2019 Mid-Atlantic Severe Wx - General Discussion

[Kmlwx]

4 minutes ago, high risk said:

        Would love to see better lapse rates tomorrow for sure, but there are still a number of things to like.        This is an anomalously strong June trough arriving at the right time of day.    (We did really well with good dynamics on June 2).     As a result, while the surface winds may be too weak or veered for widespread supercells, the overall wind profile is impressive, and the lift will be strong.     Most CAMs show full heating tomorrow with temps approaching 90.         There will be storms, and there is a good chance that at least some of them will be SVR.

        It's a SLGT day for sure, but in terms of what we need for ENH potential, the NAM nest mid-level temps are a bit cooler than the HRRR and would allow for more instability.    And the best wind fields will overspread our area more towards 23z,  so later initiation would be helpful - the low-level shear will really improve towards 00z if any storms are still around.

 

Unfortunately we don't tend to do well when we need timing or moving parts to come together

[yoda]

LWX does mention ML Lapse Rates around 7.0 C/KM and fat cape... with sig amount in the hail growth zone on the soundings in their AFD:

Mid-level lapse rates should also increase, nearing 7C/km.
This will help to make for some "fat CAPE", with a significant
amount in the hail growth zone. Thus, storms on Thursday
afternoon will have potential for large hail in addition to
damaging winds, though right now at least, the tornado threat
appears limited.

[high risk]

2 hours ago, yoda said:

LWX does mention ML Lapse Rates around 7.0 C/KM and fat cape... with sig amount in the hail growth zone on the soundings in their AFD:

 

 

            some of the guidance shows good lapse rates developing as the upper trough swings east, but others delay the mid-level cooling, leading to the crappy lapse rates that SPC mentioned in their initial day 2 outlook.     The revised day 2 outlook, though, is very encouraging and while it's unclear if they're talking about the mid-Atlantic, they do mention supercell and attendant tornado threat in the east.        As I mentioned earlier, the wind fields will definitely be strengthening later Thursday afternoon, so if we can get some local backing of low-level winds near boundaries, storm rotation is on the table.

[Maestrobjwa]

So...I know this isn't exactly on topic (although this is severe weather)...But I wasn't on these forums during the derecho back in 2012. How much in advance did the various know it was coming? (man that was some epicness that night!)

[mappy]

19 minutes ago, Maestrobjwa said:

So...I know this isn't exactly on topic (although this is severe weather)...But I wasn't on these forums during the derecho back in 2012. How much in advance did the various know it was coming? (man that was some epicness that night!)

Ian had posted about it a couple days before. the signs were there that a derecho was possible, but they are hard to solidify a forecast for until they've formed. and even then, they have to hold together as they make the trek. 

[RandyHolt]

Re: Derecho I remember folks here were posting links to traffic cameras out to the west, and watching them and seeing unreal lightning shows.   A tree took out the powerlines next to my house, but i missed seeing it as I got a face full of dirt and dust right as it all happened, looking out a screened window.  I do like the social aspect of power outages as all the coach potatoes are forced outside. Many of us, flash light and drinks in hand.

[2010 extreme]

33 minutes ago, Maestrobjwa said:

So...I know this isn't exactly on topic (although this is severe weather)...But I wasn't on these forums during the derecho back in 2012. How much in advance did the various know it was coming? (man that was some epicness that night!)

Several hours at the most other than we could see an mcs coming out of Chicago that morning . Hrrr probably did the best job.  In general, even the high res guidance have a hard time picking up on the timing and trajectory of mcs  systems.

[high risk]

Here is the midday 6/29/12 SPC outlook.    Most of the DC area wasn't even in a SLGT at that time.

[mappy]

23 minutes ago, high risk said:

Here is the midday 6/29/12 SPC outlook.    Most of the DC area wasn't even in a SLGT at that time.

and then a mod risk came out around 8pm i think. 

[adelphi_sky]

Sitting at 88F with a dewpoint of 71. Didn't expect so much sun today. It almost looks like a high pressure sky. 

[PSWired]

2 hours ago, Maestrobjwa said:

So...I know this isn't exactly on topic (although this is severe weather)...But I wasn't on these forums during the derecho back in 2012. How much in advance did the various know it was coming? (man that was some epicness that night!)

Here's the thread if you've got a few minutes:

"Then the front on Friday should bring at least a DC split." lol

[BlizzardNole]

1 hour ago, RandyHolt said:

Re: Derecho I remember folks here were posting links to traffic cameras out to the west, and watching them and seeing unreal lightning shows.   A tree took out the powerlines next to my house, but i missed seeing it as I got a face full of dirt and dust right as it all happened, looking out a screened window.  I do like the social aspect of power outages as all the coach potatoes are forced outside. Many of us, flash light and drinks in hand.

I remember hearing about people on I-70 getting caught from behind by that derecho because it was moving so fast.  That is crazy.

