May 16 - June 4, 2024 Severe Weather

[andyhb]

[Quincy]

1 hour ago, Radtechwxman said:

Man models not wanting to pop anything Sat. Very perplexed by this. 

Using the HREF mean as a benchmark, if shows 12hr (12z Sat-00z Sun) neutral or slightly rising heights from the Red River, southward. Subtle negative height tendencies are noted from NW Oklahoma into western Kansas, but more substantial height falls are not progged to arrive until overnight  

The CAPE/shear overlap is certainly conditionally favorable for significant severe. Convective temperatures on the HRRR are close to being reached by 00z Sunday. The 3km NAM shows isolated CI with multiple areas of attempted CI. SREF probabilities are a bit tame too. 

Given a robust jetmax ejecting into the Plains by 00z, it’s hard to imagine there isn’t at least isolated CI. Even if more widespread convection is delayed until evening, the environment only gets more volatile before there is some notable increase in CINH, after midnight.

SPC’s new Day 2 outlook includes a small hatched sig tor area over NW Oklahoma. Given model trends, you could see the most significant tornado threat possibly get nudged back into SW Kansas, with timing centered around early evening, but we’ll see. 

We also need to get through Friday first…

[MidwestChaser]

Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1243 PM CDT Fri May 24 2024

   Valid 251200Z - 261200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER MUCH OF
   KANSAS...OKLAHOMA...AND INTO FAR WESTERN MISSOURI...

   ...SUMMARY...
   Several strong to violent tornadoes, extreme hail, and corridors of
   widespread wind damage are forecast over parts of the central and
   southern Plains from late Saturday afternoon into the night.

[MidwestChaser]

Surprised no one's talking about this.

[Santa Clause]

Amwx is like all snow and mundane shit mainly, there’s a few good severe posters, but I mainly follow on discord and Twitter now 

[Crazieman]

There is another board, found Andy on it.

[RCNYILWX]

00z HRRR supports the strong wording in the day 2 update this afternoon.

[brianc33710]

The SPC Almost issued a day 2 High Risk. This looks serious.  @Quincy Wichita appears to be in the bullseye tonight riskwise at least. They are in 15% hatched tornado, 45% hatched wind & 30% hatched hail--the max SPC has assigned--even if Wichita isn't in the middle of the MOD Risk. Overnight/early am we'll probably see a High Risk somewhere in the MOD. 

[Radtechwxman]

This thread is dead for such a potential significant day tomorrow 

[Chinook]

The 00z NAM 24-27 hour significant tornado parameter jumps way up in western-southern Oklahoma with the low-level jet. The higher STP values really shouldn't be confined to southern Oklahoma there. The 00z HRRR finally decides to put out dozens of storms in the warm sector! (Helping to confirm that the SPC is generally right). Other CAMs tonight keep a lot of the capping with not too many storms. I still don't believe those too much. I think the SPC will be right, with big hatched areas for tornadoes, wind, and hail (see the SPC's moderate risk discussion)

 

this is the 18z NAM (12km) for west of Oklahoma City tomorrow

[Quincy]

What a shift in 24 hours. Last night, models struggled to convect anything in OK/TX Saturday night. Now there is a very aggressive middle signal across the board. It’s odd seeing the HRRR be the most aggressive, but this is not a typical parameter space.

One key difference between tomorrow and May 6th (last high risk) is that we can expect a more westerly component to the deep shear vector. Even if there is convection up and down the dryline, the wind profile alone will strongly favor a supercell storm mode.

[ICEHOCEY77]

another worst case scenario on tap, things really kick off after sunset. holiday weekend chaser convergence in potentially a major metropolitan area. danger, danger.

[andyhb]

Models playing catchup on moisture this morning/early afternoon, including basically all of the 12z CAMs.

[Ed, snow and hurricane fan]

26 minutes ago, andyhb said:

Models playing catchup on moisture this morning/early afternoon, including basically all of the 12z CAMs.

Which of the CAMs do you think is closest.  I'm wondering whether the storms stay N of I-20 or get into the DFW Metroplex proper, my mother, sisters and nieces/nephews are in Euless. HRRR doesn't look that bad so far for DFW.

[Powerball]

3 minutes ago, Ed, snow and hurricane fan said:

Which of the CAMs do you think is closest.  I'm wondering whether the storms stay N of I-20 or get into the DFW Metroplex proper, my mother, sisters and nieces/nephews are in Euless. HRRR doesn't look that bad so far for DFW.

