It was unfortunately a busy and a fatal weekend across the Plains. More than a hundred tornadoes caused long-track damage, hit homes during the darkness of night, and claimed several lives. As of Monday morning the death toll from the tornadoes has climbed to six, with one person passing away today (Monday) due to sustained injuries from the tornadoes. One tornado has been the lone deadly storm, hitting Woodward, OK.
The storms were advertised well in advance and I think the local National Weather Service offices and the Storm Prediction Center did a great job with a heads up on this system. Here's a look at the days leading up to the event. I snatched this picture off a tweet from The Weather Channel's Eric Fisher.
Follow the pictures from top left to bottom right. Top left is the forecast bullseye for severe weather a week out. Glancing to the bottom right which is the day of (with the reports in green, blue, and red) you can see that the forecast area is very close to the actual reports of severe weather damage. In fact the placement of the high risk area didn't move too much, but just got more detail in the closing days.
I know there were fatalities with this storm system, but I'm happy to see the numbers are this low. If you're talking about more than a hundred tornadoes on the ground during the weekend, and some of them hitting at night, it means a lot of people respected the warnings and got to a safer place. The severe weather threat with this system now shifts east and closer to our area.
This is the visible satellite with this same system. The picture is as of 10 a.m. EDT on Monday the 16th of April. The white colors show where the clouds are and the darker areas show the ground (lack of clouds). This is literally a look down at the earth's surface from space.
We're in the warm sector of this storm system, which usually indicates where the severe weather will take place. However there are a couple things abating the severe weather threat for our area. One is the dry air mass in place and upstream ridging taking place. Note that there is a lot of clear sky across the east coast and as this system moves east, it's going to run into that and lose some moisture. Storms like moisture. They also like heat and lift (which this storm has two of) but the moisture source is lagging behind critical values for us to get some severe weather. Two, the upper-level support with this system is diminishing. Meteorologists watch for shortwaves and longwaves in the atmosphere. This particular wave had LOTS of energy when it crossed the Plains. Now it's starting to lose that and as a result, the thunderstorms will be much more isolated and not as strong.
Still though with a summer-like day setting up shop out there, the atmosphere is becoming what we call 'destabilized.' Warm air at the surface is underlying cooler air aloft, which creates steeper lapse rates and causes air to rise more easily. It increases the buoyancy and can help fuel thunderstorms. On the left is the 10 a.m. EDT update for low level lapse rates, which is the lowest few kilometers of the atmosphere. To the right is the mid level lapse rates, which is higher in the atmosphere for 'elevated instability.' These numbers are pretty solid to support some t-storms. For potentially stronger ones, look for numbers 7°C/km or higher. As it stands these are climbing to 6 and 6.5°C/km as of 10 a.m. Again though, the lack of moisture is leading me to believe the thunderstorm threat will be minimal, but not totally impossible either.
-Meteorologist Steve Glazier