New Liveblog Posted Here
Thunderstorms are starting to fire across the Midwest this afternoon as the third day of our first significant springtime tornado outbreak gets underway. I will keep this diary updated as a liveblog throughout the day, posting a new diary later this evening if necessary. I will update the title occasionally, leaving intact the "Tornado Liveblog" part.
Below the squiggle I've reposted my diary from late last night, with updated severe weather maps. The main threat this afternoon and evening are thunderstorms much like we saw across southern Kansas and eastern Oklahoma, with extremely large hail and a couple of violent, long-lived tornadoes possible. As the storms grow in coverage into the late evening hours, the individual dangerous supercells will merge into a line and form a bow echo, with a severe threat transitioning to damaging straight-line winds.
New updates will be posted below the gray line. All times are Central Time (CT/CDT). You can follow my Facebook feed for the most urgent updates.
UPDATE 14 407PM CT:
Don't watch live coverage unless you have a strong stomach. They're pulling people -- alive, maimed, and dead -- out of the debris in live shots. This is a result of our forever-linked-in world arriving live on the scene to a raw disaster.
UPDATE 13 400PM CT:
This was the elementary school. Breyerwood Elementary School in Moore OK.
UPDATE 12 356PM CT:
If you know anyone who lives in the area, do NOT try calling them. Text them. The cell phone networks are jammed right now. Texts get through much better than calls.
UPDATE 11 344PM CT:
There are no words.
UPDATE 10 340PM CT:
Police reporting entire neighborhoods are "obliterated" like May 3 1999. Breyerwood Elementary School is seen in the smaller picture on the left. The tornado has dissipated but started to redevelop near Stanely Draper Lake SE of Oklahoma City. If/when it redevelops, it'll move into southeastern Oklahoma County.
UPDATE 9 333PM CT:
Breyerwood Elementary School in Moore has taken a direct hit with "extensive damage," and students are trapped. The tornado is moving off beyond Moore now, towards Draper Lake and southeastern Oklahoma County.
UPDATE 8 330PM CT:
The tornado is in Moore right now.
3D volumetric radar display of the tornado:
UPDATE 7 324PM CT:
UPDATE 6 318PM CT:
UPDATE 5 316PM CT:
UPDATE 4 311PM CT:
Moore is going to take a direct hit by this mile-wide wedge tornado. Homes are scrubbed from their foundations. Spotters are reporting EF-4 to EF-5 damage. TORNADO EMERGENCY. Debris is raining from the sky.
UPDATE 3 306PM CT:
TORNADO EMERGENCY FOR MOORE OKLAHOMA AND SOUTHERN OKLAHOMA CITY. VIOLENT, MILE-WIDE WEDGE TORNADO MOVING INTO MOORE OKLAHOMA. LARGE DEBRIS BALL ON DOPPLER RADAR.
UPDATE 2 300PM CT:
A LARGE, DESTRUCTIVE TORNADO IS ON THE GROUND NEAR NEWCASTLE OK, MOVING TOWARDS MOORE AND VALLEY BROOK.
UPDATE 1 -- 215PM CT:
Severe Thunderstorm Warning is up for Oklahoma City and its suburbs. Half-dollar sized hail and 60 MPH winds are possible.
INITIAL UPDATE -- 200PM CT:
Tornado watches are in effect in the red shaded areas until 1000PM Central. The blue shaded area over Michigan is a severe thunderstorm watch in effect until 800PM Eastern.
Two severe thunderstorms are roaring as of 200PM Central, moving towards the southern suburbs of Oklahoma City. They could pick up rotation over the next hour or two as they move into more favorable conditions.
Here's the risk for severe weather today. The red shaded area is a moderate risk for severe weather. Yellow is a slight risk. Green is a risk for general, non-severe thunderstorms.
Here are the probabilities for severe weather on Monday. The percentages mean there is an xx% chance for severe weather within 25 miles of any point within the shaded region.
CAUTION: the below maps were issued at 1130 AM Central Time. Check the Storm Prediction Center for the latest forecasts.
TORNADO risk for today. 2% warrants concern. Black hatching indicates risk for violent, long-lived tornadoes much like we saw on Sunday.
HAIL risk for Monday. 15% warrants concern. Black hatching indicates risk for hail larger than golf balls.
SEVERE WIND (60+ MPH) risk for Monday. 15% warrants concern.
