A complex winter storm will develop across the Finger Lakes by Sunday afternoon and continuing through Monday. This storm is so complex, I could not properly communicate the forecast in one, or even two maps. Following are three different maps, which I will explain in detail to get you the information you need to know for this storm.
This first map is for the weather this afternoon and evening. A front is stalled out roughly along the New York/Pennsylvania state line. A bundle of atmospheric energy will begin to interact with that front this afternoon, causing precipitation to break out across New York.
For areas in the northern Finger Lakes, on the cold side of the front, the precipitation should be all snow. By this evening, 3-5″ will have fallen for most areas, though some amounts could be locally higher or lower.
Further south- roughly to the south end of Seneca and Cayuga lakes, the precipitation will likely go back and forth between snow, rain and some freezing rain. Thankfully, it does not look like significant ice accumulations are likely, but even a little freezing rain can make roads and sidewalks slick. Some areas, especially in higher elevations, may even manage a couple inches of snow.
Across the Southern Tier, most of the precipitation will be rain showers. A heavy, soaking rain does not appear likely. Some of the higher elevations, especially close to the pink area, could see a little freezing rain mix in at times.
Tonight, low pressure will begin to track from the Great Lakes towards West Virgina before redeveloping off the Mid-Atlantic coast and heading towards New England. As the storm tracks southeast across Ohio, colder air will start to get dragged south. This should change the precipitation over to snow across all of the Finger Lakes.
Snow is likely to persist through the day on Monday. The snow may not be heavy in all places all day, but an additional 4-8″ of accumulation is possible for much of the Finger Lakes. Again- some areas (especially lower elevations) could see less, while others could see more if a heavy snow band develops and sits over an area.
Further west, the snow will not be as heavy as the storm transitions to a coastal system on Monday. Areas across northern Pennsylvania will hang onto rain and freezing rain into early Monday, cutting down on snow amounts there.
The snow will taper off by Monday evening, even though flurries may continue into Tuesday morning. By 8pm Monday, the bulk of the snow should have fallen, with only another inch or so Monday night.
Storm totals are probably going to vary quite a bit from one location to another, especially across the Southern Tier and southern Finger Lakes. Elevation will be a factor with storm totals in these areas, with higher snow amounts at higher elevations. Confidence is this snow map isn’t the highest, so I expect some areas to end up with lower amounts while others exceed projections.
The bottom line with this storm is this: it will be a long storm, spanning over 24 hours. The precipitation at any given time probably will not be super intense, but steadily light to moderate with occasional heavy bursts. The snow will be heavy and wet, so please be careful shoveling. Travel will be sloppy anytime from Sunday afternoon into Tuesday morning.
The forecast confidence is higher than yesterday, but still not up to average. This means that some areas will likely see less snow than projected, while other areas will see more. Confidence is highest across the northern Finger Lakes, and lowest across the Southern Tier.
Stay tuned for updates, especially if the storm starts to behave in some unexpected way.