Stalled Frontal Boundary
A sharp frontal boundary will set up from west to east across the middle of the Finger Lakes, serving as a focal point for both heavy rain and large differences in temperatures.
To start off this morning, the first batch of rain is moving northeast through western Pennsylvania. Over the next few hours, this rain will spread into the Finger Lakes.
The rain will be widespread and steady, lasting into the mid-afternoon before it starts to break up into showers. Additional areas of on-and-off rain will continue through the late afternoon and for much of the evening. A few embedded downpours will be possible during these times.
Meanwhile, south winds will build into the Southern Tier while north winds come off Lake Ontario. A sharp boundary in temperatures will start to develop, ranging from the mid 40s north of I-90 to the mid 50s in areas close to the NY-PA border. Most of the Finger Lakes should end up in the upper 40s and low 50s this afternoon.
Tonight, the temperature gradient will become even more well-defined right across the middle of the region. Using the north and south ends of Cayuga and Seneca Lake as a rough guide, areas to the north will be in the low and mid 40s, while to the south, mid 50s are likely.
In between, it will be a sharp cutoff between low 50s and mid 40s. Some areas may find themselves bouncing back and forth as the front wobbles to and fro. The temperature forecasts are uncertain in this middle zone, with as little as 5-10 miles separating the cooler and milder air.
The temperature boundary will not move much on Wednesday. The middle third of the Finger Lakes will remain highly uncertain and susceptible to sudden and noticeable changes. To the north, it will remain cooler, and to the south, mild.
Relatively quiet weather is expected after midnight tonight and through Wednesday morning. Rain will then redevelop for Wednesday afternoon, with a greater chance of heavy downpours. A little thunder is not out of the question, either.
The rain may not be as steady and widespread as today’s rain, but it will be raining frequently and all areas will see additional rain.
Especially with any downpours, two-day rain amounts should be at or above an inch throughout the region with localized amounts at or above two inches. Widespread flooding is not expected, but some localized ponding in poor drainage areas and fast flows on small streams are likely.
Turning Cooler
By Thursday morning, the frontal boundary will diffuse as it moves south, out of our area. There will not be an immediate slap of cold air, though. Temperatures Thursday should start around 40 and afternoon highs will reach the mid, if not upper 40s.
Thursday will have some additional rain showers. These will be much lighter and more scattered than what falls Wednesday. Late in the day, some snowflakes may start mixing in as temperatures fall back into the 30s.
On Friday, light west and northwest winds will continue to bring in some cooler air while also tapping into the Great Lakes for some extra moisture. Skies will be cloudy with occasional rain and snow showers.
Temperatures on Friday will start in the low 30s with highs in the upper 30s. A few places may still be able to make it to 40 degrees.
Cooler air will continue to slowly build in this weekend, with highs Saturday in the mid 30s and Sunday in the low 30s. Overnight temperatures will drop below freezing, with lows around 30 Saturday morning and in the mid 20s Sunday morning.
Both days will be cloudy, with a few flurries about on Saturday. Sunday looks dry at this time, and a little late sun poking out may be possible.
Sunshine may increase for Monday with temperatures getting a bump up as a result. A couple days of quiet weather is expected before a slight uptick in precipitation chances late next week. High temperatures should remain in the 30s with overnight lows in the 20s. Even that, though, is still a touch above the seasonal averages for early and mid January.
More Information:
» Finger Lakes Weather Radar
» Zip Code Forecasts
» Get the FLX Weather Mobile App
This graphic represents an average over the entire Finger Lakes region. Localized variations should be expected.
