Fort Wayne Radio Club

SKYWARN®

Thursday, 10 June 2010 10:20 | Written by W9LW, Webmaster |

Many members of the Fort Wayne Radio Club participate in the National Weather Service (NWS) SKYWARN® program. The members serve as volunteer storm spotters, using their radios to relay reports of certain severe weather phenomena to the Northern Indiana NWS weather forecast office (WFO) near North Webster.

IMO Skywarn and its Quadrants

IMO Skywarn is an organization of hams in the 37-county county warning area (CWA) of the Northern Indiana WFO. To coordinate the radio relay of spotter reports to the WFO, IMO Skywarn has divided the CWA into four quadrants. IMO Skywarn has designated a primary and backup repeater for each quadrant. During periods of severe weather, a specially trained ham volunteer at the WFO monitors those four repeaters.

The map below shows the four quadrants. Quadrant 1 is blue, quadrant 2 is green, quadrant 3 is yellow and quadrant 4 is red.

imo_skywarn_quadrant_map

As you can see, Allen County is in quadrant 2. The Primary SKYWARN® repeater for quadrant 2 (and Allen County) is the ACARTS 146.88 MHz repeater. The FWRC 146.76 MHz repeater serves as an alternate, should the 146.88 repeater fail. Allen County operators should keep in mind that even when there is no severe weather in Allen County, the 146.88 repeater might be needed to relay spotter reports from other quadrant 2 counties to the Northern Indiana WFO.

Guidance for Quadrant Two Spotters

View the IMO SKYWARN Quadrant Two Operations Manual.

Even though significant advances have been made in radar technology, meteorologists cannot see with radar what is happening at the surface because of the curvature of the earth. Therefore, our “ground truth” reports supplement what is being seen on radar.

The two most important aspects of storm spotting are safety and accurate reporting. For those reasons, it is best to be “situationally aware” of atmospheric conditions. One of the best sites on the internet is the Storm Prediction Center at www.spc. noaa.gov. The daily convective outlooks and mesoscale discussions on that Web site detail the specific types of severe weather expected.

Standby Mode

If the Storm Prediction Center issues a tornado watch or severe thunderstorm watch designated SKYWARN net control stations (NCS) in Quadrant Two will initiate "standby mode." This mode is used when neither the volume nor urgency of spotter traffic require suspension of normal repeater use. Stations may call each other as normal. A SKYWARN NCS monitors the frequency, periodically reminding stations of the weather situation and asking them to keep transmissions short and to leave long breaks between transmissions. A tail message on the 146.88 MHz repeater announces "weather watch." The repeater reset tone is a Morse code "W."

Directed Net

When the volume or urgency of spotter traffic require suspension of normal repeater use, a SKYWARN NCS will initiate a directed net. Stations are requested to contact NCS before making any other calls. A tail message on the 146.88 MHz repeater announces "weather net." The repeater reset tone is a Morse code "N."

Making Reports

The procedure to call in a spotter report depends on whether SKYWARN is in standby or directed net mode. During standby mode, simply call "SKYWARN" and the NCS who is monitoring will answer. For example:

You: "SKYWARN, this is W9XYZ."
NCS: "W9XYZ, this is W9GGA, IMO SKYWARN, go ahead."

During a directed net, simply transmit your call sign and a word or two to indicate the type of report you have. For example, "W9XYZ, Tornado," "W9XYZ, funnel cloud," "W9XYZ wind," etc. Then wait for NCS to acknowledge you. You don't need to indicate that you are calling NCS, because when you transmit your call sign during a directed net, NCS assumes you are calling him. A typical report during a directed net might go something like this (if your call sign were W9XYZ):

You: "W9XYZ wall cloud."
NCS: "XYZ roger, stand by. IWX?"
WX9IWX: "IWX."
NCS: "Stand by for a wall cloud report. XYZ, go ahead."
You: "At 2:05 p.m. whiskey nine x-ray yankee zulu sighted a wall cloud near the intersection of Interstate 69 and U.S. 24."
WX9IWX:"Roger, XYZ. WX9IWX, National Weather Service."
NCS: "W9NCS, SKYWARN net control."

Reportable Weather

The purpose of the SKYWARN system is to provide the National Weather Service with the information it needs and has requested. There are certain kinds of information NWS does not need and we try to keep such reports off the air to assure that needed reports can get through.

Here are the specific weather conditions the National Weather Service has requested:

Tornadoes, Funnel Clouds, and Wall Clouds (remember there must be rotation).
Hail of any size. Please report hail size as pea-size, dime, nickel, quarter, etc. Even better, measure it with a ruler.
Wind damage (do not report high wind unless you see damage).
Storm-related injury or death.
Flooding in progress (rapid pooling of water on roadways, etc).

NWS does not need to know that it's raining hard where you are! The one thing doppler radar is best at is showing where the heavy rain is. Also, NWS does not need to know that you can hear a tornado siren or what the TV weather person is saying about the storm. Please do not take up air time with such reports!

Keep your reports short and to the point. Your report should take 10 or 15 seconds at the most. If the storms are especially severe, there may be a flurry of reports in a short amount of time; this happens often. Depending on the situation, net control may ask spotters to hold lower-priority reports for a few minutes (if there is a tornado on the ground, that situation takes priority over pea-size hail!).

Please report only what you see. Don’t speculate. If you see power flashes in the distance, do not call it in as a tornado unless you actually see the funnel. Report only the power flashes.

If you believe you have a reportable condition, but are not sure, report your suspicions to the net. An example would be if you are observing low-hanging clouds underneath the rain-free base, but are too far away to tell if there is rotation. There may be other spotters in the area who can confirm your report.

Safety First

Space limitations do not permit a complete discussion of all situations which may occur during a severe weather net. Just remember to use common sense when a net is activated and always put safety first - we want you to be here for the next severe weather event. Be sure to operate from a location where you can safely observe the sky, and always have an escape plan if the unexpected should happen.