2026 Mid-Atlantic Severe Storm General Discussion

[frd]

SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 543
NWS STORM PREDICTION CENTER NORMAN OK
110 PM EDT SAT AUG 8 2026

SEVERE THUNDERSTORM WATCH 543 IS IN EFFECT UNTIL 600 PM EDT
FOR THE FOLLOWING LOCATIONS

DEC001-003-005-082200-
/O.NEW.KWNS.SV.A.0543.260808T1710Z-260808T2200Z/

DE
.    DELAWARE COUNTIES INCLUDED ARE

KENT                 NEW CASTLE          SUSSEX
$$

[vortex95]

Today's set up is almost identical to ydy.  And the SPC outlook looks very similar as well.  So multicellular clusters once again.

We do have the storms nrn areas now, but the clouds should clear out nicely behind it all for plenty of aftn heating.

And VIS currently clearly shows boundaries laid down S of the tstm area.
 

[frd]

Storms seem to be getting stronger in NE Maryland as they move East. 

[CAPE]

In the watch but this is going to be yet another miss to the north.

[AlexD1990]

6 minutes ago, CAPE said:

In the watch but this is going to be yet another miss to the north.

 

6 minutes ago, CAPE said:

In the watch but this is going to be yet another miss to the north.

Yeah doesn't seem necessary 

[CAPE]

3 minutes ago, AlexD1990 said:

 

Yeah doesn't seem necessary 

A repeat of yesterday except that was a closer miss lol. The outflow boundary didn't trigger anything and it doesnt seem to be this time either.

[yoda]

Looks like a lot of svr wind reports and a waterspout report in NE MD

[frd]

 

Machine Learning is very pumped for 8/11 and 8/12 severe potential in our area, then things get eventually drier, cooler and less humid. 

[DanTheMan]

https://www.facebook.com/share/p/191Je7oPD8/?mibextid=WC7FNe

Culpeper County sheriff with Reports of Tornado on the storm that slid just to my south earlier  

[wawarriors4]

Just got home, trees down in a lot of places in Stafford County, including our yard. Talking to neighbors it seems like it was a downburst around 4:45 PM or so on 8/8.

 

[vortex95]

Looks active Mon-Wed here.  HRRR/RRFS suggesting multiple waves of tstms and derecho potential.  Seems like there will be one in the OH Valley Tue, and the 12z RRFS is hitting that very hard.  Attached is the RRFS valid 00z Wed.  Wow.  And you have storms firing on the front WNW to ESE right into the DMV area, like a large warm advection wing seen on many derechoes.  HRRR through 48 hr seems to have the same idea.

Pattern is favorable for derechoes/long-lived bow echoes.

The issue typically is though, can an OH Valley derecho make it over the Appalachians intact?  It's hard to do.  The June 2012 did, but that was the exception.

SPC also has the region outlooked for svr DY4 (Wed).

[mappy]

Nice line of storms moving across southern PA. Can hear the thunder 

[southmdwatcher]

SPC update brings the slight risk down to the southside of DC Beltway and adds a 2% tornado risk for DC up through southeast PA/central NJ.

[toolsheds]

42 minutes ago, mappy said:

Nice line of storms moving across southern PA. Can hear the thunder 

Surprising I could hear them all the way down here by 70.

[yoda]

So are the storms currently in Ohio the ones we should be watching for this afternoon?

[Paleocene]

12z 3k NAM has a line moving thru the DC metro around 21z.

Latest HRRRs are less enthused.

 

[George BM]

54 minutes ago, yoda said:

So are the storms currently in Ohio the ones we should be watching for this afternoon?

Correct.

[Eskimo Joe]

SPC adds 30% wind risk from I-81 west for today.

[yoda]

3 minutes ago, Eskimo Joe said:

SPC adds 30% wind risk from I-81 west for today.

