A large trough of low pressure will remain in place across the Canadian maritimes over the next few days, resulting in cool nights and mild afternoon temperatures for the Mid-Atlantic region. You can see the upper level pattern (500mb) and the surface temperature forecast from the ECMWF (Euro) model for 2 PM EDT Tuesday in the two graphics below. Note the 90-degree temperatures in the central states, and the 70-degree temps in the eastern states.
The low will finally exit North America to the east late in the week, and a broad upper-level ridge will build in from the west. This ridge will strengthen over the region this weekend, with the hottest weather hitting on Monday. The two graphics below show the upper-level pattern and surface temps from the Euro model at 2 PM EDT next Monday. The 591 dekameter ridge is right over Virginia, with surface temps well into the 90s.
We’ll likely go from a high of 73 degrees in Richmond tomorrow, to a high of 94 degrees in Richmond next Monday. Not only will it be hot, but it will likely be humid as well, with the heat index approaching triple digits. Air quality could be an issue by Monday, with the possibility of elevated ozone levels. So that’s what we have on the way, which is pretty normal for this time of the year. Enjoy these cool nights and mild afternoons for the next couple of days, because true Richmond summer weather is right around the corner. -Zach