psuhoffman

GGEM shows how it COULD work out...a NS wave goes by to the north which helps to drive the baroclinic zone south, then the trough comes down in pieces with one vort into the plains and another into the TN valley which develops a coastal on the east side of the broad spread out trough. We need the same thing as this time...less consolidated system, weaker waves vs a phased amped up system in the central part of the country. It has happened plenty of times before...we are just rooting for less phasing and less amplitude and a spread out trough instead of what we will be rooting for once we have blocking.

It was a really nice event... from a few days out models were forecasting rain even though we had an arctic blast with below 0 temps the day before but the main wave was taking a west track. Then as we got inside 72 hours the guidance started trending colder and colder...but it wasn't really the track that changed just the guidance started to see the cold wasn't going to be evacuated so quick and we would get a nice WAA thump. In the end I had about 7" up here...some places just south of me in central MD got about a foot. I think DC and Baltimore ended up with like 4-6". Then we got some ice on top just to protect our snowpack! One of the best late positive trend fluke bootleg track storms ever! It kind of reminded me a little of the one frontal wave system in 1994 that dumped a foot of snow just north of our area in PA from a west track...only displaced slightly south. If you put arctic air in the way of a storm it gives us a lot more wiggle room for flaws.

Yea like i said I am really looking forward to that look getting into the analog range to see what that spits out for historical perspective. I would imagine some good results might show up. I could find some myself if the government wasn't shut down. I wonder why they still only do analogs out to day 11. It's been day 8 and 11 for a while with NCEP and that made sense 20 years ago but with skill becoming slightly better out to day 15 what would the harm be in generating a day 15 analog? I mean the system is automated and just would need to be programmed, it wouldn't take that much more manpower, I don't think. If someone knows otherwise maybe they could enlighten me.

That was February 2015 I think

Everyone busts in this game. Everyone. I appreciate that you say what you think regardless of what people want to hear. That is valuable. Doesn’t always win a popularity contest but it’s important.

@frd Just looked at 6z GEFS and it took a strong move into the blocking camp. Way less disagreement among members. You can see it in the means.

I am not sure...at day 15 I would expect there to be some disagreement within the members. Now that the flip is around day 10 I am a slight bit more concerned that there is still a decent camp of divergence. But it is NOT the majority. I wouldn't be overly concerned with it. It's still far enough out that some disagreement is normal. And one good thing, if you look at the individual members that do agree with the -nao, among them there are a LOT of classic STJ miller a gulf storms coming at us in the day 10-16 period. I would only get concerned if in the next day or two we start to see the mean move away from the idea of the nao flipping. We are about the range now where if it continues to progress closer in time I would get more confident that it's coming.

Just teasing... the soi today is -7, and I suspect that is partly why we aren't seeing the same reaction to a strong warm phase MJO as we did last month. I am not "worried" but that does not mean I am blind to the fact that long range forecasts don't always go as expected. I am more confident in this one because the guidance is unanimous in the look (a very rare thing for long range guidance) and it looks like what the pattern analogs indicated was likely. The SOI is not cooperating. All of that points towards this being real. BUT that doesnt mean its a lock and I wont be looking out for possible curves in the road. The big problem with the gfs and fv3 op runs wasn't the atlantic imo but the pacific again. It reverts back to the pacific firehose pattern. While the NAO fails to go negative I think the catalyst is on the other side. The AO gets weakened initially from the pacific forcing and then the ridging in the atlantic takes advantage of that weakness and retrogrades and links with the ridge on the EPO side. Absent that weakness the Atlantic ridging cannot retrograde and the whole process fails. But the problem is from the pacific reverting to the same crap pattern.

I am not that excited for up here either. This kind of reminds me of a couple waves in 2015 BEFORE it got better around here, during a similar -epo +nao pattern, where they started way north then trended south and got us kind of interested in the medium range, only to make the typical north adjustment the last 48 hours and disappoint. Once in a while you get a south adjustment right to the end...but usually that is when there is a vort diving down on top like the early March 2014 storm. Maybe if the trend to separate the streams continues and the NS ends up suppressing instead of phasing that might happen here. The later phase has trended things south but we would need a complete non phase I think to get it under us. Either way if we are going to see that happen it should be soon because once the wave is out into the plains the typical adjustment the last 24-36 hours is almost always more amped and that is no good if we are living dangerously on the southern edge, even up here.

