Storms ravage the Midwest

A two day severe weather marathon stretched from Kansas to Ohio with tornadoes starting near Topeka, and becoming increasingly more destructive, ultimately leaving lives turned upside down across Indiana and northwest Ohio in particular.

The system came into being in an almost textbook manner. There was a stationary boundary in the PLains that needed only be given the energy of an upper level trough to get moving. That was when the severe storms started in Wednesday, with discrete super cells cropping up in northeastern Kansas. In addition to the tornadoes around Topeka, there was very large hail seen in the Kansas City suburbs.

The system got more organized as Wednesday turned to Thursday, and the warm sector we look for in a severe weather outbreak showed up in the southern Great Lakes. Severe weather developed all the way southwest to near Dallas, with strong winds and large hail reported in many locations. It will be the tornadoes found in northeast Indiana and northwest Ohio that will be remembered, though.

Storms rotate the most near the center of an area of low pressure, as a general rule of thumb. There is enough built in vorticity that any storm specific helicity is just added to the mix, and can both make tornadoes and very large hail likely. The low tracked through the Great Lakes, and ultimately, destructive tornadoes followed.

The two areas that were most directly impacted were Winchester, Indiana, where an estimated EF-3 tornado left a swath of destruction throughout the city, and in Logan County Ohio, north of Springfield, were three people were killed by a tornado.

This is the beginning of the severe weather season, lest we forget, and we have at least three more months of the particularly busy part of the year. Fortunately, we are coming off a quiet year for severe weather, and this part of the country is having a quiet spell to recover. Let’s hope this is as bad as it gets this year, but I fear it won’t be.

Cooler air coming, but big snow not likely

The conversation I keep hearing is people being reluctant to say we are at the end of winter, because in recent years, we have seen late March and April snows. It’s been a mild winter, and many Midwestern residents can’t accept that it might just be mild all the way through.

Well, through the middle of March, we have a trend for below normal temperatures, which could certainly make some people think it is a return of winter, but significant moisture isn’t going to come with that cool down, save, perhaps, for the Great Lakes.

Expect a stormy start to the weekend

Slight risk for 3/8

The early part of severe weather season gets it’s typical kickoff in what some people call the “Dixie Alley” which is focused primarily around Mississippi. We aren’t anticipating a massive outbreak on Saturday, but storms are indeed expected the next few days, starting today in west Texas and ending Saturday in Georgia and South Carolina. That leaves tomorrow for, you guessed it, Mississippi.

Low pressure is getting organized today in West Texas, giving rise to our first round of potential severe weather. Storms should be isolated, supercellular storms this afternoon and evening. Not everyone will see storms, but those that do will be threatened by tornadoes and large hail, centered around an area bound by Abilene, Fort Worth and Waco, but possible north into western Oklahoma as well.

The system will evolve overnight and after today’s activity, with the main, original area of low pressure rocketing towards the Great Lakes, and a surface low re-emerging in the ArkLaTex region. The entire system will be more sheared than it will be today, which will mean a lower likelihood of large standalone supercells, however a line of smaller such cells which ultimately form into a line of strong thunderstorms is the likely mode storms tomorrow evening. The greatest threat for severe weather will start around Shreveport before continuing through the night past Jackson and ultimately towards Montgomery.

By the time that Saturday rolls around. we are likely only to be tracking a line of strong thunderstorms. The tornado threat will be limited, but gusty straight line winds and hail are going to be pushing through the Peach, Palmetto and northern Sunshine state before dark on Saturday.

Two points to make about all of this. First, model guidance isn’t all on the same page for severe weather on any of these days. There could certainly be some big storms, including tornadic storms especially today, but tomorrow could ultimately be a low end severe weather day. There is only a slight risk for severe weather, accounting for the uncertainty.

Second, the individual storms will be strongest probably today, in Texas, and in the early afternoon over Louisiana and Arkansas, but will have the greatest coverage in Mississippi and eventually Alabama. After they redevelop tomorrow night, there likely is no turning these storms off until they are offshore.

As is always the case, stay tuned to your local weather authorities, and keep an eye on the weather. I described a narrow corridor, but storms are certainly possible for several miles on either side of this axis.

February Forecaster of the Month

We’re through the warmest meteorological summer in recorded history for a lot of the Great Lakes region and surrounding areas. Among the many challenges of historic weather is finding meteorologists with a willingness to stake their opinion on a forecast that hasn’t ever verified before. For this historic February to cap an historic winter, it was Accuweather that was able to brave the difficult forecasts, and was the forecaster of the month.

OutletForecast Wins (year)
The Weather Channel3.83
WeatherNation1.5
Accuweather1.16
Victoria-Weather1.13
Clime1
National Weather Service0.83
Weatherbug0.33

Spring severe weather is around the corner

I know we’ve already had some rough weather, and I also realize we haven’t seen much winter, but we are now only a few days away from March, and by this point, it’s certainly not out of the question to start bracing ourselves for severe weather outbreaks. In fact, we could see one as soon as this afternoon.

