Anyone interested in severe weather, history, or both will greatly appreciate a series of posts that the National Weather Service northern Indiana weather forecast office (WFO) published on the micro-blogging site Twitter yesterday.
And the WFO’s staff should be commended for excellent work gathering a great deal of historical information about the April 11, 1965 Palm Sunday tornado outbreak and for presenting it in such a compelling way.
The WFO prepared more than 100 tweets, many with images of actual text products issued via teletype the day of the outbreak. Other tweets contained Google maps with tornado tracks marked on them and photos of the tornadoes taken by citizens and photojournalists.
To add to the drama, the WFO scheduled each tweet to appear on Twitter at times coincident with the actual times of day that the events occurred. Genius.
The WFO’s series of tweets gives viewers a real sense of how different severe weather forecasting, detection and warnings were 50 years ago. For example, one thing that struck me was the Fort Wayne Weather Bureau office relaying to local broadcast media via teletype word of tornadoes in the Lafayette area. These days, because of better detection and communication technology, you rarely see WFOs issuing text products regarding tornadoes that distant.
If you missed the live tweets yesterday, you’re in luck, because they’re still visible on the Twitter website, even to people who do not have Twitter accounts. Just follow this link. When you get there, scroll down to a point near the bottom of the page to the tweet that reads, “We are beginning the live tweet of the events of 4/11/65, the Palm Sunday Tornado Outbreak,” and then read your way up from there.
I created a new Facebook for sharing weather information, including links to posts on this blog.
I had been sharing quite a bit of stuff on my personal Facebook timeline. But most of the information I shared related to Indiana and nearby areas, and my personal Facebook account has a lot of friends who live to far away to care.
I didn’t want to clog up their Facebook news feeds with irrelevant information, so I created the new Facebook page linked below. I welcome you to check it out:
Below are some photo tweets shared by College of DuPage assistant professor of meteorology Vittorio (Victor) Gensini today as he helped with damage assessment after yesterday’s tornado in the Fairdale, Ill. area. The National Weather Service has preliminarily rated the tornado as a long-track EF-4.
The famous Palm Sunday twin tornado photo, taken along U.S. 33 by Paul Huffman of the “Elkhart Truth”
If you follow the the northern Indiana office of the National Weather Service on Twitter (@NWSIWX) and if your smart phone beeps at you every time the office tweets, you might want to change your settings before tomorrow.
The office plans to send more than 100 tweets to mark the 50th anniversary of the April 11, 1965 Palm Sunday tornado outbreak that killed 145 people in Indiana. No other tornado outbreak in the state’s history has killed that many people.
Presentation slide from northern Indiana NWS office.
The NWS office plans to send tweets in real time, as if it were live tweeting during the actual outbreak. Every tweet will include the hash tag #PalmSunday50. This will give followers a feel for how NWS received information that day and the warnings it issued.
You can follow along, whether or not you have a Twitter account. The tweets will be visible at either of the following Web URLs:
The NWS office has also created a special website that provides detailed information about the outbreak, including photos like the one at the top of this post and first-hand accounts that witnesses provided the NWS.
Explanation of new categories the National Weather Service Storm Prediction Center is using on its convective outlooks.
The National Weather Service (NWS) Storm Prediction Center (SPC) worked closely with NWS offices, social scientists, communication specialists, FEMA, forecasters, and the general public, to arrive at this description of severe thunderstorm risk categories that SPC uses in official NWS severe weather outlooks. More details are available here: http://www.spc.noaa.gov/misc/about.html#Severe
“… an important step toward moving to a day when we have zero deaths from severe weather events…”
Some members of Congress want the National Weather Service (NWS) to devote a larger portion of its research budget to improving forecasts of tornadoes and hurricanes and increasing warning lead times. H.R. 1561, the “Weather Research and Forecast Innovation Act of 2015″ would Impose that requirement on the NWS, if it becomes law. The Science, Space, and Technology Committee passed the bill late last month.
Bill co-sponsor Rep. Jim Bridenstine (R-Okla.) said in his blog, “The Weather Forecasting Innovation and Research Act is an important step toward moving to a day when we have zero deaths from severe weather events, such as tornadoes which can be devastating in my home state of Oklahoma. By prioritizing funding within NOAA’s Office of Oceanic and Atmospheric Research, we can advance critical technologies and capabilities to vastly improve weather forecasting in the United States and save lives and property.”
Bill author Rep. Frank Lucas (R-Okla.) said, “The United States needs a world-class weather prediction system that helps protect the American people and their property. Unfortunately, for the last few years, our leadership in weather forecasting has slipped and we now play second fiddle to the European forecasting offices, who often predict America’s weather better than we can. The bill before us today will help us reclaim superior weather prediction and forecasting capabilities. Our citizens deserve this.”
if you agree, as I do, that the NWS, while doing a good job now, needs the ability to better forecast and warn us about severe weather, contact your own congressman and ask him to support H.R. 1561. The Open Conress website makes this easy.
During a severe weather seminar in DuPage County, Ill. March 14, storm chaser and amateur meteorologist Skip Talbot pointed out that a horseshoe shape in a supercell thunderstorm’s updraft base is often visible before the storm forms a tornado (see figures one and two). Talbot said that this feature is a more reliable indicator of a potential tornado than is the formation of a wall cloud, which does not always happen before a tornado forms.
