Wednesday, May 25, 2022

Meteorological Mystery: Newly Discovered Information Pertaining to the Udall and Greensburg Tornadoes

Bumped to the top on the 67th anniversary of the Blackwell-Udall Tornadoes. Please see note at the bottom. 

May 4, 2007, looking north: The Greensburg Tornado is exiting the 
city while the Trousdale Tornado touches down to the east.

In my book, Warnings: The True Story of How Science Tamed the Weather, I discussed the unusual similarities between the 1955, F-5 intensity, Udall, Kansas, Tornado and the 2007, EF-5 intensity, Greensburg Tornado. The former tornado killed 82 and the latter 11. Among the similarities were the radar echoes, as shown in this figure from the book. The Udall Supercell was also responsible for the F-5 Blackwell, OK tornado that occurred an hour earlier killing 20. 

Above is an illustration from Warnings. It is a superimposure of the Tinker AFB (TIK) radar on May 25, 1955 (black pen) and the Dodge City (DDC) NWS radar for May 4, 2007. The Udall supercell runs off the top of the tracing because it moves outside the range of the TIK radar. 

Earlier this week, on Twitter, Oakhurst_Wx made me aware of a 1956 Bulletin of the American Meteorological Society paper (BAMS) that features radar photos of the Blackwell-Udall Supercell. They came from a radar operated by Oklahoma A&M (now Oklahoma State) University in Stillwater (SWO). Because of this discovery of these photographs, I wish to offer two hypothesis that are not made in my book that I outline below. There is one factual error in the paper: the range rings' interval in the SWO radar photos are not a constant 10 nautical miles. The interval varies.

Similarities in the Radar Presentation of the Two Supercells
In 1955, the term "supercell" had not yet been coined and it is not mentioned in the BAMS paper. Instead, the supercell is called a "thunderstorm complex." The images below were from ten minutes before (arrow) to the time the tornado struck Blackwell. 
SWO radar images, click to enlarge.
The range of the radar's display appears to have changed between 9:19 and 9:24pm.
There is also an issue with the location of the echoes that is partly described below. 
Figure 15 shows the classic "hook echo" that was and is a signature of tornado potential. Some caution is needed when interpreting the images. The BAMS paper notes several technical issues with the radar's output. In the photos, the direction (azimuth) is incorrectly rotated 13° in a counterclockwise direction. In that figure (arrow), the tornado is on the ground south southwest of Blackwell. Figure 16 was when the tornado reached Blackwell at 9:24pm CST (per BAMS, 9:26pm in more modern National Weather Service references) at a true azran of 347° and 40 miles. 

In Figure 15, it appears a storm is developing southwest of the supercell. It strengthens and races northeast to merge with the Blackwell-Udall supercell. If it is an actual storm rather than a radar artifact, it grows at a remarkable rate in just five minutes Moments later, it begins to merge with the primary storm.  However, the paper mentions the SWO radar was "double pulsing" and to use caution. This caution may be well-founded in that the radar tracing does not indicate an echo merger and the paper's range for Udall was half of the actual range of 
Screen capture of the BAMS article
The "hollow core" was iso-echo contouring which was used
to depict areas of hail and the heaviest rain before color 
radar was invented in 1976.
90 miles with an azimuth of approximately 356 degrees stated in the excerpt above. The photo below was captured 4 to 6 minutes before the arrival of the tornado in Udall. When the Udall supercell (Image A) at 10:29pm (after being rotated clockwise) is compared to the Dodge City WSR-88D image at the time the tornado struck Greensburg (image B), the similarity is remarkable. 
Image A, 10:29pm radar, moments before Udall was struck
For non-meteorologists reading this, when an X-band radar beam passes through an intense supercell, much of the scattered energy is attenuated (diminished) as the pulse passes through the thunderstorm's torrential rain and hail and again when the scattered energy passes through again on its way back to the SWO radar antenna. So, in "real life," the protuberance (P) would be stronger than indicted here. The location of the hook echo (H) is inferred by me with confirmation in the text of the BAMS paper.

The Dodge City radar image (image B) at 9:54pm, as the tornado was passing through Greensburg, is below. 
Image B. Radar image as the Greensburg Tornado was in progress.
Focus on the lightest gray to compare shapes with A, above.
The color version of the Dodge City radar image (image B) is below. The labels P and H are as above.
My conclusion is that the incredible similarity between the Udall and Greensburg supercells continued to the time the respective cities were hit. 

The Supercell Beyond Udall
The BAMS paper includes a map that shows -- as in many other meteorological references -- the Udall Tornado making an abrupt right turn. (path map 1, below) and, possibly, causing scattered damage. The dashes indicate uncertainty and they take the tornado toward the Flint Hills town of Atlanta, Kansas. Those dashes were based on lesser damage in north Udall and some damage east or northeast of town, based on material I have reviewed. 

