2022 Mid-Atlantic Severe Wx Thread (General Discussion Etc)

[George BM]

Just for laughs. Lol NAM.

Sounding from the 6z NAM for Warrenton at 2pm Tuesday. 

Just a small hunch but I feel like the NAM may be overdoing CAPE here just a little bit.

[Kmlwx]

Had to lol at this from the end of the NAM 12km run for Tue PM. 

 

[Kmlwx]

This from the 6z NAM looks fun. MCS-esque

[MN Transplant]

1 minute ago, Kmlwx said:

This from the 6z NAM looks fun. MCS-esque

Really, all the global have an MCS signature on Tuesday.  Different timing.

[George BM]

Day 2 SLGT

2/15/15

Exerpt for MidAtl...

... 

At this time, one area of potentially greater storm coverage -- and
   thus severe potential, given the favorably strong wind field
   forecast atop the region -- will be along and east of the higher
   terrain of the central Appalachians.  Storms should develop by early
   afternoon, and spread east-southeastward with time. 
   Organized/rotating updrafts should evolve, given the available
   shear, with these stronger storms capable of producing large hail
   and damaging winds.  Risk may continue well into the evening across
   portions of the area, as one of the more pronounced disturbances
   aloft shifts southeastward out of the Midwest and across the
   mountains during the evening/overnight.

 

 

[wawarriors4]

 

[wawarriors4]

Just South of where I am, buddy down that way said quarter size hail at least.

[ravensrule]

On 6/5/2022 at 8:11 AM, Kmlwx said:

@ravensrule would be in here in 2 seconds with a comment like that. 

I've just gone down the rabbit hole reading the "Noteworthy Derecho Events" page on the SPC site. 

If only severe made me horny like snow, you would be 100% correct. 

[WxWatcher007]

3 hours ago, wawarriors4 said:

 

 

2 hours ago, wawarriors4 said:

Just South of where I am, buddy down that way said quarter size hail at least.

Those are great shots. 

[yoda]

I've moved on to the MCS threat Monday night into Tuesday morning... and um... the 00z NAM and 06z NAM are very concerning

[MN Transplant]

3 hours ago, yoda said:

I've moved on to the MCS threat Monday night into Tuesday morning... and um... the 00z NAM and 06z NAM are very concerning

All of the models except the NAM Nest fire an MCS Monday afternoon north of Chicago and keep it going to the east coast.  NAM and GFS are north of us (NYC/Philly), but the Euro is right over us.

[SnowenOutThere]

Would be a fun 2 in the morning if this run is true. 

[yoda]

12z NAM drops MCS through SE PA and NE MD at 45-51 hours out... but what is that at 45 and 48 hours on its western flank?

[yoda]

12z HRRR at super long range aka end of its run is a direct hit with the MCS... pretty impressive UD Helicity swath as well for that far out

[NorthArlington101]

Tough to root for derechos personally, but hope folks get what they want and I can erect my house shield in time.

[yoda]

8 minutes ago, NorthArlington101 said:

Tough to root for derechos personally, but hope folks get what they want and I can erect my house shield in time.

 

 

[high risk]

First, while it's not clear how much instability will be available today, and storm coverage may therefore be very limited, the shear does support some supercell structures if any storms can be sustained.

Onto early Tuesday, it's hard to ignore the explicit MCS signals in several CAMs, and we all know that the overall pattern supports the idea.    What's not clear to me is whether it would be a severe MCS (I'll avoid the D word for now) or just a rainy, noisy elevated MCS.    Verbatim, forecast soundings suggest that the system would not be surface-based, which would reduce the threat of big surface wind, but it's certainly too early to dismiss a widespread SVR threat.

