Feb Long Range Discussion (Day 3 and beyond) - MERGED

[Weather Will]

WB 12Z para

[high risk]

GFS para is a T-H-U-M-P.      Over 1" of liquid in the 12 hours ending at 18z Thursday.

[nj2va]

Para would make everyone happy, too.  Basically 6-12” from north of EZF for the rest of the area.

ETA: ninja’d  

[Qaanaaq]

3 minutes ago, psuhoffman said:

Fair enough. From my perspective what’s annoying is some seem to focus in on the negative I say. In the last 24 hours I bet I’ve made 10x more positive posts.  And sometimes even within a post I’ll make a positive and a negative point. I’m analyzing all the possible permutations. But then the negative thing I said gets all the attention and it comes off like I cancelled storm when that wasn’t my intent. I intended to point out the NAM was bad and it COULD be right and explained why.  But obviously I suck at communicating that because it turned into “I went off the rails and cancelled the storm”.
 

It doesn’t matter what my intent is if that’s what people take from my posts.  One thing I think that’s at play sometimes is some seem to want certainty and a narrative. I view this as chaos and I’m ok with that. I am open to all the variables and outcomes. I don’t need to pretend to know exactly how it’s going to go. I don’t know. No one does. So people try to read certainty from my embrace of the uncertainty.  
 

The NAM is possible. So is the crazy 10” para gfs. I can see reasons for both. I could see the NAM being a little too aggressive with the warm layer and the heavy rates mixing it out. I can also see an argument for the NAM given this setup and history with this kind of SW flow. I’m open to both possibilities. But I think some want to be told how the bad one isn’t likely and placate their fears and so my embrace of both comes off as an embrace of the fail only. 

I really enjoy your analysis and it is clear that you have an understanding of the models, variables, their weaknesses and limitations.  I 'do" science but not in this field.  As a scientist I'd rather have it "served up cold" that does not include wishful thinking, otherwise, it's get's infected and influenced by an pre-ordained desire of an outcome and, frankly, not "science".  I think you do a great job of reporting how you think it may go, while at the same time separating your desire to see 36 inches of snow and winds of 50 mph from the NE !! Keep it up !

 

[BTRWx's Thanks Giving]

Just now, Weather Will said:

WB 12Z para

Didn't that trend north from the prior run?

[gymengineer]

6 minutes ago, EHoffman said:

We always fail in borderline scenarios in mid-to-late February like this, yes.  It's very rare we actually cash on a frozen-to-rain scenario like this.

2.6” at DCA before the changeover to ZR on 2/20/19 and 2.8” at DCA before the changeover on 2/15/16. Those performed more or less as expected and are just within the past 5 years. 

[snowfan]

That morning beat down on the para

 

[Bob Chill]

5 minutes ago, Kmlwx said:

Power outages are not the only metric. I heard plenty of reports of accidents that were definitely above the normal background from just wet pavement. Bridges and overpasses can get ugly fast even with marginal temps. But yes - power outages were minimal in Maryland. 

At my place near Arundel Mills (E of the fall line!) I had to clear off like 0.3 inch of ice from my entire car. Sure - the roads weren't terrible - but they were also salted about 4 times during the icing event. 

Nobody is going to argue with you that DC has a UHI and it DOES impact marginal events. We'll have to see what the surface temps actually end up being for the upcoming event. 

I think it was Bob Smith who took one of Mark Twain's famous quotes and modified it into legendary status. Not sure but the quote applies here:

"Never argue with an idiot. They will bring you down to their level and beat you with experience". 

Now Ehoff is no idiot. Quite the contrary. But he is a contrarian so just insert that word in place of fool and the quote works perfect. 

[SomeguyfromTakomaPark]

Just now, gymengineer said:

2.6” at DCA before the changeover to ZR on 2/20/19 and 2.8” at DCA before the changeover on 2/15/16. Those performed more or less as expected and are just within the past 5 years. 

Yes I'm glad you have the history to prove it!  Front end thumps with cold temps to start are actually one of the situations that are pretty straightforward and we are less likely to fail in imo.  We're not waiting for a column to cool dependent upon ridiculous rates.  

[WinterWxLuvr]

33 minutes ago, EHoffman said:

Writing on the wall already for this one...has the making of a classic wet snow that doesn't accumulate to brief sleet to rain for DC.  I've seen this storm many times before.

Ill promise you this post is way off. It’s not gonna be a wet anything.

[clskinsfan]

Pretty insane national accumulation map. 6" plus from NE Texas to Maine. 

[JakkelWx]

I'll take what the para is showing to get me over my seasonal average by a couple inches.

[Weather Will]

Just now, BTRWx's Thanks Giving said:

Didn't that trend north from the prior run?

6Z

 

3 minutes ago, BTRWx's Thanks Giving said:

Didn't that trend north from the prior run?

 

[EHoffman]

1 minute ago, gymengineer said:

2.6” at DCA before the changeover to ZR on 2/20/19 and 2.8” at DCA before the changeover on 2/15/16. Those performed more or less as expected and are just within the past 5 years. 

I mean yeah, it can happen for sure.  But I don't think many would be happy here with 2" on grass followed by rain.  They'd call it a fail, especially given the globals right now.  Like this storm could totally give us an inch or two before it rains, but I'd hardly call that a win or a high-impact event.  For the record I hope I'm wrong I would kill for a solid thump.

[psuhoffman]

It is positive to see the globals still trending better. One last point on the NAM. The reason it goes berserk with the h7 warm layer is actually something it’s doing synoptically that makes it a huge outlier. @CAPE made a great post early this morning about how the trough is strung out and the guidance focusing more on the lead wave is helping to keep the system under us. The NAM is the holy guidance not doing that. It has a more amplified but also consolidated trough and this allows it to amplify to our west. If that’s wrong the h7 warm layer will be overdone. 
 

