2024 Severe Weather General Discussion

[Kmlwx]

7 minutes ago, Amped said:

I haven't been looking at weather maps for a while. I am impressed with modays setup.

If @Amped is excited - that's usually a good indication for severe.

[yoda]

1 minute ago, Kmlwx said:

If @Amped is excited - that's usually a good indication for severe.

18z GFS looks like a significant severe weather episode for us Monday afternoon/evening 

[Kmlwx]

4 minutes ago, yoda said:

18z GFS looks like a significant severe weather episode for us Monday afternoon/evening 

The supercell composite maps have improved a decent bit from prior runs. If that continues to look good or even improve, I'll be on board. Still a bit too far out to be at all confident. 

[yoda]

Looks like there were a few LSRs of ping pong ball sized hail this afternoon... one on Shenandoah county; the other in Loudoun just NW of IAD

[WEATHER53]

Two trees and lots of limbs down in a 2 mile stretch of 270 10 miles south of Frederick and a wash out if the left lane with lane closed.  Probably 60mph winds and insane rain for a while 

[Kmlwx]

June 2013 (the big event) is showing up in the analogs

 

[Kmlwx]

12z GFS backed wayyy off on the Monday threat. Instability looks much lower. This is why we can't "bank on" anything days out ahead. We'll see how things look later in the weekend. 

[Kmlwx]

12z CIPS at hour 84..if you cheat a little and use the Southeast Domain instead of the one over us, April 29, 2002 at 0z is the top analog (La Plata event). Also one of the June 1998 beefy events showing up. Overall the CIPS guidance looks more robust at the 12z run versus the overnight run. I was pretty enthusiastic with how the Euro looks latest run too. 

[Eskimo Joe]

2 hours ago, Kmlwx said:

12z GFS backed wayyy off on the Monday threat. Instability looks much lower. This is why we can't "bank on" anything days out ahead. We'll see how things look later in the weekend. 

IMO, there are too many mesoscale features in these parts to accurately define severe weather risk beyond D2. I'll be back in Maryland Sunday afternoon and hope to see some storms next week. 

[Kmlwx]

1 minute ago, Eskimo Joe said:

IMO, there are too many mesoscale features in these parts to accurately define severe weather risk beyond D2. I'll be back in Maryland Sunday afternoon and hope to see some storms next week. 

Good news is that at a minimum we should have chances at a few rounds of storms late weekend and into the holiday. While that potential squall line Sun night into Mon AM could spoil Mon afternoon, seems odds for storms for most are pretty high. Remains to be seen what the actual severe potential looks like. I got all my GR products updated and downloaded some new color tables....so I probably jinxed us. 

[Eskimo Joe]

48 minutes ago, Kmlwx said:

Good news is that at a minimum we should have chances at a few rounds of storms late weekend and into the holiday. While that potential squall line Sun night into Mon AM could spoil Mon afternoon, seems odds for storms for most are pretty high. Remains to be seen what the actual severe potential looks like. I got all my GR products updated and downloaded some new color tables....so I probably jinxed us. 

Oooo...can you share the new tables?

[Kmlwx]

43 minutes ago, Eskimo Joe said:

Oooo...can you share the new tables?

I've been downloading from here - 

https://www.wxtools.org/ 

[Kmlwx]

The 18z 12km NAM looks great if I'm being honest. really nice sim reflectivity, especially for it being the 12km resolution. Of course...it's the NAM at range. I hope the lackluster 12z GFS run was a blip...we'll see here soon. 

Frankly...if we took the 18z NAM at face value...I'm guessing it would be a ENH day if not higher. 

[Kmlwx]

One other thing about the 18z NAM soundings....the SARS numbers/results have been steadily getting more impressive. It's gone from 40-50% in the TOR and hail columns to now into the 50-60+ percent range. 

