Typhoon Tip

OT, I never had a snow day in the 1980s ... Not once. Of course, that was a different cultural era - it wasn't just for dearth of snows. But there's still no mistaking, the trigger gets pulled ( starting about 15 years ago ...) at least excuse imagined when preceding pretty much anything in reality nowadays. I used to think that's because our society has evolved to be litigiously preoccupied, always looking to sniff ways to f-over some one or something else to compensate for their own stupidity or just bad luck, or both ... Eventually ... institutions had to evolve to protect themselves from lawsuit giddiness. Ha. But I wonder if there is also a "day off" undisclosed sorta motivation going on. Because unless parents really are working for some unforgivable p.o.s. employer, they can pull the 'have to be with the kids' card. Raising kids is complex... it's easy to hide that motivations behind a litany of reasons why this would require not doing one's day job along with the kids staying home. So it's very difficult to prove that mentality is part of it. lol I'm also kind of cynical so tfwiw -

The operational Euro from 00z depicted an unusually high efficiency QPF "explosion" for lack of better word, from an excessive isentropic lift, overnight between Sat/Sun. One of those morning's where a new 8-10" had abruptly occurred, and blue tinted light cleaves through curtain like a gelid peep hole from inside an igloo. Big short duration snow rates .. .Somewhat reminds me of that Dec snow in 2007 that was supposed to be 3 or 4" then IP/ZR then a light rain finish, but it positive busted on the snow side to the tune of some 10" - major ending with freezing drizzle. Never saw 32. It seems to be the only guidance with that scale and degree of proficiency, and it is a rather detailed aspect that may not survive the 3 day's worth of model runs yet to come... so by virtue of that reality as it stands now we'd have to consider that low confidence. That said, the system is quintessentially propagating - albeit fast - along the climate track that correlates well for snow from SE NY to S ME in the operational blends ... something like HFD to ASH along that axis, even without that specific Euro efficiency... either way. Unlike this event today, this 9th one is much higher confidence at this point just because of the stark continuity in the guidance et al. Whether it is 4-6" or 6-8" ... meh. I lean low end warning still and we'll see if some kind of exotic 5 hour, upper tier anomaly starts looking more likely in future runs.

I feel like for this particular winter this is kind of a 'nadir system' Doesn't have to be a stem wound coastal bomb like in 2015 with that 5 F juggernaut, 978 mb low going by to make the point. It was 8 this morning when the u/a deck capped the cold, and now it is 14 with est 3/4 mi vis of straight down micro dendrite bundles. [edit, now slightly bigger aggregates and est 1/2 mi vis ] I had mentioned some time ago in this thread that part of this system's advantage was in fact it's translation speed; it is outpacing the surface lag. By the time any WAA could scour this slab of low cold, it's long gone. The systems going forward appear to be on the polar side of the boundary so may be safer. Not sure they'll be this knuckle stinger cold at onset.

"The world warmed to yet another monthly heat record in January, despite an abnormally chilly United States, a cooling La Niña and predictions of a slightly less hot 2025, according to the European climate service Copernicus." https://phys.org/news/2025-02-la-nina-eases-earth.html

Right in 4 runs it’ll be over - I bet it’ll nail it !

20 … there are people about to graduate from college born after 2004

sorta yeah. There's actually a line up on a 2 to 3 day periodicity. It's not impossible that we're clock punching advisory and/or low end warning scenarios out there. It's very 1994 esque pumping off an ensemble line. It's physically a way to exhaust an energy saturated hemisphere when the flow is too fast for big dawgs. We could also get screwed by one or two missing, but there's 4 in the pipe line to consider so missing one meh The one the 13th looks the most impressive at the moment (notwithstanding a 6-8" 9th) but there's another on the 11th that may slip S before, and then another that showing up out between the 15-17th. 6th, 9th, 11th, 13th and 16th ... Kind of unusual but like we said, we're not talking systems so big that it makes it unrealistic to turn it over quickly. Fun pattern for winter enthusiasts... Ha, we pass out of the solar minimum on the 8th too LOL

NAM QPF is now under .25" liq eq at Logan. If that fugger coups that's be a hoot

At 10:1 snow ratio. .1" liq = 1 inch of snow. SO, that's 7 or 8" above. just sayn' Extending that 10 to 12 would require 15:1, then combining that with compaction after the first couple of inches ... it's probably not making a foot.

Yeah I'd try to tone down the intensity of your d-drips if/when taking this thing to the next level. There's plenty of reasons why that run might be 20 or so % too much. I'm still in the 6-8" camp for now.

Euro looks initially like it'll be S of prior, how much so notwithstanding

13th keeps popping up... this GFS run is a foot of snow. It would be because this one is not a straight shot from the west along a narrow inclusion field, it's coming up the coast as a quasi Miller A - but by virtue of source ( most importantly ...) has a pig ton of PWAT to lop over the polar air mass ...

