psuhoffman

The euro is trying for another NS phase job with a gulf system next weekend. Might not pull it off this run but interesting and somewhat similar to this. We were discussing this in the last few zoom chats... JB is right about one thing...this is the kind of pattern where you can get the NS to dig far enough south to get these amplified systems coming up out of the gulf coast. But they aren't going to be 1993...even for a triple phased system that was a once in a lifetime thing. We've had several other triple phased storms but they usually phase and bomb further north like the November 51 and January 66 storms. So he isn't wrong that this is the kind of pattern to get the NS to dig down and phase and get amplified storms but he goes full over the top hype mode as usual. Also its not necessarily what we want as were seeing now these types of storms can cut if we dont have enough confluence to our north. The key is to either have something blocking the flow, a well timed 50/50 or wave coming over the top in front of it... and it would also help not to have another NS wave diving in and phasing right behind it!

The euro had another decent upper level low track and improved the surface a bit. SLP tracks from ORF right up the bay then into eastern PA. If we were to continue to get these minor adjustments and the upper low were to track another 30-50 miles southeast and the surface low were to track up just east of the bay, it would cut down on the low level warmth quite a bit...might increase the WAA thump some although I think the angle the WAA precipitation is coming in at has more to do with that then anything else at this point...but it would increase our chances of some snowfall Monday morning with the upper low pass also. On the WAA snowfall...We want the trajectory to be more south to north and less east to west with the angle of that WAA precipitation. The more negative tilt that banding is the longer it will take to progress northeast and we will lose the column faster. A further east track of the mid level and surface features could help with that some also. There was a minor improvement in that regard this run over the previous one.

At long range the key is to identify the opportunities for amplification near the east coast according to the longwave pattern. The guidance will struggle with the details like phasing, which SW to amplify, track. I don't bother with the surface maps at all past 5 days.

Been busy but I see no changes...still see threats focused on the 20-22 and 24-26th periods.

My guess is they all underperform on the front and overperform on the back of the storm. In the end they probably all get at least 6" and some of the more favored upslope locations like Snowshoe and Timberline probably closer to 10-12 with the upslope being the majority of that.

I will be there also...I only expect several inches of snow/ice from the front side of this storm...but they will clean up on the backside once the winds flip to the NW. That's perfect upslope flow and it's the kind of snow they get very high ratios, 20-1. I could see them getting 8" from that late Sunday night through Monday morning.

The h5 pass is further NW on the NAM, not necessarily shocking at range...if the euro/gfs h5 pass is more accurate I think a period of snow early Monday is definitely a possibility. Especially if that feature continues to trend a little SE as it did the last couple runs on the globals.

Models are starting to pick up on the mid level warming so it’s offset this trend in terms of snowfall results but we’re finally actually getting the trend we want since 18z wrt the NS SW diving in behind and it’s corresponding interaction with our storm. 18z euro to 6z euro It was an incremental trend the last 2 runs. Results in a slightly weaker and further south h5 track initially. It’s not enough YET to change our fate, and it’s been offset by models starting to realize the warm layer issues…but if that trend were to continue it could lead to the chance for some snow with the h5 pass. It could also help with the WAA some if we continued to see this trend but we would need several more bumps and the improvement would likely only be incremental since that part is mostly baked in at this point because of how amplified and cut off the h5 is to our south and the lack of confluence over the top to resist the SE flow ahead of it.

Synoptically it’s the same. It’s simply “seeing” the mid level warm layer now as we get closer. We knew this was a risk with that screaming SE flow. Been talking about it for days. The Gfs just suddenly sees it.

0 chance i get 10

I will just use this one thread from now on with updates for zoom chats. I will open the chat tonight at 10 and stay on until the GFS is out. I don't mind leading the chats but as others have said it would be great if anyone else wanted to contribute!

I just sent it to you in a PM. People were emailing me for the link at [email protected]. We didnt want to post it online to avoid trolls.

I would love for some others to contribute... I will open the zoom tonight at 10:OO and stay on until the GFS is out.

I'll open the zoom chat around 10:00 this evening...and keep it open until the GFS comes out. Won't be on as long as last night.

all in all I would say a slight improvement on the 18z euro simply because it had a slightly better WAA thump. Pretty identical to 12z in every other way.

if that capture could just happen a few hours later...low gets to southeast VA near ORF then cuts NNW to HGR. If that could get just 50 miles further east before it starts that NNW move and ends up near PHilly instead of HGR it would make a big difference for DC metro.

It's an identical H5 track and MSLP is like 20 miles from last run. Pretty much the same. There were some minor improvements, again the SW was a little east and faster for a while. But all that is irrelevant because we continue to lose ground in the 2 areas that matter most...the SW keeps trending stronger when we need it weaker and the energy diving in behind keeps getting shaper, digging more and interacting even more. Those 2 things are offsetting any gains we get elsewhere run to run.

989 right on top of DC at 84 hours

The one trend that continues and its not what we want...is a slightly more amplified SW each run. That's what's offsetting a lot of the improvements people point out on some runs.

pretty identical to 12z so far...

I'll be at snowshoe for this one...so I am ok with these runs that are destroying WV lol

NAM sleets to Erie LOL

This year is just the appetizer for next years 100" modoki nino anyways

100% on all that...but notice the SLP on that storm moved NNW also...just it got off the NC first so that was a good thing. What we need is simple...a later phase and to get the whole thing further east before it happens. Problem is the system is so wound up by the time it gets to the southeast and the trough coming in is right on its heels...that's not the most likely outcome.