JAMESTOWN – The National Weather Service in Buffalo upgraded the Winter Storm Watch to a Warning for all of Western New York, which will go into effect 7:00 PM tonight, and lasting through 1:00 PM Friday.
Winter is coming back with a vengeance, as a Low pressure system out in the midwest will track along the Ohio Valley and the Northeast this afternoon and tonight, bringing with it, some pretty measurable snowfall.
First of all, scattered to widespread rain showers will expanse the region this afternoon. As the storm system gets closer, and the colder air is dragged in, there will be a transition period from rain to snow.
Earlier model guidance hinted that such a changeover would not occur until later tonight, into early Friday morning. Now, the models have sped up the movement rate of the of the Low, and when the cold air begins to get sucked into the storm.
It now looks like the transition will begin around 4 PM this afternoon, and will be complete to all snow by 7 or 8 PM.
The length of the transition time and how long it takes to complete, has been one of the biggest pieces of this forecast. As I mentioned yesterday, a slow transition would tend to keep down snow totals, as that would allow more rain to fall.
In this case, it appears that the transition will be quick, occurring over a period of a coupe of hours, which will open the window for more snow to fall and accumulate.
Another big piece of the forecast is the temperatures, which will determine the kind of snow we’ll be dealing with. We will hoover around freezing tonight and tomorrow, also given the base of rain we’ll lay down this afternoon, with the snow to liquid ratio, that will set the stage for heavy and wet, what we call “heart attack”-type snow.
The snow will continue in moderate to heavy form throughout the nighttime hours, into the morning on Friday.
The winds also come up as well, averaging 15 to 26 MPH, which will create blowing and drifting snow, reducing visibilities. The Friday morning commute will likely be slow, slick, and hazardous.
The snow will taper off from west to east throughout the day on Friday, as the storm system moves on out toward the eastern seaboard, and well be left with a few nuisance snow showers by later in the day on Friday.
“How much snow?” you are probably wondering. So. let’s get to it.
We’ll likely see a general snowfall between 9 and 13 inches, with areas along higher terrain, especially around the Chautauqua Ridge, Boston Hills and the Bristol Hills, where totals could be closer to 20 inches.
However, there is still, what we call a “bust potential” with this forecast. There is a chance these totals could be over-exaggerated, and snow totals will be much lower.
But, there is a good amount of certainty that this forecast will verify. It’s what we always say when to comes to computer models; “we live by them, and we die by them.”