Based on the previously unavailable radar data, I am offering a hypothesis that the damage east of Udall might have come from a third, perhaps eventually strong, tornado touching down just east of the city.

There is now good reason to believe path map 1 is not accurate in the sense of making an abrupt right turn. The map of the Blackwell and Udall paths (path map 1, below) shows the Blackwell Tornado making an abrupt left turn as it moved north. It would be unusual for the next tornado from that supercell, Udall, to go in the opposite direction. Note also the zig-zag in the path of the Udall storm in between Geuda Springs and Oxford. It is possible that the damage noted when the path was being mapped was due one or more satellite tornadoes, which we also didn't know existed in the middle 1950's (path map 3).
Path Map 1

Now, look at the detailed path map of the Greensburg Tornado and the next in its supercell's series, the Trousdale Tornado on path map 2 below. 
Path Map 2, National Weather Service. Compare to photo at the top of this article.
Like Blackwell, note that the Greensburg Tornado made a left turn that turned into a corkscrew path. Simultaneously, the Trousdale Tornado touched down on US 54/400 just east of Greensburg much like the Udall Tornado touched down near the curvature point in the Blackwell storm did 52 years later (path map 1).

If we return to the Stillwater (SWO) radar images, the supercell continued to move in its pre-Udall direction of slightly east of due north. 
SWO radar images, pre-rotation correction
Interestingly, the hook echo becomes much more distinct at 10:44pm, indicating the possibility of yet another tornado or a continuation of the Udall Tornado. This 1955 Blackwell--> Udall --> Third Strong Tornado would be similar to the 2007 Greensburg-->Trousdale--> Macksville (path map #3) three violent tornado sequence as, based on Doppler radar, they were similar in wind speeds to the infamous 1990 Bridge Creek-Moore Tornado as displayed on a WSR-88D. The official EF-ratings of Trousdale and Macksville were "only" EF-3 because they did not strike structures that were strong enough to rate a higher category. 
Path Map #3, National Weather Service
Greensburg (5), Trousdale (13) and Macksville (14) Tornado Path map. 
Please note the small "satellite tornadoes" (6-12). They were satellites
to the Greensburg Tornado's mesocyclone. 

If the tornado had continued on its existing path, it would have moved through the western edge of the Flint Hills between Douglass and Rose Hill, then north to between Andover and Augusta. These were sparsely populated areas. It is entirely possible that, once damage was found to the east, the meteorologists at the time didn't think to look farther north. 

Adding to the evidence is the BAMS article included the report of cancelled checks from Udall to the west of the town of Florence, Kansas (see below).
I know of no meteorological situation that would have carried the checks 62 miles to the north if the parent supercell had taken a turn to the east. 

As to how far the Udall or, more likely, a third tornado might have traveled, a rough guess is about 25 to 30 miles. The Blackwell and Udall tornadoes were on the ground for that distance. If that is correct, the tornado would have lifted near the location of today's Kansas Turnpike south southwest of the town of Towanda. It was then a very sparsely populated area and the tornado -- by then it was around 10:40 to 10:55 mph -- could have escaped detection. 

Where Was the Wichita Radar Data?
Much of this mystery would have been cleared up if the Wichita Weather Bureau radar had properly tracked the supercell. It did, in northern Oklahoma. However, go back to Image A. Given the orientation of the storm, it would have extended into the eastern suburbs of Wichita. Winds there were gusting to 45 mph with torrential rain and hail. That caused the WB radar to become completely attenuated (blotted out) based on my interviews with meteorologists Ellis Pike and Victor Philips who were working that night. That attenuation, which was not understood in 1955, caused the Weather Bureau to issue a misleading statement that "all warnings have been lifted." Many of the people of Udall retired for the night upon receiving that assurance. Eight-two people died in Kansas. 

Summary
I offer two new hypothesis about the devastating Kansas-Oklahoma F-5 tornadoes of May 25, 1955.
  •  The incredible similarity between the Udall and Greensburg supercells continued to the time the respective cities were hit. 
  • The damage east of Udall might have come from a third, eventually strong, tornado touching down just east of the city. It is also possible a rear-flank downdraft caused that damage and the Udall tornado itself continued on to the north. 
Please consider these results preliminary. I am going to continue investigating and will either report back or will submit a paper to a meteorological journal.

Update 5/25/22: I made my visit to the Udall Historical Society ten days ago and am working on a paper about these findings. However, it is second priority behind my paper on the Tampa Kansas Tornado and the photographs of tipping vorticity

© 2022 Mike Smith Enterprises, LLC

No, U.S. Hurricanes Are NOT Getting More Common

With hurricane season officially beginning next Wednesday, there have been the predictable number of stories from Big Climate contending that hurricanes are getting worse. They are not. If anything, the number of hurricanes hitting the U.S. is going down slightly. 

