2026 Mid-Atlantic Severe Storm General Discussion

[SnowenOutThere]

29 minutes ago, Kmlwx said:

Not saying it will happen, but every now and then a lower parameter day will surprise and out perform the prior day. Always fun because it just goes to prove microscale stuff sometimes just says F known science and does its own thing!

I want to clarify, it’s not that parameters are even bad. It’s more so a “meh” environment compared to the powderkeg yesterday was. Do agree that outflow boundaries could help out too.   

[Eskimo Joe]

2 hours ago, Kmlwx said:

Not saying it will happen, but every now and then a lower parameter day will surprise and out perform the prior day. Always fun because it just goes to prove microscale stuff sometimes just says F known science and does its own thing!

This evening has all the hallmarks of an overperformer for a select few:

• Less of a cap at 700 mb
• Multiple remnant boundaries
• Pooling of low level moisture (dews have come back up a few degrees)
• Slightly better shear aloft per SPC meso analysis

[frd]

Interesting cell in SW De. Moving North at 15 mph.

 

Severe Weather Statement
National Weather Service Mount Holly NJ
526 PM EDT Sun Jul 5 2026

DEC001-005-052200-
/O.CON.KPHI.SV.W.0146.000000T0000Z-260705T2200Z/
Sussex DE-Kent DE-
526 PM EDT Sun Jul 5 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR NORTHWESTERN SUSSEX AND SOUTHWESTERN KENT COUNTIES...

At 526 PM EDT, a severe thunderstorm was located near Andrewsville,
or 14 miles northwest of Georgetown, moving north at 15 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is
         possible.

Locations impacted include...
Milford, Harrington, Bridgeville, Andrewsville, Greenwood, Houston,
and Farmington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Mount Holly NJ.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3874 7547 3873 7570 3898 7573 3896 7545
TIME...MOT...LOC 2126Z 176DEG 13KT 3881 7560

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

 

 

[WxUSAF]

STW posted

[Terpeast]

Seeing outflow boundaries from the south and NE, hoping they collide over mby to give me much needed rains

[TSSN+]

Can’t buy a break around here. Missed yesterdays rain and missing everything around my by 2-3 miles. 0” here 3 miles away 1.8” in last hour lol 

[vortex95]

11 hours ago, Kmlwx said:

Really interesting storm movement yesterday too!

When you have light/weak winds 500 mb and below, chaotic storm motion is common.  Mesoscale factors such as storm rotation, outflow boundaries, and cell back-building (discrete propagation) can take front and center, so you get all sorts of odd storm motion.  This is basically what you see almost every day in the summer in the Southeast and Gulf Coast states!

We saw the same thing today, esp. w/ that svr storm W of Columbia.  Hardly moved at first and then started to drift/build S.

I attached a short loop of the W of Columbia svr storm.  Also, the CG LTG was intense w/ this storm (plot attached).

I think this storm was briefly a supercell before it gusted out.  It split as well, indicating rotation.  See the storm to its N moving NE fairly quickly?  That's a left (anticyclonic) supercell split!  You can tell b/c of it flared look NW to SE yet moving NE.  When a supercell splits, the mesocycylonic split slows down and turns more to the right, while the anticyclonic split accelerates and moves more to the left (in the Northern Hemisphere).
 

[vortex95]

Pasadena MD 7/5.  Listen w/ headphones/earbuds for the full effect!
https://www.facebook.com/reel/2524504421303837
 

[Kmlwx]

@vortex95 - It sure looked like it had a bit of the "supercellular look" looking west from Odenton. Sadly didn't get any pictures - heck of a storm once it got to Odenton, though. Some shutters were torn off the condo building! 

[yoda]

Hmmm... its way out there... but interesting...

Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0400 AM CDT Mon Jul 06 2026

   Valid 091200Z - 141200Z

   ...DISCUSSION...
   Medium-range model output continues to indicate the evolution of an
   increasingly prominent mid/upper high across the lower Colorado
   Valley and Plateau late this week into next weekend, which may
   continue expanding and encompassing a significant portion of the
   interior U.S. by early next week.  How far north and northeast this
   builds remains unclear;  however, a plume of very warm elevated
   mixed layer air advecting on strengthening flow around the northern
   through northeastern periphery of this anticyclonic regime will
   contribute to an environment conditionally conducive to organized
   severe thunderstorm development.  

