OceanStWx

It's been a pretty rough run of snow depth locally since 2018, and local research has definitely shown that we're losing total days with snow cover in the winter. This one definitely has the feeling of the December 2020 storm on the ratio front. That modeled 300 mb deep DGZ was definitely a strong signal for upping SLRs. It's just so damn hard to push yourself to forecast more than 20:1. GYX has at least a 23:1 from the morning observation, so my CoCoRaHS gauge may not have been far off.

I think it's only the second time since 2018 that the flag has been buried. I can't recall being over 15" on the ground all that often. Maybe my memory is still there. I checked CoCoRaHS and I have December 2020 (20"), March 2023 (18"), and today (19") as my only snow depths over 15".

You could just tell from a peek out the window. I could see the individual dendrites sparkling and knew we had ourselves a fluff bomb.

You'll never hurt yourself if you just assume all accumulation stops once the DGZ dries out. If you pick up a weenie half inch, embrace the good fortune, but most of the time that's all she wrote.

10.2" for me. But my CoCoRaHS can overflowed. I could only get 0.35" liquid out of it, but I grabbed a snow core off the board and left it at home to take care of later. The flag marking the snow boards is officially buried too as I'm up to 19" on the ground as well. Never a doubt.

There are a few reasons why I prefer the over on QPF. I'm seeing soundings supportive of around a 15:1 average in the area (200-300 mb deep could support upwards of 20:1 at times). There's a decent crosshair signature around 06z (estimating between PSM and LCI soundings), that's pretty good for 6" snow. The WAA forcing is strong and displaced north of QPF max, which is a red flag that some deterministic guidance may not have things far enough north (which is not uncommon for a high bias on QPF on the equatorward side of systems). The only pause I would have is if there is a messenger shuffle south today. That would introduce a DGZ that is starting to get a bit high in the column for ideal ratios, that's why my totals drop off sharper to the north. I'm not sure I've seen anything significant enough to warrant concerns where I have warnings up.

Let's call it 15:1 average SLR there, that's going less than .33" QPF on the high side, 0.20" on the low side. 71% of the ensemble members are 0.5" or more QPF. Gimme the over.

That's advection from DAW though.

That's how you end up with another kid.

There is a huge slug of 700 mb WAA induced f-gen (NAM slightly farther north than GFS/Euro) so I don't see how there isn't a nice dump somewhere over the southern half of NH.

I believe the HRRR is still using the Thompson microphysics scheme for ptype. So it basically is taking a fraction of snow to all accumulated precip that hour and then looking at surface temp for rain vs freezing rain. In this case, I would guess that there is minimal or no snow, so the ptype kicks it over to liquid and because it's below freezing it spits out FZRA.

It should bang 1"/hr before the DGZ dries out, but I'm always more inclined to go snizzle in the dry slot than FZDZ.

I wonder if that's the HRRR trying to do FZDZ for ptype.

I could buy the double banded look to the jackpots. The HRRR and 12km NAM both kind of have it that way.

I mean to the extent we can, yes. We're briefing partners about more snow and our long range messaging has it, but we won't be doing QPF for that event for a couple days.

I'm on board with 1/hr for SNE, but ratios look pretty climo to me. It's the dendy band that may be pure air.

I wouldn't say SLR will be poor, but I wouldn't be banking prolific for most of SNE. Maybe 10ish:1 PVD to BDL, 10-15:1 around ORH, and once you get up into NH there is some potential for a 300 mb deep DGZ and SLRs could be tickling 20:1.

BOS has a meaty 50% of the ensemble members between 4 and 6 inches. Only 14% less than 4. Nice long tail on the high side.

12km has a nice WAA band at 700 mb nuzzling up to @dendrite, so I'm automatically inclined to believe it.

There's definitely a large "AI will solve everything" contingent that has arrived in government, so if you like your forecast with 6 fingers on each hand do I have good news for you!

I don't know what these maps are doing anymore. They are relying primarily on WPC data, but also include snow from today. I think it still uses the local forecast, but I'm not not sure to what extent.

To congratulate @dendrite!

Only 96% off if you want to be literal, but there are things that go into the HREF that are part of their super ensemble. For reference, inside 3 days you get the Euro op and 25 ensemble members, the GFS op, GEFS mean, and 10 GEFS members, 10 GEPS members, a SREF mean, and then some combination of the HRRR, NAM, FV3, NMMB, ARW as available.