psuhoffman

@Ralph Wiggum there is a risk to how the pattern is evolving though. If the Hudson ridge translates east but doesn’t effect the NAO enough...the pac ridge will pull back and the AK vortex will dump a trough in the west and we will be back to an Uber eastern ridge. I get what you’re doing, lemonade and all...but a 2 day transient ridge through the southern NAO space is statistically unlikely to produce. We typically need to spend a long time in a good pattern with multiple chances to get one hit. We have a high fail rate even when things look good. A 2 day window with a mediocre look isn’t a great bet. But sometimes you get lucky and you’re not wrong. But what I’m saying is if we want a legitimate chance to change our odds we need one of 2 things. If we really simplify this every snowy pattern DC has had in the last 20 years was accompanied by either legit NAO blocking or a legit epo ridge. We either need the AK vortex to scram so the pac ridge can build into the epo or we need a legit NAO block. Not some transient weak ridge. Otherwise so long as we lack either we will keep swapping one problem for another.

It was perfect if there was cold and confluence in front. A 1993 type storm won’t work because there is no arctic air here. 1993 had a direct discharge of cross polar flow. If the upper low closes off too soon and the low bombs while it’s still to our west (even if way south of us) the southerly flow up the east coast will wreck any chance of frozen. We would need the upper energy to phase and cut off near western NC not Mississippi and we need the surface low to start to bomb in NC not the gulf coast. It has to be exactly perfect.

The gfs had a great track and it was still rain....in western maryland Too weak. The cold is gone by then. If it’s not the first wave next week after that it probably has to be a perfect track bomb with a perfect track upper low to work. Unlikely but that’s just how it is.

It’s not no hope. But people should realize the most likely outcome is a suppressed wave next week while we have the 50/50 because the ridge in Canada is a bit too far southeast. Then once the 50/50 vacates the most likely result is rain. This setup is better but still flawed. But there is enough space something could amplify enough next week just not likely. After that to make the early Feb storm work, because there is ridging ahead of it and nothing to hold cold in, we need the upper low to dive in through say TN/KY and cut off over VA not down south. The cut off south of us slows the system and blasts warm air up the east coast ahead of it. We’re back to needing the perfect upper low track with that. However this time some guidance is way further south with that and they almost always correct north so it’s not as hopeless as the last setup.

People don’t usually decide what they think of the journey when they’re only a quarter of the way to the destination!

The Dr assured me it would only take one reduction procedure...

I’m holding out for 100”

Euro weekly control thinks we do ok

But it’s setting up a blizzard day 17 if you extrapolate. I actually hope it plays out exactly like that...fail after fail after fail and everyone jumps and then we get a 20” snowstorm Feb 10th.

Can we take shifts. NPZ already put his couch out for his shift...

I don’t know why he posts that one, 3” doesn’t feel very satisfying.

What 750 mile swing? This was the furthest south op run of the gfs this is the furthest south gefs run this is what it’s projected day 3 now that is 200-250 miles at most And this is what the Gefs showed when it was 7 and 8 days out!!! There was only a 24 hour period where some guidance was 200 miles too far south, from 6 days out. Before that it was spot ok. And by 5 days it corrected again back to the correct idea. There was one fluke euro op run that was a crazy anomaly and 1-2 gfs runs over 10 days that deviated from the consensus. The guidance gave me a pretty clear picture of what was going to happen from day 9 on. Plus you have to inject climo knowledge and history to the nwp output. If a couple fluke op runs over 10 days fooled anyone that’s operator error not a tool malfunction.

If the gfs slows down anymore this could become a white Christmas threat

Are his expectations really that high or is it just an excuse to espouse his belief that NWP intentionally shows every permutation despite the fact they are run by different agencies some public some private and it would take a tin foil hat level conspiracy to believe they are all intentionally not making a good faith effort with each run to be as accurate as possible?

