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

[RDM]

10 hours ago, AdamHLG said:

 

For those unaware, 2 of the 4 victims died.  It always upsets me to see people injured or killed that hide under trees during a lightning storm.  I learned as a little kid to never stand under trees, well before I became a weather enthusiast.   So for this to happen in a metropolitan city it is upsetting when there should have been rumbles of thunder preceding the strike that signaled "we better get some shelter".  But I wasn't there.  I also read that they were from Wisconsin and I am unsure of how prevalent lighting is from their hometown.    Maybe this was a strike well in advance or after the actual cell overhead.  Posting this to point out the dangers involved.  Prayers go out to the victims, family and friends of this tragedy.   

Unfortunately, according to WTOP earlier this evening a 3rd of the 4 people struck in Lafeyette Park has also passed away and the 4th is in serious condition.  

Recall as well hearing from my dad growing up to never stand under a tree in a t-storm.  Saw what happened to a small herd of cows who sought shelter under a tree on a nearby farm when I was about 6 - a lightening strike killed every one of them.  

[yoda]

So Wednesday... I admit I was a bit caught off guard by the last sentence in this afternoons AFD

A slow moving frontal boundary will approach our region late Tuesday
and pass through the region on Wednesday. Shower activity will
increase ahead of the boundary Tuesday evening and become more
widespread on Wednesday. Debris clouds from morning convection will
likely limit afternoon temperatures to the 80s but CAPE is still
forecast to be between 1500 and 2500. PW`s are expected to remain
elevated above 2 inches with storm motions becoming low around 5
knots later in the afternoon on Wednesday. Based on model soundings
and guidance, the slowest storm motion along with the best lift will
occur later in the afternoon on Wednesday and into the evening
periods. The combination of high PW`s, low storm motion, CAPE above
2000 and the forcing from the front will lead to a threat for SVR
weather and a bigger threat for flooding on Wednesday. The main
limited factor on the SVR threat will be a lack of good shear which
should prevent long lasting supercells.

[MN Transplant]

SPC has us marginal today for downdraft winds.  Radar is starting to pop to the west.  

[midatlanticweather]

Lackluster Meso

[Lucketts Life]

30 minute t-storm just passed through with some much needed rain. Fair amount of lightning with a nice breeze. 72° now. 

[WeatherShak]

Lots of blue on the 3k for Monday.




.

[StormchaserChuck!]

It looks like today we may see a thunderstorm. 

[yoda]

Last chance severe for a while

 

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
On Tuesday, a cold front pressing eastward through the Ohio
Valley will present an active weather day across the Mid-
Atlantic. Downstream of this system, the air mass is likely to
remain very warm and humid. Forecast high temperatures are
expected to rise into the low 90s with heat indices to around
the century mark. Unlike the previous couple of days which had
subsidence aloft, increasing lift ahead of the trough will bring
more widespread convection to the area. Increasing surface-based
CAPEs of around 2,000-2,500 J/kg are noted in the guidance, but
with marginal vertical shear profiles. Accordingly, storms may
not be terribly organized aside from cells that attain more of a
line structure. Any such line segments would promote a damaging
wind threat. SPC`s Day 2 convective outlook places most of the
area in a Marginal risk for severe weather. Initially storms
should ignite along the lee trough during the early afternoon
before spreading eastward toward the I-95 corridor.
Additionally, some degree of flooding risk exists given PWATs
around 1.50-1.75 inches and the potential for repeat convection.
WPC highlights the entire area in a Marginal risk for excessive
rainfall.

[jewell2188]

4 hours ago, yoda said:

Last chance severe for a while

 

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
On Tuesday, a cold front pressing eastward through the Ohio
Valley will present an active weather day across the Mid-
Atlantic. Downstream of this system, the air mass is likely to
remain very warm and humid. Forecast high temperatures are
expected to rise into the low 90s with heat indices to around
the century mark. Unlike the previous couple of days which had
subsidence aloft, increasing lift ahead of the trough will bring
more widespread convection to the area. Increasing surface-based
CAPEs of around 2,000-2,500 J/kg are noted in the guidance, but
with marginal vertical shear profiles. Accordingly, storms may
not be terribly organized aside from cells that attain more of a
line structure. Any such line segments would promote a damaging
wind threat. SPC`s Day 2 convective outlook places most of the
area in a Marginal risk for severe weather. Initially storms
should ignite along the lee trough during the early afternoon
before spreading eastward toward the I-95 corridor.
Additionally, some degree of flooding risk exists given PWATs
around 1.50-1.75 inches and the potential for repeat convection.
WPC highlights the entire area in a Marginal risk for excessive
rainfall.

