Heavy rains and melting ice are forecast to cause flooding across parts of Long Island this weekend just as the region warms up slightly, in turn thawing from an earlier deep freeze.
A flood watch is in effect from 11 a.m. Saturday to 6 a.m. Sunday as a low pressure system moving in from the Midwest is expected to drag a cold front through the region, trapping Atlantic moisture that will produce heavy rains, according to Upton-based National Weather Service meteorologists. A wind advisory is also in effect from noon to 9 p.m. Saturday.
“In addition to urban and poor drainage flooding…small stream and river flooding is possible,” the agency said in a statement. “Conditions are also favorable for ice-jam flooding.”
Ice-jam flooding means waterways frozen in sections can cause water levels to rise when the ice melts and backed-up water rushes through. Up to 2 inches of rain is also expected to contribute to the flooding.
The anticipated flooding comes as subfreezing temperatures earlier this week give way to temps in the 40s Friday and reaching as high as the 50s this weekend. Winds up to 30 mph are expected to accompany the rain Saturday.
Once the storm breaks, sunny skies return Sunday into Monday before clouds return for another chance of rain Tuesday.