   It appears that this could focus anywhere from the central
   Canadian/U.S. border vicinity through the Great Lakes into the
   Northeast.  By early next week (the Day 8-9 time frame), in
   particular, at least some output suggests that a vigorous short wave
   trough rounding the ridge may be accompanied by strong cyclogenesis,
   which could promote widespread strong to severe thunderstorm
   development across parts of New England into northern Mid Atlantic. 
   Given the uncertainties associated with the extended time frame and
   model spread/discrepancies, severe weather probabilities remain less
   than 15 percent for this period, but it is possible that this could
   change sometime in later outlook updates for this period.

   ..Kerr.. 07/06/2026

 

[SnowenOutThere]

14 hours ago, vortex95 said:

When you have light/weak winds 500 mb and below, chaotic storm motion is common.  Mesoscale factors such as storm rotation, outflow boundaries, and cell back-building (discrete propagation) can take front and center, so you get all sorts of odd storm motion.  This is basically what you see almost every day in the summer in the Southeast and Gulf Coast states!

We saw the same thing today, esp. w/ that svr storm W of Columbia.  Hardly moved at first and then started to drift/build S.

I attached a short loop of the W of Columbia svr storm.  Also, the CG LTG was intense w/ this storm (plot attached).

I think this storm was briefly a supercell before it gusted out.  It split as well, indicating rotation.  See the storm to its N moving NE fairly quickly?  That's a left (anticyclonic) supercell split!  You can tell b/c of it flared look NW to SE yet moving NE.  When a supercell splits, the mesocycylonic split slows down and turns more to the right, while the anticyclonic split accelerates and moves more to the left (in the Northern Hemisphere).
 

Agree that it could’ve been supercellular. The interesting thing I saw with the hodographs for yesterday is how the low level winds did show some shear, while of course there was no upper level support. Would make sense you get storms that rotate a bit at the low level then build up and fall down once they reach the high level without any wind shear. 

[dailylurker]

The sun has been out for the past 30 minutes and the temps and wind have definitely increased. 

[frd]

27 minutes ago, dailylurker said:

The sun has been out for the past 30 minutes and the temps and wind have definitely increased. 

Its a swamp out there. The NW flow pattern seems to be gone. 

[BlizzardNole]

This FFW from NE VA shows how crazy heavy these storms can be when they sit over one area!

Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 1 and 1.5 inches of
  rain have fallen. The expected rainfall rate is 3 to 5 inches in 1
  hour. Additional rainfall amounts of 2 to 4 inches are possible in
  the warned area. 

[vortex95]

11 hours ago, SnowenOutThere said:

Agree that it could’ve been supercellular. The interesting thing I saw with the hodographs for yesterday is how the low level winds did show some shear, while of course there was no upper level support. Would make sense you get storms that rotate a bit at the low level then build up and fall down once they reach the high level without any wind shear. 

Good info.  In weak flow when there is lots of storms firing and chaotic, the sheer number of mesoscale factors going at once inevitably leads to a very local environment that can support a supercell for a short time.  FL this time of year, all those storms that fire daily, those isolated wind or tornado events you see, are due to the numerous storm interactions.  But it's impossible to fcst this b/c such small-scale factors can not be accounted for in the models.  It's so conditional and variable!

In certain cases, you can get an intense tornado in wind profile that doesn't look conducive at all.  This occurs most often when you have huge amounts of CAPE (5000+) and a weak front or boundary present.  A storm can fire and if it deviates a lot (more than 90 deg) from the environmental wind flow by virtue of back-building along the front/boundary, it can become a strong supercell.  So even though the environmental helicity is low, the storm-relative helicity is large, and an intense tornado can result.

The two most striking examples of this was the Plainfield IL Aug 28, 1990 and Jarrell TX May 27, 1997 events.  Both devastating F5s and the storms deviated a very hard right w/ CAPE ~7000 present.

[vortex95]

16 hours ago, yoda said:

Hmmm... its way out there... but interesting...

Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0400 AM CDT Mon Jul 06 2026

   Valid 091200Z - 141200Z

   ...DISCUSSION...
   Medium-range model output continues to indicate the evolution of an
   increasingly prominent mid/upper high across the lower Colorado
   Valley and Plateau late this week into next weekend, which may
   continue expanding and encompassing a significant portion of the
   interior U.S. by early next week.  How far north and northeast this
   builds remains unclear;  however, a plume of very warm elevated
   mixed layer air advecting on strengthening flow around the northern
   through northeastern periphery of this anticyclonic regime will
   contribute to an environment conditionally conducive to organized
   severe thunderstorm development.  

   It appears that this could focus anywhere from the central
   Canadian/U.S. border vicinity through the Great Lakes into the
   Northeast.  By early next week (the Day 8-9 time frame), in
   particular, at least some output suggests that a vigorous short wave
   trough rounding the ridge may be accompanied by strong cyclogenesis,
   which could promote widespread strong to severe thunderstorm
   development across parts of New England into northern Mid Atlantic. 
   Given the uncertainties associated with the extended time frame and
   model spread/discrepancies, severe weather probabilities remain less
   than 15 percent for this period, but it is possible that this could
   change sometime in later outlook updates for this period.

   ..Kerr.. 07/06/2026

 

Looks like we stay in semi-active to active period for the region UFN.  Showers and tstms every day in some form in at least parts of region thru Sat and maybe Sun.  GFS and ECMWF are a lot different for Sun. The GFS has a much stronger trough at 500 and actually develops a small nor'easter offshore.  ECMWF nothing at all.  The GFS solution suggests a lot of rain.  Svr risk for the region highly dependent on where the sfc low tracks.

Longer-range, it appears the mean trough position will remain in place in the E, so should be decent chances for some sig tstm events.  Last July was quite good, but ugh, next to nothing in Aug, and quite cool much of the time.  Actually had some cold air damning a few times IIRC!
 

[frd]

8 hours ago, vortex95 said:

Longer-range, it appears the mean trough position will remain in place in the E, so should be decent chances for some sig tstm events.  Last July was quite good, but ugh, next to nothing in Aug, and quite cool much of the time.  Actually had some cold air damning a few times IIRC!

Things were much greener last July.  These excessive 100 degree days has stressed a lot of the plants here and the lawns. Recent dew points and exceptional heat has started some blight in tomato plants. 

The WPC has increased rainfall in the 3 day, 5 day and 7 day outlooks.  Not sure its the Nino starting so early, but I will take it. 

Also, in regards to severe potential, the 10 th and the 15/16 th look interesting on machine learning NSSL

 https://x.com/TylerSebreezy/status/2074470678669992148

 

Day-by-day NSSL machine-learning severe probabilities for the next 2 weeks below highlight severe potential lare this week and this weekend into next week with a potential upper-level ridge pattern setting up in the Plains.

 

 

 

 

 

[vortex95]

11 hours ago, frd said:

Things were much greener last July.  These excessive 100 degree days has stressed a lot of the plants here and the lawns. Recent dew points and exceptional heat has started some blight in tomato plants. 

The WPC has increased rainfall in the 3 day, 5 day and 7 day outlooks.  Not sure its the Nino starting so early, but I will take it. 

Also, in regards to severe potential, the 10 th and the 15/16 th look interesting on machine learning NSSL

 https://x.com/TylerSebreezy/status/2074470678669992148

 

Day-by-day NSSL machine-learning severe probabilities for the next 2 weeks below highlight severe potential lare this week and this weekend into next week with a potential upper-level ridge pattern setting up in the Plains.

 

 

 

 

 

If we can get a solid EML (elevated mixed layer) to advect in from the Plains/Midwest, things could be really potent.  Big hot ridges to our W w/ WNW or NW flow aloft here is about the only way this can be done.

One thing w/ EMLs is that overnight tstms are much more common and more intense.  Diurnal heating means little w/ you have lots of elevated CAPE.  It's why there are so many overnight intense MCSs in the Plains/Midwest, and the LTG displays are incredible.  Not necessarily more CC or CG bolts, but the IC flickering is often amazing, esp. in the mid and upper parts of the CBs.

[SnowenOutThere]

2 hours ago, vortex95 said:

If we can get a solid EML (elevated mixed layer) to advect in from the Plains/Midwest, things could be really potent.  Big hot ridges to our W w/ WNW or NW flow aloft here is about the only way this can be done.

