The week ahead: Steamy and slightly stormy...
Shut the windows and crank up the A/C, and keep an umbrella nearby. Characteristic (but not extreme) DC summer heat and humidity, and the threat of late afternoon/evening thunderstorms, kick in today and should persist through much of the week.
Today
Warm and humid, PM storms possible. Warm, moist southwesterly flow will take hold of the region due to a persistent area of high pressure offshore. Under partly sunny skies, high temperatures are likely to reach the upper 80s, with dewpoints rising into the upper 60s. Thunderstorms chances are about 30% (a bit higher well northwest of DC). A few storms could produce locally heavy rain and strong winds. Overnight, it will be partly cloudy and muggy, with lows in the low 70s (high 60s in the suburbs).
Tomorrow
Very warm and humid, isolated PM storms. Humidity levels and temperatures creep up a bit more, as high temperatures flirt with 90. Dewpoints will be around 70, so it will feel like the mid 90s. A few isolated storms could pop up around the region given the juicy airmass, but the chance of experiencing a storm where you live is only about 25%. Overnight, it will remain warm, with lows 70-75.
Image courtesy AccuWeather.comWednesday
Very warm and humid, PM storms possible. We'll remain under the influence of a moist tropical airmass. High temperatures should reach the low 90s which will feel closer to the upper 90s when dewpoints in the low 70s are factored in. The chance of thunderstorms in the afternoon or evening is about 30%. Overnight conditions will be sticky, with lows 70-75.
Thursday
Sultry with more numerous PM storms. A weak frontal boundary will approach from the northwest, while the very warm and moist southwesterly feed continues. The convergence of these factors is likely to increase the chance of storms to 40-50%. Prior to any storm activity, it will likely be hot, with highs 90-95, and heat indices approaching 100. Overnight, expect more mugginess, with lows in the low to mid 70s.
Friday
No relief? Thursday's front is not likely to pack enough of a punch to either clear the Mid-Atlantic or provide significant relief from the uncomfortable conditions. Given that, it will probably remain very warm and humid (maybe not quite as humid as the previous two days), with highs in the upper 80s. Storm chances will depend on the front's location, but stand at about 20-30% right now. Overnight lows should be near 70.
The weekend
Still warm, still humid, PM storm threat lingers. The same pattern should persist through the weekend, with more southwesterly winds and warm and humid conditions. Expect highs in the upper 80s each day with a 20-30% chance of a late day or evening thunderstorm.
Climatology
The average high this week is in the upper 80s, with the average low near 70.