I think this is a reasonably straightforward forecast. Tornado threat peaks in Western OK between 5-7 p.m. then an organized MCS will roll into OKC between 7-10 p.m. with a significant wind threat and a secondary threat of large hail and an isolated QLCS tornado. The hi-res models might jump around somewhat in their exact depictions of this event as the day progresses, but I would be very surprised if the general timeline/storm mode changes too much at this point.

Lesson #1 for newcomers to OKC: Don't listen to Mike Morgan.

Likely going to see SPC upgrade most of the state to Slight Risk for Thursday. Perhaps a corridor of Enhanced Risk out in W OK where storms would begin more isolated.

The common theme of these MCSes lately has been to start as supercells, then upscale into a cluster of storms with some remnant embedded supercell structure. This is going to be initial large hail threat, outside tornado threat, then emphasis on severe wind threat.

EDIT: Also going to note that SPC is outlining 15% probability of severe risk for Saturday evening across KS and into N OK. Latest model data also suggesting a southern expansion of this threat. So expect more of the same for Saturday.

Forecast still the same. Moderate Risk for W and C OK. Also as expected, SPC has expanded the Slight Risk for Saturday to include basically the entire state.

https://www.tropicaltidbits.com/analysis/models/fv3-hires/2023061512/fv3-hires_ref_frzn_scus_11.png

Ok, everyone should take a deep breath. Will there be storms? Yes. Will there be a tornado or two? Possibly? Is this going to be a major tornado outbreak (like some have been hyping for over a week now)? Not likely.

This is going to be a wind and hail maker for OKC. The biggest threat for the bad stuff is obviously out west, but those storms will line out as per usual for this time of year. I’m sure the supercell structure will be imbedded in the line and I wouldn’t be surprised if a remnant spin up or two happens in our area, but the impacts from those are pretty minimal. Just be aware storms will come in. They’ll be severe. There will be hail and wind. Possibly very large hail and high winds. Move your cars in the garage and take a deep breath.

Now, the models are interesting this morning. The high res NAM is forming a north and south line that essentially splits the city with some follow up smaller storms after the main event. The HRRR is also trying to do this a bit as well. If those large supercells fire in the southwest, their outflow boundaries could effectively eliminate the severe weather threat for okc. Will be interesting to see how it plays out. I’m not holding my breath though for a major impact to the okc area at the moment though.

I don't think anyone here is too concerned. Most are a little bit surprised that the models started trending toward more favorable for Severe storms in the past day.

The big thing for today is how high are the cloud bases are these storms surface based meaning the cloud deck is say below 3,000 ft. The other thing to look out for is are these storms separate. There are a few computer models that keep them separated Did anybody else notice there's a slight risk for Saturday now also.

Saw a couple forecasts calling for 90 mph wind with baseball sized hailstones. That would not be very chill imo.

Saw a couple forecasts calling for 90 mph wind with baseball sized hailstones. That would not be very chill imo.

Latest NWS discussion explicitly mentions the possibility of baseball to softball sized hail and 80 to 90 mph wind gusts.

https://mesonet.agron.iastate.edu/wx/afos/p.php?pil=AFDOUN&e=202306151725

Yeah these are some crazy dynamics. Also, temps and dews are already running hotter than some of the models, which means this event is definitely uptrending

https://twitter.com/invertv_dcape/status/1669358381315035140?s=46

I feel like the recent models have pulled the most unstable air back to the west a bit. Looking at the high res NAM, it really looks like these storms start to rapidly degrade once the get to the okc area. The HRRR is still showing a good line of storms, and it shows them moving very rapidly. NAM seems to be favoring weakening by the time they are here, and the HRRR is happy maintaining that storm intensity.

Also, the dewpoints look really low right now. Wonder if we’ll see rapid intensification of those. Don’t see how we can have such monster storms with dewpoints in the low 60’s.

Actually, looking at the NAM on a different website, it looks like it has almost nothing affecting us whatsoever. Weird to see such disagreement here.

