" (...) CHAFF and its EFFECTS ON WEATHER – Violent Winds, False Readings, and Potential Health Impacts
Radio frequency (RF) chaff is an electronic, defensive countermeasure designed to reflect radar waves and, thus, obscure aircraft (ships and other military equipment) from radar-tracking sources. The chaff packets are ejected from an aircraft in cartridges or projectiles that contain millions of individual fibers. Once released into the aircraft slipstream, the chaff packages burst open and a diffuse cloud of dipoles is formed to produce a radar-reflective cloud called a “chaff corridor.”
Military-initiated “chaff can spread over several hundreds of miles and stay in the air for up to a day and it could result in inaccurate [weather] warnings of severe weather.” It is generally held by the professional weather community that “automated systems cannot distinguish chaff from rainfall. The automated systems record chaff as precipitation and overstate the amount of rain archived in the database.”
The U.S. Forest Service used cloud seeding and chaff during the 1960’s and 1970’s in attempts to suppress lightning and prevent forest fires. However, the project actually caused a massive increase in ice crystals and actually reduced the amount of precipitation by over-seeding the clouds. So, the reduced rainfall worked against the primary objective of reducing forest fires, and the experiments were abandoned in 1973.
Interestingly, in 1993, some non-military meteorologists theorized that a chaff cloud emanating from a nearby Air Force base resulted in some significant weather modification, even though it was inadvertent. From August 20/21 0000 to 0230,1993, meteorologists tracked a chaff cloud coming from a flight-restricted, military base (Luke AFB) southwest of Phoenix, Arizona during an active thunderstorm with lightning. The chaff, they theorized, neutralized the lightning as the radar cloud showed little or no lightning in the enveloped chaff cloud. However, the chaff cloud intensified the thunderstorm winds enough to actually shear off one-foot-diameter power poles in its path at the ground level.
Now that’s pretty remarkable wouldn’t you say? I would want to know and/or recognize that kind of weather modification, albeit inadvertent, in and around any wildfire I was working, wouldn’t you? We work wildfires in and around military bases more and more now-a-days. Hopefully, an Incident Commander or Fireline Supervisor would have enough time to react and pull his folks to safety assuming he “recognized the current [and expected] weather conditions.”
This one’s definitely worth looking into because this “chaff cloud” moved through portions of Maricopa, Pinal and Gila Counties, where any one of us could be on an AZ State, BIA, BLM, or Tonto N.F. wildland fire. No doubt, you will be on wildfires near this or other military bases nationwide in the future when they’re using this chaff. The military will never admit it though.
Article; AMS Online Journals, http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F1520-0450%281997%29036%3C0302%3AICSWLO%3E2.0.CO%3B2 , BE PATIENT. (...)" Schoeffler, Fred J., Fireline Leadership in the Brave New World of Weather Modification and Modern Wildland Fire Behavior http://arizonaskywatch.com/articles/articles/Weather%20Modification%20and%20Wildfires.htm
Gravity Wave
Maddox, Robert A., Kenneth W. Howard, Charles L. Dempsey, 1997: Intense Convective Storms with Little or No Lightning over Central Arizona: A Case of Inadvertent Weather Modification?. J. Appl. Meteor., 36, 302–314. http://journals.ametsoc.org/doi/full/10.1175/1520-0450(1997)036%3C0302%3AICSWLO%3E2.0.CO%3B2 NOAA, Environmental Research Laboratories, National Severe Storms Laboratory, Norman, Oklahoma
