psuhoffman

22/7 with a few inches of solid ice on everything. I think there is a chance the surface might be cold enough

Wtf is that BS? That better be a 1 hour snowfall map!

I’m holding them to that 8-12 up here. There will be consequences...might have to wag my finger even!

We have no idea how they clown map is generated. If for example, it counts ice as snow like TT does then it’s pretty much in line with everything else.

The key is getting that initial band in hot and heavy. But that’s a typical MO got juiced up gulf systems with cold on top so you get WAA way out ahead. If that gets in early and starts thumping...dynamic cooling takes over and DC can pile up a respectable total quick before they lose the column.

Fwiw I have a feeling this could be a rare positive bust in DC.

That’s my suspicion. If everything is 1-2 degrees warmer a warm layer that was right at freezing is now just above.

My 2 cents and that’s more then it’s probably worth...it does a good job showing what the structure of the storm will be. Banding features. Temperatures. Warm layers. But its too ambitious and can’t get the exact placement of those features correct. So if you understand not to rely on exactly where it puts meso scale features but use it as a clue to the structure of the system it’s useful.

It is but it can sometimes be too aggressive. This was about the range it was showing that crazy 15” solution for the super bowl storm that blasted the 850 warm layer all the way to SE DC. In the end boundary temps sucked but it was way too aggressive with the mid levels.

Like my post above said this is 100% but I think I’m coming at this from a different angle. Imo these flaws are good reasons why this isn’t a MECS or HECS. This doesn’t have 8”+ potential in DC. But it’s not a good reason Imo it’s not a regular old 3-6” SECS. Those (at least most of the ones I studied when I looked at all the warming events at BWI) were flawed in some way. Some way more flawed then this setup. It seems like “good but flawed” setups don’t break our way as much anymore and 3-6” becomes 1-2” way too often.

I see the “flaws”. It’s not perfect. It’s not a hecs setup. But we’ve had snowstorms in this kind of setup before where a cold airmass in front and a perfect track offset that kind of trough axis. I remember one in 2004 actually that was a 4-8” event across the area that did eventually go to ice but only after the WAA banding ended and we dryslotted. I guess my point is we keep making excuses for why these little imperfections were the reason it didn’t snow but imo it shouldn’t be this difficult. We shouldn’t need EVERYTHING to be 100% absolutely perfect to get a simple 4-8” snowstorm. I’m taking the 10,000 foot view that it seems pretty good but not perfect setups that used to break our way a decent (not all) amount of the time seem to break bad a lot more recently.

It’s mid levels yes but there is usually a mid level warm layer when we have a storm. I’m going to simplify this but I feel it’s an accurate summary. There almost has to be a warm layer because it’s WAA as the wave approaches that is the primary impetus for precip. The warm air is lifted over the denser cold and that lift creates the precip. But warm is relative to normally very cold air at those levels. Rising air cools and condenses so it’s cooling as it rises. So long as that mid level “warm” layer stays just below freezing it’s ok. But what happens if EVERYTHING is say 2 degrees warmer then it used to be? Then a “warm” layer that was -1 is now +1 and the mix line just jumped 50 miles north!

I just used the icon but it’s the same idea across guidance. There shouldn’t be mixing problems in DC (at least not significant ones) with that track in mid February with an Arctic high over Montreal at the start.

I should have said this up front. My post was not meant to be an autopsy or storm cancel. It could still work out. But damnit it’s a lot more difficult then it should be with that setup. Just wanted to point out how good the track is here because we often get stuck looking at the pretty colors but I look at the temps and precip panels last. And that really makes it stick out how out of whack they are and have been multiple times in recent years!

*This is NOT a storm cancel or autopsy. It could break our way. Just wanted to highlight something larger scale going on* I wanted to illustrate something. look at 6z. This is generally the same across guidance. The primary dies in eastern TN. The coastal takes over and tracks from outer banks to east of Delmarva. Look at where the banding of precip is. That blue area is where it SHOULD be snow. But it’s not. It’s mixed with sleet and freezing rain all the way to the PA line. Guidance isn’t trending north. It’s trending warmer. And I don’t know why. What are we even rooting for there? That track is absolutely PERFECT in every way! We have an Arctic high in place. Cant use the “no cold air” excuse. This keeps happening a lot lately. Tracks that should produce snow in DC find a way not too or produce way less then they SHOULD. It’s frustrating and troubling.

It’s not even trending north. It’s trending warmer. It’s still a perfect track with an Arctic high in place. Dunno what to say.

EPS

Just like everything else it depends on the situation. In my experience the Kuchera maps seem to depend way too much on heights and thicknesses. In scenarios where its cold aloft and the surface is warm its way too liberal with snow totals. In scenarios where the surface is cold but its warm aloft is can run too low so long as the warm layer is isothermal and stays below freezing.

Thanks for giving me 3 inches back. This shouldn't be that difficult to accumulate unless the rates are low since surface is torching at 26 I still like my 4-8" call for Loudon County.

@Ji this one looks better... In all seriousness the Kuchera maps are being REALLY conservative. And yes I know with warm layers and mixing ratios will be low. But even in times and places where every level is below freezing its using crazy low ratios. Maybe it uses thicknesses as part of the equation and since this storm has some unusually high heights that could be throwing it off. I think maybe 10-1 maps could be better here.

Next frame will be one closer to us finding out what the euro thinks the solution is.

get out and push

ECHO

There will be significant ice in the 1-3 and 3-6" zones. I think freezing rain will be a major problem just to the south of the 1-3" zone and through the 1-3" zone after it flips. I think it will be mostly sleet in the 3-6" zone with some freezing rain mostly during periods of light precipitation.

I am 100% confident that map will be wrong. The question is HOW wrong.