BALTIMORE — On Monday and Tuesday's heavy rainfall event in Dubai, the internet has gone ablaze about the United Arab Emirates' cloud seeding program and how it may have played a part in the event. While this type of weather modification has been around for a while it is very unreliable and is very unlikely to have been the main contributor to the heavy rains.
Cloud seeding is a weather modification process that uses a substance, usually salts, to form precipitation when the environmental conditions are right. The right environmental conditions are monitored to ensure that there is enough moisture and cold air aloft that would allow for supercooled liquid to gather on these salts. The results are usually light precipitation that fall as rain or snow depending on surface temperatures.
The salts are dispersed from specialized flairs on airplanes or cannons on the ground, with the latter being used in the Rockies to help with snowfall during winter months.
For this process to work there must be moisture in the atmosphere to work with, like storm clouds that are already forming or in the case of mountains in the west, moist air being driven upwards.
There are places in the United States that use cloud seeding, like states in the Intermountain West where lack of snow or rainfall in the mountains can lead to really bad summertime droughts. But as we have seen, even those states still end up in a drought because of how unreliable cloud seeding is.
That is why Dubai also has its own cloud seeding program to help boost its yearly rainfall amounts, as they are in one of the driest regions on Earth.
There are other uses of cloud seeding as well. For example, in the Upper Plains region cloud seeding is used to help reduce the risk of large damaging hailstones over farmlands that could damage crops.
As for Maryland, there are no known cloud seeding operations by business or governmental agencies. At one point during one of the more severe droughts of the 1960s, the Maryland Senate introduced a bill that did not allow for cloud seeding to occur over the state. The Senate bill was in response to the idea of using cloud seeding to help produce rainfall in a drought-stricken northeast region that led to impacts in the agricultural sector.
