THE NATIONAL WEATHER SERVICE
SKYWARN PROGRAM
(Questions and Answers)


  1. What is SKYWARN?
  2. Why Have SKYWARN?
  3. How Does SKYWARN Work?
  4. When Will SKYWARN Function?
  5. Who Will Activate SKYWARN?
  6. Where Will SKYWARN observations Be Taken?
  7. What Type of Information Will Be Requested?
  8. How Much Advance Warning Will the NWS Provide When a SKYWARN Net is Called Up?
  9. Danger Sign
  10. How Will the NWS Use SKYWARN Reports?
  11. How Do You Know Whether There is Likely to be a SKYWARN Net?

What is SKYWARN?

SKYWARN is a plan sponsored by the National Weather Service (NWS), using volunteer weather observers for reporting destructive thunderstorms or other severe, unusual, or hazardous weather conditions. Amateur radio operators and weather observers, generally operating through local organizations, are ideally equipped to contribute to the SKYWARN program.


Why Have SKYWARN?

The NWS meteorologists in the Upton Forecast Office in New York (on the grounds of Brookhaven National Lab in Suffolk County, Long Island) are responsible for issuing forecasts and warnings for the New York City Metropolitan Area, Interior Southeast New York (including Orange, Putnam, Rockland, and Westchester Counties) Northern New Jersey, Long Island, Southern Connecticut (including Fairfield, New Haven, Middlesex, and New London Counties) and the adjacent coastal waters; a very varied area. It is impossible for us to observe conditions in each region during severe weather. SKYWARN volunteers, like you, become the additional eyes and ears of these meteorologists, providing information that assists the NWS in issuing timely and accurate warnings to save lives and protect property.


How Does SKYWARN Work?

When severe weather is predicted, NWS staff will alert pre-designated amateur radio and observer volunteers. For radio volunteers, a two meter amateur station was installed at the NWS office for SKYWARN communications (144 - 148 MHz) during the Summer of 1994. One or more repeaters having coverage in the target area are selected, and NWS staff will specify the starting time for the SKYWARN net over NOAA Weather Radio. (Additional amateur radio equipment will be installed during the Spring of 1995 for additional SKYWARN communications (430 - 450 MHz)

At the beginning of SKYWARN activation, the net control operator outlines the situation and tells field observers what data the forecasters are asking for. Usually this information will be based on the Warm and Cold Season Call-In Lists. Then the Spotters Network is polled for the specified information. Usually, it takes only a few minutes to collect the necessary information. The process may be repeated as often as needed until the adverse weather threat ceases or passes.


When Will SKYWARN Function?

While originally started in the Midwest to assist in tracking tornadoes, in our area, SKYWARN will be activated for a variety of severe weather including: severe thunderstorms, snow storms and "northeasters, " which can cause above normal tides and flooding in low-lying areas; and of course, hurricanes, which have the potential to cause catastrophic levels of death and destruction from storm surge, flooding, and high winds.


Who Will Activate SKYWARN?

Usually, our office will contact the SKYWARN coordinator in your area, who will then activate the net on your local repeater. He or she will then gather the requested information from you and other SKYWARN volunteers, and relay it by radio or phone to us. On occasion, severe conditions might occur without the net being activated; contact your Coordinator, who will then notify us of the conditions.


Where Will SKYWARN observations Be Taken?

From wherever you are at the time - on the road, in your office, or at home - you don't have to travel to any particular location! From time to time there might be a request for information about a given area, but this does not mean that it is necessary for someone to go there. Most importantly, do not jeopardize your own safety while participating in SKYWARN - the information is helpful, but not worth risking personal injury.


What Type of Information Will Be Requested?

This depends on the nature of the weather emergency. For starters, each report should include the call sign of the observer, his or her location (state the county) , and the time of the observation. Other requested information might include wind speed and direction, presence and size of hail, rate and type of precipitation, etc. Generally, the forecaster wants you to describe what you see in plain English. However, accuracy is important.


How Much Advance Warning Will the NWS Provide When a SKYWARN Net is Called Up?

The Northeast is affected by competing weather systems from several sources. For example, our strongest winter storms result when warm humid air from the Gulf of Mexico and Atlantic Ocean tries to replace the colder, drier air from Canada. The relative strengths and the actual storm track will determine whether we get rain, freezing rain, snow or no precipitation at all. Not only does the actual position and storm track have an effect on the precipitation type, but also the distance from the coast and the elevation of the terrain inland. It is not unheard of to have rain falling in New 139 York City while over 6" of snow has fallen inland from the same storm.

In the convective season, thunderstorms which affect our area usually form over the Appalachians and then move east to the coast. Our most severe thunderstorms form in squall lines and move from the northwest into our area but sometimes a (pulse) severe thunderstorm will literally develop over our heads and release its fury within 30 minutes without much advance notice.

We will now cover the type of information that will be requested by the NWS in a typical SKYWARN operation. First, it is important to note that although April through October is considered our thunderstorm season, conditions favorable for producing thunderstorms - even tornadoes - can develop any time of year in the Northeast. Unfortunately, in November of 1989 we received a painful reminder when a tornado hit the Coldenham Elementary School (Orange County). So it pays to always be aware of the weather.

