Storm Spotting and Storm Chasing

Storm Spotting and Storm Chasing

Storm Spotter Reporting Procedures
Ten Golden Spotter Safety Rules
Storm Spotting And Storm Chasing
Skywarn Spotter Classes
Sun Behind A Thunderstorm Thunderstorm Tornado


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Thanks to Tim Vasquez, Chuck Doswell, and others for the data on this page, last updated May 2, 2014.

The 1996 movie ''Twister'', made storm chasing appear to be an exciting adventure. However, there are major differences between the movie and real life. Other excellent Storm Chasing information links include Storm Track Magazine/Storm Chaser Homepage, and Tempest Tours Storm Chasing Expeditions. Normally, March, April, and May are thought of as peak tornado seasons; but there have been tornado outbreaks, year all 50 states...and at all hours of the day and night.

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Spotter Reporting Procedures

The follwing is from the NWS Spotters Guide for identifying and reporting severe storms.


* From radio-equipped vehicles, report severe weather observations to a central collection point, and request them to relay the report to the National Weather Service.

* Law enforcement and Civil Defense spotters -- report to the National Weather Service via NAWAS, radio, or other direct communications links as described by your Emergency Operations plan.

* When the telephone is your only communications method, call your primary or alternate contact, and ask them to relay your report to the National Weather Service. If you're unable to reach the primary or alternate contact, place an EMERGENCY CALL through the telephone operator to the National Weather Service. If the call is long distance, it can be made COLLECT. Report promptly, as the storm may interrupt communications.


WHAT you have seen: wall cloud, tornado, funnel cloud, waterspout, heavy rain, flash flooding, etc.

WHERE you saw it: the directon and distance from a known location (for example, 3 miles south of Beltsville).

WHEN you saw it: make sure you note the time of your observation.

WHAT it was doing: describe the storm's direction and speed of travel, size and intensity, and destructiveness. Include any amount of uncertainty as needed; i.e. ''funnel cloud, no debris visible at the surface, but too far away to be certain it is not on the ground''.

IDENTIFY yourself and your location. Give your spotter code number if one has been assigned. If you are an amateur radio operator, give your callsign, as per FCC Rules.


1) Tornado, Funnel Cloud, Waterspout, or Wall Cloud

2) Hail, 1/4 inch or larger. Approximate sizes in diameter are:

Pea (1/4 inch)

Marble (1/2 inch)

Penny (3/4 inch)

Nickel (5/8 inch)

Quarter (1 inch...storms are classified as Severe at this size or above). Make sure that your report clarifies that the hail is the size of the 25 cent piece, NOT 1/4 inch.

Half Dollar (1 1/4 inches)

Walnut Or Ping Pong Ball (1 1/2 inches)

Golfball (1 3/4 inches)

Hen Egg (2 inches)

Tennis Ball (2 1/2 inches)

Baseball (2 3/4 inches)

Tea Cup (3 inches)

Grapefruit (4 inches)

Softball (4 1/2 inches)

3) Damaging winds, 58 mph or greater. Adapted from the Beaufort and Fujita Wind Scales, here's a way to estimate wind speeds in mph with severe storms:

25-31 Large branches in motion, whistling heard in telephone wires.

32-38 Whole trees in motion; inconvenience felt walking against wind.

39-54 Tropical Storm force winds. Twigs break off trees; wind generally impedes progress.

55-72 Damage to chimneys and TV antennas; pushes over shallow rooted trees.

73-112 Hurricane Force winds. Peels surface off roofs, windows broken, light trailer houses pushed or overturned, moving automobiles pushed off roads.

113-157 Roofs torn off houses, weak buildings and trailer houses destroyed; large trees snapped and uprooted.

158 or more Severe damage, cars lifted off ground.

4) Flash Flooding

5) Heavy Rain at the rate of 1 inch or more an hour


* The first sign of a tornado may not be a funnel at the cloud base. Your first clue may be debris or dust at the be alert to events at ground level, as well as in the clouds.

* At night, lightning flashes can aid in identifying the Rain Free Base, Wall Cloud, and Precipitation Area. Although a loud roar is frequently associated with tornadoes, strong straight line winds can also produce such a sound.

* If you spot from a fixed location, use a map to determine distance and direction to known landmarks, such as water towers, TV towers, etc. This will help you eliminate distance and direction in your reports. Mobile spotters should always have up-to-date maps, and be familiar with the area in which they are operating.

* When available, use binoculars to look for rotation, and other cloud features. Once you spot a tornado, funnel cloud, or wall cloud, be alert for the formation of others in the area.

