Last week, temperatures were higher than normal, and the lack of precipitation was causing lawns to turn brown, creek and lake levels to drop, and some crops to start showing stress. The U.S. Drought Monitor introduced Abnormally Dry (D0) conditions across much of the state with concerns that a drought could be right around the corner. In fact, this week’s U.S. Drought Monitor (that considers data through early Tuesday morning of this past week) expanded the Abnormally Dry (D0) zone a bit and introduced some Moderate Drought (D1) areas in west-central and southeast Indiana (Figure 1). To use a highly scientific term … “Yikes!”. However, since early Tuesday morning, showers and even some strong storm events have passed through our region. Power outages and downed trees reminded us that our atmosphere still has some moisture and energy to wake us up from our parched state. Another round passed through on Wednesday and this weekend has even more rain in the forecast. Will this be enough, or will this just put us into a false sense of security?
Figure 1. U.S. Drought Monitor map for Indiana based on conditions through June 27, 2024.
It is useful to first assess our precipitation deficit. Since June 1, 2024, most of Indiana has received 2-3 inches less precipitation than what has been normal for this same period from 1991-2020 (Figure 2). A few rain events will need to be gully washers to try and make that up, and even if those heavy rainfall events occur, how much of that will be “effective”. In other words, what percentage of that precipitation will be absorbed by the soils and vegetation, as well as the groundwater supplies, instead of running off into drainage stream systems? Additionally, a significant amount of moisture is evaporating and transpiring – a natural process that peaks this time of year – each day. When stagnant heat events settle in and bring mostly sunny skies, this can rapidly offset much of the precipitation that may have been absorbed.
Figure 1. Precipitation departure from normal (inches) for June 1-26, 2024.
Fortunately, the 7-day precipitation forecast is calling for another round of precipitation this weekend (which should mostly benefit northern Indiana), with the middle of next week bringing a bit more (Figure 2). While amounts are relatively moderate, this pattern of rain every few days is ideal and should hopefully discourage any potential drought from intensifying rapidly over the next few weeks. The 6-14-day climate outlooks (through July 10th) are favoring above-normal temperatures (with confidence increasing in the latter half of this period) and above-normal precipitation (with only slight confidence). Precipitation is likely to be more localized with definite winners and losers across the state. Hopefully, over time, it will all be a wash, and everyone will get enough rain to keep things growing and water supplies flowing!
Figure 3. Precipitation amounts (inches) forecasted for June 27 through July 4, 2024.