SKYWARN nets will usually be activated whenever a severe thunderstorm watch, tornado watch, or flood watch is issued for the local area. SKYWARN nets will also be activated during the Winter. Your Warning Coordination Meteorologist will keep you apprised of 163 this. Use the following format for SKYWARN reports;

  1. Identity (call sign) of observer.
  2. Observer's location. (State the County.)
  3. Time of observation.
  4. Wind speed.
  5. Rate of rainfall.
  6. Presence and size of hail.
  7. Location and direction of storm.
  1. Call sign. Self-explanatory.
  2. Location: Be precise, but remember that the forecaster might not be familiar with every subdivision and hamlet within the area. Specify your location relative to a recognizable town within your County.
  3. Time of Observation: In most cases, the word "currently" suffices. If your observations are 10 or 15 minutes old, give the actual time for your observation in local time.
  4. Wind Speed: This is an important element of an observation. We are concerned with winds in excess of 40 miles per hour. If you have a wind gauge, or know how to estimate wind speeds, give your estimate in miles per hour. Be sure to report wind damage such as downed trees or power lines.
  5. Rate of Rainfall: If you have an official rain gauge, we would like you to provide us a numerical value. Remember, heavy rain indicates a strong downdraft within a thunderstorm. Your description will help the forecaster pinpoint the exact location of the thunderstorm relative to what is seen on the radar screen.
  6. Presence of Hail: This is a very important element to report. Hail is produced in severe thunderstorms with strong updrafts. Although not as dangerous as a tornado, a severe thunderstorm might last much longer than the average thunderstorm and cause considerable damage. The size of the hail is also important and should be reported, because it is a very good indication of the severity of the thunderstorm. Tornadic thunderstorms are sometimes accompanied by very large hail.
  7. Location and Direction of Storm: You can estimate your distance from a thunderstorm by measuring how long it takes for the thunder to reach you after you see lightning. Remember, sound requires about 5 seconds to travel one mile. If you have a good view to the horizon, you might also be able to judge a storms position relative to landmarks that can be pinpointed on a map.

The following are danger signs which should be reported immediately. If one of these danger signs is observed contact the Net Controller or the NWS office. A designated spotter is available for this purpose. Calmly give your name or call sign, location, and a brief summary of what you have observed.

 
Note:    The first rule of emergency communications is to protect yourself.  Insure your own safety first; then and only then, communicate your observation.

Danger Sign

  1. FUNNEL CLOUDS. A funnel cloud extends from the base of a cumulonimbus (thunderstorm) cloud. It might not reach the ground. If the funnel cloud comes in contact with the ground, it then becomes a tornado. However, many harmless clouds can be mistaken for a funnel cloud. Don't be fooled by an imposter! A true funnel cloud will exhibit "organized and sustained rotation about a verticle axis."
  2. HAIL 3/4 of an inch or greater in diameter. This is by NWS definition, a severe thunderstorm and should be reported immediately. You can always compare the size of hail to the size of a coin. For example, a penny's diameter is about 3/4 of an inch.
  3. WINDS greater than 40 miles per hour. At 30 mph, entire trees are in motion. At 40 mph, twigs break off trees and walking becomes difficult. At 55 mph, damage to chimneys and antennas as well as the downing of trees will be observed. Damaging winds, whether associated with a tornado or a severe thunderstorm should be reported immediately.
  4. FLOODING. If you live in an area prone to flooding, torrential downpours and/or evidence of actual flooding should be reported immediately. There will always be some ponding of water in low-lying, poor drainage areas with heavy rain. We are concerned with streams which overflow their banks onto roadways, houses or industry and/or urban flooding which makes roadways impassable.
Our severe thunderstorm and tornado watches come from Kansas City. There, at the National Severe Storms Forecast Center, a sophisticated high-tech system monitors real-time weather data from many sources, issuing watches when conditions are favorable for severe weather in any given area. Usually, these alerts provide a few hours of advanced notice, and are often the basis for activating the SKYWARN system.
How Will the NWS Use SKYWARN Reports?

The primary objective of the SKYWARN program is to identify hazardous weather early enough to warn the public. Thus, the NWS is particularly interested in tracking severe thunderstorms which pass through our warning areas.

Although we have few tornadoes compared to other parts of the country, we're not immune. Each year brings a few tornadoes and destructive thunderstorms to our area. If a tornado were to touch down in a densely populated area, the toll in injuries and property damage could be high.

The NWS has a wide range of information sources with which to detect hazardous weather but their systems have limitations. For example, suppose the forecaster spots three thunderstorms near New York City. Observers in one thunderstorm report high winds and hail one inch in diameter, while reports from observers in the other thunderstorms indicate relatively benign conditions. The forecaster will focus on the dangerous thunderstorm, asking additional questions to ascertain the speed and direction of travel. If this severe thunderstorm appears to observers to be traveling toward for example, Staten Island and maintaining its intensity, the forecaster will issue a severe thunderstorm warning for Staten Island and place the warning on NOAA Weather Radio.

In another scenario, one of our infamous winter storms might bring a mixture of rain, freezing rain, and snow to the area. Direct observations will help forecasters pinpoint the location and movement of the rain/snow line. This information, in turn, is used by highway and emergency service departments to put into use response plans made specifically for this type of hazardous weather.


How Do You Know Whether There is Likely to be a SKYWARN Net?

The NWS is planning to have a Hazardous Weather Outlook available for interrogation on our packet ham radio base station in Upton, New York. The Net Controller could then interrogate our packet and alert the spotters of the potential for hazardous weather throughout the year.

During the summer, we may or may nut have any advance warning. But there are "code" words to watch for in the daily forecast. Anytime a forecast mentions thunderstorms with additional wording such as hail and strong gusty winds, the forecasters are entertaining at least a possibility of severe weather. This should have the prudent SKYWARN operator thinking and keeping an ear to the local repeater and NOAA Weather Radio.




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n8sc@arrl.net

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