Drought and Heat Get Worse
by Cody Matz
July 19, 2012 7:52 PM
The title of this blog pretty much says it all. Over the last week, not much has changed. Some localized areas have seen some rainfall. In some cases, like most of Day County, 2 or 3 inches of rain has fallen. But unfortunately with temperatures in the 90’s and triple digits just about every afternoon, its gonna take more then a nights worth of rain to begin making up ground on the severe drought that continues to grow. The picture on your left is a summary of just how bad things have become. Many areas along and south of Interstate 90 are now in a severe drought with the rest of the area not far behind. There are a couple of bright spots with parts of the north only in the abnormally dry category, but with extreme heat likely sticking around at least another week, we need rain now. Detailed pictures of the drought in our 4 states are located below followed by more statistics on just how warm 2012 has been, and how much rain it would take to beat the drought.
Here are some eye-popping numbers for you. Listed below are the rainfall totals for 14 cities in the months of June and July. Obviously we haven’t finished July yet, so these numbers may still improve. However, if we don’t see any rain before the end of July, these would be our rainfall deficits for the 60-day period. Since we have not finished July yet, to have the “average” amount of rainfall for June and July to this point, we should have anywhere between a one and one half inch rainfall deficit (that’s how much rain we would typically get the last 2 weeks of July). You can see below that there is just one city that has seen its average 2-month summer rainfall so far.
Next we have an in depth look at the drought for the entire U.S. as well as our 4 state region. You will notice very quickly that the drought has expanded across much of western Minnesota and has really increased in intensity across the south. The severe drought has really expanded through South Dakota with the overall area more then doubling in just a week’s time. Still a couple areas dealing with slightly better conditions, which are across the northeast and the northwest where we have seen rain recently and had a pretty stellar June.
Now that we are in this drought, how much rain would it take for our soil moisture to return to near normal?? Good question…. And the picture below has your answer. This picture has the entire United States split up into smaller sections based off of terrain, annual rainfall, and a few other factors. Notice that there is a wide range of rainfall totals that would be needed to bring our soil moisture back to near normal. Across central South Dakota its generally 2-6 inches. But for northwest Iowa and northeast Nebraska, it’s as much as a foot of rain. So this isn’t just something that can be fixed with an overnight rain event, this could take several months or more to get sufficient moisture back into the soil.
One factor that’s just adding insult to injury at this point is the temperatures. With high heat, the ground can dry out much faster then with cooler temperatures. So more rainfall is needed in the summer to keep things moist. Well, with streaks like the ones below, the soil will dry out awfully fast. These are the number of days that we have experienced 90 plus degrees to this point in 2012. Take notice that many areas in the east have already met the average number of 90-degree days for the whole year… and we still have 3 more months that can see 90-degree temperatures.
As for the forecast, I have some good news and I have some bad news. The bad news is it looks like the extremely warm temperatures are going to stick around at least through the end of next week. Not necessarily bad news if you like the heat, but I think all of us could use a few days break. The good news is that there are at least isolated chances for rainfall in the next few days, which could finally put some water in the fields. Just keep your fingers crossed that you are one of the lucky ones. Stay cool!!!