Typhoon Tip

Fwiw - the CCB has been trending S though the last three cycles. It's hard to quantitatively assess that because the system is really sort of two events in a 'contact binary' The other models show a lead wave triggering steady cat paw if not wet snows for 9 or so hour prior to the hog balls mid level amplitude then spinning up a main low. That lead 9 or so hours is a coin toss because of a marginal thermal layout. The GGEM and operational Euro (standard) are cold enough at 850 mb through the lead, and the 2nd more potent near bombogen deepening rates underneath is no question we all flash to snow. The AI version is sort of blurring the distinction of the two pulse scenario by just having a weird CCB that presses S with limited associated 2nd cyclone depth associated, underneath. Busted ravioli low with CCB over top is a red flag for piece of shit model handling - something more significant is liable to be there

It'll be interesting to see how fast 15-20" of blue bomb high h20 content snow disappears. As persistent as this signal has become in recent days ... so too is the handsome mild to warm signal for the 7-10th of the month. But obviously ... long range blah blah not withstanding. The Euro and GFS both implicate a middling to major snow potential, followed by a real shot at 70 F by the afternoon of the Eclipse.

Significant Miller B Nor'easter potential is signaled across Apr 3rd-4th ... A chilly 850 mb anomaly is in position over SE Canada ...infiltrated throughout the eastern GL and NE England regions, prior to a strong -NAO maxing over the western limb of the domain. This aspect is situated while there is an undercutting trough of significant amplitude. Any kind of emergent trough is highly statistically correlated with this particular kind of -NAO expression, but below we see what really amounts to a phenomenally exquisite expression of that. Given to the high correlation, notwithstanding the "stable look" to this synoptic evolution ... confidence is quite high for at least the general set up. Anomalously high baroclinic instability in situ despite the lateness of the date/spring season. As the above mid and upper level events unfold over top that lower level temperature gradient ( see the 850 mb charts from the operational Euro/GFS/GGEM further above) ... strong cyclogenesis is well within the realm of possibilities, and the only limitation on this as far as I can see given these rather elegantly, yet glaringly obvious precursor metrics is the fact that this above is about 144 to 156 hours away. Unfortunately ... confidence is only very high for an event. What that event's particulars will mean as far as specific impacts is still pending. But sufficed it is to say ...this is a classic leading layout for late season snow impact. What is also interesting about this - from a personal anecdotal/experience perspective, these spring storms tend to actually be modeled more marginal/warmer than this, at this sort of time range - only to tick colder as the time nears to a 'blue timber bender' storm. This already has the look from all sources, and has been a recurrent theme over the past week. Dynamic height falls and just wholesale evolution of common winter metrics that are involved, snow would be a slam dunk. It's worth it to follow this ...lest the new April thread has a 100 pages by the 5th of the month... I also am aware that interest in winter -related subject matter may be diminishing at this point. Seasonal awareness, along with just issue fatigue for having been abused so mercilessly over the last 4 months ( LOL )... but it is what it. It is noted that the 00z Euro CCB's the hell out of interior and eastern SNE out of this ordeal. It is also something that we haven't seen much of in recent years, a slower moving event.

Racked up another positive temperature day despite feeling miserably cold and gloomy ... this is how we contribute to CC here.

12z Euro's another flooder ...but does bring goodies to the winter hold-out types from Brian-like and points N. Also has the balmy bubble air mass formulating after that from 7th on spanning SE Canada/NE and the OV, too.

yeah... April ... particularly early April is just perfectly when that is most likely to occur around here. I'm not sure what your history is, but do you remember the 1997 "April Fool's Day storm" ? It was sunny, 64 F at 1:15 pm up at the UML weather lab, while the 12z model runs were coming in with a 4 contoured hornet stinger 500 mb closed low and attending sfc bomb just S of Cape Cod scheduled for 2 days later. The campus was abuzz with that type of passionate fever as though the prison gates were opened and the world was set free. The energy and joy was palpable on that Saturday, mid day. Monday we changed to snow, and that night 9 consecutive hours of S+ with occasional lightning all quadrants was on the Logan Metar. My buddy lived in Wayland, MA ( about 20 mi due W of Boston along Rt 20). He was describing the breath arresting wide-eye pause that overwhelmed him as he swung open the door to see that the 0" of snow on ground the previous evening was now 31" ...tenting over the cars to the point where they were completely and totally encased. This is the more typical society guy. Doesn't really concern for weather forecast, except here or there when it necessarily matters to him. Not like us in here that track cumulus clouds ( haha). So I don't even think he knew there was a winter storm warning in place - or if so, only tacitly aware of it. But then again, LOL, I don't think NWS was much better considering what happened. By the following Saturday, it was 60 degrees.

