2023 Mid-Atlantic Severe Wx Thread (General Discussion)

[Kmlwx]

And yeah that 16z run of the HRRR is robust. 

Seems like in this setup there may only be one or two dominant cells but they may be INTENSE ones. 

[Kmlwx]

Left moving supercell parameter is doing better than the normal supercell composite parameter. Also parameters as a whole seem JUICED along and east of a line pretty much bisecting MoCo running SW to NE generally. 

[AmericanWxFreak]

https://www.spc.noaa.gov/products/md/md1999.html

Watch Likely 

 DISCUSSION...An upper trough/low centered over the Great Lakes/OH
   Valley will continue moving slowly eastward this afternoon. Modest
   ascent preceding this feature and low-level convergence along a
   surface cold front will likely foster robust convective initiation
   within the next 1-2 hours (by around 3 PM EDT) across parts of
   western/central NC into the coastal Mid-Atlantic. Strong daytime
   heating has already warmed surface temperatures into the upper 80s
   and 90s across this region. A rather moist airmass, with
   precipitable water values of 1.5 to 2+ inches and surface dewpoints
   generally in the 70s, should help offset poor mid-level lapse rates
   to some extent. Around 1500-3000+ J/kg of MLCAPE has already
   developed given the ample diurnal heating that has occurred.

   While weak west-southwesterly low-level winds exist, they do
   strengthen with height to around 45-60 kt through mid levels.
   Related 35-50 kt of deep-layer shear will act to organize updrafts,
   with a mix of bowing clusters and supercells possible. Isolated
   severe hail may occur with the more discrete convection that
   initially develops. A tendency for upscale growth into multiple
   clusters appears likely given the linear forcing of the front and
   mainly boundary-parallel flow aloft. Scattered damaging/severe wind
   gusts should be the main threat as this convection spreads eastward
   through the rest of the afternoon and evening. One or more Severe
   Thunderstorm Watches will likely be needed as robust convection
   develops over the next couple of hours.

[AmericanWxFreak]

First box over NC/VA posted - ours should be coming shortly

[Kmlwx]

Activity running from Calverton, VA up to Manassas is growing nicely. 

[AlexD1990]

Activity running from Calverton, VA up to Manassas is growing nicely. 

Maybe even rotation on the cell near Nokesville?

Sent from my SM-F711U using Tapatalk

[George BM]

Severe Thunderstorm Watch coming out until 9pm for much of the area.

[vastateofmind]

Looks like we have a good chance to get clocked two days in a row, @H2O, @mattie g and @WeatherShak. My home office is currently taking on that same as-dark-as-9pm ambience it had yesterday afternoon...  

[AmericanWxFreak]

[Kmlwx]

Little shower now trying to fire up near Rockville. 

[mattie g]

19 minutes ago, vastateofmind said:

Looks like we have a good chance to get clocked two days in a row, @H2O, @mattie g and @WeatherShak. My home office is currently taking on that same as-dark-as-9pm ambience it had yesterday afternoon...  

Yup...could well be. It'd be nuts if I got nearly the same amount of rain as yesterday, but that said it's raining moderately right now, with the meat of that cell is still SW of me.

[mattie g]

Wow...lightning strike less than .25 mile outside the home office window. Big flash over my shoulder and then BOOM!

Edit: To say that there's no wind to speak of, but it's now pissing down.

[vastateofmind]

9 minutes ago, mattie g said:

Yup...could well be. It'd be nuts if I got nearly the same amount of rain as yesterday, but that said it's raining moderately right now, with the meat of that cell is still SW of me.

Indeed. We just had a 15 minute gully washer...but at least it wasn't horizontal rain like yesterday, and no bad lightning (yet). Snapped this a few minutes ago...was trying to capture the mammatus-like effect at far right for @mappy, but I was about two minutes too late to get the best of it.

[nj2va]

Torrential rain for the 2nd day in a row.

[WxUSAF]

Moderate rain. No wind or thunder.

[mappy]

11 minutes ago, vastateofmind said:

Indeed. We just had a 15 minute gully washer...but at least it wasn't horizontal rain like yesterday, and no bad lightning (yet). Snapped this a few minutes ago...was trying to capture the mammatus-like effect at far right for @mappy, but I was about two minutes too late to get the best of it.

still a great picture! 

[Eskimo Joe]

1 hour ago, Kmlwx said:

And yeah that 16z run of the HRRR is robust. 

Seems like in this setup there may only be one or two dominant cells but they may be INTENSE ones. 

Got an image for us mobile folks?

[AmericanWxFreak]

Just now, Eskimo Joe said:

Got an image for us mobile folks?

It’s posted a page back. 

[Kmlwx]

Nice outflow presentation on the LWX radar from the stuff crossing the Potomac. Outflow out to the north and south. 

The stuff down near Madison/Orange/and CHO looks decent. 

[H2O]

42 minutes ago, vastateofmind said:

Looks like we have a good chance to get clocked two days in a row, @H2O, @mattie g and @WeatherShak. My home office is currently taking on that same as-dark-as-9pm ambience it had yesterday afternoon...  

Just some light to moderate showers so far.  Worst of it split to my W and E.  All good.  Not sure I need flooding rains.

[MN Transplant]

26 minutes ago, mattie g said:

Wow...lightning strike less than .25 mile outside the home office window. Big flash over my shoulder and then BOOM!

Edit: To say that there's no wind to speak of, but it's now pissing down.

Wild that the main stripe and NW cutoff were in eerily similar positions as yesterday.  

[adelphi_sky]

Nice little thundershower here. On the razors edge to the north of the DC storm. 

[Kmlwx]

The Gordonsville area storm down in VA looks like the beefy one of the day...maybe some weak rotation on it too. 

[Kmlwx]

Actually getting bright sun right now in Colesville despite that precip being just a HAIR east of me. 

[Eskimo Joe]

5 minutes ago, Kmlwx said:

Actually getting bright sun right now in Colesville despite that precip being just a HAIR east of me. 

It's over for Montgomery

[weatherCCB]

Sunny here also

[Kmlwx]

1 minute ago, Eskimo Joe said:

It's over for Montgomery

I think you're right for severe. But we may see some showers or thundershowers scrape by as the activity down in VA passes by to our south. Look at the litle showers on the northern end of that stuff. Western MoCo probably done for anything though. 

[AmericanWxFreak]

Well that was pretty underwhelming lol 

[Rhino16]

Seems like it’s the usual pattern recently with the NC stuff, and the little bit of northern-ish VA stuff leaving a gap around richmond. I’ll wait a bit longer to be sure though.

[mattie g]

37 minutes ago, MN Transplant said:

Wild that the main stripe and NW cutoff were in eerily similar positions as yesterday.  

I noticed that on the meso runs this morning. The storm yesterday caught me flush just as it blew up (almost split me, but nope) and we ended up on the highest end of the precip totals, while today we just got striped and will likely end up with highest totals again, especially if one of these cells to the SW grows a bit and hits us again.