wxsniss

Great map Ray. Best I've seen including the TV forecasts. I also think current NWS will be increased if 12z trends from today stand. I'm thinking areas of north shore have a shot at 18-24 especially if the east/northeast fetch Monday materializes

18z NAM with the ivt into Monday night!!

Lol "the elders" For me it's more just tracking fatigue... this has been locked in for at least 2 days now, and we're still over a day away. Not much fluctuation from run to run courtesy of broad overrunning and deep cold. Not the tense tracking we typically have with coastals. Obviously the event itself will be a thrill. We've been desperate for a warning event for years.

His first call map... can't find it now it was several pages back, but it was nuanced and realistic

Was away all evening... 5 yo's first school dance(!) and other stuff What an amazing weekend ahead for SNE. Feeling very confident with widespread 12-20" just about all of SNE. 0z suite was excellent. @40/70 Benchmark's map was best I've seen. I share some of the tracking fatigue... the broad strokes have been locked in for days. Still some suspense on meso features (how high SLRs, OE enhancement, how much 925-850 easterly fetch can we sustain Monday to top off eastern SNE, especially north and south shore areas) that we'll need to get 20"+ totals. Check this out... will be puking snow Sunday evening:

Quickly catching up, haven't been able to post today... Not sure what to make of the 18z NAM… 18z ICON, RGEM, and GFS held relatively steady in terms of thermals, and Jan 23 19z NBM so far has not flinched though I’m not sure if these models make it in the blend (I do not take these NBM forecasts literally): So we watch for elevated warming nipping at south coast and beyond but remain skeptical unless further support. At worst, looks like heavy thump followed by light sleet / dryslot after bulk of accumulation. More definite takeaway from 12z-18z suite today is less promising coastal cyclogenesis CCB potential for Monday. By 18z Monday, flow at 925-850 becomes more northerly and dries out (corresponding to closing lows further northeast) on all guidance, whereas in prior runs (again, 0z ICON from 1/22 being the best depiction with easterly fetch beyond 18z Monday (with closed 925-850 low south of LI). It's 60+ hrs out so arguably that’s still in play, but it’s looking less likely.

Just found you can actually see a mean SLR... begins 18:1 Sunday afternoon, drops to 13:1 overnight Monday across SNE... nothing too crazy In any case, I agree I don't see any guidance supporting widespread 20"+ amounts

Curious what goes into this blend... it keeps revving up. Here's the 1z Jan 23 NBM output:

I haven't had 6" in 4 years... I'd be thrilled with 12-18" On the other hand, ask every single member of this board wearing a lie detector test... the answer might be "when is any amount of snow enough?"

I think the isoentropic lift portion is slightly better (despite less cyclogen-CCB Monday) hence the relatively stable / slightly increased in CNE QPF in this run But the coastal portion of the storm... 0z last night has the best depiction of coastal portion I could find, mini CCB into Tuesday 6z... that portion of the storm I haven't seen recovered yet, but there are varying hints of it across the models. Need the energy to round trough and interact sooner

ICON has not recovered it's best look for Monday coastal development from 24 hours ago (0z Jan 22). Trough tilt was too progressive this run

ICON spread goods a tick more north in CNE 1.2+ most of SNE, 1.3-1.6 eastern areas Kuchera widespread 14-20

ICON!

Great stuff. Your posts read like a thriller that educates. What I'm looking for in next 72 hours to optimize that handoff from isoentropic to cyclogenic-CCB mechanisms: beyond just looking for an 850/925 low closing as far southwest as we can get it and maintaining easterly inflow lasting to 0z-6z Tuesday, I'm thinking earlier arrival of the energy rounding the trough and better tilt of the trough will help. At the moment, 0z ICON last night was the best depiction of getting this done I could find, with widespread 20"+ possible in eastern SNE. It's backed off a bit since but there are still hints on all guidance. Fwiw, 18z NAM at 6z Monday looks alot like 0z ICON... ie., potential to get very interesting Monday.

12z AIFS crushes and continues to hint at lingering coastal through Monday evening

An example of what I and others posted earlier... 0z ICON last night showed this as well (but backed off at 12z today). This is from 12z UK, keeps low level easterly flow into 0z-6z Tuesday... this is what we'd need to get us closer to 20": (EDIT: this is 850, 0z Tuesday, from 12z UK run Jan 22):

Without digging deeper for a better example, 0z ICON last night had the closest depiction of this we have a closed low 925-850 just southeast-east with easterly flow well into 0z-6z Tuesday Not totally outlandish either for these lower levels... Higher up 850-700 probably not happening fast enough

Agree, one of the more suspenseful remaining aspects of this imo if we're looking for the more "exotic" "nirvana" solutions of SWFE + CCB to get us to 20" and over I think ICON has had some of the better depictions of this, by virtue of faster infusion of energy and tilting of the trough

Agree Jerry I think 10-16" is a lock for most of SNE... but a few model runs flirting with better coastal development and capture... that would get us to 20" and more 13z Jan 22 NBM output...

Agree, exactly why in the cold vs. qpf debate about what's more important for a snowy winter, I always go with cold, even if it risks cold dry runs. The historic ones are often preceded by an anomalous cold dome... 2-14F, –2-27 Jan 21,22, 2005 3-19F Jan 6, 1996

12z ICON is great, but did back off a bit on the coastal development and capture... you can see at H5 the energy is slower to infuse and tilt the trough compared to the 0z ICON Just something to watch if we're looking for the more "exotic" "nirvana" solutions of SWFE on steroids + CCB to get us above 20"

NESIS 4-5 likely... these geographically massive ones you can see a mile away https://www.ncei.noaa.gov/access/monitoring/rsi/nesis

Very similar to 12z run at H5 and surface Doesn't quite develop and capture coastal like 0z ICON, but still would deliver 10-20" all of SNE assuming better than 10:1

Yeah EC AIFS followed same pattern as GFS... 0z and 12z similar, 18z outlier 0z and 12z better phase, coastal redevelopment, big hit SNE especially east

I like the comparisons, was lucky to experience both In terms of phase interactions, 0z GFS resembles 12z GFS as well as 0z ICON (ie., 18z GFS disconnect was hopefully an anomaly)