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PO Box 834 Vincennes, IN 47591
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The SKYWARN program is used to provide Amateur Radio Communications in support of the National Weather Service (NWS) prior to and during severe weather that will affect Knox County, Indiana.

Objectives of Skywarn:
The objective of SKYWARN is to provide weather information for the NWS and local government by recruiting and training amateur radio operators.

The primary operating frequency is the 146.670(-) MHz repeater sponsored by the Old Post Amateur Radio Society. If you are not a Ham, this frequency can be monitored using most scanners.

Any amateur radio operator licensed by the FCC with a valid license may be a voluntary member of SKYWARN. Members shall not be expected to participate beyond the scope for which they feel they are trained or qualified.

All SKYWARN spotters must attend one training session every two years. The training sessions will be conducted by the National Weather Service and/or by their appointed personnel.

All communications within the SKYWARN program will be on two meters. All spotters in the SKYWARN program must have no less than a valid Technician Class License as issued by the FCC to operate on two meters.

Repeater use:
During activation of the SKYWARN Net, all normal radio traffic on the 146.670(-) repeater shall cease, and only necessary information shall be passed on during SKYWARN activation.

Emergency Frequency:
In the event that the 146.670 MHz repeater should fail, all Skywarn communications will switch to 443.675 MHz. If for some reason our 440 repeater goes down as well, communications will go to 146.520 MHz simplex.

When a severe weather watch has been posted for Knox County, the 146.670 MHz repeater will be put into SKYWARN MODE, indicating a potential for severe weather. Once the Net Control Station activates SKYWARN, the 146.670- repeater is in the total control of the NCS operator. All station-to-station traffic should be cleared through the NCS operator. Any non-pertinent traffic is to be passed on somewhere else.
Spotters checking into the SKYWARN Net will keep the NCS advised of their location. Should a spotter wish to leave the net, they will advise the NCS they are doing so. During and at the end of the SKYWARN Net the NCS will conduct roll calls.

Spotter Locations:
SKYWARN spotters can report their weather information to the NCS from any location. No spotters are required to place themselves in personal danger. Spotters may from time to time be requested by the NCS to go to a specific location for the collection of additional information.


When reporting weather conditions, the spotter will give the NCS BRIEFLY WHAT WAS SEEN in the following order of importance.
Give your call sign and location;
     What you have seen;

1. Damaging winds-Generally 50 MPH or greater 2. All Hail 3. Rain rates greater than 1 inch per hour 4. Flooding-Any stream out of its banks or 1 foot of water in the street. 5. Wall cloud / rotating wall cloud (not roll cloud) 6. Tornado touchdown (including direction and estimated speed of travel, if possible) 7. Funnel Cloud aloft 8. Cloud Rotation (sustained) 9. Heavy lighting in a small area 10. Ball lighting 11. Any damage from the above

Where you saw what you're reporting. Give direction and distance from a known position of storm. Check your map before you make your report. Know where you are. Stay cool. Be professional. REMEMBER THE PUBLIC IS LISTENING ON SCANNERS. What's the direction and estimated speed of the cell you're tracking. Stand by for any direction from the NCS.

A proper report should be:
SPOTTER: N9ABC, 2 miles south of Vincennes highway 41, this is estimated.

Example: This is K9XYZ, it just started to rain here. How's it over your way? WE REALLY DON'T CARE OR NEED THAT TYPE OF INFORMATION. Use good judgment during the net. So we will provide quality information for the NWS and the communities we are serving.

Net Control Station:
The Net Control Station runs the weather net and controls the communications between the amateur spotters, NWS, and local government.
Once the SKYWARN Net is called into action the Net Control Station will take check-ins, taking only callsigns at this time. This is done to check on the number of spotters available. Next NCS will inform those who have checked in what they know about the storm, then recall spotters to assess and assign locations.

Please remember: You CAN refuse to go to the location that the NCS directs you to, for whatever reason. Safety First!

Estimating information:
Measured winds, hail, and rainfall are much preferred estimated. If you need to estimate use the following guidelines
Wind speed (miles per hour)
0       Smoke rises vertically
1-3     Smoke drifts, but wind vanes do not move
4-7     Wind felt on face, leaves rustle
8-12    Small twigs in motion
13-18   Dust raised, loose paper raised, small branches move
19-24   Small leafy trees move, crested wavelets from on water
25-31   Large branches in motion, whistling in wires
32-38   Whole trees in motion, inconvenience felt walking against wind
39-54   Twigs break off trees
55-72   Damage to chimneys, pushes over shallow rooted trees
73-112  Peels surface off roofs, windows broken, trailer homes overturned
113-157 Roofs torn off houses, trailers destroyed, large trees snapped/uprooted
158     Severe damage, cars lifted off ground

Hail Size
   Pea Size 1/4"
   Marble Size 1/2"
   Dime size 3/4"
   Quarter size 1"
   Golf Ball size 1-3/4"
   Baseball size 2-3/4"

Rainfall Intensity
   Light-less than 0.2"/hr
   Moderate 0.2" to 1.0"/hr
   Heavy 1.1" to 2.2"/hr
   Very Heavy 2.3" to 4.5"/hr
   Intense 4/6" to 7.1"/hr
   Extreme More than 7.1"/hr

Many times spotters may sit through an entire net and never give a report. Some times the best report is no report at all. Net Control will keep you informed of any updated weather conditions.

Skywarn Main Page |  Knox County Skywarn Members

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