[Kmlwx]

18z NAM (12km) sounding from Pivotal site. I clicked and dragged so it would take an average sounding of MoCo essentially. Again...caveat that it is the NAM at range...but damn....MLLR that aren't horrible, ample CAPE, EHI and SRH up there...and SARS percentages nothing to sneeze at. Look at that SE wind at the surface too...

[Kmlwx]

[Kmlwx]

Screenshot spamming - but I will take my chances with this H5 look most times

[Kmlwx]

The 18z GFS is 3-6 degrees lower on dewpoints than the NAM for Monday...and lower MLLR as well. Subsequently...parameters are much lower, CAPE is much lower and the threat seems a lot more garden variety versus the NAM. The nice thing is...a lot of the other globals seem closer to the NAM. 

[Kmlwx]

The NAM and RGEM (and hinted on some of the non GFS globals) pop a bit of a low or at least something resembling one in parts of our area Monday PM. This seems to get that SE wind and enhances dewpoints. The less favorable models seem to keep it more SWerly instead of SErly 

[yoda]

Some pretty nasty looking soundings on the 00z NAM at 21z Monday and 00z Tuesday across the region 

[high risk]

5 hours ago, Kmlwx said:

The 18z GFS is 3-6 degrees lower on dewpoints than the NAM for Monday...and lower MLLR as well. Subsequently...parameters are much lower, CAPE is much lower and the threat seems a lot more garden variety versus the NAM. The nice thing is...a lot of the other globals seem closer to the NAM. 

      Seems like the GFS wants to break out convection during the morning which kills lapse rates and heating later in the day.    The NAM is dry in the morning, and noted by @yoda, the environment at peak heating looks quite good, with nice backing of the low-level winds too.     GFS does seem to be a bit of an outlier.    My guess is that unless the 00Z ECMWF looks like the GFS, we'll have a Day 3 SLGT when we wake up Saturday morning.

    

[WxUSAF]

Big slight risk area for Monday. 

[Kmlwx]

I'm still onboard for the most part. Usual caveats still apply 3 days out. Certainly the best threat from 3+ days out I've seen this year IMO. 

[yoda]

06z NAM NEST has some pretty dangerous soundings for the area at 18z Mon... though the sim radar would suggest clouds over the area I believe.  Also, 18z Monday is at the end of its run

06z NAM soundings are also dangerous for the region.

When I say dangerous, I mean like we rarely see some of these types of soundings in our area/region IMHO 

[yoda]

12z NAM and 12z NAM Nest soundings look pretty nasty as well

[Rhino16]

34 minutes ago, yoda said:

12z NAM and 12z NAM Nest soundings look pretty nasty as well

21z has almost 4000 CAPE, 54kts 0-6km shear with decent backing further east it seems, 176 3Cape, crazy stuff, but it’s the NAM, still interesting to see for now.

[Kmlwx]

12z GFS continues with lower dewpoints, lower MLLR (significantly lower!) and an overall lesser threat IMO. It's holding steady on those lower dews. I don't think we'll see the 75+ degree dews necessarily. But thinking that will be a key factor here. If dewpoints mix down to the mid 60s - it will probably be a very toned down/limited threat...if we can hold them 69+ I think the threat will be beefier. 

Definitely on board with Eskimo Joe in terms of these all being very small scale factors that we can't easily resolve this far out. 

Also remember the usual NAM vs GFS bias of NAM going bonkers with instability sometimes. 

[Rhino16]

This NAM run kept the look, perhaps beefier cape in spots, but that could be NAM doing NAM stuff + run to run variability. I do notice a transition to inverted V’s after 15z, but that was present before too.

[yoda]

18z NAM NEST and 18z NAM soundings still are really nasty.  18z NAM NEST even has some very high UDH swaths just north of DC.  Some of the hodographs are very elongated and very curved too

[Eskimo Joe]

The orientation and proximity of the warm front on Monday would have me lean towards the NAM family. Definitely a decent set up for tornadoes.