Temperatures differ a lot today in parts of Western New York. What's the cause?

It’s supposed to be a mild 58 degrees in Rochester today on Monday, but a toasty 80 degrees in Wellsville and 79 degrees in Dansville. So what gives?

The main culprit is a stationary front, caused by a cold front north of the New State Thruway and a warm front to the south. A stationary front forms when a cold front or warm front stop moving due to the two masses of air colliding, but neither being strong enough to displace the other, according to the University Corporation for Atmospheric Research.

When winds blow parallel to the front, it can remain in place, sometimes for days.

“Usually there are upper level winds that will push this front along,” said Dan Kelly, meteorologist at the National Weather Service in Buffalo. “... Eventually things will start moving and the front will lift north … either later today or tonight.”

Rochester NY weather forecast

This will lead to warmer temperatures as soon as Tuesday, with the Rochester forecast calling for 68 degrees. Areas in the Finger Lakes could see highs in the lower 70s, with temperatures closer to Lake Ontario a bit cooler.

The trend will continue throughout the week, with mid to upper 60s on Wednesday, mid 70s on Thursday and upper 70s by Friday, Kelly said.

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The unsettled air from the retreating cold front could also bring showers overnight into Tuesday, as well as the possibility for a thunderstorm during the day and rain into the evening. Western and Central New York, including Monroe, Livingston, Orleans, Genesee, Wayne and Ontario counties, are under a hazardous weather outlook from the Weather Service due to the possibility of “widespread showers and a few thunderstorms.”

— Steve Howe covers weather, climate and lake issues for the Democrat and Chronicle and held a hummingbird in his hand when helping to band birds as a kid. An RIT graduate, he returned to Rochester after working around the state and in Utah. Share with him at showe@gannett.com.

This article originally appeared on Rochester Democrat and Chronicle: Rochester NY weather: Stalled front brings temperature disparity