2026 Mid-Atlantic Severe Storm General Discussion

[yoda]

Tagged day 4... mentioned again on days 7 and 8

 

 

ZCZC SPCSWOD48 ALL ACUS48 KWNS 110852 SPC AC 110852 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0352 AM CDT Thu Jun 11 2026 Valid 141200Z - 191200Z ...DISCUSSION... ...Day 4/Sunday... The 00z models have trended toward a much stronger short-wave trough and associated mid-level jet, which will progress from the Great Lakes and OH Valley into the Northeast. Elsewhere, a short-wave trough is forecast to move from the northern Rockies into the central Plains. At the surface, a cold front attendant to the Northeast short-wave trough will move through that region with the trailing extension of the boundary pushing south through the OH and TN Valleys into the Gulf Coast states. A much stronger low-level jet is now forecast ahead of the cold front across the Northeast, which will aid in greater air mass destabilization than indicated in previous model runs. When coupled with notably stronger vertical shear, the setup appears favorable for organized severe storms across the Mid-Atlantic, potentially into southern New England Sunday afternoon and evening. ...Day 5/Monday... The models suggest the Sunday/central Plains short-wave trough will progress through the mid MS into OH Valleys with an associated belt of enhanced mid-level flow stretching from the central Plains into Mid-Atlantic. At the surface, there is good model agreement that the primary synoptic front and associated warm sector will lie across TX and the Gulf Coast states, to the south of the stronger mid-level winds and forcing for ascent. Some severe-weather threat may develop along and south of the front; however, the marginal vertical shear is expected to limit the overall severe-weather threat. Slightly stronger vertical shear is forecast across the central and southern High Plains, due to an easterly upslope regime in the low-levels. While the potential for more organized storms will exist in that region, severe-weather coverage may only be isolated. ...Day 6/Tuesday... The ensemble mean and deterministic models are suggestive that a mid-level disturbance will track from the central Plains into the lower OH and TN Valleys, contributing to overall amplification of the long-wave trough in place east of the Rockies. The primary surface front is expected to remain in place across the Gulf Coast states, to the immediate south of the stronger forcing for ascent and mid-level flow. While isolated occurrences of severe weather appear possible from the southern High Plains into Southeast, the potential for an organized severe-weather event remains in question. ...Days 7-8/Wednesday and Thursday... The ensemble means indicate the progression of a strong mid-level jet streak into the northern and central Plains Wednesday with that feature moving through the OH Valley into Mid-Atlantic Thursday. At the surface, the ensemble member low positions indicate clustering across the northern Plains and upper MS Valley Wednesday, and across the Great Lakes into Ontario on Thursday. The rapid poleward return of a moist and unstable air mass is expected to occur ahead of the surface low and associated frontal system. As such, some severe weather appears possible across parts of the Midwest Wednesday, and perhaps OH Valley into Mid-Atlantic Thursday. ..Mead.. 06/11/2026

 

 

[high risk]

Any show today looks to be a late one, per the overnight CAMs.   There does seem to be a modest consensus that a broken line will approach from the northwest around sunset, and the environment should support maintenance of the activity for several hours beyond peak heating.  As for Friday, instability looks great, but shear is not good.   Storm organization should be sufficient for some severe threat, but the current CAM consensus keeps all storms later Friday from DC to the south.

[Eskimo Joe]

SPC mesonalayis is pretty loaded at 10:30 am for us. Incredible surface CAPE, stouts LI's, and decent low level lapse rates. Only thing lacking is shear. If something fires up today it'll have a solid airmass to work with.

Hmm...even some decent mid level lapse rates west of I-81. I wonder if we have a bit a remnant EML trying to crest the mountains?

[yoda]

11 minutes ago, Eskimo Joe said:

SPC mesonalayis is pretty loaded at 10:30 am for us. Incredible surface CAPE, stouts LI's, and decent low level lapse rates. Only thing lacking is shear. If something fires up today it'll have a solid airmass to work with.

Hmm...even some decent mid level lapse rates west of I-81. I wonder if we have a bit a remnant EML trying to crest the mountains?

LWX did mention this too in their AFD 

On the mesoscale, will have to monitor the evolution of an MCV
associated with severe early morning storms over IL/IN as it
moves east toward the region late this afternoon, and how that
interacts with the above mentioned lifting mechanisms (not to
mention any residual outflow from the early morning PA MCS). It
is plausible that these features enhance convective development
by resulting in slightly higher forcing and perhaps some subtly
enhanced mid-level flow. This would result in more widespread
storms and an uptick in damaging wind potential locally.

 

[Eskimo Joe]

5 minutes ago, yoda said:

LWX did mention this too in their AFD 

On the mesoscale, will have to monitor the evolution of an MCV
associated with severe early morning storms over IL/IN as it
moves east toward the region late this afternoon, and how that
interacts with the above mentioned lifting mechanisms (not to
mention any residual outflow from the early morning PA MCS). It
is plausible that these features enhance convective development
by resulting in slightly higher forcing and perhaps some subtly
enhanced mid-level flow. This would result in more widespread
storms and an uptick in damaging wind potential locally.

Probably why the 30% wind was added.

[Kmlwx]

The HRRR which had looked impressive for tomorrow afternoon no longer does with the 12z run - unless you are south of DC. 

[Eskimo Joe]

LI's of -9, solid low level lapse rates, and healthy CAPE. If only we had 30-40 kts of shear, we'd be cooking.

