ORH_wxman

The accretion efficiency would prob be like 0.7 on flat surfaces and like 0.4 on radial. So you really want to see liquid equivalent ZR over 2 inches before thinking of 2008-esque impact. Some of the runs are pretty close though.

The biggest question mark is QPF where you are. I’m pretty skeptical you ever go above freezing so it’s a matter of how much liquid equivalent you get. Some guidance is a lot more than others...some models keep the heaviest stuff more toward the south coast of SNE in round two on Thursday night and early Friday.

Looks like utility poles are coming down in ORH.

The big QPF happens at night at least....but he's still going to have to deal with severe downsloping off the ORH hills which will also block the dewpoint drain.

First wave looks colder than 12z run though.

Yeah I think the accretion efficiency in that storm was like 0.5 or something...lol. ORH had well over 2 inches of QPF but around an inch of ice or just a bit more (I think I measured like 1.1 radial).

Yeah obviously the development of any mesolow affects how quickly the drain accelerates from the northeast. In the Dec 2008 storm, a pretty well defined mesolow developed east of MA and into the gulf of Maine late afternoon and early evening of Dec 11. It accelerated the dewpoint drain into N MA and probably sealed the fate of all those lower elevation areas along and north of Rt 2 east of FIT and NW of 495....without that, they may have been more of a 32.5F rainstorm instead of a crippling grid failure type storm at 31F. Or at the very least...maybe more of a marginal ice storm without the heavier accretion rates that the drier air blowing in from the northeast helped enhance.

At least as of now thats the way it looks...the max cold layer is around 950-975mb late Thursday/early Friday. That's really the time period to focus on....I think a lot of folks will see some light icing Thursday....but then it slowly warms to 33-34F in spots by the time we see the heavy precip return late Thursday night/early Friday....where does it stay 30-31? Elevations on the east slopes will be last to warm with that flow and sounding look.

Youll def get some on Thursday morning after the snow/sleet thump....but the question is after that when the heavy stuff hits late Thu night and early Friday....you need an earlier drain for that I think otherwise its 34F rain. It's possible, but right now it would probably be like ORH over to 495 belt/Tip's region and up toward ASH. That could def change though wither another tick flatter.

Lol...yeah he would. There's reasons to believe this would be less than 2008, even if that look verified. QPF has generally been a bit lower and the high isn't initially in as good a spot as 2008...so I wonder if we get too much latent heating before the drain can really get going. The antecedent airmass is better than 2008 though, so that could easily offset it and "buy some time" before the drain really kicks in.

It's a fricken mushroom cloud over Baffin Island...nevermind a mere pig. IF the Atlantic was even just mildly hostile, this might actually be a damned good pattern coming up. But with the death vortex over there, it's making a good pacific into kind of a crapshoot here. Hoping we get lucky....the other thing that could happen is move that vortex southeast a little and it actually becomes favorable again....that's what happened in December 2007....we took advantage of an obscenely +NAO pattenr because the vortex was so huge and far enough southeast that it actually crushed the heights over southenr Quebec and into N Maine and Nova Scotia.

Euro ensembles are similar...only question left is does it trend back warmer? Because I agree if it doesn't and plays out like that, then it's probably some serious levels of icing that hasn't been seen since 2008.

The cutoff is eerily similar to 2008.....lol

Sunday has looked like trash for about 2-3 runs now.

Yeah he's gonna get at least a foot...locked in.

Hence, the "in 2008 you would not have been far enough east for mostly liquid" response I gave.

You might be far enough east for liquid during the heaviest slug...but it's close. In 2008, you would not have been far enough east for mostly liquid.

Euro might be a grid failure for ORH.

Wondering of those other models had the right idea before they caved....guess there could still be a spike this afternoon, but starting to doubt it

Foreign models have liked the front end thump....American models hate it...NAM was meager too.

That's the flattest run I've seen in a while from any model. Doesn't get the primary west of the apps once north of TN/KY.

2008 was forecasted pretty well once about 48-60 hours out. A lot of models were terrible with the CAD though...esp GFS, but even the Euro kind of sucked. Euro was trying to drive the low over interior New England. But most of us (including Mets at NWS Box) we’re not buying it and siding with the meso models that tracked it over SE MA. NAM did well in that event though it was actually just a hair too cold until inside of 24h...had ice a little further south than what actually materialized. But back then the NAM had a colder bias at the sfc in CAD...something it doesn’t have now.

Euro def got more interesting for the siggy ice idea late Thursday night/Friday morning. Most 00z guidance did actually. The snow thump got a bit better too...esp pike north. W’ell have to see if that’s a real trend or if it just goes back warmer at 12z.

I didn’t say I believed that’s what would happen. Just that it gets a lot more interesting if it does. If it trends the other way and goes warmer, it merely goes from meh to total snoozer.

18z euro came in a little less amped. Not a massive change from 12z but another one or two like that and we’re looking pretty darned wintry again.