2022 Mid-Atlantic Severe Wx Thread (General Discussion Etc)

[Chris78]

23 minutes ago, nj2va said:

Yep sun is out here.

Sun is out in Smithsburg. Very muggy

[yoda]

I could see the SLGT risk being moved south another 50-100 miles or so on the 1630z OTLK... down the i81 corridor towards CHO... ENH risk maybe just a tad nudge south too

[Darkstorm]

Sun is out in Smithsburg. Very muggy

Muggy is an understatement. It’s miserable up here.

[Kmlwx]

15z HRRR is almost nothing. 

[yoda]

33 minutes ago, yoda said:

I could see the SLGT risk being moved south another 50-100 miles or so on the 1630z OTLK... down the i81 corridor towards CHO... ENH risk maybe just a tad nudge south too

Yup re SLGT risk... moved south a tad along i95 coprridor and now includes all of W VA

[high risk]

8 minutes ago, Kmlwx said:

15z HRRR is almost nothing. 

        So weird.    The HRRR never liked the idea of a line dropping out of PA, but it did generate cells locally.    It's not easy to spot notable differences in the thermodynamic environment in the model between the "good" runs and "bad" runs.

 

[yoda]

1630z disco

...Northeast/Mid-Atlantic States...
   An active severe-weather day is expected across the region, with
   essentially all convective modes/hazards possible. Steady
   large-scale height falls, along with a strengthening of cyclonically
   curved westerlies, will occur via the approach of the upstream
   trough over Ontario. Upstream regional 12z soundings/upper-air data
   sampled 50+ kt mid-level winds early this morning over Lower
   Michigan into Illinois (and likely Indiana).

   A very moist and potentially unstable air mass is in place across
   the Northeast, where daytime highs well into the 80s F and dewpoints
   near 70F will yield MLCAPE values of 2000-3000 J/kg with little
   capping inversion. General thinking remains that thunderstorms will
   form this afternoon along an approaching cold front, initially from
   western/northern New York into northwest Pennsylvania into
   eastern/central Ohio, with additional development possible within
   the warm sector in vicinity of the mountains and/or lee trough.

   Low-level winds are not forecast to be particularly strong, but
   favorable deep-layer shear and degree of instability suggest that
   discrete supercells will be possible, capable of very large hail and
   possibly a few tornadoes. This activity will spread
   east/southeastward during the afternoon/evening especially across
   the Enhanced Risk area that includes much of New York and
   Pennsylvania. Upscale growth into short bowing segments can be
   expected as storms spread toward additional parts of the
   Mid-Atlantic this evening, although a more stable air mass will
   likely persist for coastal areas.

[WxUSAF]

1 hour ago, yoda said:

12z NAM NEST goes nuts from DC metro to BWI metro from 00z to 06z

NAM has not draped itself in glory the last week

[Eskimo Joe]

1 hour ago, yoda said:

12z NAM NEST goes nuts from DC metro to BWI metro from 00z to 06z

It's nice

[AdamHLG]

Only 15 minutes ago in Baltimore County I would have said "its over" but son of a gun the sun is shining.  I guess we have a chance.

[mappy]

Can confirm sun trying to come out in Parkton. 75/69

[SnowenOutThere]

It has been sunny in fairfax since sunrise today, is very toasty outside. 

[09-10 analogy]

We’ve had mostly sunny conditions all day long and it is pretty gooey outside

[weatherCCB]

Mostly sunny

86/72

 

[Kmlwx]

Very, very sharp CAPE gradient right through the metro area. 

[biodhokie]

2 minutes ago, Kmlwx said:

Very, very sharp CAPE gradient right through the metro area. 

RAP holds that super sharp gradient. If we can just break through the cap, might give me hope.

[yoda]

6 minutes ago, Kmlwx said:

Very, very sharp CAPE gradient right through the metro area. 

Should move eastward a bit as we continue to have heating IMO

[Kmlwx]

1 minute ago, yoda said:

Should move eastward a bit as we continue to have heating IMO

Yes. And one thing that gives me hope is that complexes of storms love the gradient sometimes 

[weatherCCB]

Few individual storms starting to form out west.

Those will have to be watched

[yoda]

The storm in CTP's CWA (S PA) that is severe warned does have the TORNADO POSSIBLE tag on it FWIW

[SnowenOutThere]

1 minute ago, weatherCCB said:

Few individual storms starting to form out west.

Those will have to be watched

Already some thunderstorm warnings up out in southern PA, also got to watch those storms around Winchester right now to see if they can produce some outflow boundaries. 