[yoda]

Mesoscale Discussion 1087
   NWS Storm Prediction Center Norman OK
   1127 AM CDT Thu Jun 11 2026

   Areas affected...western Pennsylvania...eastern Ohio...western
   Maryland...north-central Virginia...and much of West Virginia

   Concerning...Severe potential...Watch possible 

   Valid 111627Z - 111830Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Increasing thunderstorm coverage is anticipated across the
   region through early afternoon. The main risk will be severe wind
   gusts, and perhaps some hail. A severe thunderstorm watch may be
   warranted to cover these threats.

   DISCUSSION...Amidst a relatively zonal (if not slightly ridged)
   upper-air pattern, a subtle impulse is noted in water vapor imagery
   over western Lake Erie and central OH as of 1600z. Associated
   mesoscale ascent is contributing to increasing mid-level cloudiness
   in the area. Closer to the surface, diurnal heating and warm, moist
   advection with southwesterly surface flow is driving temperatures
   and dewpoints into the low-/mid- 80s and 70s F, respectively. The
   12z PIT (Pittsburgh, PA) sounding showed steeper lapse rates around
   1-3 km AGL (up to around 7 C/km) that decrease with height, and bulk
   shear around 20-25 kts.

   Over the next couple of hours, this modest westerly shear should
   persist as the mid-level impulse moves through. Associated forcing
   and diurnal destabilization should yield scattered thunderstorm
   development through the early afternoon. Relatively large CAPE
   values (around 2000+ J/kg) will support some downbursts/severe wind
   gusts with any stronger cores or merging outflows. The moist
   environment and weaker-shear regime should temper the hail threat,
   but some hail cannot be ruled out.

   ..Flournoy/Gleason.. 06/11/2026

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...BUF...CTP...LWX...RNK...PBZ...RLX...CLE..

 

[SnowenOutThere]

2 hours ago, Eskimo Joe said:

SPC mesonalayis is pretty loaded at 10:30 am for us. Incredible surface CAPE, stouts LI's, and decent low level lapse rates. Only thing lacking is shear. If something fires up today it'll have a solid airmass to work with.

Hmm...even some decent mid level lapse rates west of I-81. I wonder if we have a bit a remnant EML trying to crest the mountains?

Still seem to have a bit of a lee trough if I'm not mistaken as well. I guess we're just missing shear and a forcing mechanism. Storms seem to be popping out near Pittsburgh as well. Quick question, and I know its not fully understood, but what conditions should we look for to get prolific lightning producers? Since the storms are coming in during the night I might try to get to do some lightning photography if I can assuming they hold together as the latest NAM suggests. 

[high risk]

17 minutes ago, SnowenOutThere said:

Still seem to have a bit of a lee trough if I'm not mistaken as well. I guess we're just missing shear and a forcing mechanism. Storms seem to be popping out near Pittsburgh as well. Quick question, and I know its not fully understood, but what conditions should we look for to get prolific lightning producers? Since the storms are coming in during the night I might try to get to do some lightning photography if I can assuming they hold together as the latest NAM suggests. 

       Around here, storms in high PW environments like today are generally more effective at cranking out the CGs.    As you note, though, questions about the evolution of storms this evening remain.

[Eskimo Joe]

Some impressive wind signatures on those storms near Pittsburgh. Wouldn't surprise me to see a 70 mph reading or two.

[midatlanticweather]

 

Mesoscale Discussion 1091
   NWS Storm Prediction Center Norman OK
   0202 PM CDT Thu Jun 11 2026

   Areas affected...the Mid-Atlantic into southern New York and
   southwestern New England

   Concerning...Severe potential...Watch possible 

   Valid 111902Z - 112100Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Scattered thunderstorm development is expected this
   afternoon across the mid-Atlantic northward into southern New York
   and southwestern New England. Severe wind gusts and hail are
   possible with the strongest storms.

   DISCUSSION...Some deeper convective attempts are underway this
   afternoon across portions of the mid-Atlantic, particularly in
   southern New York as of 1900z. This development is occurring in a
   warm, unstable airmass with surface temperatures in the upper 80s
   and lower 90s F and MLCAPE values around 2000+ J/kg. The 18z
   ALB/Albany, NY sounding sampled the northern periphery of this
   airmass (along the CAPE gradient) with 0-6-km shear of 24 kts. This
   has supported some sporadic, more organized thunderstorm development
   recently.

   As the afternoon progresses, diurnal heating should support
   additional thunderstorm development across the region. Furthermore,
   a mid-level impulse in eastern OH -- influencing the ongoing
   convection in WW312 -- will continue moving eastward and should
   provide additional support for convective initiation and maturation.
   Bulk shear is expected to remain generally in the 15-25 kt range
   which, amidst forecast large MLCAPE around 2500-3000 J/kg, will
   promote strong updrafts capable of producing wind gusts and hail.
   Uncertainty remains as to how much convection will develop and
   coalesce/strengthen in the short term, but trends will continue to
   be monitored for possible watch issuance this afternoon.

   ..Flournoy/Gleason.. 06/11/2026

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...OKX...ALY...PHI...BGM...AKQ...CTP...LWX...

   LAT...LON   39937855 42097738 42657579 42777436 42337326 41237290
               40177310 37717495 37397648 37777765 38937842 39937855 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN