Real-time reports are critical in issuing warnings and saving lives. That’s an indisputable fact. Spotters are provide this real-time ground-truth of local conditions - such as hail size, wind speed, tornado development, and local damage - to help warn the public. Even as new technology allows the National Weather Service to issue warnings with greater lead time, spotters will always serve as a critical link between radar indications of severe weather and what’s happening on the ground.

Who are spotters? Virtually every community has some form of spotter network. Often, local fire and police personnel are trained to observe and report severe weather, partly due to their extensive radio communication and 24-hour operations. Citizens may also be an active part of the spotter network, some with an avid interest in the weather and many without. Some spotters are amateur radio operators. All share a sense of responsibility to their neighbors.

What is SKYWARN? SKYWARN is a program sponsored by the National Weather Service. The program is made up of thousands of volunteers who attend regular training and then scan the skies of their communities identifying and reporting critical storm information. These volunteers, sometimes organized under the SKYWARN banner in the U.S., are typically trained by NWS forecasters to be the eyes and ears of both the warning forecasters and the local public safety networks.



Map of National Weather Service offices

For a list of which counties in each office and more information on how to report:

National Weather Service Des Moines, IowaAdair, Adams, Appanoose, Audubon, Black Hawk, Boone, Bremer, Butler, Calhoun, Carroll, Cerro Gordo, Clarke, Crawford, Dallas, Davis, Decatur, Emmet, Franklin, Greene, Grundy, Guthrie, Hamilton, Hancock, Hardin, Humboldt, Jasper, Kossuth, Lucas, Madison, Mahaska, Marion, Marshall, Monroe, Palo Alto, Pocahontas, Polk, Poweshiek, Ringgold, Sac, Story, Tama, Taylor, Union, Wapello, Warren, Wayne, Webster, Winnebago, Worth, Wright

National Weather Service Quad Cities, Iowa/IllinoisBenton, Buchanan, Cedar, Clinton, Delaware, Des Moines, Dubuque, Henry, Iowa, Jackson, Jefferson, Johnson, Jones, Keokuk, Lee, Linn, Louisa, Muscatine, Scott, Van Buren, Washington

National Weather Service Sioux Falls, South DakotaBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon, O'Brien, Osceola, Plymouth, Sioux, Woodbury
National Weather Service La Crosse, WisconsinAllamakee, Chickasaw, Clayton, Fayette, Floyd, Howard, Mitchell, Winneshiek

National Weather Service Omaha/Valley, NebraskaCass, Fremont, Harrison, Mills, Monona, Montgomery, Page, Pottawattamie, Shelby



Distance and direction from your location
Movement (tornado direction and speed)
Impacts: damage, injuries, fatalities
Tornado Behavior: growing larger? Roping out?


Wall cloud: Rotating? Persistent?
Funnel Cloud: How far to the ground Visible rotation with the funnel?
Dust or debris below the funnel? (if so, you have a tornado!)


Diameter of the largest hailstone (estimated or measured)
DO NOT report marble-sized hail! Marbles vary widely in size.
Damage to windows, cars, crops, etc.


Wind speed (estimated or measured)
Damage to trees, power lines, and structures
Trees: Diameter of limbs snapped off and health of tree (old or rotten?)


Flood Impacts: Roads, houses, etc.
Depth of the water
Is the water moving swiftly or slowly?
Damage: Roads washed out, etc.
Rainfall amounts & how quickly it fell


Amount: (measured or estimated) Take multiple measurements and average them if possible.
Damage or impacts such as downed power lines, snapped tree limbs, cars off the road, etc.


NWS La Crosse, who covers the northeastern part of the state, unfortunately doesn't offer a Google Calendar to view their spotter dates. Spotter training dates for those in Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard, Mitchell, and Winneshiek counties can visit this page for information regarding training dates.


Amateur Radio Operators are a vital link in the spotter and communication network used by the NWS during severe or otherwise inclement weather and provide a reliable means of communications to NWS offices should normal communication modes fail. Below we have listed some of the repeaters (left) that we have found and the common frequencies otherwise used by chasers and spotters. We are still researching western Iowa frequencies, there are no organized amateur radio pages from the National Weather Service offices in Sioux Falls or Omaha.

Weather Radio Frequencies

162.400 MHz 162.425 MHz 162.450 MHz 162.475 MHz 162.500 MHz 162.525 MHz

Common Frequencies

Frequency Description
146.550 MHz Simplex frequency commonly used or monitored by chasers
146.460 MHz Alternate to 146.55 MHz
223.520 MHz Simplex 1.25 Meters
446.075 MHz Simplex Often used for cross-patching to 146.550 (70cm)
446.100 MHz Alternate to 446.075
1294.550 MHz Simplex 23 cm

