The record warmth of the past seven months in the US was more than just a set of numbers or a temporary interesting headline. Along with the heat, precipitation for most of the southern half of the country has been below average during the same time period. The result is that drought conditions exists today across most of the Western US, with almost all of the Southwest (CO, NM, AZ, NV, UT, CA) experiencing Severe drought:
Figure 1. Drought conditions over the West US for the week ending 3 July 2012.
As you can probably tell from Figure 1, the Pacific Northwest had below average temperatures and above average precipitation during the same time period, thus the relative lack of drought in OR, WA, ID & MT. Drought has increased into Wyoming and recently to a lesser extent into Montana.
Interestingly, the areas experiencing the most severe level of drought are also those with the largest wildfires: New Mexico, Colorado, Wyoming, and Montana have all had very large wildfires in the past month. The effects of the drought so far in this region is extensive: early snowpack runoff, failing crops, reduced river levels, and livestock stress.
The seasonal monsoon kicked off some widespread and at times heavy precipitation across the southwest in the days since the Drought Monitor created this map. In the same way that a tropical system affected site-specific drought conditions over Florida last month, some short-term drought conditions might be alleviated in the West, which the Monitor should reflect in the next issued analysis.
The Southeast finally got some relief last month due to Tropical Storm Debby, which left behind record rainfall (and flooding) throughout Florida. Meanwhile, extremely warm and dry conditions spread north. The result is clear in the table below: the percent area experiencing some level of drought dropped significantly through last week, from over 75% three months ago to 56% last week, before rebounding back to 68%. Unfortunately, the areas with the worst drought conditions didn’t get their long-term drought busted, especially Georgia. This area typically receives some relief from drought during the Atlantic tropical storm season. Aside from Debby in Florida, the Atlantic basin hasn’t produced much in the way of help so far this year. The Southeast will have to wait a bit longer for additional relief.
Figure 2. Drought conditions over the Southwest US for the week ending 3 July 2012.
Drought has been present across GA for over one year now. The area affected by drought expanded to neighboring states during the end of the winter and beginning of spring, then shifted in the last month both north and west.
There’s no widespread crisis to speak of yet, but inhabitants as well as policymakers should monitor conditions as the year progresses. These conditions are not a result of climate change in any direct way. They are simply a result of a chain of events, some of which (e.g. Arctic ice loss in recent years) are more directly related to climate change than others. Drought is a complex phenomenon that has widespread effects, as people across the US are experiencing again this summer.