A powerful upper level low pressure system will interact with a rapidly deepening coastal storm on Friday. The end result will be a wild variety of weather across the Hudson Valley. The impacts from this storm could be quite significant across the region, as the combination of heavy, wet snow… and powerful wind gusts over 40mph, could cause down trees and power lines.
– 8pm to 11pm Thursday: Rain develops from SW to NE
– 12am to 7am Friday: Rain mixes with & changes to wet snow from NW to SE
– 7am to 4pm Friday: Snow falls heavy at times, whiteout conditions possible
– 6pm to 11pm Friday: Snow tapers off from west to east
– Catskills (Zone 1 & 2): 18 to 24 inches (locally 30″+ in highest elevations)
– Southern Catskills, Shawangunks, Hurley Highlands (zone 5 & 6): 8 to 16 inches (locally 20″)
– Majority of the Hudson Valley (Zone 3, 4, 7 & 8): 6 to 12 inches (locally 12″+ in higher elevations)
– Extreme Lower Hudson Valley (Zone 9): 2 to 6 inches (locally up to 8″ in higher elevations)
We’re going to go light on the discussion in this section, mainly because we’ve discussed so much in our afternoon discussion, which you can find at the following link:
There are some items that we do want to highlight with this system:
– Dynamic Cooling
– Elevation & Snow Accumulation
We’ve discussed the fact that this entire snow event hinges on one thing… and 1 thing only… dynamic cooling.
Our upper level low pressure will basically follow the track shown in the image above. As it moves west to east, it will generate TREMENDOUS upward motion, and it will cause the air to rise. As the air rises, it cools and condenses, and causes heavy precipitation rates. We’ll need the upward motion to play out as shown above, to get the temperatures to drop as they’re projected overnight…
Look at how fast temps drop, and this is the key to getting the temperatures cold enough to support snow. Most of the guidance, as well as weather history, suggests that the upper level low pressure will causes the temperatures to respond as indicated… which will allow a heavy, wet snow to fall.
If the wet snow falls as projected, we’re very concerned about the possibilities for power outages. This storm will really ramp up offshore, and as the storm bombs out, the rapidly deepening storm will generate powerful winds out of the northeast.
With the heavy wet snow sticking to everything like paste… wind gusts over 35 or 40mph howling against tree branches loaded with wet snow… and we could see a fair number of downed trees and power lines. As we highlighted earlier in the day, our friends at Central Hudson have provided us with links for everyone to stay informed on the situation, should conditions deteriorate on Friday.
It’s probably not a bad idea to plan for the possibility that power could be lost for a time on Friday. Something to consider, because if the heavy wet snow begins to fall… the powerful wind gusts could cause an extra dimension to this storm.
Elevation & Snow Accumulation
Finally, we want to make clear… that this storm sits on the head of a pin. Meaning, that so many factors have very little wiggle room, and no margin for error. We need to get tremendous cooling to take place, so that a heavy wet snow falls. Once that happens, elevation still plays a roll. Higher elevations tend to cool faster and to a greater extent. The higher your elevation, the better the chance you see a heavy wet snow that accumulates considerably.
However… lower elevations CAN NOT be discounted. A lot of people and forecasters are writing off the valley areas as too warm for snow. Dynamic cooling can impact those areas the same as higher elevations, and we do believe that valley areas can see the snow thump. It is worth stating, that lower elevations have a greater risk of seeing the forecast bust… i.e. the rain mixes in more than expected, and snow totals are lower… but while elevation plays a role, it’s not a deal breaker. All of the Hudson Valley could see a significant event.
And with regard to the projected accumulations… we want to be clear, that there is a LOT of variability within each range. We posted 6 to 12 inches for the Hudson Valley on average… but there will be some valley areas that see rain mix in, due to downsloping or elevation… and those areas could see 3 or 4 inches of wet snow. Not far away, in a location that is higher in elevation and doesn’t have downsloping to contend with… it wouldn’t be shocking to see a report of 13 or 14 inches of wet snow. The point is… don’t get too hung up on the accumulation forecast. This is a dynamic storm, and the forecast will be dynamic as well. We may yet have to tweak details as new information comes in.
Expect more updates as we get closer to the storm. Thanks for reading, and continuing to support HVW.