* If you find yourself in large hail, remember you are in or near the area where tornado formation is most likely in a severe thunderstorm.

* Always follow the basic safety rules. In open country, a spotter may be able to use his knowledge of the tornadoes motion, and available escape routes to drive away from the tornado safely. In urban areas, this is usually not possible because of traffic congestion. Make sure your family knows what to do in tornado emergencies, as you may not be available to direct or assist them.

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Ten Golden Spotter Safety Rules

These 10 Golden Spotter Safety Rules were developed by Randy Denzer and Joshua Jans, adopted by the NWS Skywarn program in 2011.

The following rules are to be strictly adhered to and followed while actively ''All Hazards'' spotting. Spotting involves reporting observations while either mobile or stationary (from structures) spotting. Competent all hazard spotters follow these Golden Rules every time they are “actively” spotting.

Rule number 1.

ALWAYS operate with your safety as the number one priority.

A. The spotter’s personal safety is the primary objective of every spotter. The information provided by the spotter is critical for public safety, and the spotter must maintain the ability to provide that information. The spotter must not perform any act that would jeopardize their own personal safety, or that of any other person.

B. Timely and accurate reports aid in the personal safety of self and others, which is the overall goal of the spotter program.

Rule number 2.

ALWAYS follow any and all directives from public safety officials.

If asked by an emergency official to leave an area, this should be followed. Spotters are a vital public safety function and operate within this system. Spotters are not public safety officials, and must obey all applicable laws and directives.

Rule number 3.

ALWAYS adhere to the concept of ACESc at all times.

ACESc = Awareness, Communication, Escape routes, Safety Zones


The spotter should maintain situational awareness at all times. Spotting severe weather places spotters in possible hazardous areas. Situational awareness is the mental process of being vigilantly and keenly aware of their surroundings at all times while spotting. This will require the spotter to use all media (weather radio, Internet connection, HAM radio) available to continually monitor forecasted and current weather conditions, as well as keeping an eye in all directions, at all times.

Never become complacent, keep monitoring weather in all directions before, during, and after a weather event. It is recommended that mobile spotters travel in teams of two. This allows for an increase in awareness of current conditions, while providing for safer driving. Spotter Awareness includes continued mental evaluation of escape routes and safety zones. The spotter should practice the ''Sterile Cockpit'' method while actively spotting under hazardous situations. This practice has long been used by Airline pilots, and involves only concentrating on the task of flying while in the cockpit. Adapting this to an All Hazards spotter during active spotting involves strict discipline of only performing spotter activities and safety practices during escalating hazards. If you’re in a hazardous environment, perform no other tasks except to ensure your safety and reporting.


The spotter should maintain communication through cell phone, radio, or other means at all times. It is imperative that someone knows the spotter’s location when monitoring severe weather. Never operate as a mobile spotter without someone knowing your location and estimated time of return.

Escape routes

The spotter should maintain escape routes at all times. For the mobile spotter, this means having the ability to move to a safe zone when necessary. If possible, back into dead end roadways, and have a thorough knowledge of the roadways in the immediate area. Do not get trapped between severe weather and a dead end. Be aware of traffic congestion in metro areas, and especially avoid roadways with overpasses, since civilians tend to wrongfully congregate under them to protect their vehicles. Remember that low water crossings can trap you after heavy rains. For the stationary spotter, ensure you have a clear route to a safety zone in time if needed. Locked basement doors or obstructed pathways will do you no good, in the event that you need to get to these areas for safety.

Safety zones

A safety zone is a place in which you will be safe from the oncoming severe weather event. For stationary spotters, this could be a basement or storm shelter. For mobile spotters, this could be a solid building with a basement (not a mobile home) or an area away from the storm. Know your safety zones, and how long it will take to get to them when you need them. Remember that the safest place in your home will be a basement or storm shelter. If one is not available, go to the center-most portion of your home and get low. Be aware of your escape routes to your safe zone at all times.

Rule number 4.


Mobile and stationary spotters should activate emergency services BEFORE making a weather report, when faced with incidents that cause injuries to civilians. Spotter should notify emergency officials (911, local dispatch, HAM, or other means), prior to making a weather report when possible. Once help has been notified, then a weather report can be submitted.

Rule number 5.

NEVER place yourself in a position to be overrun by, or unprotected from, a storm.