Maybe but what he said about the H5 pattern was right. But anytime you have arctic air displaced south to our latitude its never a shutout pattern and flukes can happen. Most of our snowstorms are not perfect setups. Those don't come around very often. Many come from flawed bootleg setups and we just get lucky. This setup is interesting because it has us rooting for the opposite trends than if we had nao blocking and a 50/50 low. Then we would be rooting for phasing and an amped up consolidated monster to attack the cold that is locked in. In this setup, with a transient high and WAR we want the STJ system to remain unphased and traverse across under the NS for as long as possible. Our only way to snow is either from a weak un phased system cutting under the NS OR if multiple weaker waves eject along the front and a trailing wave clips us after the boundary crosses. Both of those are the opposite of what we would want if we had the ideal setup. But sometimes you just luck your way into something and when we have a -epo and cold around it allows us the chance for that. The pac crap pattern we were in before was a shutout pattern because no matter the storm track cold air was 500 miles away.

There is a way for my area to get screwed again...if the initial WAA thump goes north and then a secondary wave forms and goes southeast...we could be left in a gap where PA north and DC east gets more snow. Not saying but just saying.

back end changeovers only work if there is a trailing wave along the boundary. If there is a wave with enough circulation to back the flow across the thermal boundary then we can get snow on the backside of a system where the first wave along the front brought rain. But without a trailing wave, once the winds flip to a westerly trajectory which brings in the cold...we are done because that is a downsloping wind for us and so it will dry out quickly. We need a second wave to develop that backs the flow across the boundary and creates moisture transport into the cold. Without that the precip will always leave as the cold arrives.

Ralph loves both op runs of the 6z GFS. Neither flips the NAO, the PV rotates up into Greenland and just sits there...pieces break off at times and drop but the AO/NAO remains strongly positive. Luckily this is not the most likely progression. However, there is a minority camp within the GEFS and EPS that agrees with that and it is why the heights up top are not increasing in the means as we get closer...that is not because it is a "weak" block but because about 1/3 of the members don't agree with the blocking at all and after a brief cold blast go back to warm pattern. I am aware of that possibility but right now its a minority showing that. The majority still agrees with the progression we have been expecting. But it is something to keep an eye on in the next few runs. IF things are going to fall apart I expect we will see it happen in the next day or two as the blocking should be coming into the magic 10 day range where it becomes more reliably modeled. We do not want to see it get delayed or pushed back...that would be a sign of trouble.

Aww that’s no fun

Ggem is a coastal for the 24th storm now.

We were lol at the nam but the gfs took a major step towards that.

Icon is the first to piss in the punch bowl.

It’s on a roll.

The flip to a -NAO stayed in place on the 27th on the eps and GEFS today so it’s moving forward in time.

@Bob Chill one thing that could save us...the tpv drops pretty far west on some runs. That would open the door for systems to run the coast and could even open the opportunity for a monster phased system like the blizzard of 66. That was such a pattern I believe. If it comes down on top of us then your right. Squash city. I’m very curious what the analogs will show. I’m kinda frustrated I thought today’s day 11 centered on the 26 would start to indicate some blocking but even though it’s shoeing a bit on the GEFS by then it’s not on the analog height anomalies yet. Guess I have to wait one more day. But I want to see what it spits out once the -NAO -epo with the displaced tpv shows up in analogs. Might be telling.

Hopefully this isn’t like 1985. That would be a nightmare.

Love how your all goofing about that frame when if you loop the h5 it’s setting up a monster bomb triple phaser a couple days later. Check out the arctic jet diving into the upper Midwest as the heights rise along the coast. I can see our Groundhog Day BECS coming.

@Bob Chill

I am not re-litigating a fight from March 2016 but that doesn't mean I forgot what you said.