All Activity

THIS. Even though our resident third graders want to moan that poor forecasts show that NWP is useless, there are certain patterns that for whatever reason just aren't predictable. The fact that all of the major world modeling ensemble systems showed something very encouraging for the end of the first week of January makes it clear that something about those forecasts (initial conditions generally driven by lack of observations or observational errors, the actual equations and parameterizations, numerical methods, or some combo of those) made skillful predictions impossible. But there are plenty of periods where guidance shows remarkable skill even at extended ranges. Here are the 500 mb anomaly correlation scores (the best measure of synoptic pattern success) for 10 day forecasts over the past 3 months for the 3 major ensemble systems (and yes, it only makes sense to verify ensembles at this range). A score of 1 is a perfect score, and the dates on the bottom are the days on which the forecasts verify, not when they're made. There were periods of poor performance by all 3 systems (early October and around November 9), periods of poor GEFS and GEPS performance but with the Euro doing fine (around November 12 and at the very end of December), periods of fair performance by all 3 (mid October), and periods of fantastic performance by all 3 (third week of November and especially the third week of December). Those scores between December 18 and Christmas are remarkable for 10-day forecasts and are numbers we could have only dreamed of 20 years ago. Advances in data assimilation and coupling of the ocean to the atmosphere in models will lead to even bigger improvements, and AI offers tremendous opportunities to run the massive size of ensembles needed to truly represent the uncertainty and potential for extreme events with more lead time. That doesn't mean that frustrations like those with the upcoming pattern will completely disappear, and it REALLY doesn't mean that we should soon expect models to lock in on a snowstorm 12 days out and never waver up until the day it happens. We just need to remember the current limitations and focus on consistency in patterns (and not details of deterministic runs at extended ranges) in ensembles, understanding that progress in forecasting the extended ranges doesn't preclude huge busts. I'll end with this plot of Day 5 anomaly correlation by year over the past 40 years (apologies for not having the values for Day 10). While the lines have flattened more than we'd like in the past 10 years (I think that AI is the way we'll see these rise again), and the GFS needs to catch up to the Euro, the progress is undeniable. Thanks for coming to my TED talk, and Happy New Year! pa

2 to 4 doesn't mean everyone gets 4 unless its Facebook in which case I heard we are getting almost half a foot.

Better get something fast,it looks rather bleak right now down the road with that strong ERW thats fixing to pass along the IDL the next few days,Maybe it will weaken some but this could cause the tropical forcing to shit towards the WP and MC,probably end up seeing RMM madness continue,you're seemingly starting to see the NINA background getting taken out now even tho it's still NINA.

I remember models kept showing it and we never fully believed it. The radar had the snow falling over the valley but it all fell over the hills. Was fascinating event . It was torched away less than 2 days later . Here’s that radar https://imgur.com/a/E6cdjp4#w4DU9Zm

Don’t know what the rest of winter holds, but this was a very solid December by our standards. Below to much below normal temps and normal to above normal snow for about everyone (sorry Winchester and Stephen’s City).

It’s always weeks away and it will stay there lol.

He comes up with these memes super quick.

https://www.jdjweatherconsulting.com/mar-22-23-2019

Lmfao…. That’s crazy funny.

..that was good.

Not the same but it reminded me of this event . What a weenie event

Completely overcast in DC (though NWS insists it's supposed to be "mostly sunny"). Haven't seen a single flake of snow, though.

OKX followed suit no surprise for continuity amongst the CWAs

WB 12Z EPS ensemble at range is cold enough: question is will it delivery anything but the same old same old for the later half of the month.

Maybe we can flip back but it usually doesn’t work that way for us. All we want is one good snow. That’s not asking for much from us weenies.

You were NAO'ed Heh... 'not the first time anyone was, whence seemingly waiting on the commitment by the analyst, that's when NAO fails to show up. Intention? Charlie Browning - Personally I find the NAO to be the biggest most stochastic POS voodoo index that was ever defined. The problems in using it are textured and varied. Firstly, ( I'm not intending to lecture you; I'm just raging at the moment lol) is that it is actually created by the dispersion mechanics downstream off the Pacific -N/A wholesale wave signature. [ Enter pita flop computing power here ...] and viola! the NAO emerges in the guidance... Secondly, there are two behaviors, which is a major pain in the ass. The first is the obvious: blocking, identified by the geometry of the heights up there in the NAO geographic domain space. The other form is insidiously hidden - the hemispheric logistics around the region act as though that geometric identity must be there, when one is not very obviously defined... See, this is an indirect proof that the forcing actual coming from somewhere else. Whether heights bloom within that behavior or not, that's when the EOF calculations finally give negative numerical values. Anyway, so the NAO is so badly handled ...or, so much worse so than the other indexes, because it is at the flop end of the Pacific hose, where is also exaggerated by interaction across the N/A continent.

That would make sense, that glacial ridge northwest of you (the Irish Hills) are probably a little snowier than Ann Arbor too for that reason.

Sleet crust in north facings a veritable winter wonderland

WWGW

Are you talking about the Irish Hills?

That's what your girlfriend says.

GEFS looks ugly through mid month, EPS is a bit better but doesn't bring much cold down until the very end of the run about 15 days from now. What a difference a couple of days make. Like I said previously, I would be happy with a 2 week at or below average period with an active storm track.

DCA _ NYC _ BOS _ ORD _ ATL _ IAH _ DEN _ PHX _ SEA -1.5 -1.4 -1.2 -1.6 0.9 +1.0 +0.5 +1.6 +1.0

If it’s not going to snow… can it at least be warm? My gas bill would benefit.

GYX and BOX--possibly already posted.