I thought the GGEM and GFS were close to identical ... It's pretty awesome from outside looking in on this thing, considering the last 10 years of everything under the sun in this maddening field and engagement ... to ever have two models in such tightly coupled appeal at still 4 days lead time. We'll see what a crank-in-butt model Euro has to say here shortly. But the GGEM/GFS either in blend or alone look like 6-8" entry into winter storm headline club

12z NAM has a really warm layer at 800 mb now over Logan that previous solutions did not have 30020969563 08014 151317 42999500 36022982927 -2109 050303 49010207 42000962729 06211 042417 46000204 +7 C seems bit much... but if that happens and there's only .2" liq up to that point, Boston proper would net gain probably 0.0 out of this piddling piece of shit event. On a general note, this was never more than a 2-4 or 3-5er - it's in the bold writing at the thread onset. But there's more to it than just that. This event has sneakily attneuated by 15 to 20% of amplitude compared to when it was in the longer mid range. We been over this a hundred times over the last 10 years, the models tend to magnify amplitude and then correct down some as the come into nearer terms - perhaps this is just that taking place. It's taking a low impact scenario and injuring it more, though.

Fwiw, that actually doesn't look that bad for me ... I see "probability for >- 12" spanning two weeks of time on this product? Cumulatively, we seem likely to receive at least 3" a pop from 4 pretty easily identifiable events in both guidance and method. I guess capping at 70% might be a conservative approach, too.

Yeah agreed .. we're not lingering as a behavior, most likely, in this pattern for any of these over these two weeks. They're screwing right along, in and out apace. When they're done, 2 hours later its clearing probably... The region already having special statements being written for the next in what is interestingly an oddly stable guidance thing going on... 6th ... 9th ... maybe 12th and then the 14th, they're all in play, having ( rather ironically ... ) dependable continuity for actually happening across all the guidance envelopes. Doing so considering the compression/fast flow, when it is more typical to have modeling errors and a systems depicted on one cycle then shuffle in space and time ( and amplitude) on the next. The last 4 days it's been about setting coffee down and checking in on any one of those in the series to see how they are doing. interesting -

agreed on QPF... I might even go 5-8" but that's a like a run-of-the-mill warning event either way. If the max amount is 7 or 9 ... meh. As far as the 'region wide' - that depends. There are challenges as to the areal extend in these compressed fields. Those constraints can be overcome, but then the low residence time is also a limitation because if the given system is strong enough to extend farther out in radial coverage ... the outer reaches are both less QPF but moving fast - threading the needles are squeeze gigs is what it comes down two.

Having said that ... one of these events may over-achieve a little over this 10 days to two weeks. Yeah, sure .. But some of these products look hefty for QPF given a pancaked compression of jet fields moving so fast for this guy

Overnighties look like a low end warning event ... I like a either a 60/40 or almost 50/50 blend of the 00z GEFs with the 00Z EPS The operational versions don't actually vary hugely - but two aspects about monitoring guidance... it is both easy to be 'overly' discrete about minute difference as though they mean more than they do (heh, call it lens biasing ), but also, some of that is still needed in a needle pattern. So how much. I feel the 00z oper. Euro was too far N in the cold air so bumping that south looks like a GEFS/EPS blend

Haven't looked at particulars but I would guess the GEFs could be too based on that climo track - even if they aren't printing that out, it's an easy modulation

Yup

These situations where it snowing at sea 20 or 30 or so mile SE of CC while it's pinging and going to zr in ALB, and still snowing moderately in HFD, tend to foster a "tuck" slosh back. That set up is more correlated to the fact that it is quite cold ahead and thus there is a lot of low level mass --> to meso forcing. The models are already coherently depicting a closing beta low down over SE mass about 2/3rds of the way thru this, and when that happens, a cold surge my tumble back S out of S NH. I could see the snow burst going to a freezing drizzle in that cold slosh as the top of the inversion remains saturated. Yeah, the front scours it all away and that's probably unavoidable. But this is a gainer

The EPS has also shifted south. 120 hours is coherently S of the 00z at 132 - which I would think really matters, because this EPS solution is far enough south that given the amount of cold air prior to this one's arrival, this solution is likely a moderate impact snow event "as is" ... and like the comparison between the GEFs mean and the operational GFS, this to is south of it's operational version. interesting

To each his / her own but 3-5" glazed over with zr ... It's more than insignificant. Shear impact to society sort of validates the former notion in my mind. Anyway, this one for the weekend: I find it interesting that the ensemble mean of the GEFs vs the operational GFS are opposit comparing the this event in the foreground. The 6th has routinely had the ens mean NW of the operational guidance... Contrasting, the present ensemble mean is pretty significantly south of the operational - so the modeled circumstance in reversed. It's hard to determine if this is true with the Euro cluster but perhaps to some lesser degree it appears to be so per 00z. In any case, the GEFs move a 1000 mb low S of LI, to between the BM and CC going toward 995 mb - we've ... or I've been comparing the 6th and the 9th as sort of twins but this GEFs behavior does have greater implication, if not hugely so ...some.

probably not worth as much to point out but the 12z ggem looks primarily snow along and N of the pike, with snow in CT/RI for at least some of the front game - an overall colder profile comparing to its 00z run