Back in the first week of June I wrote here that Kentucky needed at least 4 inches of rain during June to either improve the drought conditions or maintain it at a moderate level. Unfortunately, much of Kentucky currently has less than one inch of rain through the 20th and many locations, including Bowling Green, could end up with the driest June ever. This will push our drought conditions to severe and possibly exceptional levels over the next few months and will likely make the drought of 2007 one of the worst in the past 100 years.
The latest seasonal drought outlook from the Climate Prediction Center shows the drought worsening and spreading northward into the eastern corn belt over the next few months. The short-term outlook isn’t much better as middle and possibly upper 90s are likely across the mid-south next week. AccuWeather shows the mid-south to be hot and dry throughout July. Aside from a slight chance of rain this weekend, there are no good rain chances in the forecast during the next 10-14 days as a large heat ridge will build from the southwest where it has been over 115 degrees in the deserts.
The below chart shows that the 2007 drought will soon be among the worst summer droughts in Kentucky history. It shows the 10 worst May PDSI values (2007 was ranked 15th) along with how much rain fell in June and then the PDSI value for June. (For Kentucky Climate Division 2 – central KY)
Year | May PDSI | June precip. | June PDSI
1931 | -5.57 | 2.59 | -5.61
1941 | -4.78 | 5.25 | -4.14
1954 | -4.42 | 3.12 | -4.34
1914 | -3.12 | 2.17 | -3.68
1942 | -3.00 | 5.62 | 0.43
1902 | -2.89 | 5.50 | -2.18
2001 | -2.71 | 3.83 | 0.00
1988 | -2.63 | 1.16 | -3.34
1900 | -2.61 | 8.20 | -1.10
2000 | -2.59 | 3.59 | -2.49
2007 | -2.06 |0.50* | -3.00*
* estimated
The only year that had a similarly dry June was 1988. However July 1988 was very wet (>6 inches) which broke the drought. Therefore, if July is as dry as expected, the drought of 2007 will be the worst drought in Kentucky since 1954.