Bob Chill

I made a typo in my op and went back and fixed it. It is uncommon in winter with an upper level setup like this to have the low stack and start occluding so early. Which can still easily work for a big storm with a clean offshore track. That's not what we have here due to that stupid hallway of weakness tracking NW of the upper low. It what it is. Ultimately, we just want Feb 2010 type storms. Capture and stack just off shore near or just south of our latitude. Those types of storms never stop snowing and the finale is usually heavy high ratio stuff as things crank in the upper levels 9ver the gulf stream. We can also do well with an upper level "trailer" type progression. Jan 2011 and Feb 2014 are perfect examples. Lull in between sucks but it's still a 1-2 punch. Those progressions often smoke the NE big time because they catch the climax during the capture phase. Once a storm stacks, it's done getting stronger. It marks the beginning of the weakening process. Occlusion is well along in the weakening process. Basically, whomever is due west or NW when the upper and mid level lows move over top of the surface low will be smiling ear to ear for many hours Eta: no matter what the progression is, generally speaking you want all 3 to pass south and east of us. We can survive the upper low passing over or west on a slanted system if the surface and mid level lows draw in cold air (banana highs are so dman important because of this). We can sometimes survive an 850 low passing west or overhead. Surface low? Lol. We survived one in 2014 but that shocked basically everyone.

That low jump is just a digital thing from what I can tell. Model graphic output is programmed to stamp an L at the lowest pressure but the lowest pressure is fluid so the L jumps around inside the "bag of low pressure". I like using the shaded mslp anomaly maps to just compare the bigger bag (general center) and not the L (specific center). I could be wrong here so someone correct me if so

I think a lot of the unwillingness to accept the outcome stems from not understanding how low pressure systems evolve. There isn't just a surface low like everyone looks at on TT. There are also mid and upper level lows. At our latitude in the winters, it's uncommon to have all 3 on top of each other like this south of us. They are usually "slanted" with the surface first and upper last. When you get all 3 spinning together right over top of each other and no cold high feeding the beast,, you better be far NW from the center or you're in big wet trouble.

It does in comparison to other closed lows approaching from the south with cold around. But there's a fundamental difference here... the storm has basically fully matured well south of our latitude. We can get smoked during the maturation process and then get a second serving with the upper level low but the process of getting there is not what we're seeing at all. Because the storm is stacked without any kind of cold feed,, it's a literal warm air vacuum and circulator near the stacked low center. When these types of events develop further north, the stacking process usually happens offshore and to our NE. Then SNE gets literally blizzardeded after we already got a big event. From a good snowstorm comparison, this particular storm is really really screwed up compared to others and the idea was clear as day nearly 4 days ago. Dems the breaks man. Stuff happens.

Sim sat doesn't look much like a snowstorm at all. Cuban express

NAM prob has the right idea but I'm not locking into anything in the mid levels until the storm is on approach. At least them it will be a developed system with real time data of the layers inside. Never doubted a mix/mess. Would be a bummer to get such a hard core push of WWA into an OK airmass only to get sand blasted and washed away without covering the grass first.

The storm has been pretty much the same for 5+ straight days. The "tracking" part was mostly us finding a way to get some snow out of a storm with serious temp problems. Far from a fail since the storm is still happening and looks to be about the same as it has.

Reach arounds have happy endings, sometimes

Icon also absolutely sucks at warm noses/mid levels too. And this is the wrong storm by a million miles to be weak in that dept

Exactly. While this storm has some unique and interesting features, it's still a very typical setup and outcome for the track. Prob 50% or more (stat guys can check) of all our measurable snowfalls are mixed around the cities and burbs. We do it often and at times we do it really well. If climo really takes over, not much above freezing rain is going to fall. I've been thinking that's how it's going to play out but models had too much spread to discuss.

