Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Late April severe weather risk ~Mon thru next Mon 4/24-5/01


Recommended Posts

SPC nudged the moderate risk a bit farther north into Arkansas, although I think the greatest supercell tornado threat will be to the south, from far East Texas into western/central/northern Louisiana. While low-level flow may be more backed across Arkansas, less instability is likely and the window for discrete convection appears quite narrow. I'd suspect more of a QLCS tornado threat north of the AR/LA border.

SHV 12z sounding shows steep mid-level lapse rates associated with an EML plume and has that loaded gun-type look. The large cap should help keep the warm sector largely uncontaminated this morning, but once convection starts to fire, by early afternoon, look out. 

IMG_1378.thumb.JPG.98b86faa0ef80e3620d9a3f46b3be6b0.JPG

Link to comment
Share on other sites

  • Replies 794
  • Created
  • Last Reply

Golf balls and hen eggs this morning in Cedar Hill, TX ~30 mins SSW of Dallas.  As an aside, it's a cool place, highest elevation in the area.  Cell was semi-discrete but rather messy.  Eventually a double line structure formed in the metroplex, with the aforementioned cell growing upscale somewhat out ahead of the cold front, with another thin line back to the NW right along it.

Link to comment
Share on other sites

Nocturnal tornado threats in Oklahoma/north Texas are not very common, but latest NAM would seem to yield a chance of overnight tornadoes Friday night/Saturday morning in north TX and southern and MAYBE central OK.  This is assuming surface based convection.  Trends from 0z, 6z, and now 12z NAM are to keep inching the instability axis further north.  Warm front looks pretty close to I-44 overnight now on latest run.  Actually, matches up pretty well with SPC's Day 3 outlook.

Some of the more experienced posters can correct me if I'm not looking at something right...

Link to comment
Share on other sites

9 minutes ago, natecast said:

Nocturnal tornado threats in Oklahoma/north Texas are not very common, but latest NAM would seem to yield a chance of overnight tornadoes Friday night/Saturday morning in north TX and southern and MAYBE central OK.  This is assuming surface based convection.  Trends from 0z, 6z, and now 12z NAM are to keep inching the instability axis further north.  Warm front looks pretty close to I-44 overnight now on latest run.  Actually, matches up pretty well with SPC's Day 3 outlook.

Some of the more experienced posters can correct me if I'm not looking at something right...

NAM also favors a potentially significant event on Saturday across SE OK/NE TX/W and N AR.

Link to comment
Share on other sites

10 minutes ago, Wmsptwx said:

Becoming more and more convinced this afternoon will be active in N Louisiana. 

I still prefer that area over Arkansas. Capping inversion remains strong over Louisiana, but CINH is eroding over East Texas where we could see a mixed mode of convection develop over the next 2-3 hours. Definitely watch any prefrontal cells closely later this afternoon.

IMG_1387.thumb.JPG.f8033a6fa8d8c8f3e0053515db324cab.JPG

On a side note, if we were a few weeks deeper into the year and we didn't have the issue of depleted moisture return, tomorrow could have been a sleeper severe day in western Oklahoma. As it stands, the low level jet cranks tomorrow evening with favorable deep layer shear, but surface-based instability is poor. The area will probably see some convection, but I doubt it's significant. 

Link to comment
Share on other sites

5 minutes ago, Superstorm93 said:

I don't really believe that Saturday will be a "big" day outside of a potential MCS and the potential for flash flooding. The NAMs evolution is close to the ECMWF/GFS solution with the meridional jet, but then again its the NAM at 81 hours out. Pretty much worthless. 

I don't either. Just stating verbatim what it shows. Impressive parameter space with numerous discrete/semi-discrete storms by 00Z. Even if a significant parameter-space develops, storm motions would likely inhibit a more significant event due to the likelihood of multiple storm interactions among other things 

Link to comment
Share on other sites

GFS continuously highlighting the area south of the Red River between Wichita Falls and Dallas for CI on Fri. Parameters are pretty impressive in this area to. Nam continues to suggest the llj will be dislocated to the east while gfs/euro suggest a new branch will form west closer to developing SFC low

Link to comment
Share on other sites

Just now, SluggerWx said:

Latest vis satellite appears to show some clearing/break in the clouds in south central AR...

Moderate to strong heating occurring in that corridor from south-central AR to western LA and East TX, along the theta-e axis. Also seeing surface dew-points around 70 in northwestern LA.

IMG_1396.thumb.JPG.25b81673bebafb743c75064091586ad1.JPG

18z SHV sounding is a bit sloppy, with some capping and backed mid-level winds. Enlarged low-level hodographs, however, and HRRR suggests some veering of 700mb winds will occur over the next few hours. 

1A1756FE-3501-4CFE-96E1-8FCC2BCDB3A0-10039-0000077D5A8D722F.gif.dd1494a57fdf51bf935a5928940ea763.gif

 

Link to comment
Share on other sites

13 minutes ago, bdgwx said:

Agreed. I like that area in north central LA as well.

Overlay of CAPE, shear, low LCLs and window for supercells is greatest in northern LA, but it's still a somewhat conditional threat pending discrete convection. 700-600mb wind fields throw a bit of a red flag, but the wind profile should improve at least some by mid-afternoon. If a sustained cell goes up ahead of the line, it will have a high probability of producing a significant tornado. Any QLCS tornadoes with the line would likely be comparatively short-lived and weaker. IMG_1398.thumb.JPG.99c8a0c4ca3b8145fdb8654e3e0b5cd6.JPG 

Link to comment
Share on other sites

35 minutes ago, Superstorm93 said:

FWIW, the 12z ECMWF looks really solid for some action along the Red River area on Friday. Nice bullseye near Paris, TX

Yeah, and the Canadian doubled down on its positive trend from last night. GFS trending the right way, too, thought not as bullish with the LLJ. Finally, the 00z MPAS looks pretty solid along the RR Valley and convects explosively between 21z-00z.

The ingredients are coming together for a respectable threat over N TX on most of the global models, but the NAM is a holdout, with cool air to the N throwing off the MSLP field and kind of spoiling the setup. Unfortunately, we've seen plenty of situations where it's right about that in the early season, so I'm waiting to see whether it will cave over the next 24 h.

Link to comment
Share on other sites

I'm confident that the mode is going to remain unfavorable through this evening's event. That wind profile is not going to cut it. SPC has been really bullish with tornado probs on days that suggest an unfavorable storm mode for a significant tornado event. I'll eat my socks if that 15% hatched ends up verifying. 

Link to comment
Share on other sites

5 minutes ago, Buckeye05 said:

I'm confident that the mode is going to remain unfavorable through this evening's event. That wind profile is not going to cut it. SPC has been really bullish with tornado probs on days that suggest an unfavorable storm mode for a significant tornado event. I'll eat my socks if that 15% hatched ends up verifying. 

I agree, took a good look at output and at best we have hope for a nice qlcs spin up or two.

 

Edit: 

Looking at spc 105p update, they did say threat for strong tornadoes is lower.

Link to comment
Share on other sites

I'm actually okay with the way the end of the line looks as far as cell spacing goes, still some definite potential for semi-discrete supercells later on... But that kink in the low-level hodograph is really demoralizing and if that doesn't fix the tornado threat will be significantly tempered.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...