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.

26/7 already at KDAW. This looks good for SNE weenies. Go long the 12z ARW WRF

Dare I say the 18z NAM is onto something —only with regard to intensity though. Thinking “strung out” will be lost as the go to vernacular describing this as we get closer in. The surface low likely —as it typically does in these situations—ends up somewhere over SE MA...

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...

I’m with you. I don’t like the trends. I think it’s an all or nothing deal. Thinking you’ll want to be furthest South and East. Boston on the margin. Northeast trajectory from 50-100 miles east of BM = Eastern Long Island, RI, to SE MA, and especially cape and islands is where I think it’s a big hit; in terms of qpf. The changes have been subtle from run to run but the mid level track continues to trend south...

I guess I mean in terms of how it stacks up. Much falls as frozen...little stacks up...much wasted. Seems like a 1-3” deal. And then a break, and part 2 is when it all comes together...and south and west looks best for the second half.

CT looks like the sweet spot. Especially NW of I84. still plenty of time, but that’s the way latest guidance appears to be trending IMO...

Yea I agree with this. Could be very meh for part 1. Little accums. All the goods Monday pm and on... Still thinking the best accums will be west and south —NNJ southern upstate NY NE PA. For our sub forum still thinking this is south of pike special. Highest amounts, south and west.

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...