JAMESTOWN – A deep storm system currently centered over the midwest will track just to our east and bring Western New York and Northwestern Pennsylvania a wintry mix of precipitation through Sunday that could contain some surface-slickening ice.
The National Weather Service has issued a number of Winter Weather Advisories for the region. The Advisory for the Southern Tier will begin at 1 a.m. Sunday morning and run through 1 p.m. Sunday afternoon.
For the Niagara Frontier including the Buffalo metro area, the Advisory will start at 4 a.m. Sunday morning and last through 6 p.m. Sunday evening.
The Advisory for Erie and Crawford Counties in Pennsylvania will go into effect at Midnight tonight and run through 10 a.m. Sunday.
For Warren County, Pennsylvania the Advisory will start at 7 p.m. tonight and run through 7 p.m. Sunday evening.
Based on current model guidance, the first half of the evening tonight will be precipitation free with partly to mostly cloudy skies. As the system moves closer towards the region, precipitation will begin from southwest to northeast through the second half of the night, leading into Sunday morning.
With warmer air aloft and near-ground temperatures forecast to remain above the freezing mark, precipitation will likely start off as plain rain showers. As the warmer air holds and surface temps fall to near or below freezing, a transition to sleet/freezing rain will quickly occur and last through early Sunday.
As the storm system redevelops into a coastal Low off the Northeast coast, another transition to rain will occur for the Southern Tier while areas northward will transition to snow for later Sunday into Monday.
The key takeaway from this system will be the potential for ice accretion on surfaces through Sunday morning. While the onset of the sleet will help to reduce forecast ice accumulations, there still could be enough ice to cause some slippery roadways and make for hazardous travel.
New runs of the high resolution computer models have been indicating some ice totals between a tenth to two tenths of an inch across much of the area.
With that being said, there is the potential for ice accumulation to reach up to a quarter inch or a maybe little more with the greatest threat for that potential further south and east.
A quarter of an inch is a “magic number” when it comes to ice accretion as that is when the ice becomes thick enough put excess weight on tree limbs and power lines.
With the region very close to that cutoff point, it might be a good idea to plan ahead in case any power outages do occur or should road conditions become too hazardous for safe travel.
Cooler air will filter in behind this system and create one more changeover to all snow across much of the region for Monday. Snow totals will likely range between two and three inches across the Southern Tier with higher totals further north and east.
It will also become breezy on Monday as well with wind gusts possibly reaching upwards of 40 MPH at times through the afternoon.
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