Maintain situational awareness and avoid problem areas of the storm. Driving in large hail increases the relative speed of the hail, and the potential to lose a windshield. If no other hazards exist, it may be better to stop your vehicle off of a roadway and wait until the large hail passes. Driving will only increase the damage to the vehicle. It is strongly recommended that spotters wear protective eyewear during large hail events to protect their eyes from breaking glass. This includes hurricanes and other large events.

Rule number 6.

ALWAYS be aware of overhead obstructions or objects that could become a safety issue during a storm.

Spotters should not park beneath power lines, trees, or other overhanging structures. Stationary observers should not stand in front of windows during high wind or hail events. Be aware of items that could be carried towards you during high wind events.

Rule number 7.

NEVER enter a flooded roadway or area for any reason. Whether on foot or in a vehicle.

Practice Turn Around, Don’t Drown while in your vehicle. less than 6 inches of water can wipe a pedestrian off their feet. 6 inches of swiftly flowing water can move a car. 18 to 24 inches of water can float a vehicle. Washed out roadways, missing manhole covers, and other obstacles can be hidden under high water. Many jurisdictions are now issuing tickets, fines, and charging for rescue operations in which vehicles become stranded in high waters in which the roadways had barricades placed.

Rule number 8.

ALWAYS treat all downed power lines as energized at all times.

Downed power lines can re-energize at any time from automated systems at remote substations. The system will automatically try to re-energize the circuit multiple times before it completely shuts the line down. Electricity can travel through both wet and dry ground. Maintain a safe distance at all times, and be aware that you can be electrocuted by electricity that travels through the ground. Do not use ANY item to in attempt to move a powerline. Even dry boards or fiberglass tools can conduct electricity, due to carbon content and inherent moisture. A good rule of thumb is to stay back a full span of poles (Two Poles) from any downed line. Be aware that many power lines have ''spool memory'', which will cause recoil when they arch, burn through and break. Report downed power lines to 911 or your local emergency dispatch center. If your vehicle is in contact with live power lines, stay in your vehicle and do not touch anything metal. Summon emergency services. DO NOT DRIVE OVER downed powerlines. If they are energized, they can arch if the weight of your vehicle breaks the insulation. This could cause your tire to instantly blow out, and your vehicle to become energized.

Rule number 9.

ALWAYS obey all state, federal, and local traffic laws and regulations, AND practice defensive and safe driving techniques, especially during inclement and night-time driving conditions.

Driving during inclement weather is hazardous, and extreme caution should prevail at all times. Match your driving speed and following distances to existing roadway conditions. Rain slicked roads will cause vehicles to hydroplane. Hail will create icy conditions on roadways. When driving on icy or wet roads, drivers should avoid using cruise control. Be cautions of debris on roadways, including powerlines. Spotting and reporting of severe weather for ANY agency does not preclude state, local or federal laws or regulations. Ensure your vehicle is up to safety standards and capable of properly operating during hazardous weather.

Rule number 10.

ALWAYS Operate safely when operating alongside of roadways.

A ''Hot Zone'' or hazardous working area is to be established within 25 feet of any operating roadway. This Hot Zone is a very hazardous area, due to moving vehicles. Many people are severely injured and killed every year by being struck by moving vehicles along side of Americas roadways...especially during hazardous events, vehicle operators are less attentive on driving, and may be distracted by severe weather or other distractions. Try to avoid operating within the Roadway Hot Zone if at all possible. Pull vehicles outside of this Zone if you need to pull over for any reason. If this is not possible, attempt to find areas in different locations outside the Hot Zone (rest stops, convenience stores, pullovers, etc.). Whenever operating within the Roadway Hot Zone, the following must be done:

Wear ANSI approved reflective traffic vests or outerwear while operating outside of a vehicle. Increased visibility is Key for your safety in this hazardous environment.

Never have your back to moving traffic. Always face traffic while in the Hot Zone. This may give you the ability to dodge an approaching out of control vehicle.

If assisting at a collision, NEVER enter the roadway, until traffic in the area has come to a stop. The first priority of Emergency crews is to establish a ''Safe Work Zone'', using fire apparatus and police vehicles.

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Storm Spotting And Storm Chasing

There is a difference between STORM SPOTTERS and STORM CHASERS. Spotters take up a pre-determined position, and report severe weather. Here is a brief overview of the difference between the two:

1) A STORM SPOTTER visually observes weather as part of a local civil defense radio network...a STORM CHASER observes weather for personal or business reasons.

2) A STORM SPOTTER usually has an amateur radio handheld transceiver (HT)...a STORM CHASER may or may not have radio gear.

3) A STORM SPOTTER rarely leaves the county to spot...a STORM CHASER travels hundreds of miles.

