repeat itself, and getting to why I am calling it “discontinuous retro-progression”, it’s going to repeat in nearly the same places, which is…….unusual. Typically, when features retrograde, it’s discontinuous, i.e. one feature develops and shifts the pattern, a second feature develops and shifts the pattern, etc. until it eventually washes itself out. That’s not happening here, and in fact, a little prelude to the extended, this all looks like it reloads AGAIN heading into late-month with yet ANOTHER Atlantic domain blocking episode coinciding with a Pacific jet retraction. Honestly, this is wild, and is something that we haven’t seen in a LONG time.

So, moral to this whole thing is this: I do think that our lead energy buries itself into the Southwest like we have seen repeatedly, but with the evidence currently in front of me, I find it VERY hard to believe that we wouldn’t come away with something significant by the 20th stemming from our primary lead energy that we are currently targeting for the 11th-12th. I agree that the initial short-wave is missed on the 8th-9th, I agree that the second stands a good chance, but if we miss that one, this threat will still be alive (relative to the lead energy that we are focusing on). So I’d suggest just sitting tight and watching how this unfolds over the next couple of days, because the key lies entirely with how that lead energy behaves in the Southwest - when and how it ejects. But I do think we will get something from it eventually.