Inner Harbor reaches 100 degrees at 11 a.m.
The National Weather Service is reporting 100 degrees at 11 a.m. at the Maryland Science Center in downtown Baltimore. The dew point was 77, for a Heat Index value of 112 degrees. The forecast high downtown is 105 degrees.
It was 97 at BWI Marshall Airport, with a dew point also at 77 degrees. That gives us a Heat Index of 116 degrees. The forecast high for BWI is 103 degrees.
This week's heat comes to us thanks to a huge dome of high pressure over the eastern half of the nation. Clockwise circulation around the high is bringing hot, humid air up from the South, the Gulf and the Atlantic.
Subsidence of the air in the dome is suppressing the development of cooling thunderstorms, which need a column of rising air to form. Our first chance for relief should come tonight or Saturday afternoon as the high moves farther east, and our rain chances begin to rise again.
Any storms that do form, forecasters warn, could become severe, with a potential for damaging winds and heavy downpours.
Real relief is still a few days away, with thre arrival of a cold fron Sunday or Monday. High temperatures early next week should rop into the high 80s - pretty nearly average for this time of year.