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  Severe Storm Detector  SSD.20     by tornadoAlert ®

Alarms faster. A Severe Storm Detector can alarm faster than any other technology, because it scans for storms directly. There are no delays, which are common to  human-initiated warnings. A faster warning translates into more time to get to safety.

Works anywhere. A Severe Storm Detector operates where there is no wireless internet or Weather Radio coverage. The unit is independent; there is no software, computer or cloud access required. And it continues working on a 9V battery backup, even if an approaching storm takes down power, cell service, etc. The internal battery also allows the unit to go where there is no power (to the park, beach, etc.).

Watches while you sleep. The Severe Storm Detector is critical for notification at night. It has a bright strobe to alert you if you are awake and includes a 90 dB siren to wake you if you are asleep.

Helps the most vulnerable. The device is critical for someone who is sight or hearing impaired. Especially useful in manufactured housing or motorhomes, campgrounds and anywhere people recreate outdoors.

Is portable. The Severe Storm Detector can function in a moving vehicle – via an optional 12V adapter – without screen distraction.

Customer Reviews
"This Severe Storm Detector is great. I had warnings of a potential tornado before the National Weather Service alert.”
David Flad, VP, Avon Grove Emergency, PA
* * *
“On June 18 [2021] we had some severe thunderstorms move through Warren County, Ohio. I have 2 of the detectors, and both read "Severe Storm," but the National Weather Service Office did not issue a warning for our county at that time. Later the devices indicated "Tornado Risk" and not much longer after that displayed "Tornado." About 10 to 15 minutes afterward, NWS did issue a tornado warning and said that the tornado was in Warren County. So, I can tell you, these devices do work, and sometimes deliver alerts sooner than NWS.”
Tim, Maineville, OH
* * *
"I will share that last night about 7:45 PM my Severe Storm Detector alarm went off with 'TORNADO RISK' on the display. About 5 minutes later, my Weather Radio Receiver alarmed with a 'Tornado Warning' for our county. I thought you should know. The tornado was 14 miles south of us and did not touch down. But this Detector alerted me a full 5 minutes ahead of the NOAA Weather Radio warning.”
Jeff Gill, Franklin, NC
* * *
"The weather quickly deteriorated after suppertime (about 6 PM EDT).The Severe Storm Detector began "waking up" and reporting lightning then severe weather. Then at around 11:10 PM, the tornado warning message was displayed. The NWS weather radio said nothing about a tornado actually near us but simply a tornado warning was in effect for a fairly broad area. After a few minutes of indecision, we decided to go to the safe room. At 11:20 PM, the safe room door was closed and locked. Within a minute or so, we heard the tornado roar by. We sheltered for about 15 minutes before opening the door to check if it was safe to get back out. As best I can tell, the Severe Storm Detector gave us 10-15 minutes of early warning in which we had time to warn other family members and get to shelter ourselves. I have heard similar timeframes from others that own this device."
Gary Ownsby, AK4ZX, Chattanooga, TN
(Mouse over for answers.)
Is Severe Storm Detector just a Weather Radio receiver or internet app?
No. Just like a smoke detector triggers on the presence of smoke in your house, the Severe Storm Detector uses direct-detection technology to alert you when it detects the presence of severe storms within 30 miles. That includes lightning, severe thunderstorms and tornados. It does not rely on any commercial infrastructure such as the NOAA Weather Radio Network or a wireless internet signal.

A Severe Storm Detector independently monitors electrical activity in the atmosphere using radio frequencies – much like a smoke detector continuously monitors the air in your house for smoke. There is no service to sign up for or a signal coverage map to reference.

As a result, a Severe Storm Detector can function anywhere in the planet: even in remote areas where there is no Dopplar radar to detect tornados; even where there are no NOAA Weather Radio or wireless internet services to deliver storm warnings. Sometimes, Weather Radio and wireless services are offline due to the very storms they are supposed to be warning you about; but a Severe Storm Detector continues to protect you, unaffected by outages.

Its battery backup allows it to operate even when the power goes out. Because it senses violent weather directly; there are no “system delays” in the delivery of its warnings. And unlike Weather apps and the NOAA Weather Radio Network, the notifications you receive are pertinent only to your specific location – not an entire region or county.
How does Severe Storm Detector detect a severe storm or tornado?
The Severe Storm Detector measures the amount and character of electrical energy in the atmosphere within 30 miles of a given location, identifying specific electrical signatures indicative of low intensity lightning storms, non-severe and severe thunderstorms, the immediate risk of tornado formation and tornadoes. From a measurement of electrical signal intensity, it estimates storm distance from your position.

