METEOROLOGIST JEFF HABY
A downdraft from a thunderstorm can dramatically change the weather. A downdraft is produced by evaporative cooled air that falls to
the surface from a thunderstorm. Downdrafts can be refreshing on hot summer days. For example, temperatures can cool from the 90s F
to the 70s F when the downdraft air moves in. The temperature change occurs within minutes.
Air mass thunderstorms are most likely to develop when temperatures are at their warmest during the day. This makes the downdrafts all
the more refreshing when a very hot day is turned into a mild day. The cooling from the downdraft can be as significant as the entire
cooling that it takes in the overnight hours. A downdraft is hours of overnight cooling compacted into just a few minutes. The
downdraft also tends to bring gusty winds. The windy conditions can make it feel cooler also.
Downdrafts are common from warm season convective storms. These winds can be a weather changer in another way. That way is that they
can produce severe convective wind gusts. These wind gusts can produce damage to property and vegetation. The wind can go from fairly
light to very strong in the matter of seconds as the downdraft gust front moves through. They can also spin up brief gustnadoes
which can produce damage. Severe downdraft winds can occur from a grouping of storm cells called multi-cells. Multi-cells forming
a squall lines, a derecho, or a mesoscale convective systems can produce sudden damaging wind.