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

[Bob Chill]

At least on the gfs, run over run is better with the upper level eyeball pushing down heights/assisting confluence. Just a little better. Nothing crazy. Should avoid a rug pull this run

[SomeguyfromTakomaPark]

GFS is a front end crush job. 6+ inches for DC by 15z before changeover.

[EHoffman]

1 minute ago, SomeguyfromTakomaPark said:

This is kind of a garbage post.  You're not considering or analyzing the synoptic evolution or antecedent airmass.  You're just saying "we always fail".  I've lived in the DC area since 2009 and there have been quite a few good storms that don't fit your narrative.  

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.

 

Just now, chris21 said:

Ehhh... happens a lot... but we just had a high impact freezing rain event two days ago that was apparently “impossible in dc” even though I’ve seen it many times.

I wouldn't call 2 days ago high-impact in DC at all.  In fact, we avoided high impact by being a huge heat island and not having ZR accumulate anywhere for hours when it was 29 degrees because of the sun angle.  It's a good example of why it's sooooo hard for us to bank in borderline scenarios.

[WesternFringe]

Purple rates of snow approaching from the southwest at 69 on the GFS

[Grothar of Herndon]

3 minutes ago, clskinsfan said:

The cold push is just light years better on the GFS. 540 line is 50 miles south of the NAM at 60.

GFS starts as snow down to RIC this run. 

Beatdown for all. 

So far 12z Globals are holding and sounds like GFS continues to trend even better for us

[ovechkin]

The NAM has scored well this winter. At this point it is a reminder that accumulating snow in the immediate metro is guilty until proven innocent. 

[psuhoffman]

15 minutes ago, leesburg 04 said:

I'm not one who jumps on the snowiest model and ignores the rest, I'm just making an observation...but in the end it's just my observation. You do you man, you know your stuff and I've never disputed that. I will continue to read your analysis

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. 

[Bob Chill]

4 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.

 

I wouldn't call 2 days ago high-impact in DC at all.  In fact, we avoided high impact by being a huge heat island and not having ZR accumulate anywhere for hours when it was 29 degrees because of the sun angle.  It's a good example of why it's sooooo hard for us to bank in borderline scenarios.

There's like a dead sea scroll of climo history backing up your statement so I wont disagree much at all. I will add that temps leading in are *potentially* the coldest of the season. DC proper has the highest chance yet at starting off with snow with surface below freezing for hours instead of seconds before onset. That is the fly in the ointment of your definitive statement. Wont know how it breaks for a couple days. Dont completely discount that temps could be friendly for the first time this year. Expecting fail is def where I would put my money if forced to bet tho

[chris21]

5 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.

 

I wouldn't call 2 days ago high-impact in DC at all.  In fact, we avoided high impact by being a huge heat island and not having ZR accumulate anywhere for hours when it was 29 degrees because of the sun angle.  It's a good example of why it's sooooo hard for us to bank in borderline scenarios.

Strongly disagree, could barely walk outside my house Saturday and sat night. It didn’t accumulate anywhere? NWS reported a .25 inch ice in adams Morgan.

[Kmlwx]

I will say this - with regards to @EHoffman's comments. 

If the surface is 31-32 I would of course agree with him more. But if we are in the mid 20s at onset that wedge is going to be stubborn. Again, the warm layer is well above the surface. Low 30s probably means a wet event for DC. Mid 20s and there will be at least SOME trouble with ice. Remains to be seen as well how much of the stuff after any snow falls as sleet vs ZR. 

[clskinsfan]

The GFS is a pretty nasty storm for my area. 7 inches of snow/sleet followed by .4 of ZR. Temps finally reach 32 degrees early Friday morning. What a mess. 

Temps then crash back into the mid 20's Friday midday. Concrete incoming. 

[midatlanticweather]

Let's hope the second Ice Storm in a week does not come true for Richmond area! Would be just awful! 

 

 

 

[Weather Will]

WB 12Z 3K at hr 60 v 12Z Para at hr 60 700 MB

[Kmlwx]

5 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.

 

I wouldn't call 2 days ago high-impact in DC at all.  In fact, we avoided high impact by being a huge heat island and not having ZR accumulate anywhere for hours when it was 29 degrees because of the sun angle.  It's a good example of why it's sooooo hard for us to bank in borderline scenarios.

IIRC there were more than one or two posters in DC proper reporting icing that was a bit more than what most people would call a snoozer. I get your overall point - and to an extent I do agree with you. Could easily fail in the way you are suggesting - but the "heat island" of DC is smaller than the entire city in most cases. Think about how much better NW does versus near the airport. 

2 minutes ago, ovechkin said:

The NAM has scored well this winter. At this point it is a reminder that accumulating snow in the immediate metro is guilty until proven innocent. 

The NAM is worth looking at for the reasons PSU has pointed out. But you aren't backing up your posts with evidence like he is. Come on...at least add to the discussion...It's not hard to post something other than "NAM has done well"

[EHoffman]

2 minutes ago, Bob Chill said:

There's like a dead sea scroll of climo history backing up your statement so I wont disagree much at all. I will add that temps leading in are *potentially* the coldest of the season. DC proper has the highest chance yet at starting off with snow with surface below freezing for hours instead of seconds before onset. That is the fly in the ointment of your definitive statement. Wont know how it breaks for a couple days. Dont completely discount that temps could be friendly for the first time this year. Expecting fail is def where I would put my money if forced to bet tho

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.

1 minute ago, chris21 said:

Strongly disagree, could barely walk outside my house Saturday and sat night. It didn’t accumulate anywhere? NWS reported a .25 inch ice in adams Morgan lol.

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.

1 minute ago, Kmlwx said:

I will say this - with regards to @EHoffman's comments. 

If the surface is 31-32 I would of course agree with him more. But if we are in the mid 20s at onset that wedge is going to be stubborn. Again, the warm layer is well above the surface. Low 30s probably means a wet event for DC. Mid 20s and there will be at least SOME trouble with ice. Remains to be seen as well how much of the stuff after any snow falls as sleet vs ZR. 

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

[clskinsfan]

Just now, midatlanticweather said:

Let's hope the second Ice Storm in a week does not come true for Richmond area! Would be just awful! 

 

 

 

Hate to be rude. But we need them to be ice so we can get snow. If they rain we will get the ice. 

[LeesburgWx]

After reading the last few pages, it is clear we needed to change this picture once again...

[Bob Chill]

6 minutes ago, Grothar of Herndon said:

So far 12z Globals are holding and sounds like GFS continues to trend even better for us

I loved seeing the gfs beef up confluence/surface high thru hr 54. Putting up the good fight at a time where it usually collapses like the WFT's QB hopes and dreams

[Kmlwx]

Just now, 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.

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. 

[Ji]

PARA is a beatdown

[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.