jbenedet

28/24 with NE wind at 10 mph at DAW says it all for those locations. Incoming.

Snowing in Epping NH, after brief period of freezing rain/drizzle.

28/24 in DAW with NE wind at 10mph

Have had everything in Dover. Snow, to some sleet and now freezing rain/drizzle. And that’s happened as the surface temps has dropped...

Yea that’s my thinking as well; at least in terms of the physical processes—latent heat of fusion. I think dewpoints just above the surface would matter a lot here. Unless they are well below freezing I’d lean Freezing Rain. I’m also seeing guidance trend towards greater warming aloft, while the surface cold remains more or less constant. Trend is towards more freezing rain, less sleet...

Just east of the northern Apps the low level easterly component will not occur in a situation of cold air damming, the mesoscale pressure field will trump the synoptic flow. Some may need to open up the textbooks, for reference, but what’s being modeled as easterly wind in parts of SNE will, in reality, be a NNE wind.

Like this in general. Fits my thinking. Only major difference is would have much more East/West gradient with the “big ice threat” area, down to HFD.

Strongly agree with this. Where I disagree is the antecedent airmass is average at best, and late December climo near the coast is not nearly as favorable as late February for this, with warmer SST’s. It doesn’t take much of a low level easterly wind to send BL temps into the mid 30’s.

Without really digging into this, the ageostrophic flow has a significant easterly component which should act to warm the boundary layer well above freezing, in those areas IMO. The coastal low gets going too late to prevent that, as I see it. Zooming out, I think the surface front has that classic “kink” look following the northern Apps, where we get significant cold air damming down to BDL but mid to upper 30’s points East, up to BOS. That’s my thoughts for now anyway. Regardless I agree, sig ice is the big threat, with highest confidence from BDL to ORH.

My initial thoughts vs guidance is go long ice and sell rain/snow from BDL up to SNH. sleet favored from ORH to DAW. Freezing rain favored from ORH to BDL. SNH to ORH gets thumped on the front end with a few inches of snow...

You might be right, but I’ll say since living in coastal NH, the surface CAD is really robust, but at the same time 850 -900 warmth commonly makes its way up to where warm fronts go to die —“Lake Winne Region”. I think this is one of those setups where the surface front ends up over SE MA—*much* further southeast— than at 850.

You would think, but we lose any surface high at that point, and the coastal low isn’t sufficiently deep to generate low level CAD until it’s into Maine. It seems more likely to me that 800-900 warmth is being captured well on guidance for part II, but the surface CAD is significantly underdone. Most likely outcome is areas that are below freezing at the surface through part 1 remain so through part II. Surface temps stagnate while 800-900 warm slightly. Points south, around BDL, are mostly light freezing rain/drizzle, while points north, around PSM, are mostly sleet. Areas, in between (around ORH) are a mix of sleet and freezing rain. Seems more like a “we rot” situation, despite the coastal low development.

PAC doesn’t look bad with PNA neutral. I the PAC being slightly unfavorable is easily offset by greatly improving climo as we head into latter half of December with a -NAO (assuming it holds).

Really difficult not to like where we’re sitting with MJO likely to region/phase 1 and a -NAO/ - -AO in heading into late December. A merry Christmas indeed. I think Monday night delivers mostly white for bulk of us, northwest of I84/I90. Low end warning snowfall looks good for broad area of sub forum. My first guess...

I’m on record here saying I never really like a -EPO, for sig snow storms. As you indicated above, much of this hinges on whether we see a -NAO build around the time the shortwave is over the central conus. Not much clarity there, given the divergence of model outcomes beginning around the 10th—only time can cure this...

Both solutions are too amped to be SWFE. I know what you’re saying about a SWFE, but to me the latest guidance is saying this is either a cutter or a Miller A. I lean towards the latter but with very little confidence. Also climo still not favorable for a sig snowfall from a SWFE outside of NNE...

I like the day 10 potential. Guidance vacillating as usual, but big storm threat continues to show up across guidance. Seems the GFS and euro traded depictions but being that the majors have shown it at one time or another in the past day of runs has piqued my interest. I think this is the only one to watch for those wanting meaningful snow. But being out ~10 days, that’s about all you can say right now. Watch with interest...

12z GFS looks like the southern margin of possibilities with this. Thinking it has over-corrected here but could take several runs for that become clear. Regardless, the players are extreme in terms of persistence/climo. We do have a record low mslp hitting the west coast today... so we should shift our expectations accordingly...climo much less instructive than usual...

Personally I think it’s harder to stand your ground when every subsequent solution shows something different. We will see how many more runs of major guidance today? And the final outcome will still be ~5 days away... What’s noise vs what’s meaningful is toughest in weather forecasting imo. Updating a forecast too often can be worse than not enough. Imo the trap is the former when key information is coming over 6 hr intervals—minimal confidence gained per run, BUT its new information...

Yes. Similar. But that was with peak winter climo—northern jet stream further south— and that’s why i said a “compromise is in order”. So I think the bulk of it ends up further north—Northern Jersey, LI, cape and islands area...

Everything should be considered at this point, but as I’ve said before, I think about what the evolution should look like independent of models, and then latch onto the guidance that begins to show it first. Basically to put it another way, I run my own model in my head—and right now the 6z GEFS looks much closer to what I’m thinking on this...maybe I’m wrong and the GFS is wrong, but one run of the EPS isn’t going to shake me one direction or the other right now, just need to see how things evolve over next several days.

If not for late November/very early December climo I think we’d all already be saying “congrats philly, ACY or maybe even DC” for the December 1st potential. A Cut-off running into a monster Greenland block screams suppression to me. I’m thinking a climo compromise is in order, so at this point I wouldn’t at all be surprised if NNE is cold and dry and the bulk of the event is in the Northern Mid Atlantic. Just my first low confidence guess... In short, I think the trend on the GFS is real—it will persist—and should be taken seriously...

Yea. There was also another Nor Easter last year where the SLP ran over SE Mass but dumped widespread 30”+ in Upstate NY, near Binghamton area. That was due to a similar situarion as this with the mid level tracks being displaced well to the west.

Yea unless you live at the base of a mountain. Tell me about it.

Careful you’re starting to sound like a