The guidance has been EXCELLENT this year, unless you place unrealistic expectations on the specifics of long range. They have generally nailed the longwave pattern generalities from distance. And inside 5 days when details matter they have been good with those...no major short range busts. But yes if you expect the exact location of a synoptic system to be perfect from day 8 then I suppose they suck. But that would be like cutting any player who can't hit a half court shot every time.

It looks active with multiple waves both in the NS and STJ ejecting off the pac. Some aren’t pure STJ waves, they dive in off the western jet split. But it doesn’t matter to us how they get to the gulf coast. It’s what the do after.

You need to relax with the emotional reactions to op runs at 7+ days. I know telling you that is a waste of time but still... Imo the low point was actually 3-4 days ago. I thought this weekend was a lost cause by then, it just took some people longer to accept that, and the long range improvements were too far out to matter yet. But we have had 72 hours of incremental but consistent improvements both in the day 5-10 and 10-15 pattern. And now there are hints it might even be getting better after. Long range needs to be viewed like some abstract painting done by a drunk 4 year old. The overall ambiance is better now than 2-3 days ago. Our chances to avoid a complete disaster year are a little better today than 3 days ago. When a discreet threat makes it inside day 5 then I will worry about an op run or that specific threats fate. Right now I am taking in the whole longwave pattern picture and it continues to look better each run for several consecutive runs. Continue that and eventually we will be analyzing VV and Fgen to determine who gets the death band. Spoiler Alert: ME....it’s always me.

That look can be suppressive if the ridge in Canada is too far south and or nothing amplifies enough yes. One fail would be all the waves compete and fail to amplify. Then they all slide east under the blocking ridge.

All guidance is consistently showing a pna ridge allowing some of the cold in AK to discharge into the eastern US. This time of year AK cold will do well enough. It’s an ok workable look. But if the euro is onto something...that look there can evolve into a legit very good pattern easily. If that east based NAO ridge continues to build...I am becoming a little less pessimistic about February. But people should keep expectations in check. The goal should be to get a snowy February...not a snowy “winter” at this point. It’s unlikely we’re going to make up for losing 60% of winter. If we do great and revel in it but expecting that is setting up for disappointment.

The bigger issue is the upper low digs too far south and closes off along the gulf coast. That creates a south and even southeast flow ahead of it and slows the system down giving it time to wreck the thermal profile ahead of it. If that upper low was more in sync with the NS and further north it would be ok. Good news is I highly doubt we get a cut off low south of Atlanta.

http://climod2.nrcc.cornell.edu/

Yea you are right... my post earlier was just trying to highlight why I agree with you.

no 1993 was one of the rare examples of a full latitude western coupled PNA/EPO ridge and a full latitude eastern N AMerican Trough that worked out. Got enough of the trough to concentrate and bomb a storm. This isn't quite that because there is a blocking ridge in Canada...kind of a mini mid latitude version I guess. The 50/50 has to vacate as the trough amplifies or else the storm cannot turn the corner. Actually one of the issues here (and this is good because its likely a GFS over amplified bias issue) is how the upper low cuts off and digs so far south...that slows the system down and leaves us with a southerly flow ahead of it for too long...it destroys the airmass and then we don't recover in time. If that upper low was a little more progressive and cuts off over TN instead of along the gulf coast its a win for us. I wasnt trying to dig too deep into analysis of a day 9 storm on an op run though...but actually if we assume the upper low isnt going to cut off down south of Atlanta like that...its probably a snowier outcome for us.

I don't buy it... I doubt that is exactly what the H5 will look like...but if it is...we should do ok.

I agree...but right now that lead wave has very little upper level support and its running into a wall of supression. It has very little chance unless we see some significant changes. Those can still happen its 6 days away. WRT the more amplified day 9/10 option...that GFS solution showed how it can work...just need the thermals to be a couple degrees colder from day 10. That isn't a big adjustment. The track is perfect. The whole setup will likely undergo significant alterations by then. If one of those is "colder" we could do well.