A complex weather pattern is starting to evolve and unfold across the middle of the nation, with low pressure systems over Minnesota and coming onshore in Louisiana. These systems will work together to bring rain and snow to the Finger Lakes this weekend.The southern system, which we will refer to as System 1, will move north during the day today. Aided by southerly winds on the backside of high pressure that is over our region, warm, moist air is already surging north ahead of this system, with rain into the Ohio River Valley this morning.
Rain will gradually spread north and east throughout today and tonight. These areas have recently had significant rain and snow melt, so the flooding potential is high from New Orleans to Pittsburgh. Thankfully for our region, the heaviest rain will slide east across the Mid-Atlantic, so flooding should not be an issue.
Rain will start in the Finger Lakes after midnight tonight and linger throughout the morning. Steady rain should give way to scattered showers in the afternoon. Most places will get about a quarter-inch of rain, but there is some potential for as much as a half-inch of rain, especially across southwestern New York.
Temperatures during the day on Saturday should mostly be in the mid and upper 30s, though some 40s will also be possible across the northern Finger Lakes.
Saturday night, System 1 will absorb System 2 and develop into a single, coastal storm. Still, some energy left behind by System 2 will be moving through on Sunday. As the coastal storm strengthens, winds will strengthen from the north, bringing cold air into the Finger Lakes.
Interacting with the left over energy from System 2, this cold air will bring some chances for snow showers on Sunday, though they will mix with rain at times. Accumulations will be hard to come by though, with no more than a coating to an inch, if even that. Temperatures on Sunday will be in the low and mid 30s.