Dipping into 40s tonight; crowding 90 by Weds.
It's going to be quite a roller-coaster ride this week, Maryland. The National Weather Service forecast has BWI-Marshall slipping into the 40s early Tuesday morning. If they're right, it will be our first excursion into the 40s since May 9 - at least at the airport. The WeatherDeck in Cockeysville has been there already this month.
But we'll have lots of sunshine again this week. There is no rain anywhere in the 7-day forecast until Saturday. And as this high-pressure dome over our heads (map) moves offshore on Wednesday, we will come under the return flow from the south. And that will bring us much warmer temperatures and more humidity.
The forecast high for Wednesday is 89 degrees at BWI. Just a little nudge and we'll bump the all-time BWI record for 90-degrees days to 57. (And NWS forecasters typically undershoot the summer highs at BWI.) The rest of the week will see the highs loitering in the same neighborhood - upper 80s. Some models push them into the lower 90s Thursday and Friday afternoon. It's going to be hard not to switch on the AC again after a merciful couple of weeks without.
A cold front by Saturday could bring us a few showers, and it will drop temperatures back to the upper 70s to near 80 degrees. The average high for this time of year at BWI is 77 degrees. The average low is 55.