“Oppressive” humidity is forecast to make the temperature feel like triple digits around Baltimore through the Fourth of July holiday as a heat wave moves into the Mid-Atlantic and Southeast.
The heat index “may top 110 degrees in some locations for several days,” the National Weather Service cautioned. In Baltimore, it’s forecast to approach 100 degrees from Tuesday through the weekend.
High temperatures are forecast in the lower to mid-90s through the week. But with humidity expected to surge to the highest levels the region has seen this summer, it’s forecast to feel as much as 10 degrees hotter.
“High pressure at the surface and aloft over the southeastern U.S. will be responsible for pumping oppressive dew points in the low to middle 70s across the Mid-Atlantic,” the weather service’s Baltimore/Washington forecast office said.
The dew point is the temperature at which moisture in the air condenses into liquid; the higher the dew point, the hotter and stickier it feels. Dew points have largely been in the 60s, and sometimes lower, so far this summer around Baltimore.
The intense humidity is forecast to fuel heavy rain, at times. Storms and downpours are possible each afternoon, including on Independence Day, potentially disrupting some fireworks shows.
The weather service said flooding could be possible in areas that see repeated rainstorms, some of which could drop precipitation at rates of 2 inches per hour.
An approaching cold front could bring a slight break from the heat and humidity by the weekend, but is only forecast to drop temperatures by a few degrees, into the upper 80s.