Low temperature forecast

Lows are forecast in the 40s in outlying suburbs overnight Friday. (National Weather Service Baltimore/Washington / September 6, 2013)

The Canadian high pressure bringing cooler temperatures today could drop many suburban and rural areas into the 40s for the first time since May overnight Friday into Saturday morning.

The low forecast for Baltimore-Washington International Thurgood Marshall is 50 degrees. Out in Westminster, though, it could hit 46 according to National Weather Service forecasts, with temperatures well into the 40s across Carroll, northern Baltimore and Harford counties.

The airport has dropped into the 50s several times in the past month or so, but hasn't been as cold or colder than it may be in the morning since May 27, when temperatures bottomed out at 46 degrees.

In Westminster, temperatures got as cold as 54 degrees Friday morning, while Frederick hit 50 degrees.

The cool air is meanwhile remarkably dry, with dew points in the 30s and 40s so far on Friday at BWI.