What a boring period we have entered!!!

[high risk]

7 hours ago, yoda said:

Last chance severe for a while

       I want to be intrigued by tomorrow, but at this point, I'm just hoping for rain.     The shear is very marginal, but it looks like there will be some modest instability and a decent amount of downdraft cape.     The simulated reflectivity forecasts are all over the place, but there may be some agreement on a weakening line approaching the metro areas by early evening, possibly intensifying a bit over the eastern burbs.

[WxUSAF]

Mesos seem to be in lockstep with a line moving through the metros between 6-8pm. Agree with @high risk, just hoping for some decent rain.

[high risk]

4 hours ago, WxUSAF said:

Mesos seem to be in lockstep with a line moving through the metros between 6-8pm. Agree with @high risk, just hoping for some decent rain.

   The 12Z guidance went back to having several CAMs ripping the line to shreds as it arrives.   

[Scuddz]

Sfc dewpoints on the HRRR are dropping into the upper 50s prior to the line.  Granted, I haven't really looked at it much today but that seems a bit excessive.

[H2O]

13 minutes ago, Scuddz said:

Sfc dewpoints on the HRRR are dropping into the upper 50s prior to the line.  Granted, I haven't really looked at it much today but that seems a bit excessive.

Ellinwood mentioned this on twitter too.  Something weird about how it does that and makes the storms go bye bye

[osfan24]

NAM has a nasty looking line go through. HRRR looks like some showers maybe.

[Kmlwx]

1 hour ago, H2O said:

Ellinwood mentioned this on twitter too.  Something weird about how it does that and makes the storms go bye bye

My dewpoint is holding firm in the low 70s. Better start dropping fast if HRRR is to be correct...

[mappy]

5 minutes ago, Kmlwx said:

My dewpoint is holding firm in the low 70s. Better start dropping fast if HRRR is to be correct...

i haven't looked at the hrrr, but does it have the winds coming out of the northwest when the dews drop? that usually does it up my way.

for reference, its 88/72 with a south wind at my house

[H2O]

7 minutes ago, Kmlwx said:

My dewpoint is holding firm in the low 70s. Better start dropping fast if HRRR is to be correct...

76 here.  

[Eskimo Joe]

Wonder if this is the HRRR over mixing again.

[Kmlwx]

Radar looks pretty good thus far IMO. 

[Kmlwx]

I'd imagine at some point soon we'll have a meso discussion for our area. 

[weatherCCB]

91/71 here

[H2O]

28 minutes ago, Kmlwx said:

I'd imagine at some point soon we'll have a meso discussion for our area. 

https://www.spc.noaa.gov/products/md/md1751.html

[Kmlwx]

2 minutes ago, H2O said:

https://www.spc.noaa.gov/products/md/md1751.html

Funny that the one to the NE got a 20% and we got a 5% - our radar looks better IMO. 

[George BM]

2 minutes ago, Kmlwx said:

Funny that the one to the NE got a 20% and we got a 5% - our radar looks better IMO. 

And wind velocities are actually fairly decent (50s mph).

[AmericanWxFreak]

What time does this look like it could potentially affect the Pikesville area - my girlfriend manages a farmers market there and had a not so fun experience with the big severe event earlier this summer. I have been telling her maybe a 4pm cleanup would be best, you guys think thats a good guess? 

[Kmlwx]

May have missed a post elsewhere - but is there an ETA on when the TIAD radar will be back up and running?

[arlwx]

Looks like storms are lining up along I-81.

WAMU and LWX radar claimed a severe thunderstorm warning for SE of Winchester, but LWX isn't showing it on its clickable map page.

[arlwx]

From another source:

[arlwx]

oops:

BULLETIN - IMMEDIATE BROADCAST REQUESTED   SEVERE THUNDERSTORM WARNING   NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC   214 PM EDT TUE AUG 30 2022     THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A     * SEVERE THUNDERSTORM WARNING FOR...   NORTHWESTERN LOUDOUN COUNTY IN NORTHERN VIRGINIA...   CLARKE COUNTY IN NORTHWESTERN VIRGINIA...   SOUTHEASTERN JEFFERSON COUNTY IN THE PANHANDLE OF WEST VIRGINIA...     * UNTIL 300 PM EDT.     * AT 214 PM EDT, SEVERE THUNDERSTORMS WERE LOCATED ALONG A LINE   EXTENDING FROM NEAR MILLWOOD PIKE TO 6 MILES NORTHEAST OF FRONT   ROYAL, MOVING EAST AT 25 MPH.     HAZARD...60 MPH WIND GUSTS.     SOURCE...RADAR INDICATED.