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NWS Phoenix SKYWARN/Storm Spotter Program

South-Central & Southwest Arizona and far Southeast California (Map)

When significant, or severe weather occurs anywhere within the Phoenix County Warning Area, the Weather Service turns to the SkywarnTM Spotter Network to obtain timely and accurate reports. This network is comprised of individuals or groups, generally associated with the following: 1) Emergency Service Organizations (Fire, Police, etc), 2) Volunteer Organizations and 3) Weather enthusiasts.  Spotters should be at least 18 years of age though exceptions can be made on a case by case basis with pre-approval needed.   

Even with sophisticated technology like radar and satellites, there are a variety of atmospheric phenomena that require the human eye to detect and/or confirm.  This information is called "ground truth" and is provided by trained weather spotters throughout the year.  When hazardous weather occurs, Spotters provide detailed eye witness descriptions of the conditions to the local National Weather Service office by means of the Web, email, phone, or amateur radio.  Spotters in Southern Gila, La Paz, Maricopa, Northwest Pinal, Yuma, Imperial (CA), and Eastern Riverside (CA) counties should report to the Phoenix forecast office.  Click here for a map.

Spotters should provide the following information:

  • WHO they are (Spotter ID)
  • WHAT they saw or are seeing,
  • WHERE they are or where they were when it was going on.
  • WHEN the reportable conditions were first observed.

Reporting Criteria

The following criteria are what spotters should report to the National Weather Service - Phoenix. 

  • Tornado (on the ground)
  • Funnel Cloud (tail NOT touching the ground)        
  • Storm Damage (deaths, injuries, broken tree limbs, shingles off roofs, etc.)
  • Flooding (streets, running washes, etc.)
  • Low Visibility (less than 1 mile due to dust, sand, fog, etc. - except rain)
  • Rotating Wall Cloud
  • Heavy Rainfall (measured ½ inch or more accumulation in 30 minutes or less)
  • Hail  (diameter of largest stone - any size)
  • Structure fire caused by lightning (not tree fires).
  • Snow (accumulating or not)

Reporting Methods

Trained Spotters should utilize the methods outlined in the class (webpage, email, phone, radio).  For those who are not trained Spotters, you can send us a Tweet or post to our Facebook page. was developed in 1999 by the National Weather Service and the American Radio Relay League.



Skywarn Recognition Day       


Each Year, the National Weather Service designates the first Saturday in December (GMT/UTC) as Skywarn Recognition Day (SRD) as a means of saying 'Thank You!' to our Storm Spotter volunteers who help us fulfill our mission of protecting life and property.  SRD was developed in 1999 by the National Weather Service and the Amateur Radio Relay League (ARRL) to celebrate the contributions of Storm Spotters - many of whom across the country are also amateur radio operators ("hams").  


This year, Skywarn Recognition Day runs from 5pm MST Friday December 2nd to 5pm MST Saturday December 3rd.  That corresponds to midnight to midnight Universal Coordinated Time (also known as Greenwich Mean Time - GMT).  


To participate, checkout the national website (  From there, you can sign up for the Facebook group where you can connect with Spotters from around the country.  On Twitter, you can follow the hashtag #Skywarn2022 to join the conversation. There is a national check-in as well where you can enter your zip code (and Spotter ID or call sign if you wish) on this form and get plotted on a map that you can view on the SRD website.  


Spotters who are also amateur radio operators are encouraged to work their radios on all available frequencies to establish contacts from near and far during the 24 hour period as hams from around the country will be doing the same.  There is a registration form on the SRD website for hams to register their stations.  Locally, we will be conducting practice Nets at various times on the same repeaters used for live Nets.  Refer to the instructions in the email sent to the hams.


We encourage our Spotters to participate as we say, Thank You!




To become a Skywarn Spotter for the NWS Phoenix office requires full attendance of a free one hour training class (webinar) and successfully completing a quick post-webinar quiz. Typically, this occurs during the April through June time frame.  Refresher training is required once every two years (i.e. every other year).

The classes teach people how to properly identify and report significant weather phenomena and thereby contribute to public safety.  You will learn about how thunderstorms work, how to identify cloud features associated with microbursts and tornadoes, and how your reports tie in to warnings and advisories issued by the National Weather Service (NWS).  In addition, you will learn about all of the services available from the NWS.  

Adult SKYWARNTM volunteers are community minded individuals who understand that they play a role in public safety by providing storm information to the National Weather Service.

If you have any questions, please contact either Austin Jamison or Marvin Percha at 602-275-7418 at the NWS Phoenix Forecast Office. 

*** We especially need new spotters in more rural areas of our forecast area (County Warning Area - CWA)***


Training Class Schedule (Webinars)


Open to residents of our forecast area (Map)


Date Time Registration Notes

April 21st


Standard class (webinar)

May 4th


Standard class (webinar)


May 5th


Standard class (webinar)

May 10th


Standard class (webinar)


May 12th


Standard class (webinar)

May 19th


Standard class (webinar)

May 23rd


Standard class (webinar)

May 24th


Standard class (webinar)

June 8th


Standard class (webinar)

June 9th


Standard class (webinar)

November 17th


Standard class (webinar)

December 5th


Advanced class (webinar)

***Must have completed NWS Phoenix Standard class in either 2021 or 2022***













Amateur Radio ("HAM" radio)

When a Skywarn Net has been activated for public safety purposes, trained Spotters who are amateur radio operators may submit storm reports by radio. There are also weekly routine Nets utilizing the same frequencies (see below).  These routine Nets are a good way to test how readily you can connect to those repeaters as well as practice interacting with a Net Controller. For questions specific to amateur radio, contact Marvin Percha ( 


Maricopa and Pinal Counties - Sector 2 :

  • 443.050 MHz (PL Tone 100.0)  --  The first Wednesday of the month at 8 pm

Southern Gila County - Sector 6 (can be reached in portions of East Valley)

  • 147.200 MHz  (PL Tone 162.2)  --  Tuesdays at 8 pm

Yuma and eastern Imperial Counties - Sector 7:

  • 146.780 MHz (PL Tone 103.5)  -- Tuesdays at 7 pm

La Paz County and Blythe - Sector 9 ***NEW **:

  • 145.310 (PL 107.2) - Wednesdays 7pm


Educational Resources


Study Guide for Standard Class (pdf 336KB)


PDF Version of Standard Class presentation (pdf 9.4 Mb)


PDF Version of Advanced Class presentation (pdf 17 Mb)


Spotter's Guide (pdf 27.2 MB):


JetStream - an Online School for Weather


Severe Weather 101 (educational content from NSSL)


MetEd (hundreds of online tutorials for the GeoScience community)


Radar Basics (pdf 7MB)


Radar Tutorials from NWS

  • Introduction to the WSR-88D system
  • Principles of Radar
  • Velocity Interpretation
  • Base and Derived Products
  • Convective Storm Structure and Evolution
  • Flash Floods
  • Winter Applications


NWS Norman Spotter Resources (emphasis on Great Plains severe weather)

  • Training Videos (informational - not a substitute for NWS Phoenix classes)


Severe Thunderstorm Forecasting (video lecture series by SPC forecasters)


NSSL’s HotSeat Warning Simulator



Additional Useful Links


Rainfall Data Sources


NWS Publications and Brochures 


Climate Sites


Drought Sites