May 2024 - General Weather Discussion

[PoliSciGuy]

High risk is indeed coming for tomorrow https://twitter.com/kenjohnsonwx/sta...81328054989185

Very concerned about dusk/early twilight tornadoes on a weekend with a lot of people camping/out on the lake or just driving around after sundown. Gonna be a very dangerous time between 7pm-9pm

[C_M_25]

Who wins tomorrow? The HRRR or the NAM? The NAM has been consistent with a very large cap in place tomorrow. It almost seems like an unreasonably large cap. Guess we’ll have to see. The HRRR has blown up a day that looks absolutely horrible.

[Mr. Blue Sky]

And there you go. I would expect the point forecast percentages to go up to.

And it very well might.

[SoonerDave]

So all the discussion/flare up is due to the HRRR run that basically looks like OK is on fire?

[SEMIweather]

So all the discussion/flare up is due to the HRRR run that basically looks like OK is on fire?

Yes. Notable uptrend in convective coverage relative to previous runs. I actually think a cap bust is no longer the most likely failure mode for tomorrow. At this point, I’m thinking more about whether potential early initiation in NW Texas could act to suppress convection over Oklahoma. Maybe the environment is almost too volatile, resulting in storms choking on their own updrafts. Numerous storm-scale interactions could also have a deleterious effect, a la May 6th where the one storm that produced a violent tornado was the one that managed to remain isolated ahead of the main semi-discrete line of supercells which was largely a mess. Lastly…even with dewpoints in the lower 70’s, we could be looking at temperature/dewpoint spreads of nearly 20 degrees which tends to be unfavorable for tornadogenesis.

To be clear, tomorrow’s environment will be borderline historic, and I’d be surprised if the SPC doesn’t upgrade to a High Risk at some point (possibly as soon as the 1 a.m. outlook that’s about to be released). But always feels worth it to spend a little time thinking about what could cause a slam-dunk event to underperform, because there are no certainties when it comes to severe weather forecasting.

[jn1780]

Messy setup today. It will be a nowcast kind of day. Local forecast discussion had a lot of uncertainty.

[PoliSciGuy]

Looks like moisture is the fly in the ointment today, may prevent storms from firing and taking advantage of this atmosphere

[C_M_25]

Looks like moisture is the fly in the ointment today, may prevent storms from firing and taking advantage of this atmosphere

Dewpoints are projected to rise into the mid-70’s. Moisture is definitely not the problem today.

[C_M_25]

The latest high res NAM is coming around to breaking the cap and producing several large supercells. Looking to be a pretty rough day across Oklahoma. We still have, per that model, a strong cap in place over central Oklahoma, but the storms that initiate out west and move into the area will likely give the west side of okc some issues if we get a storm that moves into the area.

[BG918]

HRRR has storms moving into central OK around 5-6 pm. Anything that forms will likely be a supercell.

[SEMIweather]

The moisture depth in the 12z Fort Worth sounding was not great, and is definitely giving me pause about the magnitude of the threat in OKC. Could easily see an outcome where upscale growth from the initial NW Texas storms works to shut off the moisture return in OKC, not to mention the potential for left splits to come racing up I-44 into the Metro (these would still have a significant hail threat, but next to zero tornado potential). Still, it will only take a change in a few small variables to put the Metro right under the gun, so certainly would continue to keep a close eye on things.

[soonerguru]

For some reason this is giving me extreme anxiety today, much more so than other high alert days.

[SEMIweather]

About to head up to Woodward as I suspect that the most photogenic storms of the day will be along the OK/KS border. As for OKC, currently thinking a 7-10 p.m. arrival time for the storms. Significant hail threat, lower tornado threat as I expect the main event for OKC to be left-splits from the NW Texas supercells. If NW Texas convection is less widespread than what has consistently been modeled, then the tornado threat for OKC could increase as fewer left-splits could open the door for more dominant supercells between I-40 and the Red River.

[John1744]

The latest models really wants to drop 4-5 super cells along I-35. Also the storm chasing discord all seem to agree moisture is pouring in faster and stronger than expected.

Here’s hoping for a bust! Ok or maybe one picturesque tornado over a field somewhere.

[SEMIweather]

About to head up to Woodward as I suspect that the most photogenic storms of the day will be along the OK/KS border. As for OKC, currently thinking a 7-10 p.m. arrival time for the storms. Significant hail threat, lower tornado threat as I expect the main event for OKC to be left-splits from the NW Texas supercells. If NW Texas convection is less widespread than what has consistently been modeled, then the tornado threat for OKC could increase as fewer left-splits could open the door for more dominant supercells between I-40 and the Red River.

You can see an example of the above in the 16z HRRR, which models less convection in NW Texas and fires up a nasty looking supercell along the OK-51 corridor as a result.

[crimsoncrazy]

HRRR has been crap so far this year.

[C_M_25]

HRRR has been crap so far this year.

Been listening to Tuttle, eh?

For the record, the NAM is coming around for large storms today too.

[SoonerDave]

Radar showing initiation in NW Texas a good distance SW of Wichita Falls. FWIW.

[soonerguru]

Radar showing initiation in NW Texas a good distance SW of Wichita Falls. FWIW.

Can you expand on the implications of this?

[runOKC]

PDS tornado watch incoming for western and central Oklahoma.

[soonerguru]

I really miss the weather chats we had access to back in the day. It was a real service

[SoonerDave]

Can you expand on the implications pf this?

Prior discussion suggested the formation of storms in NW Texas *might* mitigate the bigger tornado threat in central Oklahoma. Stress *might*.

[SoonerDave]

I really miss the weather chats we had access to back in the day. It was a real service

I remember the guy who ran those and I think actually started this weather-specifix forum/page. Think his name was David and he was super nice
Hated to see him leave but he got a good opportunity closer to home as I recall. We had live chats and realtime reporting, really something actually. He gave great information! Anon and Semi do a.great job here too.

[Ginkasa]

I remember the guy who ran those and I think actually started this weather-specifix forum/page. Think his name was David and he was super nice
Hated to see him leave but he got a good opportunity closer to home as I recall. We had live chats and realtime reporting, really something actually. He gave great information! Anon and Semi do a.great job here too.

Went by "venture" around here.

[C_M_25]

Saw they sent up a new sounding balloon. Looks like a cap still in place but I have no idea if it’s stronger or weaker than what was expected. Anybody take a look yet?