Terpeast

Nowcast precip shield more expansive than 3k nam forecast for 14-15z, with the ice line a tick further south than modeled. But just a little bit

Welcome to meteorology!

We’ve busted low recently because the temps had been too warm at the surface - is the main reason. But that’s not the case now.

8/-8 looks like euro/gfs are in agreement… and at odds with nam/rrfs

Idk, maybe something to do with gridding on its own data

Just fell under 20. Now 19.8

Its complex, but the simple answer is that the storm is phasing much farther west than ideal for an all snow event with no temp issues. It’s still cold though.

Not me. I didn’t really believe the suppressed scenario and kept saying it would come north. And it did… more than I thought.

22 now. This cold means business

Thoughts about freezing rain? Probably too soon, but some CAM soundings are showing a warm nose down to 900mb at the bottom DC and SE. i’m hoping that doesn’t creep north because of the risk of power outages, and difficulty of crews getting to fix them due to the preceding snow/sleet accums. As for as mby, I’m on the dark blue line or just underneath. When I’m on the line I like to mentally split the difference, as in 6-10” max 12”. Which was what I had in mind as far as my own forecast goes. EDIT: Saw your reply to Snowen, that answers my question.

29 now. Was 39 an hour ago

We’re close in location, euro gives us 8-10” before we flip

We shall see, but one thing is for sure - we have another threat to track, and we will be doing a lot of tracking.

I also think that cold air will not be much of an issue because of all the snow/ice cover we will have across the country east of the Mississippi

I have a feeling that we’re gonna go another week without much sleep

That big of a change in one run, outside of range? Toss until other models say otherwise.

Unless the synoptics changed drastically, I don't think the freezing rain in the PA turnpike is right. The arctic high is already stronger than had been modeled (1050) and the cold air both at surface and aloft isn't going to go that easily. I can see a flip up to the M/D line by early afternoon, but probably not much further north than that given recent trends.

By tonight/tomorrow 0z-12z we should see NAM start handling the thermals better.

DGZ looks fantastic on the HRRR right before the flip, too. If this holds, oh my...

IAD is close to flipping at 48 (18z) on HRRR. This is probably the time it flips.

Love the HRRR run. Probably out of its range, but see its trying to start a coastal.

Yes thats snow, but probably with some riming. Think this would give us an hour before fully flipping to sleet

That warm layer on your sounding is 5-10kft. Far above 3,000 but plenty of room to refreeze into sleet

If I had to guess where the true northern extent of the 800-750 warm nose, it would be along the darkest blue line instead of that 0 line on this 700 map. Maybe not even that far.

I think the gfs and euro are meeting in the middle, with the cmc joining them. Starting tomorrow the synoptics should be in place, and we’ll start taking the thermals seriously. Hopefully the NAM is wrong today and shifts colder tomorrow. All we need is a 20-30 mile shift to the cooler side at 700-850, and double digits is in play along and west of the fall line.