psuhoffman

They got about 12" from that 78 storm up here...Baltimore did ok with 9" but yea SW of there...no bueno sharp cutoff on that miller b ish. The thing is some of the top analogs when I go look at the h5 don't even seem that similar to me..."where it matters to us" but again those analogs are on a whole hemisphere level so I wonder how applicable they are right now. We kind of have an odd pattern as Chuck has been pointing out...its pretty rare to get this level of AO blocking while having a ridge in the central Atlantic like that. I wonder if its throwing off the analogs. IMO the AO is way way way more important to our snow chances than some of the anomalies elsewhere throwing the analogs off.

Well...what are "THEY" looking at...this all looks good to me Day 15 on the EPS and GEFS First week of March on extended GEFS and EPS So is there something else out there that doesn't look good...or do they think THAT doesn't look good? If they think that doesn't look good then they don't know what good is, and I don't just mean that in a snarky way, some think because the crazy stupid high latitude block is weakening...not less nutso deep red up top there...its "not as good". But our best snow chances usually come AFTER crazy blocking not at the peak of it. Part of this can be too much blocking but another part of it is that blocking is often initiated when tropical forcing moves into the western pacific. (MJO phase 7). This causes ridging in the central pacific to move poleward and destructively interfere with the TPV. But this same forcing also promotes a PNA trough and SER. That is why at the start of blocking we rarely get a snowstorm and it usually takes a wave or two to pull the boundary south. By the time the tropical forcing enters the central pacific the blocking has often retrograded to Canada and begins to weaken. But the baroclinic boundary is south, waves are propagating across 50/50 reinforcing the confluence into the northeast, and the MJO is now favoring a PNA ridge and eastern trough so systems are more likely to dig and amplify into the TN Valley and up the east coast not up into the Ohio Valley and new england. This is the start of our best window for snow. Usually the pattern does not collapse immediately but last 1-2 more weeks from that point on when we see this degree of AO drop. So I think we have at least until March 5 and probably more like March 10 or 15 before things start to fall apart and the snow season is OVA.

Betting against you is not smart...but I'll play devils advocate. 1) The AO is about to drop to -5. 90% of the time when that happens there is a major snowstorm in the northeast. True they don't always affect DC specifically but let's just assume there will be a major storm somewhere in our area given that history. 2) The analogs aren't bad. ALmost all had some snow near the date. You also left out the HECS 1987 analog. Was that intentional because @Terpeast identified that as one of the big snows we would lose completely due to warming since the 80s? Man would that be a kick in the NADS to get a sub 990 low perfect track deform band right up 95 and its just rain. lol. That 2004 storm teased the crap out of me, I remember tracking it all week thinking it was a lock. You remember that one run of the MRF with a double barrel low dropping 2 feet on us!? Then it fell apart because the two waves didn't phase and one peice went up to our NW and the other OTS. UGH So close. 3) Those analogs are on a hemisphere level. I don't think the features important to our snow chances are any different from some of our big snows. The issue is there are some features elsewhere, the eastern Atlantic and Europe for example, where there are significant height differences. That matters a lot to those analogs but not our snow chances. With that in mind...let's see what happens when they get within day 7, that's when in the past if we had a major snow coming they started to pop up on analogs. ALso once it gets within the CIPS day 5 range that would factor out the hemispheric stuff not important to our storm and we might get a better idea how flawed this setup really is. If Feb 20 doesn't work that's our next window and I like it just as much honestly. Maybe even better.

Well the good news is you don't have to do anything...whatever is going to happen is just going to happen. lol

Those happen in a split flow nino pattern, this pattern is good but might still have too much NS zipping around to get one of those type storms...there is a reason 80% of our HECS storms happen in a nino. Our high end might be MECS not HECS. 1996 worked because there was a monster vortex in the Atlantic clogging everything up, and I mean MONSTER...not just a regular 50/50. It would probably take something like that. Or you could lower your bar and be happy if we get a 8" snowstorm.

My biggest fear is its 10 days away and ANYTHING can happen...but the details we can see for this range are pretty good setup for a snowstorm in our area. Trying to get more at this range is risky BTW this is NOT our only chance...its our FIRST chance in the window Feb 20-March 10

The fact it's been colder this year is one reason I am optimistic. But, if we are going to explore the possibility, no the deep south getting one snowstorm does not mean we are good to go and everythings fine. Anomalies will still happen. And their mechanism for snow from that was an EPO driven arctic show and a progressive wave along the gulf coast...that isn't our mechanism for big snow seasons up here...for the same reason it works for them...they are random and scattershot and they can end up anywhere...there is nothing about that pattern that focuses snow in our geographic area...depending on minor amplitude changes and trough locations the snow can end up way to our north or way to our south...or if we get lucky over us, but its not the reliable pattern for big snows here. So it's a totally unrelated phenomenon to whether a -AO/NAO driven blocking pattern still works AS OFTEN. The "as often" part is the key. I am not saying it wont ever work...I'm not even saying it wont work this time, I think it will...but if it continues to not work for the same reason we do have to discuss how often does it still work and how reduced is our snow climo due to that change in what has always been our most reliable mechanism for snow.

