2026 Mid-Atlantic Severe Storm General Discussion

[vortex95]

Four days in a row svr risk in this area, esp. this time of year?  Sure ,lots of days get upgraded to slight risk the day of and we get 4 days in a row of svr risk, but to have days 3, 4, and 5 outlooked means synoptically it is defined and impressive, which means higher-end svr wx possible.

Usually in this part of the country, you don't get multiple days in a row w/ svr wx from NW or WNW flow b/c one wave of convection and it s/w trof clears things for moisture, and it takes a bit of time to recover.  Or the front/boundary gets pushed farther and farther S w/ each wave of convection.  But the way the mid and upper level ridge is during this period looks like it may force things to be in the same general area repeatedly.  Why not?  Every so often things do work out for relentless stormy wx in a region!

One might say, "4 days in a row, *everyone* should cash in and get crushed at least once during the period!"  I hope so.  W/ an EML present, you can do some nice things during the overnight hours, esp. with crazy LTG.
 

[vortex95]

On 8/30/2026 at 8:55 AM, stormy said:

Would this EML encouragement of strong storms be more likely for the western ridges or eastern lower elevations ?

I don't know,  Many times in WNW or NW flow, mountains to the W do well, then is often a gap due to downslope flow between IAD and DCA, and then it picks up again due to the bay breeze and higher dew points E of I95,

But its not easy tell on any given days the "DC split" occurs, and w/ an EML present, that makes it more complex b/c nighttime convection is more common and often not surface-based, so downslope flow is not as much of a factor.
 

[stormy]

1 hour ago, vortex95 said:

I don't know,  Many times in WNW or NW flow, mountains to the W do well, then is often a gap due to downslope flow between IAD and DCA, and then it picks up again due to the bay breeze and higher dew points E of I95,

But its not easy tell on any given days the "DC split" occurs, and w/ an EML present, that makes it more complex b/c nighttime convection is more common and often surface-bases, so downslope flow is not as much of a factor.
 

Yesterday evening, this northwest perimeter flow developed a strong storm in southwest Augusta.

A couple locations received close to 2 inches of rain while a few miles away, little more than sprinkles.

[Kmlwx]

I'm encouraged given the favorable things in place. Then again - we have been burned many times by so many different failure methods. Will be curious to see what guidance looks like as we go forward in time and how the AI/ML guidance trends. 

[SnowenOutThere]

2 hours ago, vortex95 said:

Four days in a row svr risk in this area, esp. this time of year?  Sure ,lots of days get upgraded to slight risk the day of and we get 4 days in a row of svr risk, but to have days 3, 4, and 5 outlooked means synoptically it is defined and impressive, which means higher-end svr wx possible.

Usually in this part of the country, you don't get multiple days in a row w/ svr wx from NW or WNW flow b/c one wave of convection and it s/w trof clears things for moisture, and it takes a bit of time to recover.  Or the front/boundary gets pushed farther and farther S w/ each wave of convection.  But the way the mid and upper level ridge is during this period looks like it may force things to be in the same general area repeatedly.  Why not?  Every so often things do work out for relentless stormy wx in a region!

One might say, "4 days in a row, *everyone* should cash in and get crushed at least once during the period!"  I hope so.  W/ an EML present, you can do some nice things during the overnight hours, esp. with crazy LTG.
 

Hoping Cvill can get in on the action once the ridge starts to break down towards the weekend. 

[Kmlwx]

1 hour ago, Kmlwx said:

I'm encouraged given the favorable things in place. Then again - we have been burned many times by so many different failure methods. Will be curious to see what guidance looks like as we go forward in time and how the AI/ML guidance trends. 

Quoting myself but now settled in at the office...

My hunch is that ONE of the day performs for many of us - whether it's divided up into 2 days remains to be seen. But even with what @vortex95 said - I think most of us would be skeptical of seeing consecutive days impact the exact same areas. 

Perhaps the first day hits the M/D line counties more and skunks the rest of us, then perhaps the next day is more of the metro area(s), then a bit too far south for the bulk of the subforum the following day.

