Professional photographer James Langford got this shot of a supercell near Allen, Tex. March 27, 2014. Visit Langford’s webiste.

Want more info on the Atlantic storm? Give @NWSBoston and @NWSCaribou a follow for some great tweets!

— NWS Northern Indiana (@NWSIWX) March 26, 2014

The National Weather Service recently reported that the May 31, 2013 tornado that killed four storm chasers presented a deceptive appearance that might have impacted chaser and spotter safety decisions. Well-known tornado scientist Tim Samaras was one of the four chasers who died, despite his reputation for caution.

Below is an excerpt from the NWS Service Assessment: May 2013 Oklahoma Tornadoes and Flash Flooding:

   Several storm chasers reported the visually-deceiving nature of the El Reno storm and its apparent width. Data received, and used with permission, from a chaser compares the visible width of the tornado condensation funnels to the actual width based on RaxPol (Rapid-scan X-band Polarimetric Radar). Although the tornadic circulation was evident on radar, many chasers did not realize they were in, or as close to, the large circulation (W9LW highlighting). During the time of rapid intensification, the forward motion of the circulation increased from approximately 35 mph to more than 50 mph. This speed increase, combined with a sharp left turn and intense inflow winds, made driving away from the tornado difficult (Figures 18–20).

Figure 18:  Analysis from Gabe Garfield showing “visible vs. actual” tornado width. Red markers approximate visible tornado width and blue markers approximate actual width of the tornadic circulation. Source: Skip Talbot, via NWS service assessment.

Figure 19: Visible vs. RaxPol-derived El Reno tornado width. Source: Gabe Garfield via NWS service assessment

Figure 20: Estimate of the El Reno tornado speed. Source:  Gabe Garfield and Jeff Snyder via NWS service assessment

This information should provide impetus for all SKYWARN storm spotters to reevaluate their safety procedures as the 2014 storm season approaches. It should serve to remind us all that:

• Tornadoes can and do make drastic direction and speed changes (don’t expect them to travel in a straight line).
• Life-threatening conditions can extend well beyond the visible condensation cloud and/or debris cloud, especially in the largest and most powerful tornadoes.

The authors of the service assessment recommended that all future SKYWARN training sessions “reinforce spotter safety and the rules outlined in NWSI 10-1807, The Skywarn® Weather Spotter Program.” That document contains the “10 Golden Spotter Safety Rules,” summarized below (the original 10 rules provide significantly more detail about each rule):

No spotter report or storm data is worth any person’s life. Please share this post with anyone you know who participates in storm chasing and/or SKYWARN storm spotting. Buttons below allow convenient sharing on social networks.

For several years, a Web-based weather reporting system called “eSpotter” has been available to trained SKYWARN storm spotters. They could obtain accounts from their local National Weather Service (NWS) offices and then used the special website to make any kind of SKYWARN spotter report. The report would be relayed immediately to the appropriate NWS staff member. That system is coming to an end this month, according to a Web page on the northern Indiana NWS website.

As a result of the pending termination of eSpotter, the NWS is no longer creating new accounts on the system. Spotters who already have accounts may continue to use eSpotter until it goes off line, but the NWS is encouraging them to begin using alternative reporting methods in preparation for the termination of eSpotter.

The IMO SKYWARN quadrant two net has used eSpotter in the past to relay reports from ham radio-equipped spotters when the ham radio station at the northern Indiana NWS office (WX9IWX) was not staffed. Over the past year, most quadrant net control station operators have obtained accounts on an internal NWS chat room service called, “NWSChat.” In the future, therefore, if WX9IWX is not staffed during a severe weather event, net control stations can relay hams’ reports via NWSChat. NWSChat accounts are not available to all spotters. They are only available to staff members of the NWS and its government partners, broadcasters and members of the emergency management community (including public safety officials and SKYWARN net control station operators).

