Monday, April 25, 2016

Tornado Outbreak Likely In Central Plains Tuesday

A severe thunderstorm that had a tornado warning associated
with it near Ellsworth, Kansas Sunday.
Photo from Twitter via @basehunters.  
UPDATE 2 p.m. EDT:

NOAA's Storm Prediction Center just updated their forecast for tomorrow.

There's still quite a risk for severe storms and tornadoes in the central Plains.

When I wrote my summary this morning, I speculated that the Storm Prediction Center might upgrade the risk to the highest on their five-point chart.

In this update, they kept the risk level at moderate, which is fourth out of fifth highest.

High risk implies they expect numerous strong, long tracked tornadoes. Moderate in part means there could be some, but not numerous strong, long tracked tornadoes.

A fine distinction, but one nonetheless.

At this point, conditions don't point toward many, many super big tornadoes, but there could well be a few. Still definitely a dangerous situation.

The Storm Prediction Center also expanded the area of expected moderate risk southward into far northern Texas as they expect a greater aerial coverage of dangerous storms.


The forecast is ominous for the central and southern Plains Tuesday afternoon and evening as there is an outbreak of tornadoes and severe storms looming.

 Some of these tornadoes could be quite big and particularly dangerous.

If any of these hit populated areas, that would be very, very, VERY bad.

At this point, the area of biggest concern seems to be southern Nebraska, a wide swath of central Kansas and a good chunk of northern and central Oklahoma.

It's  the classic area this time of year to be under the gun for large tornadoes and severe storms.  In that respect, this ominous forecast isn't really all that unsual for this time of year.

The area often finds itself in a storm's "warm sector" near and just south of a warm front, and near and just east of a cold front and/or dry line, which is a sharp line with high humidity to the east and very low humidity to the west.

Add to this mix winds sharply veering winds with height and and unstable atmosphere that encourages very strong updrafts, and you get a twister outbreak in "tornado alley," which this region is often called.

The area I'm describing is under a moderate risk of severe storms and tornadoes Tuesday. It's the second highest level of alert on a five point scale from NOAA"s Storm Prediction Center.

Actually, the SPC might be toying with the idea of bringing this up to their highest risk level forecast, but they first want to see more data to determine whether that high risk is warranted.

For the record, if the SPC puts out a high risk alert for tornadoes, that's kind of rare. They only do that, on average, maybe three times a year.

Whether it ends up staying a moderate risk or a high risk, this likely storm outbreak is one to take seriously.
Tornado near Nelson, Nebraska Sunday, via Twitter @povlen13

As the Storm Prediction Center writes in its analysis issued very early Monday morning describing Tuesday's threats: "Strong, potentially long tracked tornadoes, very large, perhaps giant hail and damaging wind gusts will be possible with any storm that develops in the warm sector."

You know to be nervous when the SPC highlights the chance of strong long tracked tornadoes.

They seldom predict "giant" hail, which the kind of softball to even grapefruit sized hail that trashed some towns near Dallas, Texas earlier this month.

Of course, whether there is a lot of damage and risk to life depends upon where these potential strong and long tracked tornados touch down.

There is a lot of open, sparsely populated areas in the area of moderate risk. We can certainly hope that the strongest tornadoes and biggest hail comes down where very few people live. Big tornadoes are a thing of perverse beauty when they roll over wide open plains without hitting houses, businesses or occupied cars.

However, violent tornadoes obviously become terrible tragedies when theyslam into cities and suburbs, as they did in Moore, Oklahoma in 2013 and through Joplin, Missouri and Tuscaloosa, Alabama in 2011.

The large metro areas most at risk Tuesday from strong tornadoes include Wichita, Kansas, and Oklahoma City, where Moore is a suburb.

Let's just hope the supercells that will produce the tornadoes bypass these cities.

The threat of severe weather and possible tornadoes in parts of the nation will continue daily today through at least a week, as the weather pattern will favor this kind of weather.

There is a lot of uncertainty on many days as to exactly where and how extensive severe weather might be, though potential hot spots include areas  around Chicago, on Wednesday in the central and southern Mississippi Valley and perhaps northern Texas Friday.

There were a few reports of tornadoes Sunday in southern Minnesota and Nebraska, but it doesn't seem damage was all that great, which is a good thing.

Up until now, the number of tornadoes the nation has had so far this year is below average, continuing a trend that has lasted nearly four years now. Which is a good thing.

However, this week's storm systems will certainly boost the number of reported tornadoes this year

No comments:

Post a Comment