A low pressure system sitting off Cape Cod doused New England and the mid-Atlantic Coast with rain, while cold Canadian air pushed into the northern high plains and headed for the Midwest. The National Weather Service said one to two inches of rain fell over parts of New England during a 24-hour period, with two inches measured at Providence, R. I., and more than an inch in New York City. Heavy rain during the weekend was also reported in Hartford, Conn., and Portland, Me. Cold air followed a frontal system across Manitoba and Saskatchewan into the northern plains. Temperatures fell into the 20s and 30s over the northern Rockies.