The Severe Storm Detector monitors specific radio frequencies with an internal antenna and keys on electrical patterns emitted when severe storms and tornadoes form, much as the NOAA GOES-R weather satellite does.

When air rotates with dust or water particles, it becomes electrified. Nobel Laureate Philip Lenard, as far back as 1905, studied the phenomenon. More recently NASA has studied and measured these electrical charges extensively.

The Severe Storm Detector is based on 40 years of NASA-validated research into severe storm formation, and became reality as a result of the advent of the microprocessor, on which its design is based.

Inside the Detector is a small computer connected to a receiving antenna that is constantly scanning atmospheric radiation and running thousands of calculations at sub-millisecond rates. It then runs secondary calculations to accurately approximate the distance of the threat in relation to the unit’s precise position.
Submit your question about the Severe Storm Detector.

Click arrow to play 2-min video that explains how the technology works.

See also how and why this device was invented in "Warn Me Faster."

This revolutionary device incorporates NASA-proven technology to alert you when damaging storms or tornados approach your location. Severe weather can develop so suddenly that statistically, the National Weather Service and internet-based services are only able to issue advance warnings 60% of the time.*  But the Severe Storm Detector (SSD.20) continually monitors atmospheric conditions directly and notifies you with both visual and aural alarms when violent storms are close by, providing you valuable time to seek safety. It includes a proximity read-out, so you can determine how close a severe storm is to your location in real time. Indications include tornadic activity, the presence of severe storms and lightning. Field testing demonstrates a 95% accuracy rate, making a Severe Storm Detector a natural adjunct to conventional weather warning systems.

Pricing  -  Exclusive Safety-Agency Special

$99.95 per unit. Available only in full boxes of 10. Includes freight in the contiguous United States (**).

    Buy online by selecting the drop-down option below and your desired quantity (in groups of 10) at checkout.
    Or select the email option.

                         Or click here to email us. 


Onscreen hazard indications.
Onboard battery backup to provide up to 24 hours of protection during AC power loss.
Strobe and 90 dB siren – can be defeated for lower level events.
LCD screen with backlight for low-light operation.
Ideal for sight- or hearing-impaired individuals.
External port to activate ancillary / secondary warning devices.
AC / DC power.
Easily portable. Optional vehicle power adapter kit.
Enclosure Outer Dimensions Height 5”; width 4”; depth 3”.
Weight 0.51 lb.
Ambient Operating Temp Range 0 to 38 degrees C.
Ancillary Equipment Port 3.5mm jack, closed during alarms.
Power Supply 120VAC 60 Hz 6W 12VDC.
Power Consumption 200 mA / 12 VDC.  9V battery (not included).
Alarms >90dB siren, strobe, multicolor LED.
Status Indicator Backlit, 12-character LCD.

Within 30 days from the order date, you may return to us (in original condition with original packaging) any new Severe Storm Detector product, requesting service, replacement or a refund (minus Information Station Specialists’ original freight and handling). Repairs and labor required to bring a returned product back to marketable condition may be subtracted from a requested refund.

You must
contact us before shipping the product back to receive instructions and a RMA (Return Merchandise Authorization).

(*) National Weather Service and internet-based services like weather apps can only provide warnings to you, if 1) you have wireless coverage or are within range of their service, 2) your reception device has power at the time that the warning notification is issued and 3) the device is near enough for you to hear or see its alarm..

(**) Free shipping within the contiguous United States. Shipping to Alaska, Hawaii or outside the United States is extra and can involve a third-party agent.

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Information Radio Station is a generic term synonymous with Travelers Information Station (TIS), Highway Advisory Radio (HAR) / Highway Information Systems & Low Power Radio Stations (LPR). Operation of the stations is governed by FCC Part 90.242 Rules. A FCC license is required. Information Radio Stations may be fixed or portable. Subcomponents may include transmitter, antenna and ground system, digital voice player, wattmeter, cabinet with conventional or Corbin locks, lightning arrestors for RF, power and telephone lines, coaxial cable. Most stations employ black maximized antennas to discourage ice accumulation and security measures to prevent unauthorized program access. Options include synchronization, battery backup, solar power, remote programming by local, network or telco, multi-station audio distribution via RF or LAN / WAN or wireless network.