psuhoffman

@Ji @Bob Chill That little vort losetoa6 was talking about the other day as something to watch behind the weekend rain storm is going to suppress the lead STJ wave next week it looks like. It's there across guidance and its getting absorbed into the vortex left behind by the weekend rainstorm and suppressing the flow way too much the middle of next week. What we would need if that is the progression is for that wave to amplify enough to hold the confluence in to our north for the next wave coming, and there is a next wave...its a train coming at us...we just need to time one of these things up right...the goldilocks timing...close enough to an exiting NS wave to our northeast that cold has not vacated...but far enough back not to get squashed. OR...get the NS to phase just right...but we all know the complications with that.

The ICON could still work out...it is much stronger with the confluence and it still has a decent amount of confluence and NW flow to our north at 180. Plus the northern stream is digging in pretty far east...not too far east to develop in time but far enough to make a hard cut unlikely imo. It actually is setting up for the win option number 2. But now we are extrapolating the 180 hour ICON...lol. Its forever out there...the bottom line remains there are realistic ways to win with this and that is way better than it's been most of this dumpster fire winter.

Everything is trending that way unfortunately... remember wave 1 is the one that 36 hours ago was cutting north of Green Bay. It has been trending weaker across all guidance lately. And it is running into a lot of suppressive flow. That ridge near Hudson is a double edged sword...it is going to force things south despite the raging +AO BUT the reason I would rather it be on the west shore of Hudson Bay is that would allow more room to amplify a system along the east coast WITHOUT needing the NS to dive in and phase. With that ridge where it is...I kinda fear without phasing a weak system will shear out or get suppressed south of us...and the risk with needing NS help is it could just as easily (more likely) phase too far west and cut the storm. But...if it does phase right...that option has big storm potential so there is that.

There is some agreement beyond day 10 with where we go into February. Across all guidance there is consensus for a PNA driven +AO eastern trough pattern. Details differ at day 15 (as they always will) but the general longwave pattern is agreed upon. Doesn't make it right...but confidence in something at least similar to this is increasing imo. This is not the best look for snow...but it is way more workable than what we have had so far. The GEPS would be the coldest look...but also the least likely to produce a snowstorm probably. Clippers maybe...but while this is a cold look...true cross polar flow here...the trough axis is way too far east and historically a huge full latitude PNA/EPO coupled ridge is a cold/dry look in the eastern US. Way too hard to get something to amplify in that. Now some of the examples where something did manage to develop in that they can be huge storms. March 93 was an example...but 90% of the time that look ends in a cold dry period. The Euro is still hanging on to the AK vortex but has enough of a PNA ridge along the west coast to direct the trough into the east. This is not as cold...its not true cross polar flow...but that flow out of AK is good enough. That vortex there is going to be producing some pretty cold air near AK and getting some of that to eject into the eastern US will be cold enough in early February. This is not as cold as the GEPS but still plenty cold enough to get a snowstorm and the trough axis here is way more favorable. It's still not a look worthy of "its happening" but its a workable look. The GEFS might have the least cold but best look for a snowstorm. There is just enough flow from AK into the east to get enough cold...but that ridging over the top and in the southwest produces the best look to get a storm to amplify in the east. Ideally get that ridge a little north and pump the SW ridge a bit more and it becomes a classic look. The details wont be determined for a while...but if we can at least get the general ideas agreed upon across guidance February could be a lot more hospitable for snow than January was. Of course that is about as low a bar as possible.

The day 7-10 period could work. The setup that gives us a shot is only 6 days out and across guidance. The subtle but important differences to the setup now for this weekends fail are clear. For both the AK vortex isn’t doing any favors. But right now that vortex near Baffin (that wasn’t supposed to be there from range) forced the ridge in Canada to slide way too far southeast The result as the system develops in the central US is the flow is straight out of the south everywhere east of the Mississippi. No resistance or confluence until well north. Combined with the pac flow feeding maritime air into the ridge from the west and it’s game, set, match. but the setup next week has more promise. @Bob Chilldid an excellent job picking this out before guidance lost then found the idea again. this time the virtex has vacated Baffin. The ridge has pulled back towards Hudson Bay, and the trough near 50/50 is holding the NW flow and confluence to our north. We still have the AK problem so this won’t be a cold pattern and ideally that ridge would be slightly further west but it gives us a fighting chance to be just cold enough. From there we are in the game but still need luck. The lead wave amplifying before the cold vacates would be best. If the lead wave fails to amplify then we need luck with the northern stream digging in. It would have to amplify far enough southeast or the storm either cuts or develops too late for us. The fail option would be a weak lead wave that is suppressed south and fails to amplify enough to hold in the NW flow to our north. The cold lifts out and wave 2 cuts. The win is either wave one amplifies before the confluence breaks down, or if it is the second wave we get the NS to dig in and phase just right. Option 1 is simpler. Option 2 is less likely but holds more upside. As always the fail option is most likely. We all know that. It’s our reality. But this had a better chance than most of the lottery level long shots this year.

