'Flash Drought' Slams DC: Report

WASHINGTON, DC -- It was a pretty wet May and June here in D.C., but in case you haven't noticed, we haven't had measurable rainfall since June 27. And there isn't much rain on the horizon.

We are in the midst of what is called a "flash drought," according to a report from the Washington Post's Capital Weather Gang.

And this is despite the fact that we are in peak thunderstorm season. As a result, the soil moisture is plunging due to the lack of rain and high temperatures.

The longest the D.C. area has ever gone in the summer months without measurable rainfall was 33 days back in 1995, CWG says, so we have a ways to go to top that.

And fortunately, thanks to all the rain we got in May and June, we're still at a surplus for the year and would have to go until Aug. 18 for us to be in the deficit.

However, rain isn't really looking likely in the near-term forecast. The weekend looks dry, and there may be a chance on Monday or Tuesday with a cold front moving in, but "with each passing day, that front seems to get drier and drier in the forecast," CWG says.

"Flash drought refers to relatively short periods of warm surface temperature and anomalously low and rapid decreasing soil moisture (SM)," according to a 2015 paper by the National Weather Service. "Based on the physical mechanisms associated with flash droughts, we classify these events into two categories: heatwave and precipitation (P) deficit flash droughts."

The D.C. flash drought meets both of these categories.

We could see more of these flash droughts due to global warming, according to a Mother Jones report.

"The frequency of these rapid-onset droughts is expected to increase as the planet warms. A recent study focusing on China found that flash droughts more than doubled in frequency there between 1979 and 2010," the report states. "Droughts like these are closely linked to climate change. As temperatures rise, abnormally dry conditions across the western United States are already becoming more common and more intense. And as evaporation rates speed up, rainfall becomes more erratic, and spring snowmelt dries up earlier each year."

Image via NWS