wxsniss

30-35 dBZ entering 495 belt strong finish in the making

< 1 mile vis in Fenway area Roads still just wet obs + upstream radar consistent with a strong finish 2" seems very doable but even whitened roads would feel like a victory

We had a bit of white rain mix during that dry lull in Boston metro but back to snow with better returns I like what I see upstream and short term mesos, at least for snowfall rates 2-4pm

Complete changeover to snow in Brookline, seeing some wetbulbing at KBOS Ground is starting to whiten Heaviest 2-4pm per HRRR/RAP/HREF eastern SNE, will actually give a semblance of winter

12z HREF doubles down on finish for eastern SNE... Band of 0.5-1" / hr swings through ORH east ~2-4pm

2023-style Miller B... I'm not expecting more than sloppy 1-2" in mby, and we'll celebrate like it's 2012

Kraft on 0z HREF (a perfunctory post in an abysmal winter)

Check out 0z HREF, goes to town with the finish In any case, hard to be very confident in the finish and will be a nowcast event. We'll need good rates to overcome crappy BL temps in much of eastern SNE... very possible it looks like a 2-4" event at 20 feet elevation amounting to only a slushy 1-2" on the ground.

0z NAM keeps Orchids of Asia open

Great synopsis We're gun-shy (at least south of NH-MA border) of a positive trend of yore, but guidance is pretty solid now for one. It's really a stretched out Miller B. Initial pulse is pretty detached northeast from the main upper level mechanics... check out at 11z: By 16z, cyclogenesis (with stretched out closing 850/700 lows) continues further southwest: If we had an additional day for these trends, I wouldn't be surprised to see more consolidation around the later / southwest / better mechanics. We'll see how this all overcomes crappy BL temps, but good rates should deliver into SNE.

One for the humans. I lobbed ChatGPT an easy one curious how it would do: Explain the dendritic growth zone in snow growth The dendritic growth zone (DGZ) is a layer in the snowpack where dendritic crystals form. Dendrites are a type of snow crystal that have a branching, fern-like shape. They form in the lower part of the snowpack, near the ground, when the snow is subjected to temperature gradients and metamorphism. The DGZ is typically located between the new snow and old snow layers and is characterized by small, dense crystals that are less likely to cause avalanches than depth hoar crystals. The DGZ is important for understanding the physical and mechanical properties of the snowpack, such as its strength and deformation. The formation and persistence of the DGZ in the snowpack is controlled by factors such as snow depth, temperature gradients, and the presence of liquid water.

Funny to see the excitement as the ground whitens... we're a forgiving bunch

Yeah line (matches well with CC) has been dancing around pike, finally pushing through Cars and pavement starting to whiten!

Sorry for the nostalgia... Jan 2005 and April 1997 top all-time for me. Most extreme winter storms I've ever experienced. Feels like an imagined memory given the sewage regime we're in now, but this was real and it was spectacular. 1/22/05 Saturday night, scenes in the Longwood medical area and Harvard Square: NRB.1.22.05-TRIMMED.webm HarvardSquare.1.22.05-TRIMMED.webm (Edit: anyone know how to embed videos?)

HOF'er for EMA. It's historically a prolific week. That specific 12z Euro run left some greater potential on the table. Vague EPS signal too.

Plain rain in Boston, but unless these soundings are completely wrong, it's coming... Northeast MA / southeast NH including metrowest and city proper should see changeover followed by decent snowfall ~3pm-7pm

Yeah afternoon (~19z-23z) looks good for a few hours of 33-35F decent snow... at least the appearance of winter in the air even if we do not get the most efficient accumulations 13z HRRR likes northeast MA/southeast NH down to metrowest with the commahead

Health and Happy NY all! Back to muggy nights in the short term, but some realistic threats lining up with signs of a better pattern during good climo later this month… delayed but not denied.

I posted the Box disco an example that it was not just people on this forum who were taking yesterday's guidance and the large scale pattern to believe there was a decent chance of snow.

Let's not blame anyone for believing yesterday's guidance and the large scale pattern that we'd have a decent chance at snow... this is one of the more egregious model swings I've seen in a while. People on this forum are not alone: NWS zone forecasts still have 50% chance snow for most of SNE next Thursday... NWS long range disco from last night: Thursday... Late next week ensemble height anomalies become configured across N.A. to support a potential Northeast winter storm, with a large amplitude west coast ridge, driving an amplifying downstream trough over the MS & OH valley. In addition, anomalous Greenland ridge extending into the NW Atlantic, supporting a negative tilt trough from the OH valley into the Mid Atlantic. This likely precludes system from heading out to sea, but also possibly tracking too close to the coast for an all snow event. Storm track and ptype will remain unknown until sometime next week. Also worth noting, tides are astronomically high, with Boston at 11.28 ft MLLW 9:38 am Thu, and 11.64 ft MLLW at 10:27 am Fri. Thus, we will need to watch this closely as coastal flooding is possible.

Even folks in Chicago will be disappointed this is cutting too much on this run Only a ~700 mile shift in track since 12z yesterday. Horrendous model continuity at surface and aloft. This is completely out of range of even the 0z ensembles tracks.

I posted this yesterday in response to those rooting for a better phase... the less proficient phase was doing us a favor with the trough axis as depicted... unless we get a GFS solution digging almost to the Gulf, we have risk of a hugger At least 3 correcting factors we can hope for, and plenty of time for a combination of these to improve outcome: 1) west coast ridge shifts a bit more east 2) our main monster shortwave digs farther southeast similar to depictions yesterday 3) a minor lead shortwave establishes better confluence ahead of our main shortwave, also similar to GFS yesterday... perhaps a less proficient phase but that works in our favor

Both 18z and 0z GFS had this feature, hence the more disjointed cyclogenesis 12z GFS did not, and cyclogenesis was entirely focused at the monster digging shortwave

Agree. Like you said earlier, we aren't going to see perfect phases on consecutive run after run of OPs Also, more efficient/earlier phase (like 0z CMC) has greater risk of hugging. I like where ensembles are at the moment.

Just looked at Euro OP... piecemeal phasing that spreads the wealth in space and time, but close to a much bigger hit if that shortwave diving to Carolinas caught up GEFS+EPS look great Obviously the best signal we've had this season... Gonna be alot of distracted folks at upcoming holiday parties