Amateur Radio Frequencies

Location Primary Freq Primary PL Secondary Freq Secondary PL
Afton 442.400+ 151.4
Anamosa 145.390 77.0
Baxter 442.225+ 151.4
Bedford 147.135+ 203.5
Burlington 146.790
Cedar Rapids 146.745 192.8 145.150 192.8
Clinton 145.430 100.0
Coralville 444.750+ 151.4
Cresco 146.925- 103.5
Creston 146.790+ 136.5
Decorah 146.670- 103.5 147.165+ 123.0
Des Moines 146.820- 203.5
Dubuque 147.240 114.8
Fort Madison 146.865 100
Greenfield 444.500+ 173.8
Grimes 146.610- 114.8 443.400+ 151.4
Iowa City 146.850 192.8 145.270 192.8
Lenox 146.880- 136.5
Mason City 146.760- 103.5 147.315+ 203.5
Menlo 147.045+ 114.8
Mount Pleasant 147.390 100.0
Muscatine 145.370 100 145.370 100
Newton 442.300+ 151.4
Osceola 147.210+ 114.8
Pella 145.170- 203.5
Quad Cities 146.880 77.0 146.700
Scranton 444.300+ 151.4
St. Ansgar 147.195+ 103.5
Washington 147.045 443.000 100
Williams 444.500+ 151.4


Multi-Use Radio Service
  • Unlicensed
  • Transmitter Power Output limited to 2 Watts
  • Repeaters Not Allowed
Frequency Bandwidth
151.820 MHz 11.25 KHz
151.880 MHz 11.25 KHz
151.940 MHz 11.25 KHz
154.570 MHz 20.00 KHz
154.600 MHz 20.00 KHz


Family Radio Service
  • Unlicensed
  • Restricted to 0.5 Watts
  • Repeaters Not Allowed
Chan Freq Shared?
1 462.5625 MHz Yes*
2 462.5875 MHz Yes*
3 462.6125 MHz Yes*
4 462.6375 MHz Yes*
5 462.6625 MHz Yes*
6 462.6875 MHz Yes*
7 462.7125 MHz Yes*
8 467.5625 MHz No
9 467.5875 MHz No
10 467.6125 MHz No
11 467.6375 MHz No
12 467.6625 MHz No
13 467.6875 MHz No
14 467.7125 MHz No

*License required on the frequency if using more than the 0.5 Watts, up to the 5 Watt Maximum


General Mobile Radio Service
  • FCC License Required
  • Allowed to 50 Watts, Except on FRS/GMRS Shared
  • Repeaters Allowed (Upper Frequency is for Repeater Inputs, Lower for Output/Simplex)
  • Use of 650 and 700 channel pairs is prohibited near Canadian border. See FCC website for details.
  • 675 channel is suggested nationwide emergency and road information calling. Nationally recognized coded squelch for 675 emergency repeater operation is 141.3 Hz.
Chan Low Freq High Freq
550 462.550 MHz 467.550 MHz
575 462.575 MHz 467.575 MHz
600 462.600 MHz 467.600 MHz
625 462.625 MHz 467.625 MHz
650 462.650 MHz 467.650 MHz
675 462.675 MHz 467.675 MHz
700 462.700 MHz 467.700 MHz
725 462.725 MHz 467.725 MHz


EF Scale
Category Wind Damage
EF-0 65-85 MPH Light
EF-1 86-109 MPH Moderate
EF-2 110-137 MPH Considerable
EF-3 138-167 MPH Severe
EF-4 168-199 MPH Devastating
EF-5 200+ MPH Incredible
Beaufort Scale
Wind Speed Description
1-3 MPH Wind motion visible in smoke
3-7 MPH Wind smoke felt on exposed skin, leaves rustle
8-12 MPH Leaves and small twigs in constant motion
13-17 MPH Dust and loose paper raised, small branches move
18-24 MPH Branches of a moderate size move, small trees begin to sway
25-30 MPH Large branches in motion. Whistling heard in overhead wires. Umbrella use becomes difficult. Empty plastic garbage cans tip over.
31-38 MPH Whole trees in motion. Effort needed to walk against the wind. Swaying of skyscrapers may be felt, especially by people on upper floors.
39-46 MPH Twigs broken from trees. Cars veer on road.
47-54 MPH Larger branches break off trees, and some small trees blow over. Construction/temporary signs and barricades blow over. Damage to circus tents and canopies.
55-63 MPH Trees are broken off or uprooted, saplings bent and deformed, poorly attached asphalt shingles and shingles in poor condition peel off roofs.
64-72 MPH Widespread vegetation damage. More damage to most roofing surfaces, asphalt tiles that have curled up and/or fractured due to age may break away completely.
>73 MPH Considerable and widespread damage to vegetation, a few windows broken, structural damage to mobile homes and poorly constructed sheds and barns. Debris may be hurled about.
Hail Size Chart
Size Description
0.25" Pea
0.50" Plain M&M
0.75" Penny
0.88" Nickel
1.00" Quarter
1.25" Half Dollar
1.50" Ping Pong Ball
1.75" Golf Ball
2.00" Lime
2.50" Tennis Ball
2.75" Baseball
3.00" Teacup
4.00" Grapefruit
4.50" Softball
5.00" CD/DVD