jbenedet

H700 looks like biggest nagging issue for snow accums.

Ho hum, no kiddin' . Re: winter 2022-2023

Where? More specifically?

850 looks good, but its 925 down you have to worry about most, I believe. Easterly fetch when primary hangs on, and surface high slides east. And potentially sneaky warm tongues above 850.

It looks like we lose the -NAO though. Complete regime change.

The UL blocking is favorable, but it's not collocated with deep cold. That's what makes this blocking setup much less impressive than the setup for Tues. This also means that you can get favorable surface track, "outside of the warm sector", but ptype issues remain, bc there's a lack of cold to tap. Southern Canada has been warming since early last week; albeit from a very cold state.

This one is going to look familiar in terms of the seasonal persistence gradient. I don't think you start to feel comfortable with odds of significant wintry precip until to go from PWM, to DAW, to MA/VT border.

I believe this primary will be quite a bit stronger than what we are seeing with Tuesday event. 970’s lows don’t go without a fight. Couple that with weaker east based blocking, and then layer that with a warmer antecedent airmass. I think even if you get a Miller B evolution you have broad ptype concerns due to primary hanging on and antecedent warmth. I will concede to a cold/snowy evolution *if* the PV timing is much more EPS—esque.

Thanks. 6z GEFS is good baseline for what I *currently* believe is most likely. I think slightly warmer version of that. But confidence is low at this stage. Too early to identify track, too much uncertainty with the players in Canada.

so you think this misses south? i believe that’s the least likely outcome. Current probs in my view: Warm/Rainer for SNE, heavy snow interior NNE > New England Snowstorm > cutter> miss south

This one will be fun to watch because it’s going to be in absolute beast mode by the time it hits Texas. I think even the GFS guidance is conservative with the early intensity of the surface reflection. MJO firmly in phase 7 with the way the pacific has been this year?! We’re looking at a system that will strongly influence the downstream upper air environment —WARM. So you’re going to need very well timed blocking or staunch blocking. We don’t have the latter. But with the -NAO chances are we could score the former. For now, my forecast bias is still strongly tilted towards a warm outcome given the way the Pacific floodgates are open and we don’t have antecedent cold over the northeast US or southeast Canada.

I don’t like this one for snow chances for 90% of us. A 975 mb low will laugh at confluence that is not accompanied by surface cold anomalies. Looks quite warm out ahead. All cold behind—it will want to gain significant latitude. First guess is I think VT and upstate NY in good spot, as are far interior of NH and Maine. Mainly rain elsewhere.

I thought places that haven’t seen in inch all season would be thrilled at the prospect of 5. The euro is not pretty but it will spell a positive surprise somewhere in CT, with like 8”, a la 12/12/22. Take it and run with it.

I mean, I get that. You’re talking 988 type low at the high end. It’s capped but at a slightly higher level imo, than the alternative. I just think more can go right, with a legit miller B, and much more can go wrong with a SWFE given the players.

I see a hybrid (late bloomer) in EPS and UK. GFS mostly SWFE. ukie most miller B like, GFS least, EPS in between

When the NAO is this negative, and flow is slow, I say let cyclogenesis work its magic off the east coast strong vort be damned. You’re more likely to get positive surprises than negative, so long as temps are supportive.

Yea that’s what’s getting it twisted—an us vs them scenario. NNE wants a SWFE (primary holds on indefinitely) whereas SNE and north Mid Atlantic want a legit Miller B. The snowfall outcome is very much capped (everywhere) at moderate scale outside of an outcome that results in a weak primary that quickly transfers to Del Marva and then phases with the Northern Stream Shortwave, somewhere south of the Cape.

Again. Similarities to 12/12/22

I still believe the prevailing issue is the shortwave over Manitoba. There’s theories on what would help bring back a stronger storm—why not just look at the earlier runs which were outputting such solutions? What was the biggest change? The late phasing of the primary, which causes it to hang on later, and diffusing chance of a clean phase with the coastal. To my mind if you dampen this feature, and the primary fizzles sooner, you can get a dynamic cyclogensis —even with weak UL forcing—to occur given the slow flow over the western Atlantic. This wouldn’t be great for everyone of course, but it would give much higher totals to SNE and northern Mid Atlantic.

This reminds me a lot of the December 12 event. A more potent version.

The 6z EPS makes much more sense to me than the 12z GEFS. The GEFS is phase happy with the shortwave over Manitoba. But it could be correct. The result is much less clean; energy broadened rather than consolidated. QPF expectations should be 1/4 - 1/2 of the EPS-eque evolution. This shortwave out of a data sparce region is definitely adding to uncertainty. Am very curious to see EPS at 12z.

Freezing drizzle