2024 Severe Weather General Discussion

[Kmlwx]

Just now, NorthArlington101 said:

I don’t know anything about severe but it’s shocking to me how these storms seem to struggle to sustain once they pop with what I’m imagining is so much fuel.

Poor mid-level lapse rates/warm air aloft. Surface heat does not always equate to good instability for storms sadly. 

[NorthArlington101]

Poor mid-level lapse rates/warm air aloft. Surface heat does not always equate to good instability for storms sadly. 

We can’t do anything right! Other than heat and drought. And wind. So I guess we can’t do anything fun right

[aldie 22]

First cell fizzled second one looks more robust but may pass south of me

[NorthArlington101]

Middleburg storm is trying hard to sustain itself but feel like it may not be enough. Was hoping to see cloud tops continuing to build up but seems to be struggling to hold around 30k.

[aldie 22]

2 minutes ago, NorthArlington101 said:

Middleburg storm is trying hard to sustain itself but feel like it may not be enough. Was hoping to see cloud tops continuing to build up but seems to be struggling to hold around 30k.

So damn close I can smell it...this cell has held on a little bit longer than the first

[09-10 analogy]

Was this watch preceded by a MD? I took a spin around the SPC site and didn't see an mesoscale discussion for the mid Atlantic. Not that it's a precondition but I always like to read their reasoning. 

[Kmlwx]

Just now, 09-10 analogy said:

Was this watch preceded by a MD? I took a spin around the SPC site and didn't see an mesoscale discussion for the mid Atlantic. Not that it's a precondition but I always like to read their reasoning. 

Yeah one was out a little bit before it was issued way earlier. 

[Kmlwx]

Just now, Kmlwx said:

Yeah one was out a little bit before it was issued way earlier. 

https://kamala.cod.edu/offs/KWNS/2407161836.acus11.html

[Kmlwx]

big blunder by AlertMontgomery @Eskimo Joe - it just sent out a message for a warning in the CTP WFO. 

[Kmlwx]

And that's why the SPC folks are the guys that get paid! 

You can see on LWX radar the outflow from the WV activity and then increasing activity ahead of it - just like they indicated was possible in their mesoscale discussion. 

[dailylurker]

8 minutes ago, Kmlwx said:

And that's why the SPC folks are the guys that get paid! 

You can see on LWX radar the outflow from the WV activity and then increasing activity ahead of it - just like they indicated was possible in their mesoscale discussion. 

I'm watching it developing from Crownsville MD. It made for a beautiful, classic summer sunset. Now it looks like a incoming weather system. Let's hope for some strobe light skies tonight. 

[Maestrobjwa]

On 7/16/2024 at 7:58 PM, dailylurker said:

I'm watching it developing from Crownsville MD. It made for a beautiful, classic summer sunset. Now it looks like a incoming weather system. Let's hope for some strobe light skies tonight. 

I'm in North East, MD with a full view of the bay all the way to Havre de Grace...and it was the best light show this city dweller has ever seen! Felt like ya needed sunglasses, haha Truly spectacular...how great Thou art 

[KAOS]

[dailylurker]

Nice little storm rolled through my neighborhood. It only lasted a few minutes but it was frisky. 

[Stormchaserchuck1]

Now that we broke some of the cap today, tomorrow should be a better severe weather day I would think. 

I wanted us to get really hot for good storms, but we held too much cap this year. 

[Kmlwx]

45%+ showing on the the CSU MLP for today. SPC holds us at slight but does mention a bowing structure possible - too many uncertainties. 

[yoda]

5 minutes ago, Kmlwx said:

45%+ showing on the the CSU MLP for today. SPC holds us at slight but does mention a bowing structure possible - too many uncertainties. 

Bow echo or bowing MCS would be nice 

[yoda]

12z NAM sim radar looks decent for this evening 

[Kmlwx]

The NAM nest is pretty good too. We'll see....

[Kmlwx]

Many of the CAMs this morning seem to wait until E of 95 to get things going. Also, almost every model skunks decent swaths of the area...should be expected with convection - but seems there will be some bad shaftings. 

[Rhino16]

I hope it happens earlier so hopefully I could see some cool structure, but if anyone happens it seems like it would be 10pm before anything gets to me at the coast.

[Kmlwx]

No appreciable changes to the latest SPC outlook. 

[Kmlwx]

MESOSCALE DISCUSSION 1666  
NWS STORM PREDICTION CENTER NORMAN OK  
1127 AM CDT WED JUL 17 2024  
  
AREAS AFFECTED...EASTERN PA/NORTHERN NJ INTO WESTERN NEW ENGLAND  
  
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY   
  
VALID 171627Z - 171830Z  
  
PROBABILITY OF WATCH ISSUANCE...80 PERCENT  
  
SUMMARY...THE DAMAGING-WIND THREAT WILL INCREASE THIS AFTERNOON. ONE  
OR MORE WATCHES WILL LIKELY BE NEEDED.  
  
DISCUSSION...RELATIVELY STRONG HEATING IS UNDERWAY FROM PARTS OF THE  
MID ATLANTIC INTO WESTERN NEW ENGLAND, TO THE EAST OF AN EXTENSIVE  
CLOUD SHIELD THAT IS MOVING EASTWARD ACROSS WESTERN/CENTRAL NY/PA  
AND WV. A SEASONABLY DEEP UPPER-LEVEL TROUGH WILL MOVE EASTWARD  
ACROSS THE LOWER GREAT LAKES AND NORTHEAST THROUGH THE DAY, WHILE AN  
MCV EMBEDDED IN THE LARGER-SCALE TROUGH WILL MOVE FROM WV TOWARD THE  
MID ATLANTIC. CUMULUS IS GRADUALLY BUILDING FROM EAST-CENTRAL PA  
INTO SOUTHEAST NY, AND A GENERAL INCREASING IN STORM DEVELOPMENT AND  
COVERAGE IS EXPECTED WITH TIME THIS AFTERNOON.   
  
