psuhoffman

Use this one. Cut out the area you want.

Go to TT and zoom in on the northeast then pick some 6 hour precip map that has nothing on it and copy it onto paint, cut out the area you want and go to town

So I’ve never seen this drastic of a split between the globals and American run CAMs at this range. What’s odd about this and gives me no past reference to draw on is typically when we see this kind of thing the euro and rgem/HRDPS kind of bridge the gap as those 3 are decent at seeing mid level warming. But they are all in the camp with the other globals (UK/Icon/gfs). The impact is most drastic actually for Maryland. Around DC and south we’re talking maybe the difference between 4-5” and 6-8”. But for places NW of 95 in extreme NW VA up through central MD we’re talking the difference between 5-6” and 10-12”! The divergence seems simple. The globals along with the Canadian high res models have an intense WAA band over the area from 12z-18z that the American CAMs do not. That’s why they are warmer. Less dynamic cooling to fight off the WAA at mid levels. Also less precip. That combo means 6” instead of 12” for places like Winchester-Frederick-westminster. What this comes down to imo is which camp is correct about the precip representation from 12-18z. Unfortunately I don’t have any great insight. Usually here is when I’d be saying “in this or that situation this is what happened” but I can’t remember a single case like this to draw upon. I guess I’m gonna ride with the euro camp. It would be hard to take the NAM and a bunch of experimental stuff over the highest verification tools we have. But on the other hand those CAMs were designed for this. When they score the euro a 30 mile shift in 800 mb temps and a meso scale precip band aren’t really going to impact those scores at all! Yes I just contradicted myself. If I had to make a forecast maybe I’d hedge and go in between even though that’s probably not the most likely outcome, one of these camps is going to win and that zone is either getting 5-6” or 10-12”. So a forecast of 8 would be gutless but the least likely to bust bad. @Terpeast @WxUSAF @CAPE @MillvilleWx Thoughts?

I agree but on the other hand what is reasonable for people to expect when NWS has been predicting 10” in DC for days. Even right now thy lowered it all the way to 9!

24 hours ago we were debating if ice would make it to the PA line...now it's closer to the NY line

Ggem

Rgem

If you adjust the snow/ice line 20-30 miles NW to account for its inability to see mid level warm layers it’s not that far from the ggem and EC anymore

Down to 13 here

I went 6-10 along 95

MD is kind of dry slotted after the snow thump on the NAM so only 1-2” of sleet but a ton down in VA

It’s fine. 10” in DC. 12” IAD. 13” up here.

Trick, the FV3 is almost always similar to the gfs inside 48 hours. Similar to the rgem/ggem. So if you want to know about what the gfs is going to look like just look at the FV3 now.

It’s because the warm layer is at its greatest extent there and thin and it’s wobbling based on rates. Around 20z we’re in a dry slot then it sinks south during some heavier precip

@wxmeddler I think bc you let us know about the Dr U convo you were gonna be low. I sorta expected that too, unfairly.

Looks like the gfs only the CAM version

Not saying it’s right but the range thing isn’t why because it does things that lead to this result in just 24 hours. Now the it sucks issue might be why.

I actually like the 18z rgem slightly better than 12z. WTF I’m out. I need to find something less stressful and more reliable. Oh I know I’ll start rooting for the local sports teams!

Ok rgem calms my soul some

I had hoped 12z meant we finally stopped the bleeding. But what’s come out so far 18z resumed what had been the trend prior to 12z and in most cases lost all progress from 12z and ended worse than their 6z runs! hopefully rgem/gfs/euro come in bucking this trend but so far a major amp trend with the primary across 18z

These 18z runs continued that trend...that wasn't the issue...the problem was around hour 36 they go berserk with the primary to our west and amp the system like crazy. A little better high and damming won't offset that. That's like throwing a couple poker chips on one side of the scale and then dropping a piano on the other.

wow what did it show 12z for this area then because it cut our snow in half on the publicly available maps lol