Washington is starting Thursday under cloudy skies near 75 degrees, but the day will turn warmer and partly sunny before the next storm system arrives. Temperatures are expected to climb to about 89 degrees, with humid conditions making it feel closer to the low 90s.
Morning Showers Give Way To Heat
A few showers could pass through between 7 and 10 a.m., while winds turn west and northwest. The National Weather Service Baltimore/Washington says a cold front will bring more widespread showers and thunderstorms later Thursday and into Friday morning.
Storms Arrive Thursday Night
Rain chances increase from the afternoon into evening, with showers and thunderstorms possible. The overnight low should fall to around 69 degrees, and rain is possible overnight; a few storms may also bring gusty winds.
What Heavy Rain Can Mean For D.C.
About one-third of the District is served by combined sewers that carry sanitary sewage and stormwater in the same pipes, according to DC Water. Overflow risk depends on rainfall volume, intensity and recent rainfall; after more than 1 inch of rain, water-quality effects can last up to three days, and the utility advises avoiding waterways immediately downstream of sewer discharges. Residents can use the D.C. Department of Energy and Environment's Flood Risk Tool to check potential impacts at specific sites using FEMA, District flood-model and storm-surge layers.
DC Water says its green-infrastructure program is managing stormwater from 92 impervious acres. Its Rock Creek Green Infrastructure Project C is designed to manage 1.2 inches of runoff from at least 25 impervious acres, including through permeable pavement; such projects reduce pressure on sewer systems but do not eliminate every overflow risk during heavy rain.
Friday Is Cooler Before A Stormy Weekend
Friday starts with a chance of showers before 8 a.m., followed by mostly cloudy skies and a high near 83 degrees. Saturday warms to about 84 degrees, but showers could develop after 2 p.m., with thunderstorms increasingly likely Saturday night.
Sunday Brings Another Round Of Storm Chances
Sunday will be partly sunny and warmer, with a high near 86 degrees and a 40% chance of showers or thunderstorms. Conditions look primarily dry Monday, with temperatures in the 80s, before another storm chance returns Wednesday with a high near 90.
There are no advisories posted for the District, though small-craft advisories were in effect early Thursday on portions of the Chesapeake Bay and nearby waters. Anyone boating should check conditions before heading out, while everyone else should keep rain gear handy for Thursday night and the weekend.
