psuhoffman

For the record I’m not cliff jumping. I love to analyze this stuff. I’m curious why the CAMs are off on a tangent so close to game time. But I’ve noted they do this sometimes and the radar looks great. But I’m always open minded to all possibilities. Maybe they’re right. Doubt it but I’ve seen weirder things! It’s chips fall time. But I like to analyze all these situations. They are learning experiences. We will have another similar wave scenario to this someday in the future and the outcome here along with the performance of these guidance tools will be used to help me make a better forecast in the future.

No, but when nws had to make decisions based 12z guidance of gfs and NAM and 6z euro earlier today the blend of what NWS weights most GFS EURO 3kNAM was showing ~.5 qpf across the area and most importantly qpf was trending up at that time, all 3 were showing a good slp track and crazy insane fgen over the area and a thermal profile conducive to optimal dendritic growth and good ratios. It may have been a little ambitious but found with 3-5 and 5-8 across the area at that time wasn’t crazy given a mean qpf of .5, and up trend, and potential for decent ratios. I kind of doubt they would have gone so ambitious had they known what the 18z guidance would look like. But now they have to decide whether to lower based on off hour runs and CAMs which are notoriously unreliable or let the forecast ride despite some new evidence suggesting they are a bit liberal on snow. You were misrepresenting things to make it seem like guidance never supported what they have and I disagree. When they released it at the time I thought it was a but high, they went over my forecast numbers, but not by a lot and given trends at that time it was reasonable.

Dude you can be brilliant sometimes and others frustrating a heck. You said the models aren’t drying up. I posted the euro and gfs trend showing less qpf. I could do the same with the 3k and 12k NAM also. If you say something that’s patently false you can’t complain when it’s called out.

Yes they are. Gfs euro not worth discussing the rest when you’re not starting in reality.

Remember that rug pull like March 8 2018. Euro, NAM both, GFS, RGEM GGEM all had 4-8” across MD from that miller b? Then the HRRR started showing nothing…with the precip shield developing like 75 miles northeast if what all other guidance had. I remember us both saying to each other, We’ll die on the hill with the euro et all. No way all guidance is that wrong from like 12 hours and hrrr is right. Well… still waiting for my 4-8” from that one. Not saying I buy the hrrr and rap. We could cite 100 other times they were off on a crazy tangent. But I never ever feel comfortable unless we’re in the bullseye of some hecs with 20” 75 miles either side of me heading into it. It’s slightly troubling and perplexing they are trending worse as we get closer. People like to pretend it’s safe as some coping mechanism but I’ve had enough rug pulls and I guess I’m not a cops by lying to myself type.

this is part of the problem. I agree the mjo gets too much attention. It’s not THE end all some act like. But it is a significant part of the equation. And in a strong Nino it should look opposite what this chart shows. This looks just like the mjo plots from the last 7 years. Unfortunately the strong Nino wasn’t able to significantly alter the recent pacific base state. The warm pool near the MC continued to plague us. One issue is that water is so fooking warm even in a Nino there’s going to be convection there messing with the pattern drivers. And the water there is frankly going to be warmer than the enso regions. Maybe not the anomalies but the raw temps. Obviously this doesn’t mean we can’t get snow or decent patterns. But it’s hard to get sustained cold and great patterns with the mjo waves circling the MC hostile regions all winter. We were supposed to be in 8/1/2 from Feb 15-March 15. Want to know what suddenly changed…the better looks on guidance collapsed when the mjo signal changed.

My temp is 36 but the dew point is only 17 so I’m not too concerned

3 things. 1)Often these last second dry trends on guidance are BS. It’s happened many many many times. I can think of two that really stuck out. Last run before Jan 2004 storm after days of 4-8” guidance suddenly came in dry with like 2-4”. We got 4-8. Night before Feb 11 2010 guidance slashed qpf way down. We got what they had been showing. I don’t know why it happens. But many times I’ve observed this dry up right at game time and it was wrong. 2)Radar looks great and the forcing over the area is insane 3)they might be counting on better ratios than models think. The DGZ is perfect. It’s only ground temps. If it snows hard enough to overcome ground temps ratios could end up better than the 8 or 9-1 the models are thinking. I don’t know what to make of it. The radar looks in line with the NAM/GFS/Euro with a healthy southern precip max along the polar boundary not focusing on the arctic boundary. But the CAMs keep going harder and harder on the arctic wave and drying up the fgen associated banding which makes little sense given how intense that looks. Of course to make it worse I can’t find an outlet that shows mid level dynamics for the hhhr or rap so I have no way of knowing why they are doing that. I can’t tell much just from the crap data they provide for those.

I’ll take my chances with this

Get used to it. Boundary is warming faster than other levels

The nws map says 5-8” but my zone forecast says 3-7. I guess issuing multiple forecasts does increase your chances to verify!

Radar looks great

Clearly we live in a simulation and it’s not done Fng with you yet.

How will the plow companies calculate rates when they only have to plow half the parking lot?

Don’t you like to measure in the street?

Yea I want lots of things I’ll never get. Yea the northern max will be the better one. Could even see some isolated 8-10 totals in there. But it’s gone. The wave amplified and that shifted way to our north. We’re working with the southern max or nothing now.

That band they are focused on up there is long gone. That’s not ours. But the snow band for us is associated with the mid level fgen and better deep moisture transport. We just have to hope the CAMs are keying too much on that banding up in PA associated with the lift along the arctic boundary and are underdoing the southern max.

Maybe. 2010, 2014, 2015 would maybe indicate we can get hit pretty good with a favorable pdo still. And perhaps the wetter base state makes them more snowy. But small sample size. Howevwr there was another major temp spike post the 2016 super Nino. No telling how that’s changed the equation. Also the pdo has become increasingly hard to predict. The cycles have become more irregular so it’s impossible to say how much longer this lasts.

I didn't get your "donation" in time

Yes, there is usually a second snow max, an often its the better max, further north where the best moisture transport banks up against the arctic boundary. Higher ratios help here too. But honestly pinning that down is very difficult. Guidance has it a little south of where I placed it but I shifted both max zones north a little, just a gut call. I feel very confident in the 2-5 call but where within there are the 4-8 max zones is more guesswork in all honesty.

my thoughts

My thoughts

There is always the chance of a last minute curve ball, and there is so much guidance now you will always find something that shows either the solution you want or don't want. But I wouldn't worry about those two unless we were within 12 hours OR other more reliable guidance were to trend in its direction. The GFS did shift north some but it was south of the euro. The euro has been pretty much rock steady for 2 days now. I think this was just the GFS coming in line with it, and now the better guidance is all aligned. I am not saying NOT to worry at all but the RAP and HRRR are jumpy and unreliable and I wouldn't base my worries on them without any other support.

They have been a mess lately, never had me getting any snow with the last system, even as I already had a few inches on the ground!

I think PA south of 80 is in for a nice event here. Obviously know the local climo, ridges and higher elevation zones will do better as usual. Other than the typical upslope zones near the Laurels, I think there may be two max zones, one further north in Central PA with higher ratios where there is some enhanced lift along the arctic boundary where the moisture transport hits that brick wall...and one further south (south of 70) near the best FGEN and deeper moisture. These two zones I could see 4-6 with local 8" totals. In between probably a general 2-5" event.