psuhoffman

EPS Setup...50/50, west based block, energy diving into the midwest amplifying into the TN Valley 3 day snowfall centered on......Feb 20

Probably not, but you're assuming there is no 50 miles north jump the last 24 hours as we've seen a couple times this season. Or that there isn't some surprise not surprise banding on the northern fringe that puts down 5" with barely and QPF as we've seen at times...then if we tack on 2-3" of snow/sleet from wave 2 suddenly we had a really nice event. And those things are not crazy impossible. But yes if I had to put money on it the most likely outcome is we get fringed with 2" from the first wave and 1" of slop from the second and its not a fun time for us.

Sorry for the double post everyone, the initial post was missing something and when I tried to edit it accidentally deleted it and had to re-post.

@Stormchaserchuck1 has focused on the location of the block rightfully pointing out it originates as a AO not NAO block...but not sure I see why it matters in the long run. Here at day 5 the issue isn't the blocking IMO, we have a low right at 50/50 which is the important thing. The reason blocking is important is getting that reaction. PD2 for example didn't have blocking in a classic sense but a PV displacement into the 50/50 space created the same effect for our snow purposes. The issue here is because the tropical forcing is still in the western pacific we have a SER and a hostile PNA. The next wave is getting better but might still have a little too much SER but again the blocking worked the next wave crosses 50/50 also. Finally the next wave will enter this setup With the tropical forcing now into the central pacific phase 8 the trough axis is in the east with a favorable PNA and again we see lower heights across 50/50. Plus even though the block started out north it retrograded to the same spot a greenland block typically ends up, Baffin Island, where west based blocks go to sit and rot and where we typically see them for our big snowstorms. It got there from a slightly further north trajectory initially from a merging of an EPO and Scandy blocks, but as long as it ends up the same place with the same impact on the 50/50 domain I fail to see why it affects our snow chances. The issue with the first 2 waves is the pattern has not matured. Blocking typically starts to set up in Phase 7 but the SER takes until 8 to get beat down. Its a little frustrating that the operationals continue to show thermal issues even once we get the perfect longwave configuration out around day 10+ but I want to wait a few more days and see if they adjust before worrying too much. All 3 major ensemble guidance shows the absolute perfect 100% what we want in every way h5 pattern for a big snowstorm day 12-16 right now. If that doesn't work I don't even know what we are looking for anymore.

My area might have the highest boom/bust potential for this event. If the initial wave trends north some I could get hit good from both part 1 and 2, on the other hand it is equally or maybe even more likely I get fringed by both and get stuck in a snow minimum in between.

What a 7 day look

That wave 3 weeks ago and the waves this week are a perfect example why we need blocking to work. It’s so freaking hard to get a flush hit from these progressive boundary waves. There is nothing to lock them into a track. They can go to our south or north based on insignificant changes in amplitude. They have a relatively narrow area of heavy snow west to east that will only give a small portion of the east coast a win. But with a block and 50/50 if there is enough cold in the pattern you just need any strong wave to come along and crash into the confluence. The win zone is huge. It can try to cut and it will be turned east and we get a ton of snow to ice. It can take an imperfect track and will be forced under us. The precip coverage will be huge compared to these petty boundary waves because the wave is trying to gain latitude and throwing moisture up over the cold air locked in instead of these frustrating west to east waves where we’re at the mercy of a ton of variables any one of which can screw us over. sure we might get lucky this week. But over the long run this is a hard way to try to get a lot of snow. Throw a juiced up amplifying wave into cold with a blocked flow is simple with a huge margin for error where a minor amplitude shift won’t screw us out of snow!

We’ve had a decent number of snowstorms from a block where this one ends up. It’s a bit odd how it starts so far north but it retrogrades to Baffin Island which is where a block that starts centered over Greenland typically ends up. So in the end the effect should be the same but it starts out less than ideal which is why I’m not more optimistic for the wave next weekend. I think around the 20th and after we will have legit threats. Also we can get a AO driven snow but we need some help from either the PNA or EPO and we have that nice to around the 20th.

@Ralph Wiggum before you start a panic can we wait and see. I’m on the record sharing your concern. But if it’s true that strong high latitude blocks will continue to link to a SER the whole time we might as well just give up and stop tracking because that’s how we get 90% of both our HECS storms and BIG snow seasons. So what are we even doing here if you think it won’t work anymore? Let’s see how it plays out.

Jon Neese prefers a AVN NGM blend.

We’re on the same team finally

Yes but only when you’re in the jack 48 hours out and it screws you.

Some snow weenie in NE MD did something very very bad. One of y’all needs to fess up so they can make whatever sacrifice is necessary.

I dunno i was just trolling. We could debate that

Sorry I had to.

Let’s wait and see what the UK and Euro have to say before we panic over the worst of the global being south. Ric could win for sure but it’s not very climatological favored. Plus would be a shame that is below the “it’s supposed to snow” line. People they live there don’t deserve snow because any true snow weenie would never abide living somewhere that goes years without a snow and averages what I get in a few hours on a good day.

It has a disconnect with that fgen band to our SE. also that band is rain v snow on the gem. But I think that disconnect helps places north of DC.

Rgem is going to be a better run for the area. And remember gem will look very similar they’re essentially the same model.

Dayum the NAMs about to lay the wood on someone.

I like the trajectory better for MD. When the trajectory of the qpf is straight w-e is when it tends to sink south at game time. When it’s SW to NE is when it tends to trend north some rather end. This is in between which might mean some north nudge which is exactly what we need to keep DC in the jack but also extend it up to the northern MD folks.

Also @Ji it’s 160 out and look what it did in one run. If it adjusted 2 more times like this it’s a snowstorm. Not saying it will but not impossible