2026 Mid-Atlantic Severe Storm General Discussion

[vortex95]

15 hours ago, wxmeddler said:

I maintain that SVR-Considerable with Tor Possible wording would have sufficed. 65 mph EF-0 is only 5 mph over base SVR. I don't believe there was any threat beyond a QLCS spinup of what we saw, and that took the open water and maybe a boundary to make it happen. 

Yes, the ""tor psbl" tag gives a lot more leeway yet covers the threat just the same.  It is a good "in-between" and works b/c now we know there are so many little spin-ups in SQLN situations.  Some are very transient, but still can do damage.  Then you have gustnadoes w/ can be up to EF1 strength, but do not count as tornadoes unless they connect to the cloud base, which often not easy to determine in the more moist environment and less visibility compared to the Plains.
 

[Kmlwx]

Sunday still looks like it has a chance. Maybe next Thursday too? 

[Kmlwx]

CSU MLP has a decent area of 5+% TOR for Sunday. 

[vortex95]

4 hours ago, Kmlwx said:

CSU MLP has a decent area of 5+% TOR for Sunday. 

Can you provide a link to the CSU MLP?

[George BM]

34 minutes ago, vortex95 said:

Can you provide a link to the CSU MLP?

https://schumacher.atmos.colostate.edu/hilla/csu_mlp/csu_severe.php

[SnowenOutThere]

That storm in cvill is tor warned and seemingly has a debris ball on radar. 

[yoda]

Oh ok

499
NWUS51 KLWX 142303
LSRLWX

Preliminary Local Storm Report
National Weather Service Baltimore MD/Washington DC
703 PM EDT Fri Aug 14 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0541 PM     Hail             2 E Charlottesville     38.04N  78.44W
08/14/2026  M2.50 inch       Albemarle          VA   Local Official

            Also reports of hail damage to vehicles at the same
            location.


&&

Event Number LWX2608205

[yoda]

8 hours ago, Kmlwx said:

CSU MLP has a decent area of 5+% TOR for Sunday. 

LWX seems to be hitting the threat a bit harder in this afternoon AFD 

DISCUSSION...
KEY MESSAGE 1...Severe thunderstorms and some instances of flash
flooding are possible on Sunday.

Some residual convective activity may be ongoing on Sunday
morning. This remains to be seen and will be guided by the
degree of overnight instability and boundary placement. How the
atmosphere recovers through the day should ultimately dictate
the degree of severe thunderstorm threat during the core diurnal
heating hours. The ingredients are certainly present for a more
impactful event if meteorological parameters all come together.

Looking a bit more closely at this event, a broad mid/upper
ridge persist across the Four Corners eastward to the
southwestern Atlantic. Amplified flow north of this expansive
anticyclone will continue to be a conduit to active convection,
many in the form of mesoscale convective systems (MCS). As
mentioned above, a remnant MCS might still be ongoing early
Sunday across the region. While above average heights persist,
expect some non-zero height falls to cross the area in response
to an approaching shortwave. Within this northwesterly flow
aloft, vertical shear is ample for the time of year, generally
around 30 to 35 knots. Depending on model choice, mixed-layer
CAPE values approach 1,500 to 2,500 J/kg. The combination of
these two will easily support a risk of severe weather. While
damaging wind gusts are the most likely threat, other severe
types loom if storms can remain discrete in nature.

Additionally, a Slight Risk for excessive rainfall continues
along much of the Alleghenies eastward along/north of I-66/U.S.
50. Precipitable water values rise markedly, possibly into the 2
to 2.25 inch range. While a single thunderstorm will be capable
of torrential downpours, the bigger threat would be for repeat
and/or training convection. The latter potential exists which
supports the flash flood risk. Although drought continues over
much of the region, many areas have seen a one category
improvement over the past week. Convection will likely be
ongoing into Sunday night with the cold front not passing
through until early Monday.

[high risk]

10 hours ago, yoda said:

LWX seems to be hitting the threat a bit harder in this afternoon AFD 

There are things to like for Sunday for sure, but a morning MCS appears fairly likely, which would wreck afternoon chances, except perhaps for southern areas.    Probably more of a heavy rain event for most of us, unless the MCS is fake or delayed. 

[yoda]

1 hour ago, high risk said:

There are things to like for Sunday for sure, but a morning MCS appears fairly likely, which would wreck afternoon chances, except perhaps for southern areas.    Probably more of a heavy rain event for most of us, unless the MCS is fake or delayed. 

Understood, but seems LWX disagrees in their morning AFD?  Or am I misreading?

 

In addition to any heavy rain threat is the potential for bands
of strong to severe thunderstorms. Increased flow down into the
low levels would be favorable for organized line segments
capable of mixing down damaging wind gusts in any organizing
cold pools. The saturated profiles could result in water loading
downdrafts, though the lack of mid-level dry air may keep DCAPE
low putting a ceiling on just how high damaging wind gusts can
get (most likely in the 50-65 mph range). The increased low-
level flow and SRH coupled with moist profiles could lend to the
threat of a few tornadoes as well.

