The drought has expanded as rain opportunities have dissolved. Washington’s rainfall since the start of September, 0.27 inches, ranks as the second least on record.
Rainfall has been abnormally scarce since mid-July, when dry conditions commenced:
- 0.79 inches of rain fell in the second half of July, about an inch below normal
- 1.99 inches fell in August, 0.94 inches below normal
- 0.25 inches fell in September, 3.47 inches below normal
- 0.02 has fallen so far October, 1.08 inches below normal
In sum, Washington has racked up a rainfall deficit of about 6.5 inches since mid-July, the equivalent of missing two months’ worth of rain.
Because it was so wet before mid-July, the lack of rainfall through the end of August was inconsequential.
But in September, the drought came on suddenly. In early September, there was still no drought in the region before it spread over most of the area by the end of the month, aided by abnormally high temperatures. Because of the haste at which the drought developed, it has been termed a “flash drought.”
“The short-term dryness and heat quickly overcame the long-term record wetness we experienced between April 2018 and the early summer of 2019,” explained the National Weather Service office serving the Washington-Baltimore region in its drought statement released Tuesday. “Although the heat has ended, significant rain has not yet been observed, so drought conditions persist.”
The forecast for the next week offers little promise for substantial rainfall. A chance of light rain showers is in the forecast for late Sunday and next Wednesday. Otherwise, dry conditions are predicted.
The Weather Service statement said “impacts have been quickly building” from the drought. “The earliest impact was to lawns and gardens, which browned and growing has ceased,” it said.
Soil moisture levels have now dropped below the 10th percentile in the region.
“Agricultural interests are reporting drought-related stresses on pastures and hayfields, as well as crop stress to soybeans and other late-planted grains,” the drought statement said. “Other crops such as corn and apples are reported to be faring well, with some crops actually better than last year since last year was so wet.”
The statement said stream levels, which were above normal early in the summer, have fallen below normal in many areas.
The drought has not yet become severe or long-lived enough to have a substantial impact on groundwater in the region. “Shallower aquifers have turned below normal quickly over the past few weeks; but deeper groundwater storage is still at or above what is typical for this time of year,” the drought statement said.
While little rainfall is predicted over the next week to 10 days, the Weather Service continues to project a return to wetter conditions later this month and into November.
“There are some hints at a longer range return to at least more normal precipitation, and the Climate Prediction Center’s outlook for the rest of the calendar year does favor above normal precipitation,” the drought statement said. “Until and unless this occurs, though, all of the existing conditions will likely continue to deteriorate.”