Surprise Spring Storm Saturday Night

The weather models have shown a significant storm coming up the east coast on Saturday night for some time now. However, it was not until recently that is has become evident that heavy precipitation will fall right here in the Finger Lakes.Adding to the problem of not having consistent models with this storm is the presence of warmer air. If you remember the snow storm we had back in March, some areas got pounded with snow, while 10 miles away, less than 2″ fell. A similar thing may happen with this storm, only amounts will be less because the snow will be extremely wet and mostly over higher elevations.Further east, I am very concerned about the flood potential. Many areas, including Tioga, Broome, Cortland, and Chenango counties are estimated to be able to absorb less than an inch and a half of rain over a long, 12 hour period before flooding becomes problematic. In these same areas, 1-2″ of rain will fall, with some areas getting closer to 3″, especially further east. This could end up a bad situation.This will all start late Saturday afternoon or Saturday evening as an area of rain moves into the region. To the northwest, three things will act together to reduce temperatures: night, colder air wrapping into the storm, and falling precipitation, which acts to cool the atmosphere due to evaporation. This will change the rain over to snow and mixed precipitation. Higher elevations will see the most snow, while a couple inches are possible elsewhere. The snow amounts are extremely uncertain, as it is very sensitive to even slight temperature changes.Further east, the warm air will hold on longer and temperatures may even rise a little between the evening and midnight. Eventually, snow will overspread the majority of the region as the storm pull away Sunday morning.