A bunch of people have said this but with the track and vigor of this low, there is no stopping a mid level destruction from rushing in anywhere near or east of the low. Unforgiving setup in the mids. My 3-4" call for my yard is predicated on 2-3 hours of mod/hvy snowfall tops before other, less enjoyable stuff happens. I may not get that much but it is the heart of cold season and conditions leading in are good. We'll see

Ops appear to have done nice job on this one from a pretty good range imo. The general idea hasn't wavered for a few days and if you think about it, ensembles made it harder to forecast. Ensembles didn't do all that great at their most useful range. Pretty unusual the way it's played out so far. Only call: 3-4" IMBY

I can't think of a time when the euro gust panels were accurate for any kind of storm. Never checked gfs. Euro always seemed way overdone. I started looking at wind a different way and got much better at predicting. Look at your sustained surface winds instead of gusts. Then add 10-15mph to that for "gusts". Check 925s and see how quick it's ripping just off the deck and make adjustments in your head. Generally speaking, I95 & west really doesn't get big wind gusts without a westerly component. Maybe it's topography. My yard or neighborhood gets little if any wind damage when there's an easterly component.

I was initially thinking ops may be out of whack because the uncommon solution in the face of "ok" upper levels kept ending up inland no matter what timing difference or 500mb shift. That tells us something in the "steering" is pretty stable. Then it became more clear to me. Track has far more to do with that hallway of weakness than anything that happens before with the storm itself. This has prob been rehashed a bunch. Haven't been reading much.

Ops have been really consistent. Minor shifts and the same general idea locked in for a couple days now. IMHO- ops have lead the way here this time.

Climo and antecedent airmass pretty much yells standard thump to slot based on all guidance. We don't get many overhead tracks in real time. Anything is always possible of course. Just playing the odds would be a good heavy thump, mix, slot, drip, refreeze. Lol

More importantly, because of climo and topography, that area is simply further S and often in the crosshairs of the WAA of a developing cyclone. Circulation hasn't destroyed the column nearly as much during onset/heavies as it will when the storm reaches DC latitude. Thumps to rain for DC often have SWVA jack.

It is frustrating really. It's just a little hallway of weakness to the north/nw on approach. But since it creates that hallway, it doesn't matter much how good looks or where it's located as it turns northward. The whole trip north the upper and surface lows are gunning for that hallway

A really good way to use the 12k nam is to just compare h5 anomaly vort panels at hr48. If it looks a little better, the nam's primary usefulness in the mid range is over with how I look at this game. NAM is way too prone to do NAM things beyond hr48 IME but changes thru 48 are important for sure

I can't speak for everybody but I can 100% guaranty there isn't a single bunny or any other rodent or stray pet in my yard after snow flips to something else. You guys may think I'm odd or crazy but you haven't lived until you go on a rodent ass kicking contest in the slush, mud, and rain. Liberating. Eta: just so I don't get doxxed by PETA and harassed the rest of my life... I don't kick hard at all. I'm not playing to kill or even to hurt really. Just a "friendly nudge" to get those beady eye'd mofos off my yard so they can stop staring in my windows laughing at my pain.

Rules of thumb with insitu-CAD setups with bad tracks are surface is stubborn but mids fold like WFT QB's

There is an advantage with mixed events like this. Front side comes in hot, piles up quick, looks amazing, and as soon as sand starts hitting the windows its time to drop the subject completely and move on to something else more productive and interesting. Like kicking bunnies or something like that.

This is why I really don't look beyond storm/no storm outside of 72 hours unless it's locked an loaded. Rounding the base has always looked "ok" but there is a flaw (bruise in the banana high in a bad spot) that isn't going anywhere. Path of least resistance (for now) is overhead and while it's uncommon, the progression makes complete sense. Not much chance for the banana high bruise to go away so now it comes down to where exactly that weakness pulls the low center. IMHO, we're prob at least a full 24 hours away from having a good handle on that piece. All this said, I absolutely do not expect a clean snowstorm anywhere near my house no matter what. But it can still be a pretty solid event even in the cities. .

ICON wants to start pushing the door back open.

Yeah, not sure what this discussion is all about. I can't even remember how many bad track storms dropped 3-6" around the area. They aren't rare. Many of them had much worse conditions leading in. Bad analysis.