OceanStWx

I wasn't positive of that, but intuitively it makes sense. If you create a crystal at -5C it's going to take less heat to warm it up to 0C than if you create a crystal at -12C. Even if your crystal structure may be more delicate.

Really? I thought they were frcsting 5" or so And I ended up with 2.9" It was probably more, but I was fast asleep when the snow ended and the board was a wind blown/compacted 0.4" after my 2.5" midnight ob.

Trying to dive deep to figure out what the real failure point was here, because I don't really think it was forcing. The QPF was pretty good, right ballpark anyway, clearly there was strong f-gen in the right location relative to the storm. I keep coming back to our 00z sounding last night with DGZ up around 500 mb. That's not a great spot and indicative of a pretty torched air mass. Dropping less than dendrite ratios into a deep near freezing layer primed snow to melt at the surface. Even when rates were decent. There was a lot of 1/2 to 3/4SM snowfall that normally would accumulate if your flakes weren't already near slush by the time they reach the ground. Honestly the 04.12z NAM forecast soundings weren't bad in the vicinity of GYX, and it should've been a bigger red flag to me. We were running with ratios around 7:1, but they needed to be lower than that given the environment we were working with. Elevations did better because it shrunk the near freezing layer that flakes had to fall through and kept near surface temps slightly cooler.

It takes some stones to forecast a significant period of 3:1 or worse ratio.

Even Kuchera isn't going to save you in an event like this. 33F snow is still going to give you a 7:1 ratio. We were about half of that at the office from 1-7PM when it was nearly all snow/frozen.

Tip is right, NW winds downslope for just about everyone across the region. That does a number on precip.

Today is fun, because now I can play Monday morning QB on myself trying to diagnose WTF went wrong.

Well I think a problem is that clown maps (especially these realistic looking ones) are a relatively new feature. Because of how they are generated, you rarely end up seeing more snow than they spit out.

We were trying to tease out elevation from people when they called, but there aren't many people like Gene who know their elevation and all their neighbors elevations too. But I think it's clear that played a big role when you look at our office total vs up on Lava Rock.

2.5” at home. 2.76” liquid in the gauge. Probably a half inch rain before snow started mixing in. 1:1 ain’t going to cut it.

I think even the models that had 4:1 ratios had way too much QPF. So the end result was still a lot of snow. Couple that with DGZ sitting around 500 mb near the coast and that’s a disaster for big snow. Just west of that though, sweet spot.

Well I lost power at home, and I can't imagine it was from more than 2" of snow. So all in all I'm not happy at the moment.

We stop getting data sent to us via satellite when our dish gets caked too.

I'm not sure I can think of a time I've seen it that dramatic during a winter storm. Most of the examples I can think of come from our radar training.

Yeah, you are all looking for excuses for why this event is underwhelming and the radar was a convenient out. It's just crappy snow rates, the radar dropping out some Z isn't a sign of anything in particular.

The wedge of high ZDR is definitely all on the N/NNW side of the display.

Well the radar image is an artifact, but that doesn't mean the snow rates aren't letting up also. As has been the case much of the day, unless it's heavy precipitation overhead it's going to struggle to maintain a steady snow.

A big part of our job is figuring out WTF is happening, and diagnosing it quickly enough to shit or get off the pot.

Yes, essentially the radar is putting out full power but some is immediately taken away by the rain/snow on the dome. So when the returns from Metrowest make it back to the radar, it seems as if there was way less power returned than was sent out and the radar thinks there isn't any moderate to heavy precip there. How quickly that Z dropped out was a red flag for me. Doesn't usually happen in minutes.

Wind is NNW, so probably caking any snow onto that side of the dome.

I think we're looking at beam attenuation due to a wet radome. The ZDR is spiked for no good reason in that zone, and that will hurt other products.

This observed snowfall map is going be a piece of work.

"Friend"

N/NE winds just do so well. You can advect cooler air from the N to steepen those low level lapse rates and more efficiently mix.

Disastah