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

[Kmlwx]

So far it's an empty radar. Seems the signal for an isolated storm has backed off further on the models. Most guidance has a shower or two around, though. 

[mappy]

Is Saturday a pop up storm kind of day? Having people over and wondering how it could be

[Kmlwx]

20 minutes ago, mappy said:

Is Saturday a pop up storm kind of day? Having people over and wondering how it could be

Seems it could be more widespread but TBD of course 

[mappy]

28 minutes ago, Kmlwx said:

Seems it could be more widespread but TBD of course 

Thanks! 

[Kmlwx]

Just now, mappy said:

Thanks! 

I don't think I was much help - just model perusing! 

[mappy]

Just now, Kmlwx said:

I don't think I was much help - just model perusing! 

I’ve looked at them too. Gfs seemed more robust while euro was hit and miss. 

[Maestrobjwa]

Happy Derchoversary everybody!

 

 

[WxWatcher007]

An all-time event for the region. Just extraordinary.
 

 

[George BM]

This moment ten years ago I was standing outside with a strange sustained west wind picking up in strength immediately ahead of the gust front with a growing roar approaching from the west. - Herndon, VA.

[GramaxRefugee]

For the Derecho.....

This NWS product is worth looking at. A lot of effort must've gone into this. Impressive graphics.  Link from the LWX page....

http://storymaps.arcgis.com/stories/a86e8fc4fc814521b127602feb33db10

 

[Kmlwx]

Seems a few good storms could be in the offing for this afternoon. Better chance tomorrow. Summer doldrums otherwise! 

[George BM]

52 minutes ago, Kmlwx said:

Seems a few good storms could be in the offing for this afternoon. Better chance tomorrow. Summer doldrums otherwise! 

I definitely like the very steep lapse rates from ~650mb to the surface being advertised on CAMs such as the HRRR for this afternoon. DCAPE looks fairly decent as well. Could see a strong downburst in a spot or two later.

[Stormfly]

On 6/29/2022 at 10:02 PM, WxWatcher007 said:

An all-time event for the region. Just extraordinary.
 

 

Transformer explosions rarely happen.  The flashes visible are arc faults or simply power flashes where something comes in contact with lines or a line is on the ground arcing producing lots of light.  Pole mounted transformers are extremely robust, I've seen secondary faults burn through an entire pole and while the pole and transformer ended up on the ground, the transformer was still functional but damaged only from the fall!

In substations where larger transformers are used where 500kV may be stepped down to 33kV, for example, faults here are quite spectacular and if it goes up in flames its usually due to the oil heating up to the point where the internal pressure reaches limits and safety devices vent the oil which instantly vaporizes and ignites when it contacts something hot (like an arc).

Well known events involving substations include NYC:
 

 

Closer to home, there was an incident on 12/21/2012, the day the world was supposed to end.   Freaked a lot of folks out in the Annapolis area IIRC.

During strong winds at night when your lights start flickering, dimming or going out and come back on, listen carefully.  You may hear humming.  And if you go outside you may see that eerie looking glow.  In rural areas where overhead lines and trees are close together, this is commonplace.  It's also annoying when a limb large enough to not be cleared by reclosers trips them out and you have to wait for crews to clear the fault.

 

 

[WxWatcher007]

1 hour ago, Stormfly said:

Transformer explosions rarely happen.  The flashes visible are arc faults or simply power flashes where something comes in contact with lines or a line is on the ground arcing producing lots of light.  Pole mounted transformers are extremely robust, I've seen secondary faults burn through an entire pole and while the pole and transformer ended up on the ground, the transformer was still functional but damaged only from the fall!

In substations where larger transformers are used where 500kV may be stepped down to 33kV, for example, faults here are quite spectacular and if it goes up in flames its usually due to the oil heating up to the point where the internal pressure reaches limits and safety devices vent the oil which instantly vaporizes and ignites when it contacts something hot (like an arc).

Well known events involving substations include NYC:
 

 

Closer to home, there was an incident on 12/21/2012, the day the world was supposed to end.   Freaked a lot of folks out in the Annapolis area IIRC.

During strong winds at night when your lights start flickering, dimming or going out and come back on, listen carefully.  You may hear humming.  And if you go outside you may see that eerie looking glow.  In rural areas where overhead lines and trees are close together, this is commonplace.  It's also annoying when a limb large enough to not be cleared by reclosers trips them out and you have to wait for crews to clear the fault.

 

 

Great info, thanks for sharing! 

I remember that NYC event. People thought the aliens finally arrived lol. 

[North Balti Zen]

 

[midatlanticweather]

https://www.spc.noaa.gov/products/md/md1314.html 

[Stormfly]

Whole lot of lightning to our west!

[BlizzardNole]

Painfully close miss to the north for my parched yard.  Hope we get another shot at one later.  The nice thing is it sucked a lot of heat out of the air

[biodhokie]

SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 417
NWS STORM PREDICTION CENTER NORMAN OK
310 PM EDT FRI JUL 1 2022

SEVERE THUNDERSTORM WATCH 417 IS IN EFFECT UNTIL 700 PM EDT
FOR THE FOLLOWING LOCATIONS

MDC003-005-013-015-017-021-025-027-031-033-043-510-012300-
/O.NEW.KWNS.SV.A.0417.220701T1910Z-220701T2300Z/

MD
.    MARYLAND COUNTIES INCLUDED ARE

ANNE ARUNDEL         BALTIMORE           CARROLL
CECIL                CHARLES             FREDERICK
HARFORD              HOWARD              MONTGOMERY
PRINCE GEORGES       WASHINGTON


MARYLAND INDEPENDENT CITIES INCLUDED ARE

BALTIMORE CITY
$$

[dailylurker]

Nice loud storm passed mostly south of my area along 70. Lots of rumbling and some beneficial rain. 

[midatlanticweather]

[WxUSAF]

This is gonna be close…

[osfan24]

Decent storm here. A lot of distant thunder really faded as storm got here, but had a tiny bit of very small hail and it was fairly gusty with some much-needed rain. 

[North Balti Zen]

Round 1 (or final round) - that storm hit Monkton area pretty square. I got caught in it on 83 trying to get home - hit a hail core around mile marker 25 trying to get to exit 27.  Lots of large limbs down after I exited and had to turn around and find back way home as some sort of downed limb or tree had monkton road blocked just beyond volunteer fire station in hereford. 

[Stormfly]

Cone of silence!  Heard ONE, yes ONE rumble of thunder here.  All bark, no bite.
Before it blew in (haha) I had to snap the sky, it was MEAN looking!

YT video processing, will update with link but in the meantime...

Ok here's some video.  The original is HDR10 UHD and it will (eventually) work once processed but for now it's here:
 

 

[yoda]

SLGT risk added on 2000 SPC OTLK 

[North Balti Zen]

 

[Kmlwx]

CAMs look decent for some of us this afternoon. Seems it will be a garden variety severe day - a scattering of reports possible but nothing history-making. 

[mappy]

8 minutes ago, Kmlwx said:

CAMs look decent for some of us this afternoon. Seems it will be a garden variety severe day - a scattering of reports possible but nothing history-making. 

Fine with me! 

[Kmlwx]

Fairly respectable CAPE values across the area already. 1000+ for the metro corridor on MLCAPE and 2500+ SBCAPE. As forecast, we are on the southern fringe of a belt of shear. Mid-level lapse rates are not good, but low level lapse rates are steepening. DCAPE is lacking in the immediate metro corridor, better values in extreme southern Maryland and SEVA. We'll see if that expands with further heating. Theta-e is on the increase as well.