I have no idea if it’s wrong. Preponderance of evidence would say it’s overdoing it. I’m going to go with that.  But I sure will feel more comfortable when it drops that idea and gets on board with other guidance. That is all. 

[Bob Chill]

Someone needs to post the para 850 and 700mb fronto panels STAT. 

[deer]

5 minutes ago, BTRWx's Thanks Giving said:

Didn't that trend north from the prior run?

Just looking at the WB clownmap, I think technically yes? But it's a better run overall for just about everyone and even for someone like me, I get more digital snow despite not being in the jack zone

Ninja'd 

[snowfan]

Of course, that morning beat down is flirting w sleet in dc, but no surprise there. Unavoidable given the setup. 

[jayyy]

So… PARA or bust? LOL…

I definitely would not be mad at that solution, even though we eventually change over. Looks like a ton of snow to sleet to ZR here. 

[WinterWxLuvr]

Well at the very least the gfs brothers finally appear to have given up on the idea of a low running the west side of the apps. Finally

[Rvarookie]

I’ll take ice over cold rain. It was pretty cool to experience but having power likely made it fun lol

[Bob Chill]

Para would be the fairly common snow its eyeballs out as the sleet line is speed marching north then an earlier expected flip to sleet followed by cars being stripped to bare metal before zr in the dc area. Sounds good. I'll stick with that for now

[Ji]

Para would be the fairly common snow its eyeballs out as the sleet line is speed marching north then an earlier expected flip to sleet followed by cars being stripped to bare metal before zr in the dc area. Sounds good. I'll stick with that for now

I like bad wintet weather. This sounds like a severe storm

[LP08]

2 minutes ago, EHoffman said:

I mean yeah, it can happen for sure.  But I don't think many would be happy here with 2" on grass followed by rain.  They'd call it a fail, especially given the globals right now.  Like this storm could totally give us an inch or two before it rains, but I'd hardly call that a win or a high-impact event.  For the record I hope I'm wrong I would kill for a solid thump.

Problem is digital snow maps.  I’m guilty too but trying to get better.  I think realistically us closer in right now is 1-3/2-4” to sleet then slop.  As I have seen and you stated, warm layers race quicker than progged.  The only thing, which all guidance agrees on, is the surface being mid 20s right now.  If we see it creep up in the next few days (which past storms have to some degree) then we will know where this is headed but I’m optimistic now on a dynamic even that starts as snow.

[SnowDreamer]

para showing broad 2"/hr rates in the thump 

[clskinsfan]

CMC is a solid thump to ice for the NW burbs. Solid thump to ice to rain for the cities. 

[Miss Pixee]

17 minutes ago, EHoffman said:

That's all I'm saying though, is that historically these types of storms fail 99% of the time in DC even if we're getting slammed a few days in advance on "all the models."  Of course it's not IMPOSSIBLE we bank significantly on this, but I find it to be a major uphill battle.

Ehhh no power outages and slippery pavement that melted by the next morning.  Pretty? Sure.  High impact? In CVA and Southern VA, absolutely. Here, not so much.

I honestly think the models are too cold and we're always warmer than progged down here.

All I know is, (as a native washingtonian) you don't have to wait 50 years for mega storms. "High impact" doesn't just mean outages. It could be travel issues. Saturday an suv skidded UNDER a cement truck in front of a gas station. The truck flipped on its side, the suv went sailing two blocks and collided with another building. Was posted up i news coverage. SE DC. I couldn't get past my steps or landing because of ice. My neighborhood was a frigging skating rink...and its all hills so not fun. Ice isn't good for anything except pictures. I get it, marginal stuff is tough here because we've got a lot going on climate wise. The ocean, the mountains, hot air off the gulf. The latitude. So, duh.

I just get tired of the inaccurate narrative about DC, as if this is an eternal tropic zone that never sees snow. I get people are frustrated looking at a zillion color maps, but all anyone has to do is look up all the mega storms of the last 50 years. There's been quite a few, not counting minor events. And this 'heat island' bit could apply to any city at this latitiude. If you're talking about downtown with the heaviest traffic and concrete, ok. That's just the central core. I sometimes wonder if people ever venture out of their neighborhoods. Just sayin'. Maybe its time to just look out the window and toss all the models, I dunno.

And now, back to the mood swings over maps...

[stormtracker]

Man, I come in see the NAM and it;s mass suicides up in here.   YES, NAM has been great and sniffing out trends.  But EVERY SINGLE TIME it did, the other models began to trend toward it.  In all cases.   This time, nothing is even close to it.  Does that mean it's wrong? No, but let's stop acting like this is the same situation.  It's not.  Nobody is trending toward the NAM as with all the other storms.

[Weather Will]

WB 700 MB PARA starting 7am;

[Bob Chill]

5 minutes ago, Ji said:

8 minutes ago, Bob Chill said:

Para would be the fairly common snow its eyeballs out as the sleet line is speed marching north then an earlier expected flip to sleet followed by cars being stripped to bare metal before zr in the dc area. Sounds good. I'll stick with that for now

I like bad wintet weather. This sounds like a severe storm

We can almost write off an inconsequential 33+ degree rain event. That was locked and loaded 3 days ago (by mid range standards). Keep watching heights to the north and surface hp pressing south (even if 5 miles)and pray they dont start folding. Seem to both still be in beefing up stage. Make no mistake tho, there will almost surely be a stall and retreat at some point. We're in night drop deposit of wiggle room stage. Once the bank opens and starts auditing the skrizzle in the bag, we better hope we counted right.