[Kmlwx]

It's kind of weird seeing old posts from myself sometimes

[Eskimo Joe]

1 hour ago, mappy said:

and then a mod risk came out around 8pm i think. 

MOD came after the 00z RAOB for IAD showed a pronounced EML and CAPE.

[Kmlwx]

I'm pretty meh on tomorrow - I think we'll get some storms but I'm not sure it'll be a "big" severe day by any means. 

[high risk]

5 hours ago, Kmlwx said:

I'm pretty meh on tomorrow - I think we'll get some storms but I'm not sure it'll be a "big" severe day by any means. 

        I really, really want to be IN on this.     Even with the potentially crappy lapse rates eating away at good instability, the wind profiles are impressive for mid June, as that's a nice trough approaching.        But it's hard not to notice the fairly limited coverage of storms so far in this evening's NAM nest and HRRR runs.   

 

[yoda]

2 hours ago, high risk said:

        I really, really want to be IN on this.     Even with the potentially crappy lapse rates eating away at good instability, the wind profiles are impressive for mid June, as that's a nice trough approaching.        But it's hard not to notice the fairly limited coverage of storms so far in this evening's NAM nest and HRRR runs.   

 

Probably don't count for very much at all, but both the 00z RGEM and 00z HRDPS rock DC metro at around 00z-01z FRI

00z 3km NAM looks like it has a tiny intense storm in DC at 00z too

[Kmlwx]

3 hours ago, yoda said:

Probably don't count for very much at all, but both the 00z RGEM and 00z HRDPS rock DC metro at around 00z-01z FRI

00z 3km NAM looks like it has a tiny intense storm in DC at 00z too

I just looked expecting to see very impressive panels...and was disappointed. Those returns look okay but nothing great. 

[mappy]

blahhhh

[Kmlwx]

It is quite cloudy this morning 

[AdamHLG]

Last night around 9:30 pm we had a respectable thunderstorm with heavy downpour over Chestnut Ridge (northern Baltimore County).  Not severe by any stretch however I am taking what I can get during this week of "active weather" that was predicted last Saturday.  But other than last night this week has been a fail for me.  I am somewhat optimistic for today - the last day of this "pattern" until we reload next week.  So maybe today - the day folks let their guard down or give up on the game - is the day we profit!    

[adelphi_sky]

84F with a dew point of 73. I'm optimistic that we'll get something. A strong front is coming through. If I get nothing out of today, you may want to check in on me tomorrow to see if I'm still sane. lol 

[mappy]

6 minutes ago, AdamHLG said:

Last night around 9:30 pm we had a respectable thunderstorm with heavy downpour over Chestnut Ridge (northern Baltimore County).  Not severe by any stretch however I am taking what I can get during this week of "active weather" that was predicted last Saturday.  But other than last night this week has been a fail for me.  I am somewhat optimistic for today - the last day of this "pattern" until we reload next week.  So maybe today - the day folks let their guard down or give up on the game - is the day we profit!    

man, even that missed me. 

[high risk]

7 minutes ago, adelphi_sky said:

84F with a dew point of 73. I'm optimistic that we'll get something. A strong front is coming through. If I get nothing out of today, you may want to check in on me tomorrow to see if I'm still sane. lol 

    the problem is defining the "we".     There will definitely be some storms in the area this afternoon, and at least a few of them will produce SVR reports, but coverage in the CAMs isn't awesome.   Maybe the CAMs are undoing the forcing, and coverage will end up much greater, but it right now looks like a chunk of this forum will end up disappointed.

[mappy]

24 minutes ago, high risk said:

    the problem is defining the "we".     There will definitely be some storms in the area this afternoon, and at least a few of them will produce SVR reports, but coverage in the CAMs isn't awesome.   Maybe the CAMs are undoing the forcing, and coverage will end up much greater, but it right now looks like a chunk of this forum will end up disappointed.

eh, been the story all week. 

[Maestrobjwa]

18 hours ago, PSWired said:

Here's the thread if you've got a few minutes:

"Then the front on Friday should bring at least a DC split." lol

That...was frickin' AWESOME!!! Thanks for sharing that! Man, how unpredictable severe can be around here. But I will never forget what that looked like outside my bathroom window (was literally taking a shower when I post power, lol) The wind blowing the sheets of heavy rain down the street...felt like a 20-minute hurricane, loop (basically was!) And then the absolute tree carnage the next day...mercy! That was certainly one for the books!

[yoda]

3 hours ago, Kmlwx said:

It is quite cloudy this morning 

It's quite sunny now

[AmericanWxFreak]

HRRR pretty consistent with this large cell pushing through the middle of the state

[high risk]

storm initiation has occurred, and an MD has been issued.   Sounds like a blue box is coming soon, although we may be at the northern end.  

[mappy]

8 minutes ago, high risk said:

storm initiation has occurred, and an MD has been issued.   Sounds like a blue box is coming soon, although we may be at the northern end.  

yeah, i see the blue box being issued for Baltimore south, maybe DC south even.