Four inches of rain fell on Delta in less than 24 hours over Tuesday, Aug. 17 and Wednesday, Aug. 18, 2021. Photo: Tanya Stephenson
SALT LAKE CITY — Record-setting rain over the past few weeks makes the month of August one of the top ten wettest on record for Salt Lake City, even though the state’s longstanding drought continues.
KSL Meteorologist Grant Weyman said the month of August still has a week to go, but it’s already registering as a wet one in Salt Lake City.
“We rank as the, in Salt Lake City, as the seventh wettest August on record with the amount of water — well over two inches of water here,” Weyman said Monday.
Soil moisture helps mitigate drought conditions and can influence weather patterns. During a drought, because the soil is so dry, sometimes occasional rainfall will run off the ground rather than soak in. In turn, that makes flooding more likely.
As a result, much of the recent rain in August, while making the month one of Salt Lake City’s wettest on record, likely did not significantly add to the region’s soil moisture. Localized flooding of the area points to run-off, rather than soaking in, as a likely result of that rain.
Better explained by the US Geological Survey:
Rainfall in any form will provide some drought relief. A good analogy might be how medicine and illness relate to each other. A single dose of medicine can alleviate symptoms of illness, but it usually takes a sustained program of medication to cure an illness. Likewise, a single rainstorm will not break the drought, but it might provide temporary relief.
A light to moderate shower will probably only provide cosmetic relief; its impact is short term. Thunderstorms often produce large amounts of precipitation in a very short time, so most of the rain will run off into drainage channels and streams rather than soak into the ground.
Soaking rains are the best medicine to alleviate drought. Water that enters the soil recharges groundwater, which in turn sustains vegetation and feeds streams during periods of no rain. A single soaking rain will provide lasting relief from drought conditions, but multiple such rains over several months might be required to break a drought and return conditions to within the normal range.