Thank You for Licensing My Photography

I really appreciated everyone who is licensing my photography! Made another sale just yesterday. 

If you would like to peruse it, my photos at Adobe Stock Photography are here and at Shutterstock are here. You may be surprised by the variety!
Thanks for looking!!

Tuesday, May 24, 2022

Today's Tornado Risk

There is a significant risk of tornadoes in the brown area. 

The area red area has an enhanced risk of thunderstorm-generated wind gusts of 60-75 mph. The yellow area has a significant risk. 
Please monitor the weather in these areas today.

Why We Urge You to Secure Trampolines and Lawn Furniture

Not only did the family lose the trampoline, the neighborhood had to deal with a power failure that was likely prolonged due to having to remove the tramp from the wire. 

When a tornado or severe thunderstorm watch for high winds is issued, please secure your items. 

Monday, May 23, 2022

Drought-Denting Rains

This is the forecasted rainfall for the 48-hours ending at 7am Wednesday. It may be a little low in places. Regardless, this rain is desperately needed in much of the region. 

The Palmer Drought Index to May 15 shows the dry conditions across the area. 
The reddish colors correspond to increasing drought. 

Sunday, May 22, 2022

The Eleventh Anniversary of the Joplin Tornado

...was earlier today. The tornado killed 161 and injured 1,150. 

Until today, I had not seen this video. The tornado is on the ground, cars are flying through the air and something is missing: The sound of tornado sirens!

This was the worst failure of the modern tornado warning system (by the NWS and emergency management) since the Weather Bureau began issuing tornado warnings* in the late 1950's.

As I explain in When the Sirens Were Silent, the National Weather Service, multiple times, said the tornado was going to travel north of Joplin. Their reporting even fooled the weekend meteorologist and news anchor at KSNF-TV. Listen to meteorologist Caitlin McCardle speak in a normal tone of voice even as their weather camera shows the tornado is chewing up the southwest part of Joplin. When she realizes what is on the screen is actually a tornado, her tone changes completely, "Take cover! .. I"m telling you to take cover now!!"
When I interviewed Caitlin as I was researching Sirens, she said the was "shocked" the tornado was in south Joplin. 

But the problem wasn't limited to the National Weather Service: the sirens were not sounded for the Joplin Tornado until the first people had been killed by the storm (they were sounded earlier for a storm that didn't threaten Joplin). Sirens are sounded by local emergency management. 

The people of Joplin were sitting ducks. 

I'd like to tell you this couldn't happen again, but I cannot. I wrote a story for the Washington Post a year ago today about the growing issues in the National Weather Service's tornado warning program. Since the story was published, the problems have only grown worse (here, among many others).

Our nation desperately needs a National Disaster Review Board


* I'm referring to tornado warnings as we define them today. For a time in the 50's they called today's tornado watches, tornado warnings. 

Saturday, May 21, 2022

From Drought to Flood!

The latest Palmer Drought Index shows drought conditions over just about all of the central and southern Great Plains with orange to reds indicating increasingly dry conditions. 

The map is precipitation for the 24 hours ending at 9am. In Colorado, snow fell (70,000 homes and businesses are without power). 

Over the next five days, heavy to excessive rains will fall over the south central part of the country.
The orange is rains of five inches and the amber within the orange area is more than seven inches. If this forecast is correct, flooding will result. 

Friday, May 20, 2022

Gaylord, Michigan Struck By Strong Tornado

NWS's Warning For This Tornado Was Inadequate

The date of May 20 is one of the infamous in tornado history. Unfortunately, we are going to have to add another tornado to the list -- the one that occurred this afternoon in Gaylord, Michigan. 

8:25pm Friday

Update: At 11am pm Saturday, there are two fatalities, 44 injuries and one person missing according to the Detroit News.

While the damage reports are just starting to come in, the storm appears to have been EF-2 to EF-3 intensity as a rough estimate. I have not seen a report as to injuries. Note: NWS rated the storm EF-3 intensity -- a "strong" tornado. 




Photos: Michigan State Patrol except for screen capture which is The Weather Channel's

This morning's blog post included National Weather Service's (NWS) Storm Prediction Center's forecast of a "significant" (my term) tornado risk for northern Lower Michigan. 

Unfortunately, the forecast and warning quality went downhill from there. 

A severe thunderstorm rather than a tornado watch was issued. The chance of any tornado was rated "low" and the chance of an EF-2 or stronger tornado was rated to be "very low" (see lower left).

The warning of the approaching tornado was sub-par, also, if the report of the tornado reaching Gaylord of 3:45pm is correct. The tornado warning was not issued until 3:38pm (below) which amounted
to just seven minutes of lead-time in an obvious situation. This is less than the NWS's all-tornado average for 2012-2022 period of 8.4 minutes. Generally, and it was certainly the case this afternoon, the stronger tornadoes are easier to warn of than the weaker tornadoes. 

