The record warmth of the past six months in the US was more than just a set of numbers or a temporarily interesting headline. Along with the heat, precipitation for most of the southern half of the country has been below average in the past few months. The result? At least some level of drought conditions exists today across the Western US, with a significant portion of the Southwest (CO, NM, AZ, NV) experiencing Severe drought:
Figure 1. Drought conditions over the West US for the week ending 12 June 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.
Interestingly, the areas experiencing the most severe level of drought are also those with the largest wildfires: the High Park fire in my state and the Little Bear and the Whitewater-Baldy Complex (at 289,478-acres as of yesterday!) fires in New Mexico. An additional link to climate change here: the High Park fire is burning in an area that the the pine beetle epidemic has devastated. The epidemic has left over 3.3 million acres of forest in just Colorado with dead trees. The beetles’ population have exploded in the past 20 years as winter nighttime lows warmed enough to allow more larvae to survive the coldest months of the year. This epidemic will transform the inter-mountain West. Combined with the extensive drought, millions more acres of trees will succumb to the epidemic.
Meanwhile, the Southeast finally got some relief in the past week and a half due to very heavy rainfall. The result is clear in the table below: the percent area experiencing drought has dropped significantly, from over 75% three months ago to 57% this week. 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. The Atlantic has been quiet for the past few weeks, however. The Southeast will have to wait a bit longer for additional relief.
Figure 2. Drought conditions over the Southwest US for the week ending 12 June 2012.
Drought has been present across GA for the better part of a year now. The area affected by drought has expanded to neighboring states during the end of the winter and beginning of spring, then shifted in the last month due to weather systems moving through.
There’s no 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.