Low pressure is going to tap into the historically warm temperatures in the middle of the country, with an assist from the still seasonably strong jet flowing through the middle of the country. This is a classic comma style severe weather profile. The line from the Cincinnati area to Cape Girardeau of Enhanced Risk will likely include hail and gusty winds, while the bubble in Chicago and Milwaukee looks like a prime spot for a few tornadoes. All parts of the severe weather zone, however, will be poised to receive some of those three categories of severe weather, including some super cells in the southeast as storms develop, and some hail producers in Chicagoland.

As noted above ,the jet is still very strong, especially in the middle of the country.

The jet is a proxy for the temperature gradient at the surface, so the trough, a strong one, moving in from the west is containing the impetus for the storms coming today. The jet will sink a little further south, allowing more seasonable air into the middle of the country, at least for a day or two.

After today’s outbreak, don’t be surprised if we wind up with more again soon, after temperatures climb through the eastern third of the country over the weekend. The jet will still be strong and wavy, which will allow for the fluctuation in temperature and the strong spring storms to bridge those gaps. It’s not unusual to see strong storms this time of year, (though today’s are maybe a bit further north than normal), and they are on their way.

It looks like the Upper Midwest will miss winter

When encountering anyone here in Minnesota lately, the generic weather conversation always steers towards how snowless the winter has been. There is also always the circumspect admonishment that we are probably really going to get hammered in March and April, but the most recent look ahead from the Climate Prediction Center suggests that time is running out for a real shot at snow.

For the end of February, and then to start March, it’s going to be well above normal in the Great Lakes. This, as we head further away from the coldest part of the year means that the time for snow is likely running out, with barely a foot having fallen over the course of the year.

While temperatures have indeed been quite warm all winter, the cold that settled in persistently did so without any moisture: there was no snow during the cold snaps. Snow on the ground would have helped temperatures remain a bit lower going forward, but that was one of the many compounding factors that worked against a normal winter around here.

We’ve been trending towards this being the warmest recorded winter in many places in the western Great Lakes, and a scorching start to March will pretty much lock that in.

A regular reminder to follow the jet stream

Two of the larger weather stories in the last several weeks have surrounded the flash flooding and heavy rainfall in southern California, and now, this week, even yesterday, is the snow falling in New York City and surrounding areas. These are two major media centers, so they get more coverage than the tornadoes in Wisconsin or the severe weather in the southeast of the last couple of days, but they share more in common than just their notoriety.

As I have noted in the past, the thing you have heard of as the “atmospheric river” is basically the conveyor of systems that follow the jet stream. The jet doesn’t typically dig far enough south to be directed at the LA Basin, but that’s exactly what happened earlier this month, when flooding rain came to the region.

Typically, high pressure is in control in the Pacific off the coast of Southern California, which deflects the jet as well as features that would follow the jet. When the jet sinks south and well formed features can move into the Los Angeles area, they interact with the rugged terrain, and flash flooding can arise very quickly, as it did this month.

The jet actually sunk further south out west, but a southwest to northeast streak ran back north through Mexico, the Gulf and along the East Coast. The whole conveyor belt of energy is more familiar in this part of the world, but gave rise to the severe weather in the southern Plains over the weekend, and the snow that fell in the Mid-Atlantic yesterday.

We are used to systems following this jet streak pattern giving rise to nor’easters along the east coast. Because the area within the trough when the jet is angled at southern California is over the ocean, cold air doesn’t move in. On the East Coast, the trough is over the chillier continental US, which means snow on the north side of the jet streak. On this occasion, it was quite a bit of snow.

The jet responds to temperatures over land, but also currents and sea surface temperatures. This is the direct impact that El Nino and La Nina play on the weather over a season. It pays to pay attention when we are in one or the other, because of the role it plays in the jet stream course for a particular season. Knowing where the jet lies goes a long way to telling us what the pattern is going to be.

Video: February Tornado drops near Madison, Wisconsin

Check out the above video from the Milwaukee Journal-Sentinel. A tightly wound area of low pressure, remnant from the activity seen in southern California earlier in the week, swept through the Western Great Lakes yesterday, feasting on very warm temperatures to trigger severe storms from Dubuque, Iowa to Lake Michigan.

The tornado did cause some damage in the Wisconsin town of Evansville, which is south of Madison. The twister will likely be rated as an EF2, based on some estimates I’ve seen, which is quite strong for an offseason storm. The damage around Evansville was enough that US-14 was closed until midday today.

The system also provided very gusty wind in the wake of it’s passage, reminiscent of some early autumn systems in this part of the country. Snow is falling in northern Minnesota, Wisconsin and the Upper Peninsula of Michigan today thanks to the cold air funneled in. The intensity of this clash of air masses is atypical in what should be the dead of winter, and was clearly enough to produce this tornado.

The rest of the month of February looks just as unrelenting as the first week. Temperatures will be below normal for a lot of country, especially east of the Rockies. Meanwhile, more moisture is coming for the west coast. There will naturally be immediate consequences out west, where more moisture is not needed, but also, the change in pattern indicates a pretty wild shift to get there.