In my opinion, a tornado warning should have been issued upon the radar data available at 3:26pm. Since it takes one to three minutes to issue a warning (assume 3 minutes at 3:29pm), that would have given the town 16 minutes of lead time. Per research by Dr. Kevin Simmons, the ideal lead time is 15 to 18 minutes. 
The "hook echo" (arrow) combined with the data from a special weather balloon launch at 3pm made this rather straightforward (for meteorologists: the 0-1km SRH was 233, well above the threshold of 175 and the SIGTOR was 3). 

Instead, the tornado warning was not issued until this data came in at 3:35pm. The tornado warning was sent three minutes later. 

Here is the path of the tornado's rotation track. 
From the rotation track, it appears the tornado struck the west and north parts of the city. 

It is utterly perplexing why the National Weather Service's tornado warning quality is considerably lower now than it was 15 years ago. 

Today's Tornado Risk

The brown areas have a significant risk of tornadoes later today. Please keep up on the latest weather information. 

May 20th - Tornado Anniversaries

Ruskin Heights
65 years ago this evening was the Ruskin Heights Tornado (F-5) which launched my career in meteorology. The photo above (used with permission) was when the tornado was near Ottawa. It was on the ground nearly 80 miles with the south of the Kansas City area comprising the last 20 miles. Forty-four people were killed and about 500 injured. It was the first time what we would, today, consider a tornado warning was issued by the government. 

Codell
The town of Codell, in north central Kansas north of Hays, was a prosperous community at the turn of the 20th Century. One hundred five yers ago today, was the middle of three freaks of nature: the town being hit by tornadoes on May 20, 1916, May 20, 1917 and May 20, 1918. In 1977, Weatherwise magazine published an article I wrote (above) about the history of the torn and its tornadoes. 

The worst of the tree was the last: Ten people died in the area. Below is a photo of the destroyed high school after the last of the three. 

On May 20, 2018, a tornado memorial was dedicated in the town.
In 2022, the town has shrunk to the point that it is no longer on many maps. My interview with lifetime resident Howard Hockett said that while the tornadoes were a blow, the bank collapse in 1929 was the blow that caused the town to slowly begin to die as it was a regional agricultural center. 


Moore
The Moore, OK tornado of 2013 was the last EF-5 intensity tornado in the U.S. -- a record length of time without a storm of that intensity. There were 24 fatalities plus two indirect deaths. 

Below is a photo of meteorologist/engineer Tim Marshall surveying the total devastation.
F-5's are horrible storms. I hope this record length of time without an F-5 continues for many more years!

Thursday, May 19, 2022

Colorado: Late-Season Winter Storm Warning

As of 7:17pm, a cold front was sweeping into the Front Range that will bring a record cold spell.
Note the temperature dropped 22° in ten minutes.

Here is a map of all of the weather warnings across the region for Friday. The winter storm warning includes Denver. It is likely in the Foothills and possible in the City of Denver that leafed-out trees will be seriously damaged by the storm. Sagging limbs may cause power failures. Please prepare accordingly!
WWA = winter weather advisory, which is a lesser condition than a winter storm warning. 

Below is a map of forecast snow amounts from CBS4 in Denver. Great info from the Denver NWS are here
UPDATE, 8:50pm CDT. If you know someone camping in Rocky Mountain National Park, tell them to leave immediately. Some of the new models are forecasting higher amounts of snow than the above. If that occurs, they could be trapped or injured due to falling trees. Rescue might take some time. Get out now!

Paths of St. Louis / Bi-State Tornadoes

We had a number of rotation paths that may have produced small tornadoes in the St. Louis -  Bi-State area earlier this evening. 
Rotation path map. Red-White-Blue > chance of an actual tornado
At lower left, the circle shows the rotation around Leslie, MO where a tornado occurred this afternoon. 

In the Bi-State area, the arrows indicate the rotation paths over the area. Because the storms were moving so quickly (50+mph), the paths are not as precise as usual. From radar, it would appear the most significant rotation was between Ladue and Olivette and up the river from just east of Lemay to downtown. 

UPDATE 9:15pm: NWS graphic of the path of the Kirkwood Tornado, which corresponds to the easternmost of the cluster of 3 arrows. 

These situations are really difficult because they feature quick spin-ups and the NWS had the radar on 3.5-minute mode, so some of the spin-ups occurred between radar scans. I wish more NWS would go to the 1.3-minute mode in tornado situations. 

Farther east into downstate Illinois there is a was a significant rotation track from north of Breese to northwest of Greenville. 

Today's Tornado Risk

The brown areas have a significant risk of a tornado, along with the potential for damaging thunderstorm winds this afternoon and tonight.