Today will likely be a very bad day of weather down across the southern Plains. A rare HIGH risk day of severe storms including large hail…damaging winds and the likelihood of long tracked tornadoes are in the making for many parts of OK and parts of NW TX. IF you know anyone who lives down there…even into eastern AR…it might be worth sending them a text to remind them to watch the weather more carefully today…because as I’ll show you in the discussion…there are a lot of things coming together for big trouble down there.
For us…the main issue tonight will be additional rains…I’m not overly concerned with severe weather in the vast portion of the viewing area from this today or tonight. Some locally heavy rains are possible on saturated soils…and a flood watch is in effect for parts of the area. There are still questions though about where the heaviest rains will set up and also the rate of the rain falling which will determine any bigger flood threats. Regardless another 1-3″ of rain is possible.
Today: Increasing clouds and cool by mid may standards. There may be some rains moving in towards rush hour or afterwards. Highs should only be around 60-65°
Tonight: Rain…at times moderate to heavy. Some thunder as well. Temperatures will drop into the lower 50s. That’s important because it may keep the severe weather risk even lower…more on that in the discussion
Tomorrow: IF there is a severe weather risk it would be before 3PM in the Metro as another line of storms comes through. These will need to be monitored because there are ingredients (mainly shear in the atmosphere) that could produce some fast moving stronger storms with some rotation to them. This part of things is somewhat iffy right now. It will be a windy day too.
Wednesday: Calmer and muggy with highs in the 80s
First things first…
For KC we worry about additional rains tonight…the threat of any severe weather locally is minimal. Our viewing area as a whole will remain just rainy and rumbly but if things go according to plan…the worst of the storms will be a long way away from KC.
The issue for tonight locally will be the additional rains on saturated soils. Another 1-3″ is possible overnight although where the heaviest sets up remains to be seen…perhaps farther south of the KC Metro area. 1-2″ of rain, as long as it doesn’t come down all at once…can probably be handled pretty well…and with the fast motion of the rain movement…hopefully that will be the case for most of the viewing area. It’s worth monitoring especially south of the Metro closer to where the worst weather today will be…and that is towards the southern Plains.
It’s not often that the SPC (Storm Prediction Center) issues a HIGH risk of severe weather. That’s a good thing actually. These types of days should be rare…and the last one that was issued was a couple of years ago. The model data and the atmospheric ingredients are certainly coming together in OK and parts of TX today. This is some of the discussion for OK and parts of TX
Like I mentioned…high risk days are somewhat rare…
This is the 61st @NWSSPC "high risk" #severe forecast since 2000. Not surprisingly, ~2/3 of them have been in either April or May. Here's a brief history of these "high risks" and what they mean. https://t.co/DLhuFacyHW pic.twitter.com/F4YuVNPfGF
— Jonathan Erdman (@wxjerdman) May 20, 2019
Only 61 in 19 years…
There have been cases where these haven’t produced as much violent weather like the moniker suggests, and hopefully that will be the case today…but man there is a set-up down there that is dangerous.
Let’s add in OKC area radar…
and regional radar
The storms down there are already going…although the tornadic situation increases after lunch today into this evening and spreads eastbound overnight.
Specifically the tornadic risk…off the charts
This includes the Oklahoma City region…today is also an anniversary of the Moore, OK tornado back in 2013. It was a F5 tornado that killed 24 and injured over 200. At one point it was 1 mile wide.
8:25 AM Update: the HIGH RISK has been expanded to cover more of Oklahoma, including all of the OKC metro area. I don't know what more we can say that hasn't been said. Please pay attention. Know where you will shelter. And take action quickly if you feel threatened. pic.twitter.com/Su05GzGxFC
— NWS Norman (@NWSNorman) May 20, 2019
Flooding is also going to be a huge issue down there.
For us again the issue is additional rains…
The one thing that I’m watching, and I’ve written about this already yesterday and the day before…is how the winds above us tonight will be behaving with regard to the storms/rain.
Rain should start coming into the region towards evening. Temperatures today will remain cool..only around 60°. The rain comes in and the temperatures should drop to 50-55° or so. That is some chilly air for May in the evening at least with rain falling.
That rain cooled air is what we refer to as a “stable” layer of air. The air above it will be warmer. This is what’s know as an “inversion”. What is interesting about tonight is that the winds above the inversion will be cranking at close to 50-60 MPH…that is lower than some guidance suggested yesterday and that’s important. The data this morning would suggest that those winds would have a tough time working down through the cooler stable air…which means that the severe weather threat will be even lower for the KC region tonight at least.
Now areas farther south will need to be watched…down towards Butler…Clinton and down towards the I-44 corridor…it’s possible some stronger winds could affect that region…but for KC I think we go through the night without anything but rain.
There will be a lot of rain tonight…another 1-3″. Hence the flash flood watch issued…
Those are the counties in darker green with the areas of lighter green representing the warnings.
Then tomorrow gets interesting.
This massive Plains storm will be towards Nebraska tomorrow. It will send a dry slot towards the region later tomorrow afternoon. Along the leading edge of the dry slot, which should arrive before 3PM…a new area of storms will develop and move through. Ahead of that area of storms there will be a LOT of wind shear from the surface where the winds will be from the SE to above us where the winds will be from the south and those winds will be blowing at close to 90 MPH. That is a LOT of shear…and that means that IF things come together…especially from the KC area eastbound into MO…some of the storms may show rotational characteristics.
This means that the potential of tornadoes MAY develop…especially on the MO side…but with the storms moving at close to 60=70 MPH…they will be somewhat difficult to track. Hail is possible with the storms as well. The atmosphere east of KC will be supportive of worst storms…and I’m getting concerned about that situation especially…east of the state line…
Tomorrow is the severe weather risk day for our area…not today. ALL modes of severe storms are possible tomorrow…again that would include fast moving tornadoes.
For those who just look at certain severe weather parameters on the various websites…tomorrow is a potential “atypical” day…where instability, even low instability, can get turned into something bigger because of the tremendous wind shear that will exist from the surface upwards.
The map above seems about right to me.
Again tomorrow is the day to watch for severe storms…not today really (aside from the heavy rains overnight).
Our feature photo comes from Annette Keeter