Bubbler86

Yea, without hourly panels I had to estimate hours of snow. Most of us are good at 42 and not good at 45 so somewhere in between...I believe most of what is on the ground at 45 would be snow. Say it changes at 42 for you and myself, 43-44 for others a bit east then 3-4 hours of moderate top heavy sleet. Really not much freezing rain for central pa but some in the southern LSV.

Snow depth as it is transitioning over to sleet for most of us.

Yea looks like 6-10" for LSV just doing the math of 6-8 hrs of moderate to hvy snow. No snow map needed.

LSV loses 700MB after 6-9 hours of 1-2" hr snow rates. Assume 1 to keep this in context.

Nam has snow starting in MDT around 7AM Wed.

Yep, me as well. This reminds me of a mini version of some of those over perform 1-2 foot storms over the last ten years (which I had to watch on from the south!). I have fun making predictions but this really will be a nowcast storm as to who gets 4" and who gets 12"

All this time (MA LR thread) fighting to find a way away from this look and here we are in the cusp of what could potentially be the biggest snow of the season for some and we make do with it anyway. All we needed was a weak low to open the Gulf firehose and spray it over our transient cold dome.

FV3 also looking more NAM/Euroish. These maps are from pivotal weather and supposedly are mostly snow but I am not 100% trusting of any of them as the depth maps do not always match to the point of them being too different. I can tell from the different column temps that most of us would be snow for at least 6 hours.

18Z GFS moved north a bit with the norther area of maxes. Models seem to be converging some. Good news for most of the Central 3/4 of the state. 18Z 12Z

I thought your amounts sounded very official.

Glad we have another predict. Hated being the only one. I might make a final call tonight after I see 12z Nam's thoughts precip type/how much intrusion of warm air especially down here.

On the road but I was thinking wed am as well. Last time I looked at it specifically I would have guess 8 to 10am in Harrisburg but did not look at timing on the euro if is slowed down a bit like djr mentioned.

Whoops, I jumped the gun on the snow map. Checked it before the snow was done. 6-8" for much of the LSV for 4-6 for rest...lollipop of 8-12 over Cashtown. Some of this may be sleet but NWS should be safe calling for 5+ plus region wide for the whole Susquehanna valley.

Euro snow depth which is the best predictor of accumulation for me...the snow maps are too spotty. Note that areas north of the LSV already have snow on the ground so this is most useful, for this storm, for the LSV. General 6-8" for NW LSV when done. 4-6 most of the rest of the LSV...a tad less far east. Lots of ice afterwards.

Well the 12Z Euro basically held serve...maybe a tad less but if anything the max's are north in Central PA. Still on for 4-8" snowfall for most in PA. At this point the GFS should probably be questioned. Should see Winter Storm Watches this afternoon as they totals are just the snow side...additional ice on top.

For those that are interested in model verification there is another article linked below that discuses some of the pros and cons with the FV3 right now. Although it is scoring better than the GFS there are understandably a lot of worries about making it the official American model. It has a tendency to over amp storms especially in the mid range. In watching it this winter I would say it is much more consistent that the GFS in that it does not bounce around from run to run. In terms of actual weather and results I am not sure any model should have too much confidence placed in it. Even the HRRR has been tripping up this year. These scores are World scores in that it is for weather all over the globe. When it comes down to forecasting North Eastern US snow storms the Farmers almanac is probably in the running for the best. https://arstechnica.com/science/2018/10/noaa-is-about-to-make-some-big-changes-to-its-global-weather-model/

Mainly two distinct camps of progs right now....all based on how far north the best forcing (conveyor belt) gets. 6Z EC, 12Z Nam focus the prceip up into PA with Wide Spread 5-10" amounts though much of the state 12Z GFS, 12Z Icon, 12Z FV3 favor more of a cut off north of I80 and the GFS especially has max snows south of the DC area but still 6-10" into south central PA. Here is the 12Z GFS. GFS is the outlier right now as to the area of max snows.

We need to check into that...this article suggests it is the other way around. https://arstechnica.com/science/2016/06/the-us-weather-model-is-now-the-fourth-best-in-the-world/

The subject of verification scores interests me and I was always under the impression that the first number was the actual score re: GFS did worse than FV3 in that plot. I believe these scores focus mostly on evolution of 500MB features vs. apparent weather so while the UK may have done ok with big picture stuff the actual results on the UK have been terrible this winter. I stopped looking at it as it was rarely sending cutters west of us, which is what has happened almost every time, until the last minute. Edit-I found what I believe is confirmation that the numerical value is the number to look at here...not the order they are in. This plot shows EC-UK-CMC-FV3-GFS-FNG-CFS in that order.

Yea, that is the reason behind those crazy NAM maps. I do not think the Euro map is including sleet. Otherwise we would all be hugging this! LOL.

6Z Euro Snow Depth. Not the same as 0 but still a major hit for many.

If I had to rank the models from some light verification and memory I would do these as such...just my opinion LR and MR- Icon Euro GFS CMC UK FV3 SR- Euro NAM Icon GFS FV3 CMC UK

Took a look at the NAM and GFS it appears we lose the column around hour 63 which is after most of the precip has come...and both models are forecasting 1" or so along the southern tier of PA so without any more ado, here is the first call with a wide berth on this one until a final call of snow (not sleet or frz included in this call...that would be extra). Blizz, Canderson, Sauss, Carlisle, Voyager-4-8" Nut, Dax, Wmstpwx-3-6" Mag, Cashtown, Bubbler-6-10" Hour 60 full column temps on the NAM

Headed to bed....GFS is not much snow and is a bit of an outlier at the moment,

Icon is at least 6 hours of 1-2" per hour snowfall for most of the LSV.