Phase I – Wednesday Night-Thursday
All the Finger Lakes, Central New York, and Western New York are under Winter Weather Advisories from late tonight into Thursday.
A Winter Weather Advisory is not as serious as a warning, but is issued when wintry weather will cause travel concerns.
The culprit will be an area of low pressure that will track northeast to a position near Elmira by Thursday afternoon. The interplay between incoming warmer air and preexisting cold air will make for a wide range of precipitation types throughout the region.
Precipitation will first move into the region between 11 PM and 1 AM tonight. This precipitation will start as snow, but for the southern half of the region, will quickly turn over to sleet. Further north, mostly snow is expected.
The initial push of precipitation will only last a few hours before tapering off. Before dawn arrives, new precipitation will be moving in from the south.
This precipitation will be a bit less widespread compared to the first batch, but will still be significant enough that everyone should see at least some additional precipitation in the 6-9 AM window. This second batch will mostly be sleet to the north and freezing rain further south.
Already by 8 or 9 AM, plain rain will start to take over in the areas shaded in the gray T-1” zone on the map above.
On and off showers are likely throughout Thursday. Areas north of a Dansville-Geneva-Syracuse line, or roughly the I-90 and I-390 corridors, will continue to see freezing rain with temperatures failing to climb above 32 degrees. Travel conditions here will remain slick.
Further south, precipitation should stay rain through the late morning and afternoon hours. Temperatures here will be in the mid and upper 30s.
Phase II – Thursday Night – Friday
Showers will continue through Thursday evening, but cold air will start to advance southeastward. Rain will turn to freezing rain, then sleet, then snow. The entire region should become snow before 6 AM Friday.
Most of this precipitation will be light, but travel conditions will remain less than ideal through the night thanks to the ice.
A new low pressure will then track into southeastern New York, enhancing the precipitation Friday morning. There are a couple major questions that remain with this phase, however.
First is how quickly the cold air takes over and changes precipitation to snow. If this happens before the precipitation intensifies, snow totals will be higher.
Second is the placement of the heaviest band of snow. A relatively narrow corridor will see 3-7 inches of snow in a short time Friday morning. This could happen over the eastern Finger Lakes, or it could set up outside of our region to the east.
Areas further west will see an additional couple inches, but it should not cause too many problems. The snow will taper to flurries Friday afternoon and evening before coming to an end.
This is an extremely complex set up for our region. Most of the time, there will be a variety of precipitation types falling across the region. Elevation and terrain will have a large impact on localized variation and the timing of transition from one type to the next.
With that in mind, I have attempted to give as much detail as possible in my descriptions and on my maps. There will be variations in what actually happens, though.
The bottom line is to prepare for icy, snowy travel over the next two days. The best window for travel will be in the late morning and afternoon on Thursday for areas south of I-90 and east of I-390.
Second, the snow map I published above is ONLY for the first part of this system. I have seen maps that lump both parts in together, making for the appearance of higher snow amounts. However, since there are two distinct phases, I feel breaking things down gives a better feel for the impacts of the event.
Lastly, there were a couple comments in my recent survey about my preference in publishing a single map per event and holding off until there is confidence. I do not do this to make myself look good, but to decrease confusion and increase usefulness of the forecasts.
Especially in the social media age, publishing multiple maps leads to confusion, as Population A will only see the first map, Population B will only see the second map, and a much smaller Population C will get to see both and realize there was an update.
That being said, I do understand that some people need to make plans further in advance. Please, if that is the case, just ask me what you need to know. That is the power of my core value of ACCESSIBILITY, which is on equal footing as accuracy.
I frequently give people personalized information to help their specific needs days ahead of an event. While publicly I need to keep the narrative consistent and clear, privately I can go into more detail to fit your personalized needs.
I will continue to work towards finding the balance between waiting for clarity and giving lead time for events. My additional map above for Friday is an attempt at doing so. Every event is different, and some are more easily put into a graphical format than others.
In the end, know that I take every comment and suggestion seriously and will continue to do my best to give you the information you need to prepare for and deal with whatever the weather throws at us.
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