Steady rain will develop by midday Tuesday and will persist well into the evening hours.
The first significant storm system to move through the Finger Lakes in 2017 will be a rain maker.
Temperatures Tuesday morning remain in the mid and upper 30s or low 40s after holding steady or rising slightly overnight. Temperatures will increase a little today, but should not get much higher than the low 40s in most locations.
Clouds are thick this morning, but the region remains dry for a little while longer. Then, a complex storm system will move towards the Finger Lakes, pushing rain into the area later this morning.
Steady rain will develop by the middle of the day and will likely continue through the afternoon and evening hours. The rain will probably not taper off until after 11pm or midnight for much of the Finger Lakes.
This storm system will have two areas of low pressure. One low will track northeast along the coast of New England. The other low will lift north from Ohio into southern Ontario. Both lows will be strengthening and the two will interact with one another.
In similar scenarios, a band of enhanced precipitation can develop in a connection of sorts between the two low pressure systems. That could happen today over the Finger Lakes, resulting in some downpours this afternoon.
How much will it rain, and what if it was snow?
The Finger Lakes region should see close to a 12 hour period of primarily steady rain. The rain will be widespread across the entire Finger Lakes region and beyond, so everyone should see a healthy soaking from this event.
Most areas will see close to three-quarters of an inch of rain. There is also local variability, so some places may end up closer to a half-inch. On the flip side, some areas could see closer to an inch of rain should the heavier downpours develop overhead.
Any time a rain event happens during the winter, and especially when temperatures are just warm enough for the precipitation to not be snow, people get curious about what would have happened if it were just a bit colder.
Translating rain to snow is not as straightforward as it may seem, as the temperatures throughout the atmosphere all have an impact on the snow time. We can make some generalizations though.
If we took this system and dropped the temperatures about 10 degrees, temperatures would be in the low 30s. That would result in a heavy, wet snow. In such situations, an inch of rain would commonly yield anywhere from 7 to 10 inches of snow.
Most areas will probably not see an inch of rain today, so those amounts are too high. Using the same rations with three-quarters of an inch of rain, however, would result in about 5-8 inches of snow.
Snow is not back in the forecast for the Finger Lakes until later in the week, however, as this system will be rain from start to finish.