Typhoon Tip

Heh... I haven't railed on about BDs since 2010. I know that. I was late getting my Met head wrapped around the total mechanics of what BD synopsis is/why ... but once that light turned on - Understanding goes a long way to ameliorating once vexations. Those are 25 dollar words to say that if you get why, it's not as frustrating nor annoying. LOL BDs are a decoupling of the synoptics in the vertical. Basically, around 250 mb above the surface ( expressing altitude in pressure) ...so ~4,000 feet(1300 m) give or take, the bulk troposphere no longer cares what's happening below that level. Down here in the basement, the air is moving NE --> SW, and above that level the pattern may only look vaguely like that could even be taking place below. These become disparate circulation modes. This is caused to happen because of topographic layout over the eastern continent. Everywhere E of the eastern cordillera, particularly E of the Berks to White Mountain axis... there is a drop off in elevation down to sea level. Given the normal trajectory of the westerlies ( flowing WSW or W or NW over those elevations, causes a "curl" vector which points back SW underneath as the elevation descends. That vector is overcome much of the time... such that we dont' have a BD flow always. But, at other times, such as when there is +PP ( pressure pattern) over Maine/GOM/Maritime, that imbalance will take advantage of the vector immediately. Rollin' on back SW the air comes, because air always moves from +PP to -PP. That action of doing so, is the uncoupled state. There are reasons by the +PPs set up. They range from S/Ws moving SE out of Quebec toward the lower Maritime, where backside NVA/downward motion piles the air. There's a cold front up there that passes by and piles air precariously close to the vector ... so that can get the air rolling. The other way is just aggregate cold Labradorian current modulated air density, which is intrinsically +PP in a narrow lowest level. If that sniffs the vector, it'll start rolling back SW. Kind of a fuzzy different between that kind and seabreezing. In March through early June really ... both these kinds of BD means are aplenty. So anyway ... in understanding all this, heh. It's built in.

You can almost see that decoupling on the cinema ... there's a sw moving subtle kink in the geometry of the isobars sliding down the coast behind that weak wave's exodus, like moving a dowel under a rug. That's a BD for the MA.

Not quite a redux coming up next but some similarities. That looks like like a narrower snow production, possibly from Rt 2 N. Those areas in N CT up through the SW 'burbs of Boston probably don't fare so snow well. But they'll be cool and cooling off, so IP fest? Not a ton of either tho. The whole thing is moving really fast. There does appear to be a tiny 2 hour period of tuck potential.. It's interesting because as that shallow near surface slosh back is happening the total troposphere thicknesses are rising. Our regional topography can sometimes force the atmosphere to decouple, where the lower 150 mb may as well be a different planet

I'm wondering a couple of things. one, will all this snow really be down to just piles in time. That's only 6 days away and the specifics of the CMC/GFS/Euro ops offer enough clouds and mean frontal position headaches to perhaps level the melt potential some. I mean, I've seen it approach 70 over a snow pack, sure. But that's with howling S gales and tons of steam rollin off the fields in firehose melt off that will be bare ground in a coffee break. I'm not sure it is environmentally possible to put 80 F over a geographic pan dimensional cryosphere and keep it sunny, when heights are really only marginal for mid 80s. There's kind of a 'absurdity limit' lol. two, if so ... does this approach on te 10th/11th period possibly expose a flaw in these AI versions? ie., not defining or integrating that aspect of the environmental precondition. For that matter, are we abundantly confidence the standard versions are doing that proficiently enough. I suspect the answer's no on the AI's, anyway. They still illustrate like 1993 MRF runs with that larger fuzzy granularity. That doesn't look like discrete systemic awareness really. Thing is... even the operational runs are bursting warm sector surge through all across those two days. The CMC with it's own 570+ dm plume now. Probably just go with whatever model's most conservative with temperatures until the ground snow is much much less.

My sense is there’s kind of like a contest in some people There is none It was always going to warm up and then likely cool back down We’ll see what that entails on both ends of that, but there is no contest

Ayer, MA

S est vis 1/2 mi 3.5" 27 f

S est vis 1/2 mi just under 1" 28

In terms of personal druthers? agreed - I can objectively admit to this winters cold and snow. But personally - I know I'm probably in the minority - I can honestly say I did not like it. I did not like the deliveries. I did not like the fact that an extraordinary, historical bomb bumped SE in the magic moments just enough that a comparatively select few got the big goods while we pretended it was historic out side the smaller geographical area. I did not like the fact that there was snow on the ground deep enough that we suspended our disk golf season. I did not like the cold... we don't need that much cold to get that much snow...and we prooobably could argue the cold is why some of these storms shirked for bigger taxes, too... Didn't like the winter. Prefer that when those 70+ers arrive ( assuming they do) next week, by then the modeling/indicators would have collapses in favor of the inevitable seasonal change, and we would in fact not ever see this white shit on the ground until after Halloween.