For those spotters who are not eligible for NWSChat accounts and who prefer to use an Internet-based reporting method, below are the best alternatives. (This list is focused on the northern Indiana NWS office. To learn how to send tweets, Facebook messages, etc. to other offices, contact those offices):

Of course, non-Internet reporting methods remain available, including ham radio (for licensed operators) and telephone, using the special toll-free number that the NWS provides to spotters when they attend training (if you attended training but don’t have the number, use the email address above to request it).

Indiana’s statewide tornado drills today provide excellent opportunities to practice what you would do if the National Weather Service issued a real tornado warning for your area. Here are the basics:

1. Listen to or read the entire warning. If your first notification is from hearing a siren, turn on a radio or television or go to the Web to get the details. You’ll learn exactly what areas are covered by the warning, what prompted the warning and what impacts to expect from the storm.
2. If you are in the warning area, take shelter. Do not go outside to look for the tornado. Assume that you are in immediate danger and act accordingly. Below are official recommendations on where to take shelter based on various situations.
3. Remain sheltered until the storm has passed and/or the warning has expired.

If you practice these steps today, when the test tornado warnings come out (once in the morning and again in the evening), you’ll be better prepared for a real warning.

Below are recommendations from the Federal Emergency Management Agency regarding how to take shelter from a tornado:

Earlier this week I wrote about why you should stop believing in tornado sirens and some better alternatives to sirens.

Assuming you’ve chosen a method to receive tornado warnings, tomorrow, you’ll have a chance to see how well the method you’ve chosen works. Throughout the state, the National Weather Service will issue two test tornado warnings tomorrow; one in the late morning (when most people are at work) and one in the early evening (when most people are at home). These test warnings will trigger all the alerts that a normal tornado warning triggers, including weather alert radio, smartphone apps, wireless emergency alerts, radio and television alerts, and yes, even tornado sirens.

So, if the morning goes by and you don’t become aware of a test tornado warning — that is, you don’t hear sirens or get the test warning by any other means — you’ll know you would have missed a real tornado warning. Likewise, for the evening test.

There are a couple possible exceptions. If true severe weather threatens any part of Indiana tomorrow, officials will postpone the statewide drill. Also, in previous years, local officials have unilaterally decided not to activate tornado sirens during the drill. So, if you don’t hear a siren, it might be because you’re not in range of a siren, or it might be because the local officials who control the sirens decided not to participate in the drill.

If you read this blog regularly, you know that the northern Indiana office of the National Weather Service has been supplementing live and online independent-study SKYWARN storm spotter training with “chats” via Facebook and Twitter.

During one of the Facebook chats, a spotter asked an excellent question: If he sees a tornado, should he call the NWS first, or 911? The spotter reasoned that if he calls 911, local public safety officials would learn of the tornado and would relay the report to the NWS.

The NWS replied that they’d prefer to get the first call. This makes a lot of sense, for the following reasons:

• 911 call centers get very busy answering calls and dispatching emergency responders during severe weather. They are often so busy, they don’t have time to call the NWS with the reports they receive. We should never assume that a report made via 911 will get to the NWS.
• 911 call centers might be able to activate tornado sirens, but they cannot issue the official tornado warning that triggers NOAA Weather Radio (NWR) alerts, broadcast radio or TV alerts or cell phone wireless emergency alerts (WEA).
• The NWS, on the other hand, can issue the official tornado warning, which will go to the 911 center, the broadcast media and directly to the general public via multiple channels, including NWR, WEA, smartphone apps, etc.

There can be an issue, however, with calling the NWS. Sometimes, their unlisted spotter report line is busy when spotters call, especially during a widespread event. That’s one reason that the NWS increasingly suggests that trained storm spotters use Twitter (include @nwsiwx or #nwsiwx in your tweet) or Facebook to send reports. These social media channels also allow spotters to add credibility to their reports by including photographs. During periods of severe weather, NWS monitors Twitter and Facebook constantly, so a social media report can actually reach meteorologists faster than a telephone report, especially if the phone line is busy.

Of course, for spotters who are also ham radio operators, ham radio SKYWARN nets provide another alternative to telephone and social media. And ham radio transmission allows other radio-equipped spotters to hear reports as spotters make them.