Much more rain needed to break the drought in Green Country

TULSA, Okla. — The Tulsa area picked up just under 1.5 inches of rainfall to start off the week. While this was one of the lighter amounts in Green Country, it was the heaviest rainfall Tulsa has seen in months. Overall, has received about 28 inches of rainfall since Jan. 1, 2022. This is a rainfall deficit of nearly 7 inches for the year.

It’s clear to see we have both a deficit and our overall drought still with us in spite of the soaking rainfall.

One measure of the dry spell is the Keetch-Byram Dought Index. This is related to both wildfire risk and soil moisture in relation to the drought. Even in areas with the heaviest rain recently are still halfway up the Index’s Scale. The greatest need for rainfall is for parts of Osage County based on this index.

So how much more rain is needed to fully remove the drought?

According to the Palmer-Drought Severity Index, Green Country needs another 7″ to 12″ of rainfall accounting for our most recent soaking. That also would need to happen between now and the end of November. That means, we would need to see nearly 3 times the average amount of rain for this drought to break by then. Otherwise, the amount of precipitation needed will be higher over a longer length of time.

As we head into the colder months, we also tend to receive less moisture overall because colder air cannot hold as much water. At the same time, the ground doesn’t lose as much moisture to evaporation with a lower sun angle and cooler readings.

The good news, in the short-term, is that the risk for wildfires is lower. Our vegetation is wetter and soil moisture is higher which will help to curb that threat which is why several counties in Green Country have removed the Burn Ban, including Tulsa County. With more rain on the way, it appears we’re headed in the right direction.