Bubbler86

It smoothed NC PA out of 6-10". That is a Kruger Industrial Smoothing job if I have ever seen one.

This is not far from the Icon or EC.

3K snow map is much different than 12K and basically a medium westerward jump from 12Z with some upped totals in East LSV. But seeing a fold in 12K gives me extra caution about it now. Until it folded I gave it a chance to tell its story.

I get almost nothing on the Nam. Right on the edge of the 2" line to my west.

The Nam Kuchera map is a very strange one. LOL. Yea TT is slower, use pivotal. Plus the snow maps are bad in marginal situation.

The qpf presentation is weird, will wait to see the 3K.

Low nicely positioned over far S VA or N NC at hour 48.

Yes, it is a fold by the Nam IMO.

Nam looking like it could be better again. Has a better reflection in the SE.

Yep, just doing the PBP. Most people should know it is a situation where things are subject to change and not to take too much out of it.

It looks like it would be headed to cutting over SE PA. Would be some serious snow on the back end if it does not transfer.

Yep, it is riding almost into PA at 48 hours. Just a discussion...I say that to avoid the inevitable complaints about how bad people think it is. Very heavy snow in central PA as the low passes. ITT/MJS are enjoying a showery mid-upper 30's mid day Sunday.

HRRR starts off as rain for most of the Southers. Not a predict nor backing the HRRR thermals but it does have the SLP far enough north that some warm air push is taking place. SLP is in WV and that is too far north west for my liking.

That list I broke down were the only op models showing 5" or more for a large part of the area. They are looking at a lot of other stuff including percentage based progs. I thought since the GFS is over 5" they should do a WSW but if they do not, it is not crazy talk.

FWIW, HRRR still looks like it will have more qpf than some of the drier suites.

There is no WSW coming if that is their true predict. Many models are not WSW level snows.

If they are going to do a Winter Storm Watch it should be this evening. Tomorrow is too late. Warning time. (My opinion not a predict)

Remembering below is not day to day weather, it is climate/UL stuff. From June 2024. Discussion: To evaluate AI forecasts, some preliminary verification results are recently available. The verification presented is for climate signal forecasts for the 6-10-day period from the past 30 days (Fig. 1). Evaluated is the mean average error (MAE) for North Atlantic oscillation (NAO), Pacific North America (PNA) index, East Pacific oscillation (EPO), and West Pacific Oscillation (WPO). The MAE for each climate signal is combined for 5 operational models and 5 AI processes. Final skill scores are reasonably close. The Artificial Intelligence Forecast System (AIFS) ranked no. 1 overall followed closely by the Canadian Ensemble (CMC ENS) and Global Forecast System (GFS). The Forecast Net GFS ranked last in this comparison. While AIFS ranked No. 1, operational models ranked 2 through 4. Clearly, based on this sampling, AIFS is “competitive”. Combining all 10 models and their forecasts of NAO, PNA, WPO, and EPO for the 6-10-day period from the past 30 days, most skillful was the PNA forecast while least skillful was the NAO forecast (Fig. 2). Implied are the upper air forecasts across western North America is best, easter North America worst, and middle of the road results in-between as identified by WPO and EPO.

https://www.ecmwf.int/en/newsletter/178/news/aifs-new-ecmwf-forecasting-system Data driven instead of old fashioned physics.

So camp wise I think we have Rgem, FV3, GFS and AI....UK is sort of a middler but leaning toward Camp 2....then Icon, Euro, Nam on the progressive side. Nam is the driest of all of them as we discussed but the progression and areas that get decent snow are similar. All in the first camp (somewhat guessing on AI) show precip totals of .5-1" over areas of the LSV (rgem even over 1" in some places). Second camp is more .2 to .4 levels.

The low progresses off the coast faster and does not throw the same level of prcip back west.

I was looking at the low position. It scooted off the coast faster.

Euro a bit more progressive than 0Z in the end. Totals will not be rgem or GFS like.