40/70 Benchmark

Tuesday (2/28) Winter Storm Verification Problematic Northern Stream Detrimental to Forecast Here is the Eastern Mass Weather Final Call snowfall forecast map for yesterday's event. Versus what actually took place. Clearly the northern and northeastern third of the forecast did not materialize, as the forecast 2-4" and 3-6" ranges across northeastern Mass verified as 2" or less. However, the northern portion of the forecast area had the worst verification, where 4-8" was forecast for the northern Connecticut river valley and northern Worcester county, and 1-3" verified. The issue is that late northern stream injection of energy that was expected to revitalize the precipitation never materialized, which is where most of the snowfall in these areas was expected to occur, during the afternoon. The marginal low level temps across eastern areas did verify, which is why northeastern areas experienced slightly less snowfall (2" or less) than northern locales well inland (1-3"). In summary, confluence was expected to prevent the heavy snows from reaching the northern and northeastern areas during the first portion of the storm, as evidenced by the soundings referenced in the Final Call. Thus round 1 on Monday night went as planned. But round 2 during the afternoon never materialized. The 3-6" and 2-4" forecast ranges across southeastern Mass and the upper cape verified because enough lift made it into these areas to negate the marginal lower levels to some extent. The rest of the forecast back to the west and southwest verified very well, including the 5-10" of max snowfall over the eastern slopes of the Berkshires, as a result of easterly flow resulting in an upslope component that enhanced snowfall slightly in this area. FINAL GRADE C-

C- effort on this one...Round 1 went as planned to the west and south on Monday night, but Tuesday PM was a no-show from the N stream insert for round 2 to the north and northeast. https://easternmassweather.blogspot.com/2023/03/tuesday-228-winter-storm-verification.html

He is a better spot for high end events, but it's much more feast or famine.

We'll see about that....there is a reason you average like 20" less than I do.

Regression is a bitch.

08 was good NOP...great north of rt 2.

I will say GFS is improved model IMO.

Agree. Warning event NOP-interior, advisory otherwise.

You can see why GFS socks me with 1'+....I'm right at the northern edge of that nascent H7 low.

Yes...mid levels close off, which also caps mid level warming.

You would think that discrepancy should become clearer soon.

Not really. I explained where I was coming from..just let it go.

I feel like its rushing that evolution.

I don't buy the whole sale Miller B detonation attm....but, we'll see.

Yep.

That is clearly a Miller B take over, as opposed to confluence forced attennuation. Guidance tried to do that at the last moment with the Tuesday deal and it was total BS.

I don't buy a foot in Boston, either.

I guess to me, it was like breaking the balls of someone who thought the Sox would be great, in spring training.

Hey, if we get to mid March and its still like this, bust away.

Yea, I had a more east-west gradient inside of 128 and 495 up there.

Yea, I like gradients, but numbers are conservative right now, which is course of least regret for then..I get it.

I guess I don't see what this system likely sucking for you has to do with how much you end up with in March. I made it clear precip type issues would be prevalent across the southern half of the region due to MJO-7 WAR...IOW, I have my eggs in later baskets for region wide big snows.

If we get the 00z Friday and the NAM is the warmest piece of guidance in the mid levels, then I will capitulate.

Bingo.

100% my sentiment.