Figure 1. Horseshoe-shaped updraft base drawn on example radar image of a supercell thunderstorm. The “T” in a circle represents the location of a tornado. Image from presentation by Skip Talbot.
Figure 2. Photo of actual supercell thunderstorm with horseshoe-shaped updraft base indicated by orange line. Image from presentation by Skip Talbot.
Talbot’s presentation was one of several during the annual, day-long Severe Weather Seminar hosted in a western suburb of Chicago by the DuPage County Office of Homeland Security and Emergency Management.
Talbot’s presentation was titled, “Anticipating Tornadoes in Visual Clues,” and focused primarily on tornado-producing supercell thunderstorms. Fortunately, we don’t often see supercells in northern Indiana but all spotters need to know what to look for when those huge storms do arrive.
How big is a supercell?
Speaking of huge, Talbot cleverly superimposed a radar base-reflectivity image of a Plains supercell over a map of the Chicago area. This provided a clear idea of the scale of such storms (see Figure 3).
Figure 3. Simulation of a supercell thunderstorm radar image over map of Chicagoland. From presentation by Skip Talbot.
Tornado red flags
Talbot also provided a valuable list of “tornado red flags:”
Rain moving rapidly from left to right (as viewed from beyond the right side a supercell)
A sudden surge of wind flowing into the supercell
A sudden barrage of positive cloud-to-ground lightning.
While none of the above meet the SKYWARN storm spotter reporting criteria, they can help spotters remain alert to the strong possibility that a storm is about to produce something reportable!
Storm spotting squall lines (QLCS’)
Meteorologist Ben Deubelbeiss of the Chicago National Weather Service (NWS) office did a presentation that focused on “squall line” thunderstorms, to which meteorologists refer as quasi-linear convective systems (QLCS’). These types of storms are quite common here in northern Indiana, especially during the summer.
A QLCS is a line of thunderstorms that can extend hundreds of miles and persist for hours. It typically produces straight-line wind damage. Shelf clouds form along the leading edges of many QLCS’. Deubelbeiss pointed out that the bottoms of shelf clouds often contain a great deal of turbulence that results in many false reports of funnel clouds (See Figure 4). As trained storm spotters, we must guard against getting fooled by that turbulence.
Figure 4. No funnel cloud or wall cloud, just turbulence that often forms on the bottom of shelf clouds, resulting in false reports to the NWS. Photo from presentation by Ben Deubelbeiss, NWS Chicago.
Deubelbeiss also offered some important comparisons between QLCS’ and supercell thunderstorms. One relates to where the action is. In a supercell, our attention is at the right, rear portion of the storm, where tornado formation is most likely. But with a QLCS, “worst is first” as Deubelbeiss put it. The heaviest wind, occasional weak, short-lived “spin up” tornadoes and damage occur along the leading edge of a QLCS, followed by heavy rain.
Deubelbeiss also made an important point about spotter location. We’ve long been told that the best place to view supercell thunderstorms is where the storm’s heavy rain and hail are to our right and updraft is to our left (typically southeast of the storm). But where should we be when a QLCS approaches? Deubelbeiss strongly advises taking shelter in a building before the leading edge arrives, putting as many walls as possible between us and the outdoors. He reminded spotters that QLCS’ can have storm motion of more than 60 mph. He suggested waiting until the wind dies down to look outside for wind damage to report.
Technology for storm spotters
College of DuPage meteorology professor Dr. Victor Gensini provided an informative presentation, “Technology and Software for Spotter and Emergency Personnel.”
Among his recommendations was the GRLevel3 radar software available for PCs for a one-time fee of $79.95. The latest version is available for download at www.grlevelx.com/grlevel3_2/. GRLevel3 displays live and archive NEXRAD Level III data. It displays high resolution base products, dual polarization products, and derived products along with local storm reports, severe weather warnings, the positions of spotters who are registered with SpotterNetwork.org and other data.
For mobile devices, such as smartphones and tablets, Gensini recommended Radarscope (for iOS and Android) and PYKL3 (for Android only). You can find information about Radarscope at www.radarscope.tv and PYKL3 at www.pykl3radar.com. Like GRLevel3, both products integrate with SpotterNetwork.org.
Another valuable resource for spotters – especially the serious “weather geeks” among us – is a Web page maintained by the College of DuPage meteorology department (weather.cod.edu). The “Weather Analysis Tools” menu of that page offers a wide range of nationwide data, including surface maps, upper air maps, upper air soundings, satellite and radar data, numerical model data, etc.
Late season start
Finally, a note about complacency. The severe weather season nationwide got off to a late start this year, without a tornado reported anywhere in the country until March 25. Meteorologist Greg Carbin of the NWS Storm Prediction Center advised the spotters at the DuPage County seminar that climatologically speaking, severe weather someplace in the continental United States is likely to increase through the month of April. Remember also that in the 37-county area served by the northern Indiana NWS office, tornadoes are nearly twice as likely in April as in March, 1.8 times as likely in May as in April, and 1.7 times as likely in June (our peak tornado month) as in May.
Similarly, in the northern Indiana NWS area, severe thunderstorm winds (58 mph or stronger) are nearly 2.5 times as likely in April as in March, three times as likely in May as in April and nearly twice as likely in June (also our peak severe thunderstorm month) as in May.
So, don’t let the late start to the severe weather season fool you. As we get closer June, it becomes much more likely that our area will see severe weather and SKYWARN spotter activation. Be ready!