OH I get it... just pointing out the silliness of it. Truth be told, all that grading BS is is how well did one's dopa get its hits. Who cares ultimately if one gets their rocks off. Everyone has a different number for weather boner inches anyway.

that's funny we're musing over that.. I was just texting with some Met buddies a little while ago how this year really seemed to us to be a "snowy year" Granted, we're not dyed in the cloth snow zealots, but in principle, we just see this year as having had snow on the ground almost always. Two huge storms.. and lost track of all these tweener event/constant reminders. I like the numbers method frankly. If it is 100% of the seasonal norm, that is an A+ tough shit otherwise.

Isn't 93% and A/A- ?

Right, and people are giving this year B-'s and shit for grades.

yeah, especially this one... If I were going to use 2-m temp to reflect where my estimation of the snow retreat was, it would like just like this. It's probably estimating the snow pack in the first place, but relative to that - Notice Watchusett and ORH AP elevations are warmer? that's snow pack inversion with those els poking out.

It's as though it is also estimating the retreat of the snow pack across those days... interesting. It may actually look something like that, as reflective in the 2-m temperature shrinking cold

If anything the 12z AI GFS is even warmer a week from Thursday ... that's 570dm warm sector, well mixed heat...

This whole event is quite warm frontal like. I was thinking it was more symbolic of that yesterday but now it looks like it is an actual WAA/overrunning venting out ahead of a diffused warm transition. Noooormally I'd go above machine guidance when looking at those synoptic params for tomorrow ... Not so sure over a foot of corn snow pack. It'll be an interesting ob. Either way, with unnoticeable light zephyrs but noticeably warmer March sun it's going to sensibly appeal pretty fantastic for spring enthusiasts circa 2:15 in the afternoon.

yeah it'll actually be quite balmy tomorrow with light winds and mid 50s under mostly sunny. That'd be the new warmest day so far

My reality of this goes something like Too cold today Snow later on and night Some nape value tomorrow, but otherwise annoying during a reprehensible pattern that's become quite consistent with this piece of shit month that used to be viable but has become too mangled by CC to be what it used to be

It's almost like there is built in synergistic feed-back now, anywhere outside of direct polar sourced modulation/forcing on Earth. Where ever there is warm look to an outlook, relative to region, ... it seems to become historic more commonly than not. Regardless of where. The aspect ( Meteorologically...) that enhances that prospect for PHX most likely has to do with the perennial flow across N/A, which features a flat ridge over the continental cordillera, tending to nadir as a flat trough exiting the east. PHX, and surrounding of the S/W - which by the way has just registered the warmest winter ever from Canada to Mexico, reside within that flat ridge. That supplies a perpetual positive/constructive resonance potential at all times. It's not major... but, when we are dealing with synergy, the whole product after smaller additive forcing, tends to be larger than amount of the individual addition. You add 1 to 10 ... you get 12 so to speak. In other words, this gives them a bit of an advantage. There may be some urban expansion feed backs as well - I haven't heard/read of any studies that use scientifically discipline in conjunction with mathematics which quantifies how much. Not beyond speculation. It's likely fractionally playing a role but cannot atone for the whole occurrences. Nor does that diminish the significance of the record breaking occurrences, nor the standard elevated mean temperatures - in fact, .. it substantiates "why" that is happening. Particularly when considering how well that fits in with the planet as a whole, where warm events are consummately over performing above leading predictive indicators/methods.

It's March ... go wonder.

Two aspects going on at the same time. One, the operational models are physically doing everything shy of violating physical laws to shirk the overall warm pattern (attempting to do so without notice too. lol). Two, the ensemble smoothed means are showing that the warm pattern is transient. It seems the operational/tradition models ( not AIs) are ending up with looks that are sort of rushing to the latter. There might also be some environmental feed backs going on that I wonder if the AIs actuallly handle. Not sure.. speculation. Like, 10-20" of ambient geographic cryosphere. The sun needs to be unabated, because under clouds with that at the bottom might be a heat sink. Probably have to take the dailies one at a time and not forecast with much confidence beyond 72 hours. I wouldn't. Keep it at a principle level and allow for bigger errors. This is kind of what we discussed all along - well, I discussed... Not going for more than melt and mud with any confidence. I realize the AI versions show no shame but they are also not lasting very long, either. The 00z GEFs extended index looks similar to March 1993

It's mostly an overrunning type scenario.. so don't look for coastal machinery per se.

That's gotta chance at being a legit moderate impact winter storm if this sets up like this (GFS) on Friday

I don't know if it's just the Euro being like the GFS in early March where it does a seasonal roll-back beyond D7 .. 10, but that extended may as well be Feb 2nd