Freeze Watch tonight west of I-95
After a week that saw two record-warm overnight lows, autumn will come rushing back to Baltimore tonight as clear skies and diminishing winds allow radiational cooling to drop temperatures into the 30s.
Forecasters at the National Weather Service's forecast office in Sterling, Va. have posted Freeze Watches (dark blue areas on the map) for Maryland west of the I-95 corridor (and east of counties that have already seen a freeze this fall):
"A FREEZE WATCH MEANS SUB-FREEZING TEMPERATURES ARE POSSIBLE.
THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION."
UPDATE, 4 p.m.: The NWS has bumped the Freeze Watch to a Freeze Warning tonight (light blue) for Washington, Frederick and Carroll counties in Maryland, with overnight lows expected to reach 30 to 32 degrees. Earlier post resumes below:)
The forecast low for BWI-Marshall Airport overnight is 35 degrees. Westminster could see 34 degrees and Hagerstown's forecast shows a low of 32. It could get colder in the usual rural locations and low spots, producing the first freezing temperatures since last spring. Freeze Warnings and Frost Advisories may be issued for some locations later today.
The cooler weather is coming to us with high pressure that is drawing cold air out of the northwest on brisk winds. As the high moves to our south, winds will shift to the west and calm, allowing whatever solar heating we manage today to radiate back into space tonight.
The weekend should continue sunny and seasonably cool with highs in the low 60s and overnight lows near 40 degrees.