psuhoffman

The NAM can sometimes score a coup. I can remember a few times it was the ONLY model showing something and that happened. The problem is it's so inconsistent and unreliable and goes off on tangents with feedback issues and problems with chasing exponential errors...that you have no idea when its on to something or just being the NAM. On the whole it probably just adds more confusion and stress even if once in a while its right.

Was looking at that in the chat earlier...it really is classic looking. If the NS could just back off a tad this would be a region wide winner... One thing I wonder...usually when we see these sharp cutoffs that kill our northern zones the airmass is much colder. I don't remember many instances where we get this kind of cutoff when it's still in the 40's up here even up here just a few hours before the storm. I know the mid level flow has a lot to do with it and not just the airmass but I do tend to think (maybe hope) that maybe the moisture can press a little further given the marginal airmass. I agree with you but this region is bloodsport with snow and you just have to be tough and ignore the rude BS, or dish it back at them!

BTW... the SREF's are mostly useless due to the crazy output of some of the members...but if I was going to use anything at all from them it would be the probabilities.

Someone broke WB, too many people trying to view it...but the probabilities updated and it was a huge increase in the probability of 3" and 6" across Maryland. Gets the 50% probability of 6" up into southern PA now when it was down near Baltimore last run. From the probabilities you can tell it shifted NW quite a bit. But the actual panels didnt update yet when I looked.

I'll open the chat again at 9:30. Same link

I changed the setting so that others can share their screen and I welcome anyone who wants to take over and lead the discussion for a while to do so. This does not have to be just me leading all the time. I would love to hear others input as well.

I will be on again at 9:30 and will stay on for as long as we have something interesting to talk about. Just use the same link as earlier today.

That was fun. I wish we had done one before there was a threat to just chat and get to know each other. But I got Covid then the holidays…but maybe we can do a more laid back chat after the storm to discuss long range and just chat more relaxed. I’ll set up another for this evening to discuss the 0z as it comes in and the huge north trend in the precip!

got it, you should have it now

I just checked and sent out the link to everyone I had. If you still didn't get it please email me again. [email protected]

I just sent the invite to the emails on my list. If you didn't get one please let me know.

The WV is often the easiest way to see the mid level flow and moisture transport. Start of the loop you can pick out the mid level low and associated flow. It’s still positively tilted here (flow has a west to east component to it). Here it’s SW to NE but by the end of the loop you can see the flow is “backing” or taking on less W to E component. It’s almost neutral here. If the flow actually takes on some E to W component that’s when it’s negative (against the predominant W-E mid lat flow). The sooner the flow backs the more likely the system will be more amplified and come further north. Or at the least have a more expansive precip shield due to better moisture transport into the cold sector north of the low track.

https://www.tropicaltidbits.com/sat/satlooper.php?region=us&product=wv-mid The WV loop is a thing of beauty. The flow is really backing in the TN valley. This has a classic look for the mid Atlantic! Btw I still like to look at the WV sometimes just to get a feel for the flow. I’ll never forget being in the psu weather center the day before the Jan 2000 storm trying to argue with the meteorologists on duty that it was clear from the WV and IR that the mid and upper levels were way more amplified and the flow was backing much more than any of the nwp was showing over the Miss Valley. They were pretty dismissive…”it’s only 24 hours, the models would be picking up on it” lol

I can do a zoom chat 4:30 this afternoon. If there is enough interest I could do another later this evening as the 0z guidance comes in. I’ll email everyone who signed up the link. If you didn’t sign up but are interested please email me at [email protected] and put Amwx zoom in the subject so I can search/filter and I’ll add you and email the zoom link.

You’re right that it’s not typical. And I know you’re kidding but we do have some who think there are numerical patterns and while storms that fringe the NW zones are rare they can happen in bunches. There were a few in 1980 for example. Hence the rare year Richmond and DC had more snow then up here. Not saying it’s likely now…just that there is chaos at play here. I’m not worried. I do think there is a good chance I get fringed tomorrow but it will even out over time so it’s ok.

It can happen. I only got 2.5” from the Jan 2019 storm. There was a storm in Jan 1987 that gave DC a foot and fringed up here. Jan 2010 also was like that. The orographic banding and super high ratios you described is why there will typically be that “deathband” up here. The added terrain lift along with colder temps typically causes better snow growth conditions here. I often have 20-1 ratios. But those factors won’t happen if we’re in the subsidence zone and that can happen if the storm track is far enough south. Right now the track is iffy if there will be enough mid level moisture transport into this area. One more tick north like last night and we probably would see the typical orographic effects up here but there needs to be good enough moisture to take advantage of that.

Zoom chat tomorrow?

If it still looks good I can set up something tomorrow.

No one is debating that it’s getting warmer and snowing less. But you exaggerate and talk about nothing else. No one in here has the ability to wave a magic wand and fix it. So all you’re doing is harassing people who mostly agree with you.

The bar on your posts can’t get any lower.

@WxUSAF btw this is the scenario to test “can we get cold”. If we get a PV split, pna/epo ridge with the cold currently built up in Canada and don’t get some serious cold period from it…then it’s time to just give up.

If it does good for them. I’ll get snow up here eventually. I’ll live if I miss a couple storms. Doesn’t mean I won’t be a little irked seeing deck pics from central VA while I have bare lawn but I’ll get over it.

On the coming “waves” in the next week… these are the type systems that depend on discreet details that won’t be known until the last minute. And to make matters worse there is often a nice band that develops in response to where the confluence/subsidence cuts off the precip. There is likely to be a very sharp cutoff and models won’t nail that until within 24 hours. I’m not going to waste you’re time pretending I know where it will be but obviously places southeast seem favored ATT. The next threat will develop as a wave forms in response to the jet on the front side of a digging amplifying trough. This is somewhat similar to waves we got in 2014-15. Where this ends up will depend partially on how the PV split happening at that time evolves. The whole trough is pinwheeling and amplifying around that process. It’s way to volatile to try to pin down at range but I do think the idea of a healthy wave in response to this process is correct. Long range I like this evolving pattern quite a bit. I know I poo pood pac with no high lat help recently but that’s now what I see happening now. All guidance is now showing a significant TPV disruption happening due to a wave 2 hit this week. The TPV elongates with a lope getting displaced south on our side. The euro has backed off a raging +AO. The numbers might not look great but I’ve said the numerical index can be deceiving. Below are the Gefs end EPS both show the elongated tpv (red). Both have ridging in the HL. The gefs connects a ridge bridge all the way across the top because it completely splits the tpv. EPS severely elongates and displaces the tpv but both have plenty of ridging up top to do what we need which is displace the tpv and get cold discharged into the mid latitudes. The pac pattern puts the trough in the east. That high lat wouldn’t be good enough if the pac was garbage but that’s a good combo there. Again trade offs. Great pac longwave pattern and decent high lat is a winning match. This look reminds me a lot of 2014 and 2015 where the details up top helped enough for a pac driven longwave pattern to work. 2014 with enough ridging poleward in the epo side and 2015 with a displaced tpv on the Atlantic side. This is kind of a combo of both. This is not a hecs look. But this is the kind of look that would produce boundary waves and some would be suppressed enough. This isn’t the kind of pattern nwp is going to pick out threats at long range though. Remember most of the snows in 2014 and 2015 weren’t on our radar at all past 72 hours.

It’s super rare but not impossible. Richmond got more snow than up here in 1980 for example. But I’m not worried and if it happens oh well. Things balance out in the long run.

But the pac looks good…isn’t that what everyone wanted???