For northern MD crew. I was holding out some hope that 2 things could save us. A sneaky h7 associated band on the northern fringe and maybe getting a couple inches then ice from wave 2. Both of those hopes are fading. The h7 forcing is going north of us. It’s very disconnected from the main moisture feed, very similar to Jan 6. This will limit that bands effectiveness but could mean a 2-4” surprise for some places up in central PA that aren’t forecasted to get much snow at all. But we are likely stuck in between again like Jan 6 only worse, I think there is more dry air and less healthy moisture transport with this one. The second option doesn’t look good either. The euro showed the mid level winds ahead of the amplifying second wave to be more s-n which eradicates the mid level cold faster and doesn’t allow for much WAA associated precip to break out ahead of the low. You need resistance to get lift and precip. If the warm just bullies the cold away you don’t get the lift. The gfs and NAMs were showing a more SW-NE wind trajectory which lead to more cold resistance and a nice WAA thump snow. Alas they caved to the euro. My best guess for us is 1-3” from wave 1 and then maybe a little sleet and freezing rain to start wave 2 before it all gets washed away. If the coming period is what I expect our area should have our more typical geographical advantages in a more amplified pattern.

@Maestrobjwa but I think this time will work. This winter has been colder. The pacific base state isn’t has hostile. Look at this weeks it’s snowing in what was a torch pattern the last 8 years usually. So it should work better, if it doesn’t…uh oh.

Well let’s be clear what we’re talking about. There is always some ridging in between waves. That’s basic wave physics. Trough ridge trough. What he is calling the SER linkup is just the heights/ridges in between the troughs getting too high. In other words too warm. It simply a function of it being warmer. What 20 years ago would have been white or a shade of blue is now red on that plot. What that could mean on the surface is as the wave/storm approaches the antecedent airmass is now 35 instead of 30. That resists the WAA ahead of the wave less and pushes the thermal boundary NW and now 95 is on the rain side instead of snow. But all that is a fancy way of saying “is it getting too warm for that setup to work anymore?” We could debate how much of that warmer issue is from warm Gulf of Mexico and Atlantic SSTs or “you know what” or a decade pacific cycle but the question remains “in the current thermal base state does that work”. My answer is it better because those plots show exactly how we get 90% of our big snowstorms. Again progressive waves are not going to replace that part of our snow climo. Baltimore is not getting a 30 or 40” winter or a 20” hecs from a epo progressive wave pattern. That isn’t the path to our big snowy winters or storms. Yes it’s concerning this linkage that he is talking about keeps happening for the reason above. We NEED that to work for us. So I’m going to keep beating my head into this wall and praying blocking starts working again until it’s been proven 100% if can’t and at that point I’ll put my cap on the wall, hang up my coat and bid you all a fond farewell and check out for the last time and simply wait a few years until I can move to Vermont where blocking has still been working lately! Because in the end I don’t really do this for a 20” winter or a 5” snow. I track to try to get those 50” wingers and 20” snows we historically get a couple times a decade. And among the way I’ll take those 5” scraps as consolation. But if we can’t get the real goods anymore this will just be frustrating to me and for my health I’ll stop doing it and move somewhere that can still get what I want.

Because it wasn’t north it was just faster

Thing is even the runs lately that move that fgen death band north don’t help north of 70 at all it just tightens the gradient. Models seem to be locked in that the dry air wins lie up here.

Hmm the FV3 looked awful for MD and I wrote off the GFS since it usually is pretty close.

The low is 4.3 miles north of 50/50

You’re thinking of March 2017 that was ruined by a lakes low.

Second highest east of the Appalachian trail. Get it straight.

Sorry I’m still hung over. The range is 2-5” for the Baltimore area. Say inside the beltway. More south less north. But the difference might not be 2-5. If the 5 is right for the south maybe 3-4 north. If the south gets 4 the north side might be 2-3. This is way too specific but if you want a range for like Towson maybe 2-4”

But why is your bar a HECS? Those are super rare. If we get a 6-12” snowstorm across the area that’s a win.

Why do you keep talking about March 2018 as a fail? It gave us one of our biggest snowstorms since 2016! generally 4-8” across the population corridor with 8+ north of 70! And had it been a couple weeks earlier that storm would have been 12+ across the whole area. That block didn’t develop until the very end of Feb. The storm hit 20 days later after a few misses. This block is developing around Feb 15 so if the same progression repeated that storm would be March 5 and a 10-20” snow across our area!

Unfortunately wave 2 is coming in line with euro less snow so the bust option for northern MD if a south north split seems very likely. I’ve shifted my focus back to the long range.

We seem to do better when I’m skeptical so…

2-5” in Baltimore north to south. Not much of anything up here, maybe 2-3”. I might add some wave 2.

I’m telling you when the HRRR is dry and under amplified sometimes it’s onto something. Not always but I pay it more attention when it’s doing that then when it’s wet and amped. Also I don’t like the trajectory. When waves are projected to be this west to east at our latitude on guidance 24 hours out make up all the times I can remember when things sunk south at game time. The early March 2014 storm was the kind of that. Took a 6-10” storm down to 3” across northern MD. I know the trajectory is just a symptom of the true cause, wave that’s not amplifying enough to overcome the cold press but I’ve found guidance tends to underestimate the northward progress of the moisture transport when a wave is amplifying and over estimate it when it’s not and the trajectory is a good simple way to see it. These things aren’t universal. I’m still watching. I’ve not given up. But I don’t have good vibes. ETA: this is for MD north of 70. I think DC is fine. I’d be excited if I still lived in VA.

On the day of those storms yes numerically the NAO was neutral to positive. But there had been blocking and I consider the loading pattern days before more important. Second most don’t consider the nao by the numerical metric. If they see ridging near Greenland over a vortex under it near 50/50 they call it a -NAO, but numerically it’s actually a -AO. But I’m not interested in a semantics argument about terms. My point is that’s a good pattern for a snowstorm. I don’t care what we call it.