Significant Severe WX Event Expected Thursday

051717 Forecast Map

A significant severe weather event is expected over portions of central and south central Kansas and NW Oklahoma tomorrow. Strong tornadoes and very large hail will be possible and there is a real threat to life and property so if you live in that area pay close attention to the weather tomorrow afternoon and evening.

A very moist air mass with dewpoints in the mid to upper 60’s will move north into the plains tomorrow east of a dryline and south of a warm front. The warm front will be lifting north into southern Kansas tomorrow morning. It looks like the warm front will slowly start advancing through Wichita around 8am or so, which will most likely make for a bit of an eerie feeling in the air. It will be very humid and hazy as the warm front lifts through and I absolutely love those types of mornings in the spring where you can just feel it’s a tornado day. That should happen tomorrow morning when the warm front pushes through. By afternoon a dryline will run from near Dodge City south along the OK/TX border, with a warm front running east/west roughly along a Dodge City to Newton line.

Okay, so the surface boundaries stage is set. See the above map for the rough locations of where I expect the surface boundaries to be around the time of storms initiating tomorrow. Storms will likely develop off the north side of the surface low in the moisture wrap around area in SW Kansas first. The high resolution NAM has been very consistent in showing that. Those storms may pose a lower end tornado/hail threat, but moisture quality will likely be an issue. The more significant storms should develop along the dryline, starting near Dodge City where the warm front and dryline come together. What time exactly storms will fire is always tough to know. My guess is 4-5pm. With SBCAPE around 4000 ahead of the dryline and 50kts of deep layer shear the environment will be very favorable for supercells and storms could be explosive when they initially fire. Storm motions will be perpendicular enough to the dryline that discrete supercells should be the favored mode of convection. That being said, I do have concerns about how tightly packed in storms will be coming off the dryline and how long they will remain discrete. I’ll come back to that here shortly.

Judging the extent of the tornado threat tomorrow is tricky. The devil is in the details with tornadoes and everything has to come together just right for you to get higher end tornado potential. The parameters will be there to support it tomorrow. Initially 0-1km SRH is not that strong over the open warm sector. The exception will be in the vicinity of the warm front where backing surface winds will have low level shear supportive of strong tornadoes all through the afternoon. After 7pm 0-1km SRH strengthens over the open warm sector in NW Oklahoma and south central Kansas and the entire area I boxed in red on the map becomes supportive of strong tornadoes. Below are forecast soundings for tomorrow. The first one is from up around Greensburg and the second one is from NW Oklahoma.

2017051800_NAM_024_38.02,-98.77_severe_ml

NW Oklahoma sounding

If you look at the hodographs you can easily see how much larger the low level portion of the hodograph is closer to the warm front near Greensburg than it is in NW Oklahoma. That is one way of looking at low level shear. The easier way would be me posting a 0-1km SRH map, but COD’s new page doesn’t let me copy those maps any more so I won’t lol. Basically though, low level shear is going to be strongest along the warm front and after 7pm it really starts ramping up across the warm sector. One of the tricky things about tornado forecasting is that you can have great parameters all day long, but if you don’t have favorable convective evolution, namely discrete storms, then that potential is not going to be realized. How convection unfolds tomorrow is going to play a big role in how bad of a tornado event this is.

I plan on heading to Dodge City for my starting point tomorrow. The exact location of the warm front and dryline are still a little uncertain, so I may adjust slightly from there, but the triple point is my target and it will be somewhere around there. I think a triple point storm will go first. Hopefully there is a lag in time and/or space between when a storm develops at the triple point and other storms start firing farther south along the dryline. If that’s the case, conditions should already be supportive of tornadoes near the triple point and if a storm coming off the triple point is able to remain discrete for a period of time it will most likely produce tornadoes and very large hail. Triple point storms in general and especially ones on days like tomorrow with a negatively tilted trough have a tendency to get sloppy after a while. I’m guessing that will happen tomorrow, so as soon as I see the storm getting sloppy or losing it’s tornado potential, I’m bailing east and getting out ahead of any dryline storms coming up from the south. That’s my chase plan for tomorrow. If I weren’t doing that, another good play might be the tail end play and going for a more discrete/tail end storm down around I40 in Oklahoma. That would most likely be easier chasing with a photogenic storm option, but I’ll stick with the more hectic and volatile Kansas play.

Time to wrap this rant up lol. I am virtually certain we will get tornadoes tomorrow. The parameters are too strong in the right time of year for us not to get tornadoes. The question is how bad will it be. The parameters will be there to support strong long-track tornadoes if there are discrete supercells across the warm sector all the way until dark. The question is how discrete will storms remain and how long will they stay discrete. My guess is storms will be more tightly packed than I’d like coming off the dryline, but there will be a handful of dominant supercells that track from NW Oklahoma into south central Kansas capable of strong tornadoes as they do. Around dark I imagine they’ll start to fill in more, reducing the tornado threat with most storms, while any tail end or remaining discrete storms still pose a tornado threat after dark.  I think we are probably looking at a major severe weather event with some strong tornadoes. It’s the type of day you need to take very seriously if you live in the threat area. There are usually only a few days a year where there is a high risk to life and property from severe weather and tomorrow is one of them.

It should be a little more clear how storms will unfold with morning CAM guidance, so check back then if you’re interested. I’ll be posting regularly through the day. Once I get on a storm I post pictures to Facebook and twitter, so you can follow me on either one if you want to see my pictures while I’m in the field. If you are chasing tomorrow be careful and good luck.

 

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2 Responses to Significant Severe WX Event Expected Thursday

  1. Samuel Stone says:

    Exactly what i was thinking miky, pending morning hi-res guidance ill be heading south west from manhattan towards pratt. I dont want to get too close to the triple point at first unless i want adjust my plan to further south. But right now i like the WF/TP play. It may be only an hour or so that TP storms stay discrete but tha may be all it takes w/ this amount of CAPE and SRH

    • Administrator says:

      It seems like the reasonable play to me right now. Good luck and be careful out there tomorrow.

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