One thing w/ EMLs is that overnight tstms are much more common and more intense.  Diurnal heating means little w/ you have lots of elevated CAPE.  It's why there are so many overnight intense MCSs in the Plains/Midwest, and the LTG displays are incredible.  Not necessarily more CC or CG bolts, but the IC flickering is often amazing, esp. in the mid and upper parts of the CBs.

A question I’ve wondered about for a while is if our area always benefits from emls. The tor threat way back in March had a weak one and it kneecapped our cape. It seems that sometimes that temperature increase (or slower rate of decrease) does more harm than it helps. 

[vortex95]

1 hour ago, SnowenOutThere said:

A question I’ve wondered about for a while is if our area always benefits from emls. The tor threat way back in March had a weak one and it kneecapped our cape. It seems that sometimes that temperature increase (or slower rate of decrease) does more harm than it helps. 

EMLs are tricky.  They are most prevalent and strongest when the atmosphere is very warm ("warm" being relative to the time of year).  This mean things are often capped.  So despite tons of CAPE and shear, no storms will develop.  But if you storms to fire, then you have a primed environment for svr storms.

Weak EMLs are often present, w/ mid-level lapse rates 6.5-7.0 C/km, in many tstm days here.  However, you want to see at least 7.0 C/km solid for noticeable results or differences.  And just a 0.5 C/km difference is huge b/c the range is small.  The dry adiabatic lapse rate is 9.8 C/km and the moist adiabatic lapse rate varies depending on temp and moisture, but in the warm season, anything under 6.0 C/km is not good (it does not mean you can't get big storms though).  Generally, look for greater than 7.0 C/km at mid-levels in a fairy thick layer on an observed or fcst model sounding.

On the models for mid-level lapse rates, they use 700-500 mb.  However, that can be misleading.  You may have at 150 mb thick EML between those two levels, or say from 750-550 mb, and this qualifies.

EMLs do a couple of things that lead to better storms.

1) EMLs promote elevated CAPE, and this CAPE exists independent of diurnal effects, so loss of daytime heating is not as much a factor.  And during the day before the convective temp is reached, you already have CAPE aloft just waiting to be tapped, and links w/ building sfc-based CAPE.  In the end, you get considerably stronger updrafts in CBs.

2) Where an EML exists is often the best hail growth zone in a CB, so hail at the sfc and/or larger hail is more likely (steep lapse rates and higher mid-level CAPE mean more vigorous updrafts at mid-levels).

3) And along the same lines as above, the EML can be in or close to the mixed phase layer of the CB where charge separation occurs the most, so that means more LTG, esp. in-cloud LTG.

Solid EMLs on the East Coast are not common, at least those that occur in sync w/ proper low-level moisture and dynamics/forcing to result in significant svr wx events.  Two of the biggest ideal EML events are June 23, 1944 Mid-Atlantic tornado outbreak and the June 8-9, 1953 Great Lakes-New England tornado outbreaks.  Another one was July 10, 1989, which is the record for most tornadoes in a single day in New England.  That day I experienced first-hand, and that’s when I took note of the EML factor.  IAD sounding 00z on the 11th had a distinct EML present.  However S of NYC, not storms occurred b/c it was capped.

So for the Mid-Atlantic and Northeast's biggest tornado events, typically a solid EML is present, but everything else has to line up almost perfectly for an actual high-end event.

In general, having an EML present is a good thing if you want more intense tstms and more overnight storms.

I really like what I see coming up for the CONUS 500 pattern.  Big hot ridge to our W and we are in persistent WNW or NW flow aloft.  This is how you advect a solid EML from the Plains to the East Coast, and WNW or NW flow historically had led some of the biggest svr wx outbreaks in the summer months for the Mid-Atlantic and Northeast.
 

[Deep Creek]

On 7/5/2026 at 8:20 PM, TSSN+ said:

Can’t buy a break around here. Missed yesterdays rain and missing everything around my by 2-3 miles. 0” here 3 miles away 1.8” in last hour lol 

Same thing here, unfortunately. Measured 0.17” since Friday. The other day was plastered with flood warnings just a few miles west, south, and east of me, yet we were sandwiched in between and got nada.

[WxUSAF]

Upgrade to slight for tomorrow for DC and points east?