Rain arrives in the Finger Lakes as warm air pushes north

Rainy Thursday

An area of rain will move into the Finger Lakes during the late morning hours on Thursday and persist into the afternoon.

This rain has developed in response to a push of warmer air that is working northeast between low pressure over the Midwest and high pressure over the Carolinas.

Rain will spread from west to east during the latter part of the morning and should spread across much if not all of the region by noon.

The initial band of steady rain will last 2 to 4 hours before heading off to the north and east. Some additional scattered showers will remain possible into the late afternoon, however.

Total rainfall today should be around a quarter-inch.

Temperatures will mostly remain in the mid and upper 40s until the late afternoon when 50s start to arrive from west to east.

Most areas should get into the 50s by the early evening hours with mid and upper 50s along and west of I-390.

Sharp Front Sets Up

Overnight, high pressure will build into central Canada, resulting in a competing push of cold air from the north.

By Friday morning, this colder air will be pushing through the Finger Lakes and a sharp gradient in temperature will begin to develop.

The Finger Lakes should be north of this boundary to start Friday morning with temperatures generally around 40 degrees.

During the day, warm air will push back north. While areas along and north of I-90 remain in the mid and upper 40s, the Southern Tier could push towards 70 degrees.

A few rain showers will be possible on Friday, mostly in the morning hours.

The front will sag a little further south overnight and into Saturday. While still subject to adjustment, it looks like Saturday will mostly be chilly across the Finger Lakes with warm air locked south along the NY/PA state line.

The European model is currently predicting a 2 PM temperature of 47 degrees in Ithaca, yet 73 degrees in Binghamton — a 26-degree difference over about 30 miles!

Ice Threat Remains

By the evening hours, temperatures will be falling to near 30 degrees across at least some of the Finger Lakes. The best chance for these sub-freezing temperatures will be near Lake Ontario and in the western Finger Lakes, but the entire region should be aware of this potential.

A wave of precipitation will move into the region as temperatures fall Saturday evening. Some of this precipitation could fall quite heavily, especially over more western areas.

While surface temperatures will be in the low 30s, a mile above the surface, temperatures will still be in the 40s to near 50 degrees. As precipitation falls through this significant warm layer, it will melt, only to refreeze in the cold air near the surface.

Models seem split on whether precipitation would then fall as sleet or freezing rain. Either way, icy conditions will be possible throughout the night and into early Sunday.

While confidence is growing in the potential for ice, uncertainties remain. It is better to hope for sleet, which bounces off objects, compared to freezing rain, which falls as a liquid and then freezes on branches, wires, and cars.

Flooding & Wind Threats, Too

Precipitation will move back out of the region for a time on Sunday as warm air makes another push into the region.

At this time, 50s seem like a reasonable forecast for Sunday, but temperatures could get even warmer.

Rain will move back into the region Sunday night, falling quite heavily at times.

Winds will also become gusty, with 35-45 mph gusts commonplace.

A few thunderstorms may also develop, leading to locally heavier downpours and the potential for 50 mph wind gusts.

Rain will end as some snow on Monday, possibly with an inch or two accumulating over some of the higher elevations of the eastern Finger Lakes.

In all this weekend, over two-inches of precipitation may fall. This could lead to some localized flooding issues.