Randy, Jim and Mig,

I found the following to be a really good explanation from the Pittsburgh NWS about net activations during severe weather conditions. Although this doesn't mention winter weather conditions (snow, ice, etc.) the NWS does request net activation during winter weather as well.

Mig, please distribute the following to the members.

73,

Jeff, WB1AAL

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An effective SKYWARN net usually follows some form of guide or outline. This is especially helpful in making it through the rougher times that occasionally occur. Usually it is in these tough times that your communications to the NWS have the utmost value.

Remember, SKYWARN is NOT a club. By putting aside any differences that do not support the goals of SKYWARN, you'll find your SKYWARN net to be at its most effective level.

A great amount of the work is done by the amateur radio community in fulfilling the goals of SKYWARN. The NWS appreciates your assistance. The Pittsburgh National Weather Service office has over 2000 trained spotters in our 36 county warning area that covers four states. 

THE GOALS OF AMATEUR RADIO SKYWARN

 1) TO HAVE A NETWORK OF SPOTTERS IN PLACE TO REPORT SEVERE WEATHER
 2) TO ACTIVATE THIS NETWORK AS NEEDED
 3) TO COORDINATE REPORTS FROM THE SPOTTERS IN A PROFESSIONAL MANNER
 4) TO RELAY THESE REPORTS TO THE NWS IN A TIMELY MANNER

ACTIVATING THE NETWORK

If your county is under a Severe Thunderstorm/Flash Flood/or Tornado Warning, there is no doubt that the NWS needs your reports. Tune to your local repeater, where SKYWARN nets are held. Others may have begun to activate the net.

Please note: The need for activation occurs when only one of these criteria are met.

CRITERIA FOR REPORTING

• TORNADOES
• FUNNEL CLOUDS
• WALL CLOUDS
• ROTATING THUNDERSTORMS
• WIND GUSTS (ESTIMATED OR MEASURED 45 MPH OR MORE)
• WIND DAMAGE (TO LIMBS, TREES, ROOFS, ETC.)
• HAIL (WITH DIAMETER OF LARGEST STONES)
• FLOODING (BASEMENTS, EXTENSIVE STREET FLOODING, SMALL STREAMS)
• HEAVY RAIN (0.75 INCHES OR GREATER IN 1 HOUR OR LESS OR 3 INCHES IN ANY TIME FRAME LESS THAN 24 HOURS)
• CONTINUOUS LIGHTNING FIRE/DAMAGE CAUSED BY LIGHTNING
• ANY DEATH OR INJURY DUE TO ANY OF THE ABOVE

Remember to always give the three most important parts of a report

TIME - TIME OF OCCURRENCE
EVENT - HAIL, TORNADO, FUNNEL CLOUD, ETC.
LOCATION - COUNTY AND DIRECTION/DISTANCE FROM NEAREST TOWN

One person, often the SkywarnTrained Observer, should be delegated to relay severe weather reports. This will avoid duplication and ensure that the necessary information is relayed to the NWS. It is up to the net control operator to determine what level of net activation is required given certain circumstances. 

Net activation to STANDBY

When a Severe Thunderstorm Watch has been issued, but no weather activity is occurring in the area. A net control station will then be established and take and log check-ins. The net control station will also relay watch information frequently. Normal use of the repeater will continue, however, please leave a pause between transmissions should net control need to break in to take the net to a higher level.

As the storms approach your area, the net may need to be fully activated. The first priority would be taking and relaying weather reports to the NWS. Second would be check-ins. The Net Control Station takes control of frequency and gives frequent updates on net status and weather watches. Prepare for further upgrade as storms approach or if severe weather reports begin coming in.

If a SEVERE THUNDERSTORM WARNING and/or FLASH FLOOD WARNING has been issued for your county. Priority must be given to collecting and relaying weather reports, No check-ins or checkouts at this time. Net Control will announce warning information frequently. Only reports meeting the criteria mentioned earlier should be requested. "It's not raining here" reports are not needed, unless requested.

If a TORNADO WARNING has been issued for your county, the Net Control Station takes total control of frequency. Net Control requests tornado, funnel cloud and wall cloud reports. If there are no tornadic reports, Net Control requests reports meeting the above severe thunderstorm criteria. Stations without one of the above reports should maintain radio silence. Net control will relay Tornado Warning information frequently.

Tornado events are rare. However, real emergency organization in these instances is what will make the NWS, trained spotters and all licensed amateurs involved with ARES fulfill their missions and shine