[yoda]

12z NAM soundings seem to like Wednesday evening into Thursday morning (21z to 06z).  What i mean is they suggest some significant severe if everything came together

[Kmlwx]

That NAM run also suggests the EML plume (at least somewhat) will be in play. 

[Kmlwx]

Though I will also say both the NAM and the GFS keep favoring areas to our north and east...hopefully it can bleed south. 

[yoda]

Just now, Kmlwx said:

Though I will also say both the NAM and the GFS keep favoring areas to our north and east...hopefully it can bleed south. 

Well the NAM only goes out to 84... and IIRC, SPC didnt really focus on our region severe-wise until Thursday and Friday - which is near the end of its run and after.  

[Eskimo Joe]

3 hours ago, Kmlwx said:

That NAM run also suggests the EML plume (at least somewhat) will be in play. 

Never underestimate an EML in NW flow events.

Source: https://journals.ametsoc.org/view/journals/wefo/25/4/2010waf2222363_1.xml

[high risk]

Not much to add to the ongoing discussion:  trying to place and time particular events between now and the end of the week (best chances between Wednesday morning and Friday midday?) is likely to be futile, but higher end events in the Mid-Atlantic are certainly on the table.   A taste of the potential.....

 

[vortex95]

14 hours ago, stormy said:

Yesterday evening, this northwest perimeter flow developed a strong storm in southwest Augusta.

A couple locations received close to 2 inches of rain while a few miles away, little more than sprinkles.

I have only lived in the DC area for 8 years, and I am still trying to get an overall feel for local nuances when it comes to tstms, esp. when the "DC split" occurs.  That seems more than just a random coincidence.  And it is apparent the corridor from about 30 mi W of BWI to the city is a favorable area, so is just E of I95 to the Delmarva, and it seems really apparent CHO-RIC-ORF area in terms of a "hot spot!"  Also, w-cntrl and swrn VA get some really nicely-structured supercells at times!

[vortex95]

10 hours ago, Eskimo Joe said:

Never underestimate an EML in NW flow events.

Source: https://journals.ametsoc.org/view/journals/wefo/25/4/2010waf2222363_1.xml

Yes, NW flow events are *notorious* in New England for its biggest tor events and outbreaks.  Historically, it is a little less defined in the Mid-Atlantic b/c it does well in SW flow (College Park, Sep 2001) and TC events (remains of Ivan in Sep 2004), but you have June 23, 1944 (WV hit hard) and June 2, 1998 (Frostburg MD F4).
https://www.weather.gov/lwx/events_19980602
https://www.tornadotalk.com/june-2-1998-tornado-outbreak/

And, of course, the derecho on June 29, 2012.  I think an EML present is important for high-end derechos.
 

[high risk]

39 minutes ago, vortex95 said:

And, of course, the derecho on June 29, 2012.  I think an EML present is important for high-end derechos.
 

 

         I'd say that there isn't much doubt about it, especially in the East.    We've had several derechos over the year die an ugly death over the mountains to our west when no EML was in place downstream.   One event in 2000 led SPC to issue a rare PDS severe thunderstorm watch here due to an intense bow echo over southeast Ohio blasting east.    Our environment did not have an EML, and the Appalachians shredded the system - we ended up with line of showers featuring gusts to 30 kt.

 

[vortex95]

It appears today will remain capped.  HRRR and RRFS have next to nothing.  700 temps warm from around 8C at 06z to 11 C by 00z and 1000-500 thk gets to 580, so that should cap things off.

However, some nocturnal action appears possible as the BDF approaches from the NE.  The RRFS MPAS looks impressive at 03z.  It is on its own, but look at the MUCAPE axis on the HRRR at 07z Wed.

And Wed aftn looks good w/ the front NNW to SSE across the areas.  Surprised SPC does not have at least 2% tor risk in the area.
 

 

[Kmlwx]

SPC discusses potential/conditional need for CIG1 and higher probabilities for D2 depending on timing and such.