OceanStWx

FWIW, coop average depth is just add up all the daily depth reports and divide by the number of days in the month.

Yes, that's the current regional criteria.

You get some leeway with criteria (theirs is 3") if you want to say impacts will be a problem. They can claim the commute will make 1 or 2 inches problematic and thus issue an advisory for it.

Reaching?

I always sign my last name, Legro. I still think someone in SNE could pull off a 3-4" report, but the question is how do you want to message it. Do you prefer to paint a narrow band and potentially put it in the wrong spot? Or would you rather broad brush 3-4" everywhere and know some of that will be wrong?

Oof, on the HRRRX reflectivity product you can see clouds streets showing up in the Gulf of Maine starting around 08z tonight. Not great if you're looking for snow on land up in NNE.

The tough part is that 850 mb f-gen is well east of the 700 mb forcing. i.e. way too sloped to really help enhance omega for warning criteria amounts.

Even the crappy solutions show pretty intense f-gen in the mid levels, it's just narrow. Could be a classic couple of inches for E MA while Dave is staring up at starlight filtering through the cirrus.

Also bring 'em down with the first update of the morning...

The though part is that the meteorology rules of thumb are flipped on its head for this event. We typically think in terms of the best snow falling W of forcing, but in this cast it will be E of forcing. I think if you rip and read through the models quickly that's going to bite you on the forecast. If you generate snowflakes at 700 mb falling at an average 1 m/s they could drift as far as 15 miles E before they reach the ground.

I think the grand irony there is that we probably pay more attention to southern NH than we should just because that's where all our population lives.

I really, really wanted to keep any accumulating snow basically offshore with yesterday afternoon's forecast, but alas I had to try and shoehorn in around 2 inches to match up with neighbors. Didn't like getting dragged a bit on twitter for "ignoring" southern NH. Just looking at our midnight shift grids and I'm going to have to chop even more than they did.

More or less correct. It's different between the zone forecast (which the local office can modify) and the point and click (which is nationally implemented). But you have the categories correct I think. Light = 1=3", moderate = 3-6", and heavy = 6+

Front is already through PWM.

Fog all sitting north of the surface warm front. Waiting for that to blow through GYX.

Just no hint at mixing at the moment across the CWA. Winds pegged at 00000KT.

The snow eater fog has arrived at GYX.

Easterly component is preferred. Can still get WAA but not torch from those directions, or it's pure CCB. S, SW are too warm for all snow typically, and W/NW downslopes across much the region (powderfreak will keep his fake snow though).

Well snow maps are almost always going to give you way more snow through a model run than you actually receive. So in that sense, yes looking at snow maps will hype any pattern.

Definitely a Cape Ann to EPO climo max, but I would also prefer this set up to see the 500 mb pattern not progressing through the area so as to give any inverted trough a chance to form and drop some precip before it's whisked east. Color me skeptical at the moment.

Maybe we can tack on another fraud five member and go for the Downeast inverted trough late Wednesday too!

Anecdotally I always zeroed out any accumulation at >= 37, and really limited it above 35.

FV-Wheee

Tip's right that we do have some dry air to contend with for much of the area, but the strong jet is going to induce some late advection. The GFS is trying to bring in a swath of low level moisture and pressure advection late Tuesday. The pressure advection is kind of weird though, basically pressures on the isentropic surfaces are falling so quickly behind the front that SW flow behind the front is actually blowing from high to low pressure (i.e. ascent). Normally you get pressure advection due to wind blowing normal to isobars, not from local changes in pressure. So you can see why these set ups are tenuous.

Definitely not my first choice for a fake cold radiational night.