You know what ... it's not out the question that we end up with a snow pack than 2 days later hover 70 F over top. With mud gully rivers flowing out of it, of course. I have seen it be 70 F with snow still on the ground due to an March or April sudden switch. Firstly, sell 20+" for now. But a 4-6" late season urinal blue cookie snow aching to melt when the storm's pulling out, knowing the next day the forecast is 59 F because even though the profiles allow for 72, no one has the ballz to forecast that over a snow pack.... that's always an fun bun for me.

But yeah...that warming look was even more impressive in the 00z run. How far and wide/long a any warm up in the range ultimately is...the entire continent below the 50th is in general seasonally flushing out the cold. It's like - symbolically - this coastal on the 3-6th is the spring exit event. Thickness gradients relax right after and with much more shallow cool loads that are easier modulated by the powerful April sun.

'cept laying down a bd boundary that close by is going to see that bd down to cape may nj

Well sure... but I was just speaking to that chart/interval, specifically. It maybe too warm. ... like I said, the GGEM tends to be too warm in the bl in that mid range stuff. I think it's overall an impressive homage to potential that it's as blue painted in ptype as much as it is at this range. That -NAO over the western limb in the multi-model blend has been hugely consistent for days now - it's like all but definitely going to happen. And it argues that anything delivered out of the NE Pac WILL descend in latitude underneath - the telecon on the shipping route is centered over the Mid Atlantic... The question - for me - is whether that result would bias on the N or S side of the general statistical domain. Because the entrance intervals ( time ) just prior shows heights in positive anomaly, albeit modestly so, over the lower Tenn Valley and adjacent Gulf o/ Mex/Florida and off the SE coast. That's a "Miami Rule" no-no... Some of the wave mechanics in the descent will get absorbed when the flow compresses down there, and is forced to speed up velocity. That's probably why we are seeing these solution - at present - that take the closing mid level centers straight over SNE instead of the idealized S of LI track like those biggies of yore and song. The feed-back process end up more N where more of the wave mechanics are less neg interfered.

That's like snowing really hard with nothing sticking ... not below 1200 or so... I think though that the GGEM having a warm bl bias in this time range above, 'might' make that interesting with the perfunctory correction.

Told ya .... https://phys.org/news/2024-03-extratropical-ocean-atmosphere-interactions-contribute.html ...15 years ago

oH man ... I hope that 00z GFS is right about the 7th - 10th ... madly deserved. 552 + dm hydrostats everywhere S of 50 N for three days of sun working on the landscape. The funny thing is, the 6th has the last of the -NAO driven coastal system still whirling in 38 F cat paws, and two days later it may be in the upper 60s or even 70 given that synopsis. Plus it has the upshot of less impeded eclipse viewing. It'd be nice but can't be confident about that unfortunately at this range.

Actually to be fair and honest, I noticed looking out the kitchen window when waiting on the tea kettle this morning that the lawn suddenly has green patches that were not there last week. I don't qualify it as "growing" just yet, but the uniform beige is now more a patchwork of vaguely greener and dormancy. I don't think that is early in and of itself. My recollection is that grass will tinge green at lesser environmental excuse - few mild days in February passing out the solar nadir into Ray's favorite - warm bum car seat season - and that patchwork look will flash over fields. That seems more like where we are at here in the Nashoba Valley. Which is interesting ...because what part of an icing event just last week flicked the turn green trigger ?

I think it's interesting that we've had about 9 consecutive months of above normal precipitation - I think? - on a regional scale, yet we never seem to really push the flood threat over the top. We're getting the Headlines out of the official offices but it seems by and large we're in a kind of "hydrostatic balance" (sloppy usage) where the outflow and inflow into the geography are in equilibrium; above climo, but below flood gauges. Playin' with fire? It's like sustaining a primed wick and never getting a match event

He's like a cat sticking its head in a paper bag - thinking it's all safe in there because of course ... that's the world in what it can see. Only his paper bag is his front yard.

yeah, that's a good point. From a sensible/experience approach, March is really a winter month - though CC's been fuggin with it, no doubt. If the 'weather machine' welshes on that end of the deal, there's really nothing redeeming left over - not to me anyway. Ooh, 42 F endless more clouds than sun, sign me up! I will, one day, be set enough to afford a 2nd residence possibly in California or even in Arizona or New Mexico, that I can flee to at this time of year ... open ended return date based upon the tenor of the spring/length of the dildo inches of that particular year

mm... I think April is but it's probably 6 to 1 half dozen of the other. perhaps "Marpril" is the better way to look at it. And May is the dirty cousin that shows promise but once in awhile still abets in crime.