I don’t mind clippers at all. And sometimes they can really put down good totals up here. There were 2 in the 2000s that dropped 6” up here. Plus to get clippers the northern stream has to be pretty far south so it’s at least usually a cold pattern and often those clippers came before or after bigger storms. In Nina years with no STJ often those are all there is. But we haven’t spent enough time in cold patterns lately to get many.

Gfs has way too much going on to even think it has a prayer of being close to the right solution. But the period officially got my attention now. Goodnight.

A descending qbo, IO sst, shortening wavelengths all would suggest increasing chances to break the pattern as we move later in Feb or March. But beyond that I would be lying if I pretended to have any concrete insight. That PV has been a beast and isn’t going to give in easy.

Not if you move to northern New England.

So long as that wall remains up across the arctic no pattern in the mid latitudes can get that cold. But perhaps maybe cold enough with luck. Lots of luck.

I wish you luck. I do think we will have a few more opportunities to snow. I’m not yet resigned that DC ends up with a total skunked season. But odds of a “good” year are increasingly dwindling.

I get where you’re coming from. But part of using the guidance effectively is correcting for biases. The guidance won’t be perfect from range. It’s also incorporating climo and historical reference with the NWP guidance. The most logical correction right now is to assume the gfs is over amplified. But you are correct that could be a mistake. And that’s why forecasting long leads is low accuracy. But at day 8 we really shouldn’t expect that level of accuracy. Right now we can say with some confidence based on guidance that there is likely to be a system in the east day 8-10 with about seasonal temperatures that is likely a rain or maybe snow threat. That’s good enough. A day 8 forecast shouldn’t be more detailed. Exactly how strong isn’t necessary.

It’s ok, you can use my name.

The main difference is the depth of the system in the southeast. But all the guidance agrees on the main players. AK vortex. +AO. +NAO. Southwest ridge connected to a ridge across Eastern Canada. Trough in the southeast. That’s amazing agreement for that range. You’re stuck on specifics that should not be looked at day 8-10. Plus if you correct for the known bias of the gfs they look remarkably similar.

Not this weekend. The airmass is just too putrid. Way too much ridging ahead of it. But the next couple “could”. I know not to ever rule anything completely out. I showed that Hudson Bay composite. The pattern is close enough. Get lower heights in front, maybe from this weekends system bombing, and it could work. It will be a struggle with the crappy air mass though. But we’ve snowed before in a similar pattern. We’ve also cold rained more often. Like HM said...need luck. If we want a pattern that needs less luck we need that AK vortex to scram or the NAM to flip.

Read isotherms post an hour ago. Solar minimum is happening. We could get several -NAO years coming up. We just had a string of +++AO/NAO Years. That makes getting a good pattern in January when the wavelengths are least helpful in disrupting that very unlikely.

2017 and 2018 the pattern flipped late because both years featured a cold enso aided pattern with a strong PV. During mid winter when the PV at its strongest and wavelengths in the mid latitude jet are broad and shallow disrupting that PV was a lost cause. Then both years when wavelengths shorten aiding more ridging to transport heat to the high latitudes and create blocking and the PV weakens then we saw some better patterns set it. 2018 also was aided by a strat warm in Feb. It wasn’t bad luck it was logical pattern progression. It’s why some Nina years have snow late.

All 3 major ops agree on a dual wave system on the east coast day 8-10. That’s amazing for that range.

That isn’t that different for 240 hours. The longwave pattern is actually somewhat similar. If your focusing on exact strength and location of storms at day 10....plus the fv3 gfs has a known over amplified bias so...

Given our regions reliance on the NAO I think this would get a collective hallelujah

There were a lot in the 2000s. A couple in 2002/3. One in Jan 2004 gave MD 2-4”. There were several 1-3” clippers in 2004/5. A couple in Jan/feb 2007 and a big one Dec 2007, the only good snow that year. Then I remember a couple in 2009. This decade has been less common. There have been a few but we spent a lot of the decade in either a blocking pattern likely to squash clippers or a warm pattern where they would be way north of us.

That would just hurt more...a bombing coastal deforming the hell out of us and its 38 degrees and heavy rain...probably mixed with slush bombs at times just to make us want to kill cute fluffy animals

My elevation combined with being "just far enough north" have prevented my snowfall climo from being impacted much. Actually the last 10 years have increased my "avg" here some. As of right now I am still just cold enough to eek my way to a decent total in bad years "usually" and hit really big in the big years. What it has done is increase the difference between here and places like Baltimore. If the warming continues it will eventually impact up here also.

The EPS is already kicking the can again...compared to the weeklies from Monday. This was the weeklies run for what is now day 15 on last nights EPS...it was leading to that better pattern mid February there by already obviously moving the NAM state towards neutral and a developing EPO ridge... but as usual as we get a day closer look what is happening...the NAM state is still strongly positive now for the same time and the EPO ridge is being shunted south of the EPO domain by the strong Vortex. This has happened again and again.

It was agonizing up here...I did have a clipper put down about 2.5" at the start of the pattern...but it was dry and the next day we got high winds that blew all the snow into the woods. Then we got nothing but incredibly minor snowfalls the rest of the pattern...so I spend a long period with frigid cold...uncomfortable to go out cold...high heating bill, and no snow on my lawn to show for it. One of the more frustrating periods in the last decade to me.