Although the prospect of early morning clouds and precip may at
first glance seem to preclude a higher potential for heating and
severe weather later in the day, the high low-level moisture
content coupled with steady height falls aloft means that
heating will not need to be as robust to result in sufficient
CAPE for strong to severe convection, especially given the shear
that will be present.

Some severe weather or flood threat may persist into the night
given the above listed factors.

[WxUSAF]

More recent guidance leaning toward morning rain, perhaps a brief break early afternoon, and then more storms later in the afternoon and evening.  Juicy precip totals.  

[vortex95]

I don't think the AM convection Sunday will be a detriment for later.  There is solid support for the aftn-eve w/ a 700/500 trof moving in.  PWATs increase in the aftn to as high 2.5" on the GFS/ECMWF/NAM, and there is very good directional shear w/ nicely looped hodographs and strong veering 925/850 to 700/500.  Wind fields 925-500 ramp up in the aftn to 35-40 kt at all these levels.  So supercells likely and the 2% tor risk is warranted.  Could see upgraded to 5% given the strength of the 925 winds (30 kt+ is excellent and we have it fcst as high as 40 kt).

Everything moves steadily W to E, unlike the previous events that were NW to SE and that pushed all the moisture and boundary focus S, so solid recovery for instability after the AM convection is a good bet.

FF threat, as noted, is there are well.  RRFS is quite aggressive for cntrl and nrn VA showing up to 7.5" of rain.  This model tends to overdo things, but 4" in some locations high prob IMHO.
 

[Eskimo Joe]

2 hours ago, vortex95 said:

I don't think the AM convection Sunday will be a detriment for later.  There is solid support for the aftn-eve w/ a 700/500 trof moving in.  PWATs increase in the aftn to as high 2.5" on the GFS/ECMWF/NAM, and there is very good directional shear w/ nicely looped hodographs and strong veering 925/850 to 700/500.  Wind fields 925-500 ramp up in the aftn to 35-40 kt at all these levels.  So supercells likely and the 2% tor risk is warranted.  Could see upgraded to 5% given the strength of the 925 winds (30 kt+ is excellent and we have it fcst as high as 40 kt).

Everything moves steadily W to E, unlike the previous events that were NW to SE and that pushed all the moisture and boundary focus S, so solid recovery for instability after the AM convection is a good bet.

FF threat, as noted, is there are well.  RRFS is quite aggressive for cntrl and nrn VA showing up to 7.5" of rain.  This model tends to overdo things, but 4" in some locations high prob IMHO.
 

12z HRRR had a general 1" - 2" regionwide, with a narrow strip of 3" - 4" near Laurel.

[Eskimo Joe]

18z HRRR lights up NOVA with 3" - 5" of rain tomorrow

[vortex95]

4 minutes ago, Eskimo Joe said:

18z HRRR lights up NOVA with 3" - 5" of rain tomorrow

18z RRFS is the same.  Both models show more than one wave of storms after the AM convection.

I like the significant sfc dew point advection tomorrow aftn over the region

[batmanbrad]

On 8/14/2026 at 10:25 AM, Kmlwx said:

CSU MLP has a decent area of 5+% TOR for Sunday. 

As of this morning's output, they seem to be holding onto the 5-10% TOR for our area tomorrow...

[vortex95]

1030pm last night.  Dang!  Ton of CGs as well.
 

[Eskimo Joe]

37 minutes ago, vortex95 said:

18z RRFS is the same.  Both models show more than one wave of storms after the AM convection.

I like the significant sfc dew point advection tomorrow aftn over the region

That's a recipe for someone to get soaked.

[Eskimo Joe]

The Canadian tries to paint a 2" - 3.5" stripe of rainfall right along Mason-Dixon tomorrow afternoon. South of I-70 is less than an inch.

[vortex95]

4 minutes ago, Eskimo Joe said:

That's a recipe for someone to get soaked.

And it shows solid destabilization despite lots of clouds.  You can do a lot more for CAPE by adding to the dew point than temp per deg.  GFS has DCA 69 dew point at 15z up to 74 by 00z.  Also it backs the sfc winds to SSE.  This is w/ WNW winds at 500 so that's over 90 deg veering sfc-500.  That should mean robust supercells.

Speed shear is common here but good directional shear is not so this may be a best tor risk of the year so far Sunday.

[high risk]

6 hours ago, vortex95 said:

I don't think the AM convection Sunday will be a detriment for later.  There is solid support for the aftn-eve w/ a 700/500 trof moving in.  PWATs increase in the aftn to as high 2.5" on the GFS/ECMWF/NAM, and there is very good directional shear w/ nicely looped hodographs and strong veering 925/850 to 700/500.  Wind fields 925-500 ramp up in the aftn to 35-40 kt at all these levels.  So supercells likely and the 2% tor risk is warranted.  Could see upgraded to 5% given the strength of the 925 winds (30 kt+ is excellent and we have it fcst as high as 40 kt).

Everything moves steadily W to E, unlike the previous events that were NW to SE and that pushed all the moisture and boundary focus S, so solid recovery for instability after the AM convection is a good bet.