 

And 2% tor

 

[vortex95]

3 hours ago, mappy said:

Nice line of storms moving across southern PA. Can hear the thunder 

Like the other day, this area has likely laid down subtle boundaries across nrn VA and cntrl MA, perhaps providing local focus for storms later.

[wxmeddler]

The squall line pushing across PA looks healthy.

[yoda]

I'm guessing a MCD for us by 230pm

[yoda]

26 minutes ago, yoda said:

I'm guessing a MCD for us by 230pm

Or now... watch coming soon 

 

https://www.spc.noaa.gov/products/md/mcd1896.png

 

Mesoscale Discussion 1896
   NWS Storm Prediction Center Norman OK
   1159 AM CDT Mon Aug 10 2026

   Areas affected...the Maryland and West Virginia Panhandles into the
   Delmarva

   Concerning...Severe potential...Watch likely 

   Valid 101659Z - 101900Z

   Probability of Watch Issuance...80 percent

   SUMMARY...The threat for locally damaging winds is expected to
   increase this afternoon, likely requiring a severe thunderstorm
   watch issuance.

   DISCUSSION...Daytime heating combined with boundary-layer dewpoints
   in the upper 60s to lower 70s has contributed to a moderately
   unstable air mass as of early afternoon with steepening low-level
   lapse rates and MLCAPE of 1500-2500 J/kg. Upstream convection over
   southwest PA is gradually developing a tighter leading-edge
   reflectivity gradient and more robust trailing stratiform region,
   suggestive of an organizing cold pool. 

   Current thinking is that the evolving convective system will further
   intensify as it continues east-southeast and encounters an
   increasingly unstable environment across the discussion area. The
   current KPBZ VWP is sampling strengthening west-northwest flow above
   2 km AGL, which will likely aid in further cold pool organization.
   These factors will lead to an increasing threat for damaging wind
   gusts across the area this afternoon, likely requiring the issuance
   of a severe thunderstorm watch.

   ..Mead/Hart.. 08/10/2026

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

   ATTN...WFO...PHI...AKQ...LWX...

   LAT...LON   39117919 39457922 39687831 39607644 39657577 39167542
               38627575 38367675 38547793 38717879 38877919 39117919 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN

[yoda]

Watch up till 9pm for entire LWX CWA except St. Mary's 

[Eskimo Joe]

Decent velocities on that line approaching Garrett County. Might be an overperformer today west of I-95 into the mountains.

[yoda]

6 minutes ago, yoda said:

Watch up till 9pm for entire LWX CWA except St. Mary's 

URGENT - IMMEDIATE BROADCAST REQUESTED
   Severe Thunderstorm Watch Number 555
   NWS Storm Prediction Center Norman OK
   115 PM EDT Mon Aug 10 2026

   The NWS Storm Prediction Center has issued a

   * Severe Thunderstorm Watch for portions of 
     District Of Columbia
     Maryland
     Northern Virginia
     Eastern Panhandle of West Virginia
     Coastal Waters

   * Effective this Monday afternoon and evening from 115 PM until
     900 PM EDT.

   * Primary threats include...
     Scattered damaging wind gusts to 70 mph likely
     Isolated large hail events to 1 inch in diameter possible

   SUMMARY...Thunderstorms will spread southeastward across the watch
   area through the afternoon and early evening.  Hot and humid
   conditions will combine with favorable winds aloft for a risk of
   damaging wind gusts in the stronger storms.

   The severe thunderstorm watch area is approximately along and 45
   statute miles north and south of a line from 85 miles west southwest
   of Martinsburg WV to 40 miles east northeast of Baltimore MD. For a
   complete depiction of the watch see the associated watch outline
   update (WOUS64 KWNS WOU5).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A Severe Thunderstorm Watch means conditions are
   favorable for severe thunderstorms in and close to the watch area.
   Persons in these areas should be on the lookout for threatening
   weather conditions and listen for later statements and possible
   warnings. Severe thunderstorms can and occasionally do produce
   tornadoes.