(State) Expansion of the ‘Abnormally Dry’ category was found in the state of Iowa’s latest Drought Monitor Index.
The D0 category is growing in the state. “Which isn’t drought, but it’s an indicator of persisting dryness over the last 30-60 days. Southwestern Iowa has missed out on a lot of the rainfall over the last 14-30 days so that’s where we she a shift to the west in the D0 Category.”
State Climatoloigist Justin Glisan admits it’s likely to get worse before it gets better. “Very high probability of warmer than average temperatures coupled with a dry signal.” Glisan says, “The expectation is August 4th and 5th should be the peak of this upcoming heat wave with the possibility of having multiple 100 degree days strung together. When we see temperatures like that that’s when we see abnormally dry conditions expend and unfortunately those drought categories expand as well.”
Glisan admits this is becoming more and more common. “If you look at the last ten years we’ve actually seen a dip in the amount of July rainfall. This does exacerbate drought conditions, but the crop as it is maturing starts to use more water from the subsoil. All of those factors come into play-windier days, warmer days, low relative humidity- it produces an atmospheric thirst and water vapor just diminishes at the surface.”
Glisan calls Northwest Iowa the biggest problem area of the state with an expansion of D1 all the way to D3. Additionally, D1 Moderate Drought has been introduced in Southeast Iowa.