Folks shouldn't hold on a snow event on Friday... most guidance far enough west to matter have a known bias of being far enough west to make people think it'll ever matter. Best is to be pleasantly surprised should that happen. Folks shouldn't hold on substantive warmer times until we're on the far side of that -NAO over the next 7 to 10 days. I do think the 2nd week of April we see a more momentum than we already have, into green up.

`FYI - I started a thread in this sub-forum that hosts 'general pollution' topics ... I don't personally care where it goes but it may be apropos there. Granted it's a slower burn and not as attention getting as this one.

yeha ... if this thing were to somehow pass under Li instead of abeam of PWM ... most people in this sub-forum either meet or exceed their seasonal quota in snow.

NAM has a NW bias at this range, too.

I wouldn't necessarily blame decreasing b-c on climate change this late in the season - assuming that's what you meant there. We're losing gradients via seasonal forcing at this time of year pretty fast, anyway, while CC moves much much slow than the forcing of any single transition season. It's almost impossible parse out the contribution down to a discrete level of either. But you know the former statement is right - The heights being modestly in positive anomaly across the deep S/SE, that is more of a larger scale limitation. It's physically preventing 'as much' N/S amplitude expression, because height falls sandwiched in between that and the NAO blocking becomes a compressed field - which speeds up the flow which stretches things W/E ... Just call it destructive interference. If this latter limitation somehow alleviates, that trough diving through the Lakes has a chance to slow down while passing under Long Island and that would be interesting

I actually don't have problem with it. Blues have odd behaviors - difficult to pin point that sort of thing. It's probably more of an homage to general possibility ...less 'where' exactly that happens. In fact, I can imagine the cackles and ridicule over the NAM this and that ... all the while missing that point. We're still technically reeling off that pretty crazy late season -EPO last week. It's modulated(ing) positive, but the loading takes time to extinguish - at this time of year, these indexes sometimes reflect more so in the mid level thermal complexion. If we look at that 850s mb, it doens't appear like there's warm problem to this thing being a kind of red flag - Although heh... anyone that thinks this week's been warm at the surface is probably trying to sell snow to Eskimos. I'm just saying ... that's why spring blue bombs happen.

It's close ( all hating and despising aside...) re April 3rd-ish Henry's chart above is remarkably consistent, as well ..shared with only irrelevant differences between the EPS/GEFS/GEPS ensemble means. In all --> a deep coupled response to that western limb -NAO you see over the D. Straight, should evolve nearby our lat/lon - that is the teleconnector incarnate. That's just a 101 interpretation that cannot really be argued. The problems with it are obviously A... the lateness and climate but excusing that obviousness for moment ( we've have blizzards in early April before, anyway - ) ...the heights in the west and how they transiently balance against the heights between the GOM and off the SE U.S. coast, are preventative. The GEFs mean for dailies is actually a very good fit on the 06z, taking a strong primary up the ST Seaway to about Watertown NY ..then, forcing a secondary E of PWM ... because it compromises the -NAO forcing a storm S, while also negotiating those heigher heights underneath/foundation of all that scaffolding down in the deep S/SE. It can change... a little more western ridging would help. But, I also suspect the entire 35N band around the entire hemisphere/planet on both sides of the Equator, being some 3 to 7 dm higher than they were 50 years ago ... would continue to impose resistance even if those mid latitude features became better aligned. The flow would compress, not "yield" in that sense... and compression speeds up the flow - it's basically just that the lower latitudes are destructively interfering. Complex... For now, we need the Pac --> N/A flow structure not be going into a -PNA mode, while these other inhibitors are going on, before we can be more confident in a finale bomb. I will say though that the 2nd week of April, the seasonal 'flash' is now showing up on the guidance across the board. It's probable any 1st week system would be the season's mortality gasp in the models.