FF threat, as noted, is there are well.  RRFS is quite aggressive for cntrl and nrn VA showing up to 7.5" of rain.  This model tends to overdo things, but 4" in some locations high prob IMHO.
 

Everything you said about the environment later tomorrow is spot on, but the one parameter you left out is cape, and that could certainly prevent a bigger day tomorrow.   There is certainly solid model consensus for a “round 2” of storms later Sunday, but forecast soundings don’t look great.  I certainly agree, though, that IF we can destabilize, supercells and tornadoes are on the table. Otherwise, it’s a noisy heavy rain event. 

[SnowenOutThere]

I’m finally coming back from Madison WI tonight/tomorrow so excited to see how it plays out. I think tomorrow might be okay. Already earlier this week we say some strong supercells hit along I-64.  

[vortex95]

1 hour ago, high risk said:

Everything you said about the environment later tomorrow is spot on, but the one parameter you left out is cape, and that could certainly prevent a bigger day tomorrow.   There is certainly solid model consensus for a “round 2” of storms later Sunday, but forecast soundings don’t look great.  I certainly agree, though, that IF we can destabilize, supercells and tornadoes are on the table. Otherwise, it’s a noisy heavy rain event. 

I am thinking the dew point advection will be enough in the aftn.  They all show a finger of high CAPE (HRRR shows up to 4500, but that seems overdone, GFS and ECMWF have 2500 max) to n-cntrl VA, stopped just W of DC (really close, only about 20 mi W).  So there is good CAPE available, just not widespread.

It appears there will be a N-S warm or stationary front bisecting VA Sun aftn.  Look at the HRRR fcst for 21z Sunday.  That is quite a temp gradient, and such a boundary is ripe for tornadogenesis.  Any storm crossing or latching on to such a boundary can go tornadic very quickly.  Even on the cooler side, it can be favorable a short distance in b/c the cooler air is very shallow so a supercell is still effectively sfc-based.

[SnowenOutThere]

Seems that the MCS in Ohio is doing rather well with the 0z NAM initializing it correctly. Should roll through around mid-morning and bring some nice rainfall/storms with it. The soundings for the afternoon are impressive kinematically but lack instability despite our 70 degree dewpoints. I think it'll be a day where if a cell manages to pop ahead of the evening/nighttime line of storms it could produce a TOR. Only question is if/how many will happen. 

[Kmlwx]

Cloudy and dreary is the theme today (so far). Not seeing much clearing potential on visible sat either. But we'll see if we can get robust convection later with dewpoints being high. 

[vortex95]

16 minutes ago, Kmlwx said:

Cloudy and dreary is the theme today (so far). Not seeing much clearing potential on visible sat either. But we'll see if we can get robust convection later with dewpoints being high. 

Yes, quite stable looking w/w a mid level deck (almost asperitas).  However, there is instability above that, as evidenced by the sharp showery nature of the rain, Driving a short time ago, I'd literally hit a wall of rain, but the shafts are very narrow.  Drove another 500 ft, and it would just stop!   No vis reduction. And the rain was heavy not b/c of big drops, but the density was very high, so warm rain process and shows how tropical juiced things are!

I did not like that the 12z HRRR showed almost nothing for the DC area this aftn, but the 13 and 14z runs bring it all back.  Not quite as intense as say the 00 and 06z runs, but at this point, we'll just have to see how the mesoscale details work.

Due to the rain and cloud cover, hard to tell if this is any real front across the region.  Winds are all generally light S from the PA border and S.  No real temp gradient either, all in the mid-upper 70s.  No 80 until RIC and that just SE of there.  Still early though.  The AM convection is on schedule and modeled well.

[Kmlwx]

The RRFS looked pretty good too. I feel like it has tended to be very bullish on convection this season. 

[batmanbrad]

CSU-MLP latest still painting the maximum TOR possibilities right over the general DC area:

[vortex95]

Just now, Kmlwx said:

The RRFS looked pretty good too. I feel like it has tended to be very bullish on convection this season. 

It loves to make giant convective blobs on its composite reflectivity fcst.  Once it goes operational, and ppl use it more, I bet that will be a sig complaint, and they will address it.

A big issue w/ mesoscale models now is that the more hires they get and more directly simulate the atmosphere processes, the challenge to get everything in balance goes up in a non-linear fashion.  In other words, any small tweak to fix one issue can have big impacts to another part of the model.
 

[Kmlwx]

2 minutes ago, vortex95 said:

It loves to make giant convective blobs on its composite reflectivity fcst.  Once it goes operational, and ppl use it more, I bet that will be a sig complaint, and they will address it.

A big issue w/ mesoscale models now is that the more hires they get and more directly simulate the atmosphere processes, the challenge to get everything in balance goes up in a non-linear fashion.  In other words, any small tweak to fix one issue can have big impacts to another part of the model.
 

Good demonstration of how more resolution is not always automatically "better." 

There's probably a "happy medium" where errors can be smoothed while still having good resolution...but I imagine if we had like 0.25km resolution models it would be chaotic at best. Until better computing comes along I guess.