MIDLEVEL LAPSE RATES ARE WEAK (AS NOTED ON REGIONAL 12Z SOUNDINGS),  
BUT CONTINUED HEATING WILL SUPPORT MLCAPE INCREASING ABOVE 1000 J/KG  
WITH TIME. MODESTLY ENHANCED MIDLEVEL FLOW WILL SUPPORT 30-40 KT OF  
EFFECTIVE SHEAR, SUFFICIENT FOR SOME STORM ORGANIZATION. MULTIPLE  
STORM CLUSTERS AND POSSIBLY A COUPLE OF SUPERCELLS MAY EVOLVE WITH  
TIME, WITH STEEPENING LOW-LEVEL LAPSE RATES SUPPORTING A PRIMARY  
THREAT OF DAMAGING WIND. SOME THREAT FOR ISOLATED HAIL AND/OR A  
BRIEF TORNADO IS ALSO POSSIBLE IF ANY SUPERCELLS CAN BE SUSTAINED.  
ONE OR MORE WATCHES WILL LIKELY BE NEEDED THIS AFTERNOON TO COVER  
THE DAMAGING-WIND THREAT.  
  
..DEAN/HART.. 07/17/2024  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
  
ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...CTP...  
LWX...  

 

[yoda]

MCD out for extreme N MD 

[AlexD1990]

2 minutes ago, yoda said:

MCD out for extreme N MD 

Starting to sound like a repeat of yesterday 

[09-10 analogy]

2 hours ago, Rhino16 said:

I hope it happens earlier so hopefully I could see some cool structure, but if anyone happens it seems like it would be 10pm before anything gets to me at the coast.

That's why I like at least two rounds -- one before and one after dark -- to solve the insuperable dilemma between wanting to see dramatic cloud structures, and a great light show. 

[nj2va]

I’d imagine we see a MD and watch issued. 

[yoda]

 

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
200 PM EDT Wed Jul 17 2024

.SYNOPSIS...
A strong cold front will slowly cross the area through tonight
bringing increased chances for showers and thunderstorms. Cool high
pressure builds back into the area from the north Thursday as the
front sinks south and east of region. The front will remain stalled
to our south Friday before retreating back to the north this weekend
into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 18Z, a small shortwave/vortmax (remnant MCV feature) was
moving across the Appalachians in eastern WV up into SW PA.
Surface winds, albeit light, have occasionally backed to the SE
over portions of the Shenandoah Valley, indicative of enhanced
cyclonic flow around this feature. Guidance seems to be
underdoing the effects of this MCV, so anticipate a bit better
low-level convergence and mid-level shear as it progresses east.
This will likely result in a rapidly developing band of
thunderstorms over eastern WV over the foothills west of I-81 by
mid afternoon. This band of storms should then progress E/NE
crossing the Blue Ridge around 4 PM, then entering the metros
around 5-6 PM. These storms may further be enhanced along and in
the lee of a pressure trough that arcs from northern DE
southwest to near Charlottesville; higher CAPE exists east of
this boundary as of 18Z. The main threat with this activity
given meager mid-level lapse rates is damaging wind gusts, with
a conditional risk for an isolated tornado where surface winds
become sufficiently backed to the SE ahead of the MCV, or east
of the surface pressure trough.

Additional shower and thunderstorm activity is possible this
evening as the synoptic cold front (currently over OH/northwest
PA) pushes in. Interaction between the surface trough, MCV, and
cold front could result in multiple rounds of thunderstorms over
the I-95 corridor into southern MD. With ample moisture in place
(PWs rising to over 2" by evening), this supports the ongoing
Flood Watch for potential flash flooding. Rainfall rates under
the heaviest storms could approach 2-3 inches per hour, with
localized/isolated totals under repeated storms possibly
approaching 5 or 6 inches.

[yoda]

SPC MCD sounds completely opposite to what LWX wrote in their AFD above

[yoda]

Severe Thunderstorm Watch up until 10pm

URGENT - IMMEDIATE BROADCAST REQUESTED
   Severe Thunderstorm Watch Number 553
   NWS Storm Prediction Center Norman OK
   240 PM EDT Wed Jul 17 2024

   The NWS Storm Prediction Center has issued a

   * Severe Thunderstorm Watch for portions of 
     District Of Columbia
     Delaware
     Central and Eastern Maryland
     Southern New Jersey
     Central and Eastern Virginia
     Eastern Panhandle of West Virginia
     Coastal Waters

   * Effective this Wednesday afternoon and evening from 240 PM
     until 1000 PM EDT.

   * Primary threats include...
     Scattered damaging wind gusts to 70 mph possible

   SUMMARY...Thunderstorms are intensifying over the mountains of
   western Virginia.  These storms will track eastward through the
   afternoon, posing a risk of locally damaging wind gusts.

   The severe thunderstorm watch area is approximately along and 110
   statute miles east and west of a line from 45 miles northeast of
   Baltimore MD to 10 miles southwest of Richmond VA. For a complete
   depiction of the watch see the associated watch outline update
   (WOUS64 KWNS WOU3).