 

[WeatherShak]

First, while it's not clear how much instability will be available today, and storm coverage may therefore be very limited, the shear does support some supercell structures if any storms can be sustained.
Onto early Tuesday, it's hard to ignore the explicit MCS signals in several CAMs, and we all know that the overall pattern supports the idea.    What's not clear to me is whether it would be a severe MCS (I'll avoid the D word for now) or just a rainy, noisy elevated MCS.    Verbatim, forecast soundings suggest that the system would not be surface-based, which would reduce the threat of big surface wind, but it's certainly too early to dismiss a widespread SVR threat.
 

Some nice clearing inbound and observed sun here.

[Amped]

That's an impressive long lived MCS Tuesday comes all the way from the ND.  Impressive to see that showing up on so many mesoscale and even global models.

[snowfan]

Some timing differences, but 12z guidance likes it. 
 

[yoda]

Anyone else waiting for the new Day 2 OTLK? Lol

[high risk]

1 minute ago, yoda said:

Anyone else waiting for the new Day 2 OTLK? Lol

 YES!!!!!     You would think that, given the delay, it's going to be "interesting".

[yoda]

15% wind in north-western LWX CWA (i81 corridor and to the north and west)... hatched wind is pointing in our direction 

[H2O]

is everyone poo poo'ing todays threat?

[osfan24]

1 hour ago, H2O said:

is everyone poo poo'ing todays threat?

Well it's almost 4 pm and there is nothing on radar so that probably doesn't bode well.

[Kmlwx]

All our eggs in tomorrow's basket I guess 

[southmdwatcher]

We might be too far north or east to receive the storms forming out in Ohio and West Virginia. However, at least one of yesterday's SPC Convective outlook discussions, mentioned that the shortwave coming out of the Ohio Valley today and crossing over the Appalachians would produce some strong to severe storms well into the night for some portion of the Mid Atlantic region.  Probably going to be a Richmond target.

[high risk]

1 hour ago, osfan24 said:

Well it's almost 4 pm and there is nothing on radar so that probably doesn't bode well.

     It doesn't, but 18Z HRRR and NAM Nest still suggest that a cell or two is possible closer to sunset, especially in central or northern MD.     And as mentioned earlier, any sustained cell today has potential to rotate.

[Kmlwx]

It's been a busy weekend...but I'm just now having a chance to come up for air and take a look at everything. 

We tend to get lines of storms ahead of schedule...not sure if this would apply to the D-word or large MCSs as well...but I'd assume so. Still, the current timing is well into the overnight period tomorrow night and even closer to 12z Tue AM on some of the models. That's not ideal as @high risk already said for true surface based activity. 

The 2012 derecho came through late into the evening - but it was also a ridiculously hot airmass area-wide and it was before midnight. 12z is like the worst time entirely for anything severe t'storm related (it's happened, yes...but it's rare). 

MCS activity (and particularly derechos) are insanely tough to model/predict...and when we are talking about sensible weather, a different of a hundred miles or two is going to mean a ton for your specific location. 

Few things that I'll be watching for - 1) how much instability is left if the line/complex comes through at that awful time in the diurnal cycle. 2) If the timing really is 12z Tue AM - I think even 6 hours earlier would increase the risk substantially - make it 8-12 hours earlier and even better for severe odds (I think 12 hours might be a tall task, though). 3) We'll need to see where the instability gradient sets up - it's a razor sharp margin on some of the models and if you're too far NE of that...game over. 

I think EVERYONE is in the game in this subforum for right now. That will obviously change as we get closer to (and into) the event. 

Doesn't mean anything - but that day 2 Outlook has "the look" of 2012...obviously not basing that on any other analog factor other than map drawings (which don't mean much). 

I think today will be a feast or famine - if a supercell or two form, somebody will get pummeled - but I'm punting. If something pops this evening, I'll track it of course. 

Buckle up...let's see what tomorrow holds as we get closer to the potential.

[Kmlwx]

Also - looking at CIPS - it's pretty darn quiet and unenthused with anything in the short term (may not mean a ton). Around 100hrs and shortly after, there's a decent signal from the GL region/midwest and into our region. Bears watching since we are potentially entering a period with increased chances for a "ring of fire" pattern.