We've got dews in the 70s in SW OK and surging northward. Wouldn't be surprised if we're in the high 60s/low 70s by the time the line gets here

Tornado Watch coming for Western OK. Guessing they will wait to issue anything for the Metro as we are still 4+ hours out from anything reaching the US-81 corridor.

https://www.spc.noaa.gov/products/md/md1076.html

Watch is out, includes the metro. 90mph gusts, "DVD sized" hail https://twitter.com/NWStornado/status/1669427828432195584

I guess just err on the side of caution today, but I don’t see why OKC is included in this. Almost every model has backed off on the impacts of this system on the city. I guess we’ll see. Regardless, I’ll have my car in the garage just in case.

Watch is out, includes the metro. 90mph gusts, "DVD sized" hail https://twitter.com/NWStornado/status/1669427828432195584

dvd sized. does that mean it will be flat?

Initiation north of Mangum.

Initiation north of Mangum.

That thing went from blip to severe warned in like 10 minutes, jeez

That thing went from blip to severe warned in like 10 minutes, jeez

That's what 3500 J/kg of MLCAPE will do lol. Summer instability combined with spring shear means big trouble.

As long as it's not Blu-Ray size, should be okay.

As long as it's not Blu-Ray size, should be okay.

or Laserdisc sized hail.

I think okc has 2 things going against us tonight:

1. Low dewpoints (that could change)
2. The outflow boundaries from the southern cluster of storms that will move out ahead of the main MCS will drastically lower severe weather chances for us.
3.

Norman dews are up to 68 and surging north. We'll be into the low 70s by the time the line moves through most likely

The NAM has completely backed off of any rain for the okc area.

or Laserdisc sized hail.

That would be a record.

Watch probabilities show 90% chance of hail greater than 2" diameter with tallest storms. Hobart storm is ready to party ~ 3;33pm.

Storm east of Granite has a nice velocity couplet developing.

Do you all have a place that the weather "nerds" chat during storms? Discord etc?

Do you all have a place that the weather "nerds" chat during storms? Discord etc?

Ryan Hall's Discord server isn't a bad place to start, though it can get a little unwieldy during big events https://discord.gg/ryanhallyall

What time are we thinking these will get to OKC?

What time are we thinking these will get to OKC?

The storm(s) down across SW OK will stay south. Any new development north of that and into the cells firing up in the panhandle will be the sweep-thru action that could impact OKC later this evening.

The storms there should continue to upscale into large MCS. Damaging wind threat will exist all points SE of there.

SERIOUS supercell down there just passing E of Lawton.

SERIOUS supercell down there just passing E of Lawton.

Lawton has been hit hard by storms this week

Storm passing through Southern metro

Won't this little storm rumbling through SW OKC kinda beat up the atmosphere a bit?

Won't this little storm rumbling through SW OKC kinda beat up the atmosphere a bit?

Nah, if anything it'll put down some outflow boundaries that will stir things up even more. There's more than enough juice in the atmosphere for multiple rounds

Does anything show a mini tornado or something similar near SW 104th and Macarthur Our neighborhood had sudden high winds that took out trees, blew furniture and firewood all over the neighborhood. Was about 415-430 ish

Does anything show a mini tornado or something similar near SW 19th and Macarthur Our neighborhood had sudden high winds that took out trees, blew furniture and firewood all over the neighborhood. Was about 415-430 ish

Nah, not a tornado. Most likely just bursts of wind from these storms trying to pop up across the area. They are moving very fast so it happens in minutes.


Mesoscale Discussion is out for MCS development across NW OK.

https://www.spc.noaa.gov/products/md/mcd1083.png


NWS Storm Prediction Center Norman OK
0453 PM CDT Thu Jun 15 2023

Areas affected...southwestern Kansas...eastern Oklahoma/Texas
Panhandles...and northwestern Oklahoma

Concerning...Severe Thunderstorm Watch 306...

Valid 152153Z - 160000Z

The severe weather threat for Severe Thunderstorm Watch 306
continues.

SUMMARY...The severe wind threat is increasing across the southeast
portion of Severe Thunderstorm Watch 306 as storms continue to
organize and grow upscale and move eastward through the late
afternoon and evening.

DISCUSSION...The convective line is beginning to orient north-south
across southwest Kansas into the northern Texas Panhandle with
occasional severe gusts already being measured. Westerly shear
vectors through the low-to-midlevels should favor this orientation
for forward propagation to the east as the storms/cold pools
continue to merge. The downstream environment and latest WoFs runs
support this organization and eastward movement, including the
potential for significant severe wind gusts.

