Storm Spotter Online Training
NWS Springfield, MO

NWS logo
Spotter Reporting

Training Objectives


This training was designed to provide SKYWARN spotters, dispatchers, emergency management and the public in general with an understanding of:

  • The importance of relaying quality storms reports to the National Weather Service. 

  • What reports should be relayed to the National Weather Service. 

  • How to report severe weather to the National Weather Service.

Spotter Reports

A storm spotter does more than just chase and observe severe weather. An effective storm spotter accurately relays critical weather information to emergency management and law enforcement officials, the media, and the National Weather Service. These spotter reports are an integral part of the warning decision process and may lead to life saving action.

Spotter reports are...


Crucial to NWS warning decision process: 

  • Radar Interpretation 

  • Environmental Data 

  • Spotter Information

Crucial to public safety:

  • Provides specific reports to include in warning product
  • Provides detailed reports that results in response

Crucial to other spotters:

  • Other spotters will know where to position
  • "Heads up" information

Real-time Spotter reports have several benefits to the warning process including:

  • Gives greater confidence to the NWS warning decision maker

  • Adds credibility to warnings

  • Enhances public response

  • Improves warning accuracy


Effective Spotter Reporting

Remember, being at the right spot at the right time isn’t enough!  Effective communications are even more important than spotting a tornado!

Reporting Severe Weather


Call your NWS office via phone or via amateur radio and follow the format below when relaying a report.

  • Who is reporting/is it a relayed report? ( name, spotter network, trained spotter?)

  • What type of event occurred? Give an event description (be as specific and detailed as possible) 

  • When did the event happen? ( observed time or old report )  State the start & end time of the event (be sure to differentiate between event time & report time) 

  • Where are you located or where did it occur? Give your exact location and location relative to the event.   ( direction/distance from a city, road intersection, etc.  )

  • If event is still occurring, provide frequent updates (continuous for tornado)

Do not assume that if a warning is issued, the NWS knows for certain that severe weather has occurred. (we want to hear from you!).

Never assume your report is not important.

Do not exaggerate your report!  If you are uncertain, let us know why.

When to Report

Make you report as soon as it is possible after the weather event occurred.

Reports do us the most good when they are received as the event is occurring or shortly after the event occurred.

Even reports received the next day though help verify warnings and evaluate radar signatures.

What to Report


The following elements should be reported and are most critical to warning operations.

  • Tornado, funnel cloud, or rotating wall cloud

  • Hail 1inch (quarter size) or larger 

  • Flooding of roads or low water crossings

  • Trees or power lines down; Wind gusts 58 mph or greater


Severe Weather Reporting



Tornado Reports


Tornado Warnings are issued when a tornado is sited or indicated by NWS doppler radar.



  • Were buildings damaged? 

  • If no damage is visible, relay

                -  Storm structure clues

                -  Trees and/or Power lines down

                -  Dust or debris swirling

Funnel and Wall Clouds with Rotation, Upward motion

Suspicious Clouds – Indicate uncertainty!



Wind Reports


Severe Thunderstorm Warnings are issued for wind gusts of 50 knots (58 mph) or actual wind damage.


Wind speed is very difficult to estimate without damage and extra care should be taken in relaying a wind report.  Report specific impacts or damage caused by the wind (large branches broken, shingles blown off roof, several trees down, etc.)


Wind Reports Include: 

  •  Estimated Straight-line wind speeds

  •  Damage Reports (Structures, signs, etc.)

  •  Size and number of trees down. Downed power lines

Wind Speed
Wind estimate method
25-31 mph large branches in motion 
32-38 mph whole trees in motion 
39-54 mph twigs break off, wind impedes walking 
55-72 mph  damage to chimneys and TV antennas, large branches broken and some trees uprooted 
73-112 mph removes shingles, windows broken, trailer houses overturned, trees uprooted
113+ mph roofs torn off, weak buildings and trailer houses destroyed, large trees uprooted



Flood Reports


Flash Flood Warnings are issued when flash flooding is sited or indicated by NWS Doppler radar.


Flood reports include the flooding of : 

  • Roads

  • Low water crossings

  • Low lying or poor drainage areas

  • Urban Flooding

  • Rivers and Streams out of their banks

  • Dam Breaks

When reporting flooded roads, specify whether the water is ponding or flowing over the road, and whether or not the road is impassable.


Also report heavy rainfall amounts: wet soil – 1 inch, dry soil – 2 inch.



Hail Reports


Severe Thunderstorms Warnings are issued for hail one inch in diameter or larger.


marble to coin example

Avoid reporting “marble size hail.”  As can be seen, marble sizes differ. Some marbles are big enough to be considered severe hail while others would not. 

Instead, reference hail size to that of a coin (i.e. penny, quarter, etc.), sports ball, (i.e. golf ball, tennis ball, baseball), or specifically state ½ inch, 1½ inch, etc. 


If different size hail stones are falling, report the size of the largest stones. The best way to get an accurate hail size is, of course, to measure it with a ruler.



Hail Diameter Size
Pea size
Mothball size
Penny size
Nickel size
Quarter size
1 ¼”
Half-dollar size
1 ½”
Walnut or Ping -Pong ball size
1 ¾”
Golf-ball size
Hen-egg size
2 ½"
Tennis-ball size
2  ¾”
Baseball Size
Grapefruit size
4 ½"
Softball size




How to Report

Organized spotter groups use your normal communications methods.

Non Affiliated Spotters & General Public:


Amateur Radio 


SKYWARN Amateur Radio (HAM) Operators play a vital role in collecting and disseminating critical weather information during a severe weather event.


A HAM radio net control center is set up at the NWS by volunteer HAMs during severe weather. This allows for effective and timely communication between mobile spotters and the NWS.


Regional Net: Initiated for widespread severe weather 

  • 145.490 MHz Primary

  • 146.910 MHz Backup

Radar Summaries, warnings, and warning updates are broadcast every 10 – 15 mins 


Local Nets: Liaison to the regional net Encouraged to link up to regional net


Regional Amateur Radio SGF

Springfield 145.490, 146.910, 145.190
Joplin 147.210
Nevada 145.350 
Lebanon 145.450
Rolla 146.790 , 147.210
Houston 146.790  147.135
Gainesville 147.390






eSpotter logo

Developed to enhance and increase timely & accurate online spotter reporting and NWS-Spotter communications. For trained spotters and Emergency Managers

Trained spotters are encouraged to register and participate by transmitting reports directly to the NWS in Springfield, Missouri.


espotter web example




Connections made to this system are monitored. Your e-mail address is used to verify that you are authorized to access the system, and to contact you to follow up on your eSpotter reports.



espotter web example



Request access to eSpotter at and you will receive an e-mail (including password) granting E-Spotter privileges




Thank You!



The National Weather Service thanks all of those who volunteer their time and energy in providing crucial storm reports. 


Your reports are critical to providing life saving warnings. is the U.S. government's official web portal to all federal, state and local government web resources and services.