[yoda]

Mid 80s at DCA/IAD at 2pm with DPs near 70... with southerly winds bringing in a decent breeze

[Kmlwx]

Given that the radar already is different from the HRRR... I like our odds

[biodhokie]

1 minute ago, Kmlwx said:

Given that the radar already is different from the HRRR... I like our odds

So officially we're in AmWx-MA SVR Step 2 mode?

[yoda]

Waiting for our MCD soon

[yoda]

Tornado Watch for all of PA/NY just issued right down to the M/D line... in effect until 11pm

[biodhokie]

 

Mesoscale Discussion 1190
   NWS Storm Prediction Center Norman OK
   0146 PM CDT Thu Jun 16 2022

   Areas affected...Western Maryland...eastern West Virginia...and
   northern Virginia.

   Concerning...Severe potential...Watch possible 

   Valid 161846Z - 162015Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Continued storm development is likely through the
   afternoon with a threat for large hail and damaging winds.

   DISCUSSION...A cluster of storms has developed over the mountains in
   southern Pennsylvania this morning with a few severe thunderstorm
   warnings issued. Satellite and radar trends show additional
   development in the vicinity which should also pose a threat for
   strong to severe storms. Effective shear is in the 25 to 30 knot
   range which will support multicell clusters and occasional rotating
   updrafts. Damaging winds and isolated large hail will be the primary
   threat through the afternoon, especially if any forward propagating
   clusters can develop. The primary limiting factor is the more stable
   airmass to the east, but southward moving clusters should be able to
   maintain themselves with moist/unstable air west of the surface
   trough. 

   A severe thunderstorm watch may need to be considered if severe
   storms become more numerous/show greater organization.

   ..Bentley/Guyer.. 06/16/2022

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

   ATTN...WFO...AKQ...CTP...LWX...RNK...

   LAT...LON   38957926 39677868 39807793 39697757 39477749 38827748
               37667811 37177884 37217929 37987950 38957926 

 

Our pity MCD is here.

[yoda]

Re today for severe threat from LWX afternoon AFD update... i'm intrigued by the 2nd period of interest

Regarding the severe weather potential today, there are two periods
of interest. The first is from late this afternoon into this evening
along a lee pressure trough. Hi-res guidance has trended toward
a more robust environment this afternoon from I-81 east with
sfc CAPE of 2000 J/kg+ and deep layer shear of 35-45 kts. This
area is colocated with the pressure trough and terrain
circulations. Should any storm form in this area/environment,
it could quickly become severe posing a damaging wind and large
hail threat. These storms would also likely be efficient rain
producers due to the anomalously moist airmass, though storms
should remain progressive to some extent.

The second period of interest is late this evening into the early
parts of tonight. A cold front will be positioned across the
southern Great Lakes. Storms will develop along the Lake Erie lake
breeze and progress southeast. Uncertainty arises with the areal
extent of the storms in part due to the warm air aloft since these
storms will not be on the actual cold front. Several scenarios
exist, with bowing segments possibly extending into the local
region. Areas near the bay may have more of a stable airmass by the
time the storms arrive, but will continue to monitor.

[yoda]

Then the middle of next week has my interest too... also from LWX afternoon AFD but in the extended section @Kmlwx @Eskimo Joe

By Tuesday into Wednesday, ridging aloft will start to build in from
the west. We`ll remain on the frontside of the ridge both days,
placing us in northwesterly flow aloft. Heat and humidity will start
to build in from the west, with highs approaching 90 by Tuesday, and
then well into the 90s on Wednesday. The return of the heat and
humidity will bring along with it chances for showers and
thunderstorms as disturbances descend down the frontside of the
ridge in northwesterly flow.

[yoda]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Baltimore MD/Washington DC
251 PM EDT Thu Jun 16 2022

The National Weather Service in Sterling Virginia has issued a

* Severe Thunderstorm Warning for...
  Northeastern Frederick County in northwestern Virginia...
  Northwestern Clarke County in northwestern Virginia...
  The northern City of Winchester in northwestern Virginia...
  Western Jefferson County in the Panhandle of West Virginia...
  Southwestern Berkeley County in the Panhandle of West Virginia...

* Until 315 PM EDT.

* At 251 PM EDT, a severe thunderstorm was located 8 miles northwest
  of Winchester, moving east at 25 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Damaging winds will cause some trees and large branches
           to fall. This could injure those outdoors, as well as
           damage homes and vehicles. Roadways may become blocked by
           downed trees. Localized power outages are possible.
           Unsecured light objects may become projectiles.

* Locations impacted include...
  Winchester, Martinsburg, Inwood, Brucetown, Glengary, Gerrardstown,
  Gainesboro, Cedar Grove, Clear Brook, Ridgeway, Bunker Hill,
  Stephenson, Wadesville, Cross Junction, Arden, Cedar Hill, Albin,
  Gore, Whitacre and Greenwood.