Here's the basic setup that's causing the severe weather:
A strong mid-level jet stream between 18,000 and 19,000 feet above ground level is expected to move over Oklahoma and Kansas on Monday afternoon, packing winds of about 60-70 knots (the filled-in shaded region). These winds are generally going to be from the west-southwest (the skinny part of the barbs points in the direction of the winds).
At the surface, the low pressure system will draw in very warm and moist air directly off of the Gulf of Mexico. The following image depicts surface winds tomorrow afternoon around the same time as the mid-level jet above. The winds across eastern Oklahoma are almost straight out of the south.
The clash between fast west-southwesterly winds at 18,000 feet and slower low-level winds from the south will produce horizontal rotation in the atmosphere due to vertical wind shear -- winds that increase with speed with height. Think of the cardboard tube in a roll of paper towels, laying on its side, spinning above you. That's what happened Sunday over Oklahoma and Kansas, and that's what's going to happen again today over Oklahoma, northwest Arkansas, and southwestern Missouri.
The horizontal tube of rotation caused by vertical wind shear (winds increasing in speed with height).
The next ingredient is the thunderstorms. The air is going to be a soupy mess -- it is almost the end of May, after all. Very warm temperatures with ample moisture will create an unstable airmass as we get into the afternoon hours across the eastern half of Oklahoma. Very cold mid- and upper-levels will allow the air at the surface to begin rising rapidly once something sets off the spark, so to speak.
This spark will come in the form of a front. A sharp cold front will serve as the focus to fire off thunderstorms. The boundary acts as a ramp of sorts, allowing the surface air to rapidly rise into the upper atmosphere -- an updraft -- generating massive thunderstorms.
Jump back to the horizontal tube of rotation. When these updrafts run into this horizontal rotation, it starts to bend it. One half will tip vertical and begin spinning counter-clockwise; the other, clockwise. The counter-clockwise spinning rotation almost always wins out in the northern hemisphere (depending on the winds, but that's another story), and this now-vertically oriented tube of rotation sort of absorbs the updraft.
The horizontal tube of rotation is titled vertically by the updraft, denoted in this image by the orange arrow. The resulting vertical rotation is the heart and lungs of a supercell thunderstorm.
The result is something called a mesocyclone -- a somewhat broad area of rotation that serves as the heart of a supercell thunderstorm. This mesocyclone is like a "super updraft" of sorts, to use a term that would get me kicked out of a meteorology course. Those strong winds 18,000 feet above the ground has a hard time penetrating this rotating updraft and killing it. In fact, it
tilts the updraft. This tilted updraft is really hard to kill, so the supercell lives on for dozens (and sometimes, hundreds) of miles.
The stronger this mesocyclone rotates, the higher the likelihood of a tornado.
The atmosphere in eastern Oklahoma tomorrow is ripe for supercellular development. In addition to the risk for violent, long-lived tornadoes (like we saw on Sunday), very large hail (to the size of baseballs) and damaging winds in excess of 60 MPH are possible.
As was the deal today, I'll post a severe weather liveblog if things start getting nasty. Remember...even though these are deeply red states, people are people. Many DailyKos readers live in these areas. Think before you post -- we're supposed to be the compassionate ones.
GET A WEATHER RADIO
National Weather Service Main Page
National Weather Service -- Central Oklahoma
National Weather Service -- Tulsa OK
National Weather Service -- Springfield MO
National Weather Service -- St. Louis MO
National Weather Service -- Kansas City MO
National Weather Service -- Arkansas (whole state)
Storm Prediction Center Main Page
Storm Prediction Center -- Current Severe Weather Watches
Storm Prediction Center -- Convective (Severe Weather) Outlooks
Storm Prediction Center -- Mesoscale Discussions
Storm Prediction Center -- Storm Reports
Storm Prediction Center -- Mesoscale Analysis Pages
Wunderground's Detailed Radar (click the + nearest to you to see your local radar)
NOAA Weather Models
TwisterData.com's excellent GFS/NAM/RAP model website.
ChaserTV-- live streaming video from storm chasers.
News9 in Oklahoma City provides extremely thorough severe weather coverage. This is Gary England's station -- the pioneers of on-screen weather warnings and chasing tornadoes with helicopters. Their efforts, along with those of storm chasers, have saved thousands of lives.
I'll continuously post updates to my Facebook page on this and most other major severe weather outbreaks.