4) STORM CHASING IS EXTREMELY DANGEROUS, AND NOT FOR AMATEURS. Those who have been chasing have done it for years...knowing what to look for, and escape routes. Chasers will NOT intentionally put themselves in harms way. Storms can move as fast as 90 miles per hour, and can be quite fickle in their movements...changing direction before you realize it. If the tornado you're observing doesn't seem to be moving, but is getting larger...chances are it's heading right for you!!

5) Chasers travel in is foolhardy (and stupid) to travel alone, or without another experienced chaser. You will NOT become a chaser takes several years to become an experienced, mature chaser. It's advised to NOT have your children/kids with a severe weather situation, you need as little distraction as keep your wits about yourself, should you need to get out of the danger area quickly.

6) Many chasers analyze the weather conditions in detail before a chase, so they know what to expect. Much of chasing is actually a ''waiting game''...waiting for the storms to develop. You will NOT see a tornado every day, after every meal, etc. Many days you'll see NOTHING at all!! It's best to be knowledgeable about severe weather... much of this can be obtained through a SKYWARN Storm Spotter course, conducted by local National Weather Service offices...but this alone does NOT qualify you as a chaser...just as a spotter. If you obtain data from a National Weather Service office... remember that you are A GUEST there...keep your opinions of their forecasts TO YOURSELF...and DO NOT touch their equipment without permission...have them look the data up for you, if they have the time to do so. Irresponsible chasers have caused many National Weather Service offices to take a dim view of chasers as a whole.

7) Chasers have a wide range of communications equipment, to stay in touch with emergency services personnel, and the National Weather Service and each other. If you don't know how to use the equipment, or are not authorized to (such as Ham Radio, where an FCC license is required), do NOT use it!!

8) Chasers, for the most part, are responsible. These will not drive at breakneck speed to try to intercept a storm. Road conditions and traffic laws must be dealt with. There's always another day to chase. Also, be aware of the small towns that ''roll up the sidewalks'' at dusk. Also, be aware of your surroundings...isolated areas can be prime territory for snakes; as well as roaming livestock...hitting cattle can severely damage your vehicle. Have a First Aid kit in case of an emergency.

9) If you find yourself in an area with large hail, you are in or near an area where tornado development is likely to occur. Be sure you have an escape plan to get out of there fast!! Besides the tornadoes and hail, lightning, strong wind, and heavy rain, which can lead to hydroplaning, are all dangers of severe weather; be alert for rapidly changing weather conditions, and be prepared to get out of danger on a moments notice. Large hail can also destroy your vehicles windows and windshields.

10) Do not try to drive and videotape storms at the same time...driving is more important!! It's best to have a partner to videotape, or to let you know which route to take. That chase partner will also need to have a lot in common with you, as it'll be like ''a spouse''. You may drive over 1000 miles in a day...and at the end of the day, you'll need to find lodging.

11) Take care of yourself with your eating, sleeping, and other personal hygiene habits. Also, do not sacrifice your family, your job, or your studies, just to chase storms. This is purely irresponsible. Also, be aware that, with few exceptions, storm chasers DO NOT GET PAID for their work.

12) Make sure your chase vehicle is well maintained. Watching a severe storm rapidly approach you is NOT the time to discover that your battery just ''bought the farm'', or realize that you have a flat tire, etc. Be sure you're able to get fuel, etc. for your vehicle especially after dark...many small towns, as noted above, close many of their businesses at dusk.

13) Do NOT try to drive right into the center of the storm (core punching). If you find yourself surrounded by wrapping rain bands, you're in extreme danger, as the tornado could come on you without warning. This is especially true at night, when all the dangers of severe storms are hidden. The most violent area of the storm is known as the ''bear cage''. On a good day, you can eat the bear...but on a bad day, the bear can have you for supper!!

14) Remember that severe weather affects not just open areas...many homes, businesses, and lives, are damaged or destroyed when storms hit where people live and work. Be aware that someone could be dying in that tornado that you're watching.

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Storm Spotter Classes

Due to COVID-19, most in person Skywarn Spotter Training courses have been suspended, with virtual classes being held instead. Schedules could change...and the classes may be postponed or cancelled, if either severe weather or winter weather is occurring or forecast...or if the NWS in the County Warning Area that is doing the Skywarn Storm Spotter Training Class, is doing damage surveys following severe weather outbreaks.

The best way to find a class is to go here, then click on the desired area of the map. Once there, click on the link on Skywarn Spotter Training Classes for more information.

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