HRRR definitely was a lot more bullish yesterday and early this morning.

But yeah, we've been socked in low clouds all day (and still are as of 1pm) and temps are only in the low/mid 80s. 

With the lack of surface heating to fully erode the cap, I'm pretty confident DFW will miss out on any real activity (other than maybe more cirrus debris and remnant showers).

[Ed, snow and hurricane fan]

15 minutes ago, Powerball said:

HRRR definitely was a lot more bullish yesterday and early this morning.

But yeah, we've been socked in low clouds all day (and still are as of 1pm) and temps are only in the low/mid 80s. 

With the lack of surface heating to fully erode the cap, I'm pretty confident DFW will miss out on any real activity (other than maybe more cirrus debris and remnant showers).

I'm hoping, although satellite shows the clouds burning off quickly, and it is only noon solar time.  I can see where the dryline is now on vis.  Nothing trying to develop, but cu are forming.

[Powerball]

1 hour ago, Ed, snow and hurricane fan said:

I'm hoping, although satellite shows the clouds burning off quickly, and it is only noon solar time.  I can see where the dryline is now on vis.  Nothing trying to develop, but cu are forming.

Part of the reason the storms struggled yesterday in DFW proper is because, aside from the somewhat erractic vertical shear profile causing the storms to easily split as well as somewhat unimpressive mid-level lapse rates, the activity that did pop off along the dry line quickly became outflow dominant due to low-level lapse rates not having a sufficient opportunity to steepen.

Today seems to be playing out similarly (for N. TX that is), but even when the low clouds do finally erode, it will then be a race against time with the high clouds from the TX panhandle blowing in (also working to limit heating).

 

[Ed, snow and hurricane fan]

First dry line storm firing N of SJT.  MCD issued.  https://www.spc.noaa.gov/products/md/md0951.html

[Quincy]

18z surface analysis, along with an auto updating map for Oklahoma dew point trends:

Warm front is moving quick and it’s movement north and will be a key factor with influencing significant severe potential from northern Oklahoma into southern Kansas.

[Ed, snow and hurricane fan]

HRRR shows nothing near I-20 and meanwhile a cell S of ABI showing a hook.

[Quincy]

Incoming PDS Tornado Watch for portions of the Southern Plains. Most high res models are doing a very poor job with moisture return over Oklahoma. HRRR has dews dropping, where they’re continuing to steadily increase. 

With that said, the 18z NAM shows numerous supercells up and down the dryline by 5-6 PM with 19z HRRR trending in that direction. Adjust for erroneously low dew points and the NAM solution seems plausible, if not likely. 

It could be a very ugly evening. 

 

[Ed, snow and hurricane fan]

Speaking of the NAM, I'm pretty sure a forecast STP of 51 is probably top 10 all time.

[Quincy]

90/80 probabilities (2+ tornadoes, 1+ significant tornado) for the PDS Tornado Watch. Summary says hail up to 5” in diameter is possible. 

 

[canderson]

2 Tor warned cells in Texas already. One hat N of Throckmorton and the other just S of Abilene. 

[MidwestChaser]

I'm watching Ryan Hall's stream; some of the questions people ask in chat are making my eyes bleed.

[Ed, snow and hurricane fan]

Reed Timmer drove into a developing tornado E of Windthorst (bits of debris floating around, a couple of small vortices around him) on a dead ended dirt road.  The tornado became fairly large about a minute after it passed him.

 

It has taken him about 10 minutes to find a paved road again.  Edit to Add:

https://x.com/lorigraceaz/status/1794494190216519685

 

[KoalaBeer]

Some nasty looking cells popping in OK now in quite the favorable environment. At least the cell heading towards the OKC metro is looking on the downtrend as it might be getting robbed of its potential by surrounding storms. 

[canderson]

That is massive hail near Woodward - perhaps approaching tennis ball size.  

[CheeselandSkies]

2 hours ago, Ed, snow and hurricane fan said:

Speaking of the NAM, I'm pretty sure a forecast STP of 51 is probably top 10 all time.

That's the supercell composite; STP is 15.7 (cin)/11.8 (fix). Still very impressive numbers.

[mob1]

That isolated supercell east of Wichita Falls that's crossing into OK now is really taking off. I think that's the strong cell the HRRR has trekking through southern OK for the next few hours.