2025 Severe Weather General Discussion

[Rhino16]

23 hours ago, high risk said:

The NAM Nest is the gold standard.  The HiresW ARW2 is decent.  HRRR and especially the HiresW FV3 are the worst.  When they both showed the warm front staying south of DC yesterday, I started writing off severe potential up our way. 

Are there any good resources to learn little things like this, or is it all just time, experience, and networking? It feels like there’s still so much to learn. I should practice forecasting while I’m not doing anything.

[high risk]

7 hours ago, Rhino16 said:

Are there any good resources to learn little things like this, or is it all just time, experience, and networking? It feels like there’s still so much to learn. I should practice forecasting while I’m not doing anything.

       Experience, for sure.    I always look at as much available guidance as I can, and when they don't agree, I make mental notes on which ones did well and which didn't.   It's not as tough to keep track of as it sounds.   

       Or you can just cheat and use AI:   

[Kmlwx]

CIPS has casually been showing June 4, 2008 in the analogs (not the top one at all) for the upcoming period. Not giving it much thought for now - but we'll see if we can squeeze some storms out. 

[Kmlwx]

June 2008 is still showing on the 12z updates to the CIPS guidance. Interestingly, if you sort solely by 500mb rather than all fields, it is the top analog with a score of 0.918. While I doubt we realize that high end of a threat - it's definitely got my attention. Worth noting that some of the neighboring domains on there also have June 4-5 2008 showing up as well.

Obvious questions remain in regards to day-of factors like instability - but my interest level has risen a bit. 

[WxUSAF]

 

[frd]

3 hours ago, WxUSAF said:

 

 

Seriously, almost 80 degree DP in certain locations in the Midwest, wow ! 

 

 

 

[yoda]

1 hour ago, frd said:

 

Seriously, almost 80 degree DP in certain locations in the Midwest, wow ! 

 

 

 

Interesting website... never heard or seen it before.  What do you think of it?

[frd]

57 minutes ago, yoda said:

Interesting website... never heard or seen it before.  What do you think of it?

Still exploring it in beta at this time, an account is free. 

[coolio]

Thunderstorms. 

https://x.com/thetimes/status/1933194649457262720

 

[Kmlwx]

39 minutes ago, coolio said:

Thunderstorms. 

https://x.com/thetimes/status/1933194649457262720

 

"EXCLUSIVE!" 

[Eskimo Joe]

9 hours ago, WxUSAF said:

We do best with derecho climatology when we have BIG heat and a stout EML. 

[George BM]

On 6/11/2025 at 1:09 PM, Kmlwx said:

June 2008 is still showing on the 12z updates to the CIPS guidance. Interestingly, if you sort solely by 500mb rather than all fields, it is the top analog with a score of 0.918. While I doubt we realize that high end of a threat - it's definitely got my attention. Worth noting that some of the neighboring domains on there also have June 4-5 2008 showing up as well.

Obvious questions remain in regards to day-of factors like instability - but my interest level has risen a bit. 

The end of the 18z HRRR for Saturday afternoon DOES look a little interesting (yes fantasy range HRRR, I know... plus, verbatim, weak MLLRs and a saturated atmosphere in general limiting DCAPE).

ETA: Others CAMs show hints of us being backdoored by a cool front by late Saturday.

[high risk]

15 hours ago, WxUSAF said:

 

 

              Lots of things obviously need to align, but that's certainly what we want to see if we're hunting derechos.       We would be well within the hot, humid air mass, but also just barely within the faster flow aloft, giving organized convective systems the opportunity to race to the east-southeast.

[high risk]

 

     Thinking we have a shot at a MRGL on Saturday for a few localized wind events.   Lapse rates are lousy, but there will be decent instability and modest deep layer shear.

 

[Kmlwx]

The NCAR AI convective page is highlighting some impressive severe potential next Thursday...honestly very impressed with how robust it is this far out...(link below) 

https://www2.mmm.ucar.edu/projects/ncar_ensemble/ainwp/?fbclid=IwZXh0bgNhZW0CMTAAAR3_KcoSRHWhY1lxCTCfOqSNC0AD8SUSmL_c7R_N8rtpvo-PsNNvuY3vuI4_aem_Stpgx3ntIqB8IVErFY76cQ

[yoda]

19 minutes ago, Kmlwx said:

The NCAR AI convective page is highlighting some impressive severe potential next Thursday...honestly very impressed with how robust it is this far out...(link below) 

https://www2.mmm.ucar.edu/projects/ncar_ensemble/ainwp/?fbclid=IwZXh0bgNhZW0CMTAAAR3_KcoSRHWhY1lxCTCfOqSNC0AD8SUSmL_c7R_N8rtpvo-PsNNvuY3vuI4_aem_Stpgx3ntIqB8IVErFY76cQ

45%... impressive indeed 

[Kmlwx]

Just now, yoda said:

45%... impressive indeed 

From watching this tool this spring so far - it seems like it way overdoes things - I'm not even sure it works on the same percentages as SPC...so take those maps with a grain (or a handful) of salt. I've been using it more of a "first look" at which days to look at closer. 

[Eskimo Joe]

11 hours ago, high risk said:

 

              Lots of things obviously need to align, but that's certainly what we want to see if we're hunting derechos.       We would be well within the hot, humid air mass, but also just barely within the faster flow aloft, giving organized convective systems the opportunity to race to the east-southeast.

We also need a respectable 500 mb pattern. Looks like the "best" climo is one that features a ridge flexing NW -> SE from Kentucky to Bermuda. Kinda of laying the train tracks for us.

[vortex95]

FWIW, this is what it looked like just to the N of College Park at 5pm today.  It tried for a brief time.  Definite supercell with a long inflow band to the E.

I had to take this pix through a window.  
 

[George BM]

2 minutes ago, vortex95 said:

FWIW, this is what is looked like just to the N of College Park at 5pm today.  It tried for a brief time.  Define supercell with a long inflow band to the E.

I had to take this pix through a window.  
 

Yeah. That cell definitely has a little bit of a supercell appearance on radar.

[Kmlwx]

Cool looking outflow on radar as well!

[vortex95]

Look at these GIF loops from late this aftn.  Classic supercell split mirror pair in
n-cntrl MD.

The left split accelerates and moves N, and the right split moves ESE and is
slow-moving.

 

In a more unidirectional environmental flow w/ wind shear, the supercell

splits both have an equal chance of surviving.  Most of the time tho when

there is directional shear present, it is veering w/ height, so that favors 

the right mover (cyclonic meso), and the left mover (anticyclonic meso) 

does not last long.  

 

Supercells by default split, but often since the right split is so favored

so often from the shear profile, the left split never has a chance and is 

wiped immediately, so you see nothing on radar!

 

And when overall flow is weak/disorganized over an area, the mesoscale

takes over, leading to some odd storm motions and evolutions, as we see

today.