..Jirak/Grams.. 06/15/2023

Cell coming up in Weatherford is potential C OK impact. It is in clear area with high instability. ~6;35pm

Cell coming up in Weatherford is potential C OK impact. It is in clear area with high instability. ~6;35pm

In Binger currently, about to head N/W towards this one. It has the classic “knuckling tops” look that occurs when a storm is quickly intensifying.

In Binger currently, about to head N/W towards this one. It has the classic “knuckling tops” look that occurs when a storm is quickly intensifying.

Yea get up into Hinton and see if it is going to hug I-40.

Cell coming up in Weatherford is potential C OK impact. It is in clear area with high instability. ~6;35pm

Yeah and we've got the LLJ about to kick in in the next hour or so

50mph gusts registering on Mesonet up in NW OK associated with the cluster of storms. The southern end of the complex has embedded supercells dropping monster hail and potential tornados. There is a lot going on right now.

Wow that supercell in SW OK heading into TX is a sight to behold

Wow that supercell in SW OK heading into TX is a sight to behold

Looks like three distinct TW’s attached to it?

Man. Blair down in southwest ok getting slammed again. Another impressive supercell down there.

A lot of cells coming up now between the main line out in NW OK and into C OK. Localized flash flood threat will be increasing as we head into the night.

It is starting to get really junky in OKC. So many storms are popping up.

Hopefully that line doesn't split and miss OKC altogether.

Raining hard at my house... It feels like one of those storms where there is going to be some hail.

Glad I put fertilizer down today!

The NAM has completely backed off of any rain for the okc area.

I think the NAM missed on this system

I think the NAM missed on this system

In retrospect, they all missed on this system. In fact, the early morning HRRR runs were closer to what actually happened today vs the HRRR runs this afternoon. It seems like they were all struggling with the dew points as the day went along for whatever reason.

The line is weakening heading to the city so the NAM did get that one right.

Very messy event and did not really unfold at all like what was modeled due to the early initiation (I’m guessing there was a subtle disturbance that kicked things off) but ultimately the Moderate Risk will probably verify.

Still going to be a wind damage threat with this final round about to move through but the fortunately the higher-end potential no longer seems to be there.

I guess on to the next one. Saturday is already looking kinda spicy especially in NW Oklahoma. Will have to watch carefully.

Man, OKC can't buy a major rain event. It's gong to be dry for a long time, with upper 90 degree temps next week. This was our chance to get caught up on rain, or maybe even ahead. But no. Mother nature is still against us.

Thank you all for your coverage! It was much appreciated!

Man, OKC can't buy a major rain event. It's gong to be dry for a long time, with upper 90 degree temps next week. This was our chance to get caught up on rain, or maybe even ahead. But no. Mother nature is still against us.

Thank you all for your coverage! It was much appreciated!

They're still Saturday night early Sunday morning

These complexes haven’t been dropping as much rain as I had hoped. Very different than the MCS complexes last June that consistently dumped 2-3”. Very odd weather pattern that we’ve been in for the past month

These complexes haven’t been dropping as much rain as I had hoped. Very different than the MCS complexes last June that consistently dumped 2-3”. Very odd weather pattern that we’ve been in for the past month

I easily agree. The storm in Stillwater when it came in just consisted of a fairly mild gust front, wind didn't get over 30 mph, and light rain that never turned heavy and so rainfall amount was only around a .1". Hardly any lightning and thunder. You can't get totally out of a drought with such consistently light rain amounts. That storm system moved so fast across the state that it didn't produce any 1 inch plus amounts except in part of the southern part of the state.

Depending on the model, tomorrow looks almost like a carbon copy of what happened last night. Probably won't be as much instability, however. The high res NAM and the HRRR are differing quite a bit with what to expect. Looks like the NAM is expecting a bit higher dew points and a messier system overall with some larger storms down to the southwest and an MCS that initiates southeast of the city. The HRRR looks a bit more concerning with large supercells remaining intact and isolated heading into the city followed by a large MCS that initiates northwest of the city and hits us pretty good. I get the feeling like if dewpoints stay low and rapidly increase prior to storm initiation (like yesterday), the results will be more like the HRRR run, but if dewpoints are high early, we could get a messy complex of storms and rain showers.