psuhoffman

The EPS 25-75% doesn't look far off from what @MillvilleWx has been saying all along ETA: Keep in mind this is pure 10-1 so in the NW zones these numbers would be underdone a little

I used the EPS to create this map using the 25% and 75% snowfall output

EPS did shift NW slightly overall, but there is some good under the hood. The 10 and 25% snowfall actually shifted southeast...the 10% snowfall is now 6" in DC, up from about 4.5" This would seem to indicate a floor of about 6". There are less disaster members with under 6". The 50% did drop from 11 to 9" and the 75% dropped from 14" to 11" so we are losing the upside potential as the jack zone is shifting further and further northwest the last several runs.

I'm not sure we want that... if you disregard the GFS pretty much everything else is about the same in terms of when we lose the mid level thermals...between 15-21z depending on where you are south to north. So we want as much precip before that as possible...

TT does also but won't have it updated for another 2 hours probably

it ends up speeding back up...in the end it simply trended further NW, primary hangs on longer...looks kinda like last nights GGEM

yea there's that too lol It's just one data point...just one run of one model...but the AIFS trend is not good... 24 hours ago when it was showing what we wanted we were rightfully pointing out how good it's been and that having it on our side was a big deal...so losing it to the more amplified NW camp is not what we want. But again...it's just one piece of evidence not the whole show... if the op euro and EPS come in good that would outweigh the significance some.

AIFS trend

It's slower so comparing the same time period doesn't necessarily indicate a trend

Actually it's warmer than the GGEM, pushes the 850 about 20 miles further NW than the GGEM.

AIFS is not a disaster...but over the last 24 hours it went from being one of the best solutions to now maybe the worst at 12z. Its 8-9" for DC and Baltimore...about 10" up here. Jack zone shifted quite a bit to our NW. Looks similar to GGEM with track and thermals

12z AIFS is significantly NW and warmer...

Just one damn time...

This... I mentioned this after Mitch posted the 6z UK ensembles...the UKMET 10-1 snow maps counts sleet as snow so they are inflated on the southern end. Can't compare them to other models that don't do that...it gives the false impression the UK is further south than it is...if you just look at those maps...which you shouldn't anyways

I've been using that storm as a guide here but displaced 75 miles south or so...very similar but the thermal boundary is a little further south this time.

The GFS doesn't see mid level thermals as well as the Euro or NAM...that is a known thing

It definitely won't see the mid level warm layers as well as the euro/nam when we get closer... but could it be correct about a less amplified system? Sure. Would I stake anything I care about on it...no.

mod to heavier precip would be I would think...light stuff mix but who cares. We know the drill

GFS is noise level changes...as close to a "hold" run as you will ever see at this range

I was somewhat giving you a hard time...but Frederick is in a shadow zone between the Catoctins and Parrs Ridge and doesn't do as much better than places closer to 95 as you would think. Places closer to DC and Baltimore like Damascus and Mt Airy actually do better.

If you moved to Frederick for snow purposes...umm...we need to have a talk

Oh that RGEM was a significant improvement and was 90% snow for us on that run...we ride the mix line for 12 hours BUT its rate dependent, during dry slots its sleet and the snow line sinks south during heavier periods...and even during lighter periods the mix line never gets more than a few miles NW of us...1 degree colder and it's 100%...a huge improvement from 12 hours ago! BUT...that stuff you see to our SW won't make it here...we are about to dry slot at the end of the run and its over. The stuff in WV and OH won't make it across the mountains because with the primary going to our NW the flow ill be out of the west and downsloping and the mid level dynamics are going to our NW so there won't be anything to cause additional precip.

It's the high res version of the GFS so....

the mid level low is tracking pretty far NW to hope for any meaningful snow on the back end. Typically we need that to be tracking over us or to our south for that to work out...its tracking well to our NW. Unless we see that change I would not really put any stock in any significant snow on the back end.

That post was specific for northern MD and southern PA. Closer to 95 the warm layer is a bit more significant the last 6 hours.