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Tracking severe weather for Monday

We discussed yesterday the pressure cooker situation of the atmosphere and how much potential energy there was. Refer back to the Skew-T charts I posted talking about the CAPE (which was over 3,000 J/kg). Yet, everything held off. Even what rolled over KC late in the evening was a far cry from what the atmosphere was capable of. Ah, then something happened.

Overnight, after about 1:30am, we finally saw the blow-up of t-storms across the area. Storms on the North end put down hail near ping pong ball size at times. Other locales picked up rain and in some isolated spots: a lot of it.
3

4

So what happened? The Low-Level Jet is what happened. We had the energy in place, we had enough juice in the atmosphere, and we had the lift needed. But the jet helped to feed warm, moist air into the area that was then pushed aloft and created the storms. The Low-Level Jet (or LLJ) is something that happens often in the central part of the country. It’s a small, but strong river of air that resides around the 850mb level, or about 5,000 feet up.
I cannot tell you have many times the LLJ was a key component in generating late night storms in Central Kansas. It was almost like clockwork during May & June.

Here are few charts that might give you a better idea. Both of these were from 7p last night (I was unable to find a decent, understandable upper air chart from 3am). These give a decent idea of what was going on.
850SunAM 500mbSunAM

I know, the charts can still be a little hard to read, especially that bottom one. Basically, the area I circled is Eastern KS and Western MO. The numbers given an indication of the amount of lift going on.

As I mentioned in one of the last updates I posted last night, it seems the RPM model from 6p was actually on to something the whole time! I will give it credit for doing a decent job of indicating storm development after 1am East of the Metro.

Turning our attention to Monday: we could see another round of severe weather in the area. The calendar may say July but the atmosphere plays by its own set of rules. Already the Storm Prediction Center out of Norman, Oklahoma is putting most of our coverage area in a Slight Risk:
3 PM

Don’t be fooled by the term “slight”. There is a big debate within the weather world over the use of that word because the casual person doesn’t perceive that as meaning much. Then, when a monster storm tears up their town they don’t understand why because it was just supposed to be a “slight” risk.
The takeaway here: the area in yellow has a respectable chance of seeing thunderstorms develop. Of the storms that do get going, some will likely be strong to severe. Of the ones that DO reach severe criteria, winds over 60mph and hail the size of quarters to even golf balls is possible. Does this mean everyone will see that? NO. Not at all. But this is why it’s a “slight risk”…. there is a “slight risk” that anyone inside the yellow area could see a storm that produces hail and high winds. Also, a tornado or two cannot be ruled out. The problem here is that despite all of our technology and computers, we cannot tell you with great certainty where exactly a severe storm will occur. No meteorologist can. And if anyone SAYS to you they can, you better hang onto your wallet as well! This is why we use percentage chances.  And when it comes to the SPC, they have a method to what they do. Here is a quick breakdown:

Slight Risk: Means there will be well-organized areas of severe weather, but in a relatively small coverage area. Storms would be on the lower side of severe, with hail mainly around quarter to golfball size and a tornado or two possible. Damaging wind gusts near 60mph are also possible.

Moderate Risk: Well-organized areas of severe weather over a larger coverage area and/or the storms that form may pose a more serious risk (such as hail near softball size or good indications of a tornado outbreak).

High Risk: Not used often, but when put into place it indicates a higher confidence of a significant severe weather outbreak featuring a multitude of severe components (very large hail; numerous large and/or long-lived tornadoes)

Here is a breakdown of how the SPC arrives at their terminology for Slight, Moderate, & High:

That’s just a basic crash course on how the SPC does what they do. You can see how they convert percentages to the various levels. There is talk this year of trying out some new words and changing things up a bit all in an effort to better inform the public.

To get us back on track for the Monday severe weather potential, this is what I believe the threat looks like in the viewing area:
1 PM

Indications suggest the most likely area for severe weather would be North of I-70, mainly from St. Joseph to Chillicothe. This is how the SPC is drawing it up right now:
day2probotlk_1730_any

As you can imagine, we’ll be tracking this all day Monday. And odds are things will likely change just a bit. I encourage you stay with us and be weather aware Monday afternoon. Now, I have to go give the forecast on air. See you in a few minutes.
-JD

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17 comments to Tracking severe weather for Monday

  • Dobber

    Better drag out the garden hose and water the foundation!

  • Weatherfreak01

    With all the thunder and lightning last night I’m surprised we got so little rain here in Lee’s Summit. Nice day here, in the 80’s.

    J.D. I really like your blog write ups. Very well done. They remind me of how the blog used to be, a place to learn!

  • terrydsnowy

    Ready for some strong to severe storm’s for Monday!

  • robyn corzine

    JD great write up once again! Thanks for the informative information. Great information to learn from.

    Once again PLEASE do the blog 5 days out of the week! It is so informative and you offer so much knowledge to learn from. Better then the LRC junk science that was always thrown out here! Keep up the great work!

    I know I need the rain. My sprinkler system is close to coming on. I have soil sensors that measure the amount of moisture in the soil and are set to come on when it gets to a certain level. Just from looking at the dirt around the foundation I would bet they are going to come on in the next few days if we do not receive any rain.

    Hume glad to see you guys finally received some nice rains. I think you will still be in the drought classification when the new report comes out.

  • Drought Miser

    Ummm JD,
    Are tonight’s tornadic cells in Iowa anything to worry about for the metro area tonight or are they just a preview for tomorrow’s (possible) setup??

  • Hockeynut69

    The most likely area for little rain is my house.

  • Drought Miser

    From Drought to Diluge Flash Flood watch now for heavy Rain ?? what gives folks?

    • Dobber

      Droughts over….. That’s what’s gives

      • Pete Capone

        That’s it, Mowermike Dobber (same IP address = same person).

        Don’t let the facts get in the way of your proclamations. We have been below normal EVERY YEAR, including the present year, since 2010:

        KCI year to date: -3.53 inches.
        KCI since beginning of 2011: -26.43 inches.

        JOCO Exec year to date: -4.75 inches.
        JOCO Exec since beginning of 2011: -30.93 inches.

        Facts beat no facts every time, DobberMike.

        • Drought Miser

          Yes I agree we still have some lingering Drought effects but Gary brought up a good point last week if the rivers and ponds and grass is green then we’re doing better.

  • Jerry

    Dude knows how to write a blog — quite impressive.

    Every time I see a lengthy post by JD, or one of his live blogs, I always envision him drafting it quickly, rich with on-point information and confident forecasts, and then staring at the screen, hitting submit, dropping the mic, and walking away.

    Well done.

    • yewtrees

      JD is indeed a very good writer and an excellent weatherman. He explains current or past weather condition in layman’s terms. His explanation as to why the forecast did/didn’t pan out without bias is so genuine. His blogs make my days!!! Keep up the good work, JD!!!

  • sedsinkc

    JD certainly writes an excellent blog. And it’s free! A worthy successor to Mr. Moneybags and his get rich quick schemes.

  • Drought Miser

    Drought Miser reporting live from Merriam Ks…we picked up just a trace of rainfall this morning I guess the flood watch is for later tonight??